4:10's????

[60sec_assassin]

will 4:10's actually hurt the mm top end performance and gas mileage?? i just wanted to ask some people who had them already to see if they are worth putting in...:cool:

[jstevens]

Will improve performance. 1 mpg loss possibly, I don't know as I don't keep track.

[Bradley G]

Thier worth it:D :twocents: With a good tune to correct the speedo and shifting The small mileage drop you will see is mostly from the added :burnout:

Bradley G

[Rider90]

Common sense says it will hurt top performance too.

[Bradley G]

Yeah your right I can only get it to 138 :censor: ............;) :banana2:

Bradley G

Common sense says it will hurt top performance too.

[Fourth Horseman]

When I was following the Teamropes back to Marauderville 2 in Indianapolis, my 4.10 equipped car averaged only half a mile per galon lower than their 3.55 equipped car.

Not too shabby, I'd say.

[RF Overlord]

^^^what Rider90 said^^^

Unless you have a place where you can legally and safely operate your vehicle at top speed, who cares? The improvement in overall driveability is worth it...

[jcooper]

I have 4.10's with Dennis Reinhart tune. I get about the same around town, 13-14 MPG, but about 2 MPG less on the road, about 21 MPG instead of 23 MPG.

The driving around town is much more pleasurable, and seems to be easier on the heavy car. I do mostly in town driving. If one were to do mostly road trips, I would think I would stay with the 3.55's and a tune job too. The tune job will improve your mileage, but the gears will reduce the mileage.

I don't know when I would ever try out top end, I hope never, but I imagine top end would not be a concern for anyone except perhaps if one were driving in Germany.


John Cooper
Tuscaloosa, AL



will 4:10's actually hurt the mm top end performance and gas mileage?? i just wanted to ask some people who had them already to see if they are worth putting in...:cool:

[wchain]

Yeah your right I can only get it to 138 :censor: ............;) :banana2:

Bradley G

Divide that by two....and you get everyones Favorite Number....... :D :D :D

[teamrope]

When I was following the Teamropes back to Marauderville 2 in Indianapolis, my 4.10 equipped car averaged only half a mile per galon lower than their 3.55 equipped car.

Not too shabby, I'd say.And I can verify that. :) We have since swapped to 4.10's in our MM's. Seeing that sold me. THe milage dropped a little, but the SOTP performance gains were AWSOME!

[mpearce]

will 4:10's actually hurt the mm top end performance and gas mileage?? i just wanted to ask some people who had them already to see if they are worth putting in...:cool:
I love mine. Top end and gas mileage don't matter to me at all. I got them when I got my superchip tunes from Alternative Auto. The car launches the way it should now. They make for a very different feel over stock IMO. Good luck with your choices.

-Mat

[CRUZTAKER]

SITE SEARCH RESULTS (http://www.mercurymarauder.net/forums/search.php?searchid=334276)





This sites search engine will provide you instantly with hundreds of PRIOR comments regarding gears and fuel milage.

[Smokie]

will 4:10's actually hurt the mm top end performance and gas mileage?? i just wanted to ask some people who had them already to see if they are worth putting in...:cool:You don't say what it is that you want, will the 4:10's reduce gas mileage ? Yes. Do you care ?
Will the 4:10's reduce the top end ? Yes. Is the difference between 135 mph and 150 mph important to you ?

The only potential problem with the 4:10's is that you may encounter driveshaft vibration due to flexing at a lower speed than with the 3:55's, "if" this happened to you, it would take place at speeds over 100 mph, a Metal Matrix driveshaft would take care of that "potential" problem.:)

[SergntMac]

Concern for top end performance and miles per gallon in one post...Unique?

[MarauderMark]

SITE SEARCH RESULTS (http://www.mercurymarauder.net/forums/search.php?searchid=334276)





This sites search engine will provide you instantly with hundreds of PRIOR comments regarding gears and fuel milage.


This is best answer to your question.. :up:

[Rider90]

I've been on the edge for two weeks, questioning if I should get them, I already have DR in my cell phone and atleast six times I have almost called him and told him to send em'.

The reason I am hesitant is because I think about what it will feel like flooring it from 60 or 70 MPH like I occasionally do on the highway to impress myself, and not getting much of a response, less of what there is now, and all I hear is a revving engine :alone:

So until I figure that part out, maybe ANOTHER couple weeks, I will keep my 3.55s

[RF Overlord]

The reason I am hesitant is because I think about what it will feel like flooring it from 60 or 70 MPH like I occasionally do on the highway to impress myself, and not getting much of a response, less of what there is now, and all I hear is a revving engine

Dude, that is absolutely NOT what happens...with 4.10s you still get plenty of oomph at 60 or 70...it's only when you get into the 100-110 range that there would be anything even remotely like you're describing...well, I'm only GUESSING there might be some effect at that speed, as I've never had my car to 110...but I haven't experienced any kind of power loss at any rational speed...

[Rider90]

Well I had a CV with 3.08s and a CV with 3.55's

The 3.08s felt like a god on the highway, lower RPMS and flooring it from 70 was great in comparison to the 3.55s that just revved higher so thats what I am basing this on. If I am nuts, lets get enough people to share their stories :beer:

[CRUZTAKER]

...... lets get enough people to share their stories That's what I am getting at here...hundreds of stories HAVE been shared.

I am sure I have said this before in atleast a dozen of those threads, but what the hey...this is the 19th post in the 35th thread regarding 4:10's and fuel/performance.... :shake:

....I guarantee that not only will I outrun your MM with 3:55 gears from a 70 mph hop, I'll do it to a 5.0 mustang as well. I have pulled WOT to 128 +/- in 3rd gear with 4:10's and shifted to OD and went on to over 145 mph....

THIS THREAD - READ BEFORE YOU POST (http://www.mercurymarauder.net/forums/showthread.php?t=14960) needs to be on the homepage in BOLD letters.

[Rider90]

....I guarantee that not only will I outrun your MM with 3:55 gears from a 70 mph hop, I'll do it to a 5.0 mustang as well. I have pulled WOT to 128 +/- in 3rd gear with 4:10's and shifted to OD and went on to over 145 mph....

You have much more power than I do, I never doubted that. But I get your point.

[CBT]

[QUOTE=CRUZTAKER]
:bows: I have pulled WOT to 128 +/- in 3rd gear with 4:10's and shifted to OD and went on to over 145 mph....
QUOTE]:bows:

[RF Overlord]

Well I had a CV with 3.08s and a CV with 3.55's
Rider, your CVs also had the 2V motor, which, while similar in many ways, does not have the high-rpm breathing capability of the 4V in the MM...in other words, it makes its peak lower in the RPM band, so your CV may indeed have "run out of steam" with the 3.55s...you will NOT with the MM...unless you put in some insane gear ratio...like 4.56s (BillyGman :eek: )

Please understand that I'm not trying to "talk you into" something you're not comfortable with...I just don't want you to deny yourself the distinct improvement in overall driveability the 4.10s offer due to an inaccurate perception of how the car might feel at higher RPMs...

[BillyGman]

When I hasd the 4.10's in my Marauder (before the 4.56's) I got only 2 MPG's less than I did with the 3.55's, and the only loss in top end was above 120 MPH which should NOT concern anyone driving on the street IMO. And keep in mind that I had the 4.10's in BEFORE I ever considered purchasing the supercharger.

[FordNut]

That's what I am getting at here...hundreds of stories HAVE been shared.

I am sure I have said this before in atleast a dozen of those threads, but what the hey...this is the 19th post in the 35th thread regarding 4:10's and fuel/performance.... :shake:

....I guarantee that not only will I outrun your MM with 3:55 gears from a 70 mph hop, I'll do it to a 5.0 mustang as well. I have pulled WOT to 128 +/- in 3rd gear with 4:10's and shifted to OD and went on to over 145 mph....

Me too, yet another thread doubting the 4.10s :dunno: . With my 4.10s, I get quick acceleration instead of just a bunch of exhaust noise when I kick it at "normal" speeds as well as the top end. It'll still go faster than the speedo registers, so the only downside to the 4.10s is the slight reduction in mileage.

[Smokie]

If you make the decision to go to 4:10's, ask for advise on the Brand to buy and how complete an install to do. Ideally a Ford dealer should do the job....or you may wind up with some sounds that might make you unhappy.

Installing gears is not like installing an air filter...there is bit of an art involved and if your install artist draws with crayons...you may not like what you hear afterwards.

[valleyman]

What Smokie ^^^ said. I took mine to to a shop that does nothing but rear axle and differential work, paid more for it, got a two year guaarantee, got all my questions answered as they did the work, and got the feeling my car was being handled by people who knew what they were doing.

[BillyGman]

As far as what brand of ring & pinion gears to purchase, I wouldn't buy anything but Ford gears for a Marauder since they're easier to install, and because some other brands (such as Richmond ) will make a whining noise even when they're installed properly, whereas Ford gears will NOT. All the Richmond gears that have a numerically higher ratio than 3.90:1 always emit a whining noise because of the way the teeth are cut during manufacturing.


I was in a Chevelle that had 4.11's and it sounded like riding in a big truck because of the way the gears whined. And the Richmond gear tech department told me over the phone that this is how their gears are in the 4.10 and numerically higher ratios.

[RF Overlord]

All the Richmond gears that have a numerically higher ratio than 3.90:1 always emit a whining noise because of the way the teeth are cut during manufacturing.

I heard that, too...the shop I was originally considering using for my install used nothing but Richmond, and tried to tell me they wouldn't whine if they were set up right...I'm SO glad I got my gears from Dennis...silence is golden.

[BillyGman]

I also considered getting the Richmond gears for my Marauder. They have an installation video that I ordered that was interesting, but I decided against getting them too. So I just bought the Ford Motorsport gears from www.summitracing.com (http://www.summitracing.com/) the 4.10's were $180 and the 4.56's were $190

BTW, for the other do-it-yourselfers here, summit racing also sells the Richmond installation video. It doesn't show you everything you need to know, but it's a good start. however, for that job, you better do your homework thoroughly. I know that I did (which included studying the 2003 Ford shop manual for Marauder, CV's, and Marquis).

[Warpath]

The Cobra mentality is the numerically higher the gear, the better. These engines love top end. So, the numerically higher gear gets the engine there quicker and improves performance. 4.10s are the starting point for the Cobra clan. Some consider them a waste and suggest 4.30s or 4.56s. I'm surprised more of you don't get higher gears. Perhaps its the auto tranny and t/c that changes things.

As for top end, in Cobras, top speed is about 140 in 4th gear with the stock 3.27 gears. It goes up to about 155 in 5th gear with 4.10s. The reason is the tranny gearing. The engine doesn't have enough power in 5th w/ 3.27s to go faster than 140. Its actually slower. 4.10s allow the engine to get higher in the power band to make it faster in 5th. So, the assumption that higher gears lowers top speed isn't always true. 4.56 and higher gears will lower top speed from 155 though.


Divide that by two....and you get everyones Favorite Number....... :D :D :D

I guess that would make a foursome?

[BillyGman]

With the Marauder, there's the weight issue. The engine will simply not carry the weight of the car as fast as it would a Mustang or Cobra which has the same gears. With 4.56's you'll be faster at the track, and I've proven that with my car running better ET's than other S/Ced Marauders are which are running more boost pressures than my car is, and therefore 20-30 RWHP more than my car is, but have the 4.10's instead of the 4.56's. The 4.56 gears enable me to run some fantastic 60' times, and 330' times that aren't obtainable with Marauders running less than 450 RWHP, and 4.10 gears. Atleast not unless they use slicks. I haven't tried running slicks, and perhaps I'd obtain an even better 60' time if I did.


However, even though I've obtained a trap speed of 114 MPH on the track, I also have noticed that on the open highway, the car accelerates a bit slower if you punch the gas pedal after 100 MPH. That doesn't bother me, since I never take my car over 120 MPH, and it's very rare that I even will do that. It certainaly isn't a daily thing nor a weekly thing either. I also noticed that my gas mileage has dropped 2 MPG from when I had the 4.10's, and 4 MPG from when I had the 3.55's. So my conclusion from all of this, is that it depends what you're looking to do with your Marauder, and what your priorities are. if you want the ultimate ET's that any gear ratio can deliver, and are willing to sacrifice a little bit of top end that you usually won't use anyway, along with some gas mileage, then I'd recommend the 4.56's. But if you aren't willing to make those sacrifices, and are looking for a gear ratio that will be a good compromise for both highway driving, and the dragstrip, then I recommend the 4.10's for your Marauder.

[Haggis]

Sounds like good advice Billy. :up:

[Bradley G]

"When he punches it over 100!", ...................he he!:drive:

Bradley G

[BillyGman]

"When he punches it over 100!", ...................he he!:drive:

Bradley G
I will say this......as much as some people think that there isn't any high RPM HP to be had with an Eaton roots type blower, I have noticed that even with the 4.56 gears that I have in my Marauder, once I Trilogized it, I noticed a respectable acceleration increase, even after 100 MPH. :)

[Rider90]

Gears installed correctly will not whine. My bro has done Richmond, Dana, Yukon, Precision, GM, And Ford gears with no problems.-no noises. Over 3.90 richmonds make noise? Never had that happen before. :nono:

[Marauderman]

Talk...Talk...Talk....golly gee guy---.....just drive an MM that has 410's in them --compare and decide---gee...surely there must be some owner nearby --within driving distance on this board--at a local meet maybe--somewhere--that you could do this---IT will solve your doubts!! .cause I don't recall reading here that you have--if so I just over looked it and forget what I said above...Tom

[Bradley G]

You can drive mine but I just took off the stock wheels and tires and had snows and steelies put on for the next couple months.But if I have to switch them back for a dyno then come to Dynopro (next week) in Fox River Grove and you can feel/see for yourself.I will post as soon as I make the appointment for the Dyno.

Bradley G

[BillyGman]

Gears installed correctly will not whine. My bro has done Richmond, Dana, Yukon, Precision, GM, And Ford gears with no problems.-no noises. Over 3.90 richmonds make noise? Never had that happen before. :nono:That's funny, because the tech people at Richmond gear told me that the 410's and up DO whine. So why would they tell me that if it wasn't true? And I was in a car myself that had the Richmond 4.11's, and boy did they whine. And the gears of that car never blew either. So just make a phone call to Richmond yourself just as I did, and ask them, and you'll see. ALL their gears numerically higher than 3.90 are catagorized with a different series # since the teeth are cut differently, and that's what causes them to whine.

But regardless of that, I spoke to Richmond over the phone myself about this, and I've also purchased their video. The Ford gears do NOT whine unless they're installed incorrectly, but some of the Richmond gears are different. That's why I chose to install the Ford gears. because they don't whine.

[Agent M79]

And let's not forget that when you have the work done (and you will, you know you really want to do it) to include the little blue bottle of friction modifier...

http://www.brothersperformance.com/shop/_images/m0263.jpg

[stevengerard]

you are welcome to try mine as well.

[metroplex]

4.10s w/ the stock tire sizing on your MM would be the equivalent to 3.55s on a 98-02 CVPI w/ 225/60R16s.

Long story short: Yes, you want 4.10s on your Marauder. No it will not hurt your top end speed enough to actually hurt 1/4 mile performance.

[Rider90]

hmmmmm 2 sets of richmonds 4.56 gears installed for customers and no noise. They have to be set up perfect though. 1 in a Ford, 1 in a Mopar.

[BillyGman]

hmmmmm 2 sets of richmonds 4.56 gears installed for customers and no noise. They have to be set up perfect though. 1 in a Ford, 1 in a Mopar.Well now that's a bit puzzling I must say. I just don't understand why the tech guy at Richmond has told me that. Oh well, I guess it's nothing that I have to worry about anyway, since I went with Ford gears, and my 4.56's don't make any noise either. Nor did my 4.10's when I had those in the Marauder. :)

[WantOneSoBad]

Can gear ratio's go any higher than 4.56 and if so why don't more of you have them. I am guessing that they don't though since I've spent hours on end looking at all the threads on this board and haven't seen any yet.

[FordNut]

Can gear ratio's go any higher than 4.56 and if so why don't more of you have them. I am guessing that they don't though since I've spent hours on end looking at all the threads on this board and haven't seen any yet.
Sure, you could put in 4.88 gears. It would kill the top end speed and really wind up the motor at cruising speeds.

BTW, a higher number is a lower gear ratio.

[GodOSpeed]

I've been 125 shift and 145 in mine also. With 4:10s. As far as 4:56s and up I think there would be an issue with pin and ring gear clearance. If a person wanted that low of gear I would suggest 4:30s and try going down with tire and rim sizes. I think 3" down = one gear change. Now that would be a gas guzzler and top end killer. But damn decent in the quarter or 1/8mile. :burnout:

[WantOneSoBad]

Okay, so basically what you're saying is that 4.56's on up would be bad ass 0-60 and 1/4 mile MM's but would give up lots of MPG and engine/transmission life since the car would be running at such high RPM's most of the time.

P.S. Thanks for that side note FordNut at the end of your post, shows you how much I know.

[FordNut]

Okay, so basically what you're saying is that 4.56's on up would be bad ass 0-60 and 1/4 mile MM's but would give up lots of MPG and engine/transmission life since the car would be running at such high RPM's most of the time.
Correct.


P.S. Thanks for that side note FordNut at the end of your post, shows you how much I know.
You're welcome, it's a very common mistake.

[AzMarauder]

Common sense says it will hurt top performance too.
Just for the sake of discussion... it isn't as simple as you might think.

Many cars with overdrives or such will achieve their highest top speed in a lower gear. Certainly gas mileage might be lowered... as you are turning higher RPMS. But if you are talking about lowering the car's top speed.... chances are the car needs the mechanical advantage offered by the lower gears to achieve its topspeed.

So you might find that the Marauder would actually go faster in 3rd gear than in OD.. because it can better apply the available horsepower. The same might be true if you have 4.10s vice the 3.55s.

[AzMarauder]

Talk...Talk...Talk....golly gee guy---.....just drive an MM that has 410's in them --compare and decide---gee...surely there must be some owner nearby --within driving distance on this board--at a local meet maybe--somewhere--that you could do this---IT will solve your doubts!! .cause I don't recall reading here that you have--if so I just over looked it and forget what I said above...Tom
The only 4.10 geared MM I've seen belonged to CruzTaker....
I gave him a ride in my '03 Cobra... from Cleveland to Vermont....
I gave him a ride in my '03 MM .... from Vermont back to Cleveland....

Think I've been for a ride in a 4.10 geared MM....:rolleyes:

NOPE !

:depress:

[AzMarauder]

Can gear ratio's go any higher than 4.56 and if so why don't more of you have them. I am guessing that they don't though since I've spent hours on end looking at all the threads on this board and haven't seen any yet.
Depends on the car and application....

5.13s used to be a very popular drag gear .....

I wouldn't want to do more than 4.56s on the street tho. Had them in my '69 Camaro SS years ago. Was like driving a diesel truck. With the 396CUI up front... I could start in 3rd or 2nd depending on grade.... never needed 1st unless I was racing.

[BillyGman]

you'll give up some top end with 4.56 gears, but not a whole lot for street driving, and only for some real crazy street drving at that. With the 4.56's you'll begin to notice aloss of acceleration as comared to the 4.10 gear ratio once you go over 100MPH. my car still pulls very hard after 100 MPH, but that's only because it has the Supercharger on it.


I had 3.55's, then 4.10's, and now 4.56's in my Marauder, and I received a 2 MPG fuel econamy loss going from the 3.55's to the 4.10's, and then another 2 MPG loss going from the 4.10's to the 4.56's. I get the best quartermile 60' times and ET's at the dragstrip with the 4.56's, but the 4.10's were the best overall compromise for the street. but again, that's if you're into driving beserk on the highway. other than the loss of the gas mileage, and the top end loss over 100 MPH, a Marauder with 4.56's in the rear still only revs at 2,700 RPM's on the highway in overdrive while cruising at 70 MPH. So with the tall 18" tires, and the O/D transmission the 4.56's aren't as bad on the street as most people think. if the car didn't have a transmission with overdrive like it does, then i wouldn't even think about puting 4.10's in the rear let alone 4.56's.

[Warpath]

I've seen ratios as high as 5.13:1 for 8.8".

[BillyGman]

I've seen ratios as high as 5.13:1 for 8.8".Yep....there are 4.88's and 5.13's available for the Marauder rear (Ford 8.8) however, based on my experience on the street and at the dragstrip with the 4.10's as well as with the 4.56's in my Marauder, I don't belive there would be any benefot at all from choosing anything more extreme than the 4.56's even for the dragstrip unless you want to run the car in the 1/8th mile strip only. And who wants that? With 5.13's in a Marauder, you'll be reving at 3,000 RPM's on the highway at 70 MPH, and that's in overdrive.

[Warpath]

I think the 4.88 and 5.13s are probably more for lifted trucks with large diameter tires. I wasn't implying to use them on MMs.

[BillyGman]

As far as 4:56s and up I think there would be an issue with pin and ring gear clearance. Once you go with the 4.56's or taller(numericly higher), you have to use a cross shaft pin that has a step ground into it for clearence of the ring gear teeth. That's what I had to do.
Richmond gear sells a special pin that can be used for $34 which is what I did. I bought it from www.summitracing.com (http://www.summitracing.com/) The aggrivating thing for me was that Fordracing doesn't even inform their customers that with the 4.56, 4.88, and 5.13 gears that they sell, a speacial cross shaft pin is needed. Instead, they let you find it out the hasrd way once you have the gear installation almost complated, and you realize that you'll have to remove the ring gear and carrier all over again, because the stock pin won't slide out past the ring gear teeth in order for you to slide the axles back in. :rolleyes:

Last time I looked, the Ford Motorsports catalogue didn't even have an asterisk with a footnote despite the fact that I had called them to request that they do that over a year ago. Their answer was that I should grind down the corners of all the teeth on the ring gear in order to slide the stock pin out!!! Yeah right. Obviously the catalogue department doesn't care about their customers.

[JohnnyB]

You should go with installing Ford Motorsport 4:10 gears. This is what the car should have been built with at the factory. Off the line acceleration is greatly improved and there is still enough engine to give a WOT punch at 70 mph. Your best bet for an install would be a FLM dealer ship or a reputable Mustang speedshop. I have them an have not experienced any significant drop in mpg...

[valleyman]

What he ^^^^ said. :coolman:

[BillyGman]

You should go with installing Ford Motorsport 4:10 gears. Off the line acceleration is greatly improved and there is still enough engine to give a WOT punch at 70 mph. ..Yep, the same can be said about the 4.56 gears, however after having them in my Marauder for awhile now, I must tell you that although they're better for the quartermile, I think that the 4.10 gear ratio is the best compromise for the street (atleast for a Marauder).

[NAVCHAP]

Very happy with 4:30s, might have gone with 4:56s if doing it over again.

Really like the way the higher ratio frees up rpms. Easier to get into the boost.

Leaves unsuspecting CV & Roadmaster Cabbies in the lurch early each morning on the way to work, LOL.

Especially the ones who want to pass on the right at the lane drops. The best defense is a strong offense. Should have seen the grin on the alignment tech today when he road tested it, priceless. -kjs-

[GreekGod]

:beatnik: No one has mentioned the likely-hood of lower tranny fluid temps w/higher numerical rear gears. A highway driven car w/4.10 gears would have cooler ATF than the same car w/3.55 gears, assuming an inadequate ATF cooler. [Think of riding a 10 speed bike in 10th gear or 5th gear all the time] p.s.:my 1966 Ford XL got 3 to 5 mpg in town w4.57 gears![9.5 cr 428/C6]

[BillyGman]

Your 66 Ford got such poor mileage w/4.56's because it didn't have an overdrive transmission like our Marauders do, and there were more cubes under the hood as well. As far as the comment about the transmission running cooler, I don't see why that would be when 4.56 gears require the transmission and driveshaft to turn at a greater speed than 3.55 gears will. So I think if anything, you have that backwards.

[BUCKWHEAT]

I just drove my 4:30's 600 miles and got 20mpg. The 4:10's will be wonderful. Do buy the better drive shaft so you don't worry about the triple digits.

John


will 4:10's actually hurt the mm top end performance and gas mileage?? i just wanted to ask some people who had them already to see if they are worth putting in...:cool:

[JohnnyB]

One reason you may see a drop in MPG is that you find yourself getting on it more to feel the increase in off the line acceleration. Otherwise, at cruising speed, the RPM's are only a few 100 rev's higher than with the stock gears.

[BillyGman]

The following is a list of the RPM differences of some of the gear ratios available for our cars. The RPM listings should be fairly accurate (within 50 RPM's) as long as you have the stock tire height on your Marauder (the back tires):



gear ratio....... RPM@70MPH in O/D

3.55................... 2,080

3.70................... 2,168

4.10.................... 2,402

4.30................... 2,520

4.56................... 2,672

4.88................... 2,859

5.13................... 3,006

...for those who want to experiment more, and find out the RPM ratings for 3rd gear (w/out O/D) or any other gear with any of the gear ratios then below is a link to the gear calculator......


http://www.richmondgear.com/101032.html

[NAVCHAP]

Thanks for the quick and easy chart, BGM! -kjs-

[BLMMCO]

So..Lets say I have a stock MM and want to go the 4:10's. Can I drive down to Ford and have them installed? And will they also re-tune the car? Reason why is I live in Colorado with altitude difference and lack of "tuners". Its very difficult to perform any "mods" due to the lack of Dyno's and Tuner Shops. Help :bows:

[BillyGman]

So..Lets say I have a stock MM and want to go the 4:10's. Can I drive down to Ford and have them installed? And will they also re-tune the car? Reason why is I live in Colorado with altitude difference and lack of "tuners". Its very difficult to perform any "mods" due to the lack of Dyno's and Tuner Shops. Help :bows:Some dealers will install different gears for you, and some will not. you're best off finding a Ford dealer that is an "SVT" dealer since they're usually more performance oriented. But most of them will not re-tune the car for you. And yu're definayely going to need that for the car to take advantage of the new gear ratio. otherwise, the car will not accelerate any differently. Not to mention that the speedometer will also be thrown off. But you can just get a mail-order chip that's burned for 4.10 gears. I just sent you a PM about this.......

[BLMMCO]

Thanks Gman , I think the 4:10's will be my first mod...can't wait to get started

[Sully008]

Hi everyone,

I don't want to start a flame war or anything, but I was just on the other panther site reading about 4.10 gears and while most of everyone here agrees that you can run them with out the MMX driveshaft, over there they say not to. Now, I don't really know if there is much of a difference in the driveshafts of a CVLX to a MM. I've been talking to BillyGMan about my car and he's really opened my eyes to what I can do with "two tons of fun". I want to run 4.10s. I don't want/need to buy the MMX shaft. I don't plan on running triple digit speeds on the highway, but I will be doing travelling with the car. Honestly, I don't think there will be any problems if/when I switch the rear gears and install a LSD. So how come there's a difference of opinions?

I've read/searched everything I could on 4.10s here and there, including this thread. I'm 99% leaning towards the 4.10s, depending on the size of my tires. I will be going with 18s, but I haven't chosen what tire yet.

[BillyGman]

Hi everyone,

I don't want to start a flame war or anything, but I was just on the other panther site reading about 4.10 gears and while most of everyone here agrees that you can run them with out the MMX driveshaft, over there they say not to. Now, I don't really know if there is much of a difference in the driveshafts of a CVLX to a MM. I've been talking to BillyGMan about my car and he's really opened my eyes to what I can do with "two tons of fun". I want to run 4.10s. I don't want/need to buy the MMX shaft. I don't plan on running triple digit speeds on the highway, but I will be doing travelling with the car. Honestly, I don't think there will be any problems if/when I switch the rear gears and install a LSD. So how come there's a difference of opinions?

I've read/searched everything I could on 4.10s here and there, including this thread. I'm 99% leaning towards the 4.10s, depending on the size of my tires. I will be going with 18s, but I haven't chosen what tire yet.
If you're getting contrasting opinions from the Crown Vic boys, then one of the reasons might very well be simply because of the tire height difference. With our Marauders, the factory stock tire height is 28.4" while the factory tire height for the standard 16" Crown Vic tire is merely 26.6". So with practically a two inch differnce in tire height, the driveshaft on the Crown Vic that has the factory tires will be turning a couple hundred RPM's faster at 70 MPH.

That's one factor, and another factor is what you've already mentioned...which was the question about what exactly is the difference between the CV driveshaft, and the Marauder one. I don't know if anyone really knows the answer to that. But this is one of the reasons why I've stressed to you the need to first decide on your tire height before you choose what gear ratio that you'll go with. But after all is said and done, you can always try the 4.10 gears along with the driveshaft. After the gear installation, take it up on the highway during a low traffic volume time, and where there's plenty of open room on a dry pavement, bring her up to about 90 MPH with the radio off, and windows closed, and listen for a vibration. I garantee you that you will immediately notice the vibration if it's occuring. I did with my car. If it occurs, then you'll either have to try getting a high speed balance on your stock driveshaft(which would be much less expensive), or purchase an aftermarket one.

[sailsmen]

A drive shaft can be prefectly balanced and still cause a vibration. At a certain RPM the drive shaft begins to "whip" or get out of round due to it's rotational mass and flexing even though it is perfectly balanced.

The drive shaft shape becomes that of a "banana", hence the vibration.

[BillyGman]

A drive shaft can be prefectly balanced and still cause a vibration. At a certain RPM the drive shaft begins to "whip" or get out of round due to it's rotational mass and flexing even though it is perfectly balanced.

The drive shaft shape becomes that of a "banana", hence the vibration. that sounds like somebody's sales hype to me. No offence brutha, but that's just my gut reaction. Being "perfectly balanced" is NOT neccessarily the only issue here. it's also at what RPM the driveshaft in question was balanced at. Typically, most factory stock driveshafts are NOT balanced at an RPM as high as some aftermarket ones are for high performance applications. So when the gear ratio is changed, which causes the driveshaft to spin faster than it did with the factory stock gear ratio, then the higher speed balance is sometimes needed. I have both the factory stock Marauder driveshaft as well as the Dynotech driveshaft in my possession. put them side by side, and they both look exactly alike. Same dimensions. Same diameter, and they're both aluminum. So I cannot help but to suspect that the only difference might very well be in how they're both balanced. More specifically at what RPM they both are balanced at. Yeah, yeah, I know all about the claim of the Dynotech one being a "Metal matrix" material (whatever that is supposed to mean), but they sure do look the same to me. Infact, if this debate continues, I might just decide to bring both of these shafts to work with me to do a rockwell hardness test on the both of them to see exactly if the aluminum of the two shafts are really any different at all.And a harness test will tell that.

What I think is amusing here is that here we are debating this issue with intensity, while the person who originally started this thread probably got his answer along time ago, and incidentally, he hasn't even been on this board for three weeks now since his last sign in was on the 6th of this month. :rofl:

[Joe Walsh]

[QUOTE=BillyGman]If you're getting contrasting opinions from the Crown Vic boys, then one of the reasons might very well be simply because of the tire height difference. With our Marauders, the factory stock tire height is 28.4" while the factory tire height for the standard 16" Crown Vic tire is merely 26.6". So with practically a two inch differnce in tire height, the driveshaft on the Crown Vic that has the factory tires will be turning a couple hundred RPM's faster at 70 MPH.

Billy is exactly right....The Marauder has a MUCH tallet rear tire than a CV.
I've got pictures of my Marauder parked next to my brother's CV and my Marauder is quite a bit higher in the rear due to the tall rear tires. It kinda looks like I have Gabriel air-shocks on the rear because the height difference between the two vehicles.
4.10s in a CV will spin the engine significantly higher than 4.10s in a Marauder. Couple the elevated RPMs with the CV 2-valve engine, which runs out of breath WAY before the 4-valve Marauder, and a 4.10 CV WILL feel like it has 'short legs' on the highway.

[FordNut]

that sounds like somebody's sales hype to me. No offence brutha, but that's just my gut reaction. Being "perfectly balanced" is NOT neccessarily the only issue here. it's also at what RPM the driveshaft in question was balanced at. Typically, most factory stock driveshafts are NOT balanced at an RPM as high as some aftermarket ones are for high performance applications. So when the gear ratio is changed, which causes the driveshaft to spin faster than it did with the factory stock gear ratio, then the higher speed balance is sometimes needed. I have both the factory stock Marauder driveshaft as well as the Dynotech driveshaft in my possession. put them side by side, and they both look exactly alike. Same dimensions. Same diameter, and they're both aluminum. So I cannot help but to suspect that the only difference might very well be in how they're both balanced. More specifically at what RPM they both are balanced at. Yeah, yeah, I know all about the claim of the Dynotech one being a "Metal matrix" material (whatever that is supposed to mean), but they sure do look the same to me. Infact, if this debate continues, I might just decide to bring both of these shafts to work with me to do a rockwell hardness test on the both of them to see exactly if the aluminum of the two shafts are really any different at all.And a harness test will tell that.

What I think is amusing here is that here we are debating this issue with intensity, while the person who originally started this thread probably got his answer along time ago, and incidentally, he hasn't even been on this board for three weeks now since his last sign in was on the 6th of this month. :rofl:
The older CVPI ones were also Metal Matrix material, which looks just like the aluminum. I would also like to see exactly what the difference is but if even FoMoCo believes there is a difference I have to believe it is not just sales hype.

[BillyGman]

The older CVPI ones were also Metal Matrix material, which looks just like the aluminum. I would also like to see exactly what the difference is but if even FoMoCo believes there is a difference I have to believe it is not just sales hype.Perhaps you're right, I dunno. Maybe one of these days I'll do some kind of Rockwell harness test on them both, and/or have the factory stock one balanced at a higher speed and install it to see if it still causes that obvious vibration that it did with the 4.56 gears right before I had removed it. that would be revealing. ;)

[sailsmen]

that sounds like somebody's sales hype to me. No offence brutha, but that's just my gut reaction. Being "perfectly balanced" is NOT neccessarily the only issue here. it's also at what RPM the driveshaft in question was balanced at. Typically, most factory stock driveshafts are NOT balanced at an RPM as high as some aftermarket ones are for high performance applications. So when the gear ratio is changed, which causes the driveshaft to spin faster than it did with the factory stock gear ratio, then the higher speed balance is sometimes needed. I have both the factory stock Marauder driveshaft as well as the Dynotech driveshaft in my possession. put them side by side, and they both look exactly alike. Same dimensions. Same diameter, and they're both aluminum. So I cannot help but to suspect that the only difference might very well be in how they're both balanced. More specifically at what RPM they both are balanced at. Yeah, yeah, I know all about the claim of the Dynotech one being a "Metal matrix" material (whatever that is supposed to mean), but they sure do look the same to me. Infact, if this debate continues, I might just decide to bring both of these shafts to work with me to do a rockwell hardness test on the both of them to see exactly if the aluminum of the two shafts are really any different at all.And a harness test will tell that.

What I think is amusing here is that here we are debating this issue with intensity, while the person who originally started this thread probably got his answer along time ago, and incidentally, he hasn't even been on this board for three weeks now since his last sign in was on the 6th of this month. :rofl:

Drive line Critical speed

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What it is –
Every rotating object has a “critical” speed or resonant speed, which is a function of its design, mass and stiffness. This is when the driveshaft is whipping in the middle, rather than spinning on a true centerline. For a driveshaft, this is also called “first bending mode”, indicating the shaft actually bows out into a boomerang shape (on a micro-scale). This first mode bending speed is usually referred to in a driveshaft frequency.

What it does –
The energy stored and released through the deflection of the driveshaft through the resonance creates lateral and vertical accelerations of >10g at the problem frequency, which results in broken transmission extension housings, cases and causes moderate to severe vibration at highway speeds (> 70 mph), particularly with axle ratios numerically higher than 3.27:1. This energy release, when compounded by excessive driveshaft imbalance (some is good, too much or too little is not), companion flange run out/imbalance and excessive driveline angles provides the driver with excessive vibration and boom and tortures the driver and driveline components in general.

Because of this, most vehicles have a speed limiter to prevent from entering this mode and causing damage to the driveline.

Some detail –
As mentioned above, the driveshaft rotates at a certain speed based on rear axle ratio; tire size and road speed, but is independent of engine speed (unless you have a vehicle such as a Porsche 944 or C5 Corvette which utilize torque tubes and transaxles, in which case the driveshaft turns at engine speed).

The factors governing driveshaft critical speed include its material properties (i.e., Bulk Modulus of Elasticity which is roughly analogous to material stiffness), diameter, and length and to a lesser degree, wall thickness.

The only factor you can really modify to affect critical speed is material choice. Length is package-dictated, and diameter is usually constrained by driveline tunnel space as well. The answer then becomes a bit simpler – replace your steel shaft with an aluminum or MMC (metal matrix composite) shaft. Both offer reduced weight, which is key in this frequency range. MMC offers the additional bonus of additional damping and stiffness over a typical aluminum alloy.

As mentioned above, at the frequencies in question, a change in rotational mass has a greater impact on resonant frequency than a change in stiffness does, partly since it is easier to reduce mass than increase stiffness (adding stiffness almost invariably means adding mass -- a vicious circle), but particularly since resonant frequency is equal to the sqrt (k/m), where m is mass and k is stiffness. Here m is a stronger function being the in the denominator of a square root. So you can see that as “m” gets smaller, the resonant frequency “f” gets much bigger.

The use of an aluminum shaft provides a dual purpose – increasing critical speed out of the operating range AND directly reduces the rotational forces since those rotational forces are governed by:

F = mr w**2
Where w is rotation speed, m is the mass and r is the radius at which it is spinning.

This means that a 50% reduction in rotational mass results in 50% less rotational force. So, when a driveshaft rotates out of true, due to run out of the shaft itself or due to trans output shaft or axle companion flange run out, the reduced mass * the radius of gyration (i.e., run out) product is smaller than for the same conditions with a steel shaft.

This becomes important not only at critical speed, but at more normal operational speeds where the effects of run out and mass imbalance are more evident than those of resonance:

For a typical Fox or SN95 Mustang, driveline critical speed is around 95-100 Hz. Using stock tires we have the following:

225-60R15, 225-55R16, 245-45R17 all rotate at 812-820 revs/mile at 60 mph.

This give is 13.5 Hz wheel frequency at 60 mph, and assuming a 3.27 axle, we then have:

812/60*3.27 or 44.25 Hz , driveline frequency.

So, 100/44.25*60 yields a driveline critical VEHICLE speed of 135 mph. A good rule of thumb states that the objectionable driveline forces will start becoming significant at 70% of resonant frequency, so for the case of the 3.27 axle, the boom and vibration may be felt beginning at 95 mph.

Typically, 3.27 axles don’t provide the driver with much to complain about; it is 3.73 and above which create the concerns. Using a 3.73, we find that

13.53*3.73 gives 50.5 Hz wheel frequency at 60 mph (substantially higher than the 3.27)

And the critical VEHICLE speed then becomes

100/50.5*60 or 119 mph.

Taking 70% of 119 mph equals 83 mph, certainly a speed at which some Mustang drivers experience occasionally.

For a 4.10 axle, the “70% speed” is 76 mph!

Compounding this problem are factors like transmission output shaft run out, imbalances and run outs from components such as the reverse sun gear, driveshaft, companion flange and pinion pitch line run out (a torque induced run out created when the pinion tries to crawl up the face of the ring gear involutes).

Combine these factors and the already marginal NVH resulting from proximity to 1st bending (critical speed) and the NVH becomes absolutely agricultural.

The aluminum shaft minimizes the contribution from companion flange run out and the driveshaft’s own run out, directly due the lower mass. The pinion is free to pitch +/- 20 degrees and adding in any run outs of the companion flange or driveshaft at the pinion end results in the driveshaft mass having a large eccentric path to wobble about. It is this path times the mass of the driveshaft, which gives the characteristic boom and vibration at highway speeds.

Thus, as Newton predicted, as mass decreases so will the forces. That is why an aluminum shaft is your friend when coupled to 3.73s.

One side note: that great big mass on your pinion nose, fondly named by driveline engineers after the appendage on a male moose, is tuned to 45 Hz, the frequency at which the 2nd order forces created by u-joints as they rotate, force the pinion to bounce or pitch up and down and shake you by the seat of your pants and create an uncomfortable boom in the car. Once again run outs and imbalances will modulate this 2nd order driveline phenomenon to make it worse, so the moral is, LEAVE THE MOOSEB-, uh, DAMPER ON the pinion nose!

Another item: you CAN expect more axle noise when using an aluminum shaft however, which does not necessarily mean the pinion depth or side shims are incorrect, or that the gear cutting process is flawed. It just means that the aluminum shaft is more willing to “bend” circumferentially, torsionally and in a double hump (2nd bending) much more easily than a steel shaft.

Recall my prior statements at the very beginning about aluminum stiffness vs. steel? Picture a piece of sheet metal ducting. Bend it and it makes a WA-WA sound. That is pretty much what a driveshaft does, but at a much higher frequency – higher than even the dreaded “critical speed” of 100 Hz.

Axle noise will occur from about 350 Hz all the way through 500 Hz, sometimes even higher than that. The energy comes from the teeth meshing at the pinion/ring gear interface. This energy is transmitted to the driveshaft (and suspension components) and makes them deflect in the same sense as a piece of sheet metal goes WA-WA. Aluminum is less stiff than steel and takes less energy to deflect it, so it is far more inclined to make your axle go WOOOOO as you drive down the road at 45-70 mph.

Assuming again a 3.73 axle ratio, which has 11 teeth on the pinion and 41 on the ring gear, the axle noise frequency is calculated as (at 45-70 mph):

815/60*3.73*11 or 557 Hz at 60 mph.

This means the WOOO you hear at 45 mph is about 418 Hz and the WEEEEEE you hear at 70 mph is way up there at 650 Hz. You can’t SEE the driveshaft is bending and breathing and twisting, but it is telling you that precisely that is occurring.

So, now armed with this information, you now understand the basics of your vehicle’s driveline.

Information provided by JW

[BillyGman]

Drive line Critical speed

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a piece of sheet metal goes WA-WA. Aluminum is less stiff than steel and takes less energy to deflect it, so it is far more inclined to make your axle go WOOOOO as you drive down the road at 45-70 mph.


This means the WOOO you hear at 45 mph is about 418 Hz and the WEEEEEE you hear at 70 mph is way up there at 650 Hz. You can’t SEE the driveshaft is bending and breathing and twisting, but it is telling you that precisely that is occurring.

So, now armed with this information, you now understand the basics of your vehicle’s driveline.

Information provided by JWOkay, all together now........ "WA-WA"..and "WOOOO".... and let's not forget..."WEEEEEE".......:D

hey, actually, some of that made alot of sense to me, and I noticed some of that going on after changing the gears in my Marauder.

[Joe Walsh]

Like I said in a previous post.....

You can minimize two problems with one material.....CARBON FIBER!

VERY STIFF AND VERY LIGHT.

[sailsmen]

I put in 4:10 and did not notice a vibration, if I did not run at the track so often I could get by based on my driving habits w/out the MMX Drive shaft.

I drove another MM with the MMX Drive shaft back to back w/ my car w/out and his car was significantly smoother over 80mph. That is what really sold me on the MMX.

[BillyGman]

Like I said in a previous post.....

You can minimize two problems with one material.....CARBON FIBER!

VERY STIFF AND VERY LIGHT.I was thinking about that too as i read that. What about enduring the elements? Will carbon fiber neccessarily hold up as good, as metal will while being exposed to snow and road salt?

[Sully008]

Sorry everyone,

I should've started a new thread on this. So, basically I should get my a$$ in gear and select my wheels and tires, then figure out the gearing. I will keep the MMX option in mind, IF I have to go that route. All the posts after my first one gave me more insight on what I need to do.

Thanks!

[BillyGman]

Sorry everyone,

Thanks!No real harm done. :)

[Captain Steve]

I was thinking about that too as i read that. What about enduring the elements? Will carbon fiber neccessarily hold up as good, as metal will while being exposed to snow and road salt?
Probably better. The resin holding the carbon fibers together is pretty stable stuff. Much more so than aluminum or steel.

Fibreglass boats are much better at surviving in salt water than aluminum or steel. The metal boats need sacrificial zinc plates to prevent the hulls from corroding away due to electrolosis.

There are two common resins for putting together fiberglass boats. Polyester resin and epoxy resin. The epoxy is about 5 times as expensive as the poly. It's also about 10 times as strong. So, my question about the carbon fiber shafts is, "what's the glue holding it together?" .

[Joe Walsh]

Probably better. The resin holding the carbon fibers together is pretty stable stuff. Much more so than aluminum or steel.

Fibreglass boats are much better at surviving in salt water than aluminum or steel. The metal boats need sacrificial zinc plates to prevent the hulls from corroding away due to electrolosis.

There are two common resins for putting together fiberglass boats. Polyester resin and epoxy resin. The epoxy is about 5 times as expensive as the poly. It's also about 10 times as strong. So, my question about the carbon fiber shafts is, "what's the glue holding it together?" .

You can check with Mark Veldhuis @ PST (Precision Shaft Technologies) 1-888 575-7888

[BillyGman]

Some very interesting points you have there Steve. I'm not at all sure about how "Crarbon Fiber" varies from fiberglass though. But while we're on the subject of these unanswered questions, I'll throw out yet another one.....does anyone know if there are any funny cars that use carbn driveshafts? but even more importantly, how about Nascar vehicles, or any other circle track cars? Do any of them use carbon fiber driveshafts? that would be impressive if they do, since they're endurance vehicles that have drivetrains that are subjected to grueling punishment.

[BlackHole]

Some very interesting points you have there Steve. I'm not at all sure about how "Crarbon Fiber" varies from fiberglass though. But while we're on the subject of these unanswered questions, I'll throw out yet another one.....does anyone know if there are any funny cars that use carbn driveshafts? but even more importantly, how about Nascar vehicles, or any other circle track cars? Do any of them use carbon fiber driveshafts? that would be impressive if they do, since they're endurance vehicles that have drivetrains that are subjected to grueling punishment.

I know a few Austrailian Super Touring cars use Carbon Fiber drive shafts. The only thing high tech that Nascar experimented with was the Heat tiles like the Shuttle uses to deflect the exhaust heat away from the drivers feet.

[Joe Walsh]

PSTs website shows a Turbo'd Drag Mustang running 7.4s @ 196 MPH as well as a 557 CID Monster Truck....both with a Carbon Fiber Driveshaft. I wonder if NASCAR vehicles are allowed to run Carbon Fiber Driveshafts?
Where's Joe Morganti/ 'Long Live #3'?? He'll know the answer to that question.

[AzMarauder]

that sounds like somebody's sales hype to me. . :rofl:
Billy,

I don't know much about any of the technical stuff... however... when I was sourcing a new driveshaft for my Fairlane.... the guys who built it for me wanted all the particulars... what gears I was running... what the car would be used for... manual... auto.... weight of the car.... horsepower range of the motor.

I was asking about certain materials.. whether to go alum or steel or carbon etc...

One of the things the driveshaft guy talked about was the diameter. When I asked about that... he said... that a drive shaft of a certain diameter... going a certain speed... would suffer from a harmonic and could damage itself.... there are many things that needed to be figured into building the right driveshaft for the application.

So... I'm not sure that it is all hype...

Now I asked here about doing the balancing on our stock shafts... but was told it wasn't just balance that was a problem but that the shafts "flexed".
:dunno:

[BillyGman]

oKay, thanks for that info AZ:2thumbs:

[GodOSpeed]

Im not sure about the carbon fiber. The only requirement is that you have a drive shaft loop and that it is painted white.(to the Nascar question)
Carbon fiber would make sense to the fact that you are lightening up rotating mass.(Mabey free up a few RPM for quicker throttle response)