Knowledgeable Foxbody Mustang people, I need some help!

[sflrainmaker01]

Recently (since I have purchased my Marauder :P), I have been neglecting my 86 Mustang GT vert.:o Mainly, because I have been having a hard time finding some good (and detailed) help regarding the speed density computer system on it. I have posted on the Mustang sites, but usually, all I get is convert the computer system to Mass Air.:rolleyes: That doesn't answer or address any of the questions I have. I was just wondering if there is anyone on MM.net that might be able to help or know someone that can help me.
Thanks!

[Mr. Man]

PM Jim Signorrelli (jsignorelli) if he doesn't know he can probably put you in touch with whoever can. :)

[yjmud]

speed density systems are good for all out racing but for everyday street use the mass air is the way to go
what are your questions anyway

[martyo]

It is old technology but our shop still handles quiet a few of these cars.

[RoyLPita]

I was told to get the A9L pcm. Late Model Restoration has the harness for $50. The Maf, however, can be had as long as it is programmed for 19# injectors. Since you have the 86 model, see if the 87-93 upper intake and EGR spacer is available. It is made for the 60MM TB but your 58mm TB will fit just fine.

[sflrainmaker01]

PM Jim Signorrelli (jsignorelli) if he doesn't know he can probably put you in touch with whoever can. :)

Thanks for the lead. He already contacted me. So, I sent him a book (I mean email) about the situation. Thanks a million! I love this site!:marauder: You all are great! :beer:

[sflrainmaker01]

speed density systems are good for all out racing but for everyday street use the mass air is the way to go
what are your questions anyway

The short version is, I replaced motor with an Explorer short block, crower 15511 cam (114 lsa, proven to be SD friendly), E7 Powerheads, ported stock lower intake, stock 86 upper intake and t/b (but just had the matching ported upper w/75mm tb opening powdercoated and ready to put on) along with stock 19lb injectors and BBk shorties with a full 2.5" hi flow catted exhaust.

Other than the annoying idle surge and stalling when coming to a stop, it drives as if it has a double pumper 4bbl carb on it where at the point the secondaries (4bbl) should "kick in", they usually don't. Or, it might also be explained like a turbo lag, except the turbo never spools up. Now, occasionally, it does accelerate like it is supposed to and damn its powerful! :burnout:

So, right now, I am getting ready to re-install the matching ported upper with the matching valve covers (I posted a pic of them recently on here). I am also going to but on a NEW BBk 70mm TB and spacer, fuel pressure gauge and a AFPR.

FYI, the original 58mm tb had the stop screw all the way out and stripped so it can't be moved. The car idles around 750-800 rpm.

[ITSA 91]

I've found that with the 86 SD computer that you can change most anything except the camshaft,It must stay mild.If you want a radical camshaft and drive on the street, you need to go to mass air.The 86 pistons have no valve reliefs and have a neg deck clearence of .007 to.011 so changing heads can be a problem with piston to valve clearence.

[Curless]

What is your fuel pressure at idle and under load (WOT pulling down the road)? But I would say you should switch to mass air, that cam is gonna want the adjust ability that a mass air system can do...also, stick or auto??

[Vortech347]

Speed density systems are designed for the exact engine combo that came from the factory. Once you start adding flow it gets very pissed off. I know they say "SD safe cam" but to be honest it isn't if you want to get 100% out of the cam and best drivability. Plus you have heads, exhaust, and intake that flow more than stock.

I've tuned several foxes. MAF'd A9L with a quarter horse and binary editor is the way to go.

[yjmud]

^^^^^^what he said sd doesn't like more than 10%flow increase convert to mass air

[sflrainmaker01]

Speed density systems are designed for the exact engine combo that came from the factory. Once you start adding flow it gets very pissed off. I know they say "SD safe cam" but to be honest it isn't if you want to get 100% out of the cam and best drivability. Plus you have heads, exhaust, and intake that flow more than stock.

I've tuned several foxes. MAF'd A9L with a quarter horse and binary editor is the way to go.

Right. So, now I am officially throwing in the towel on the SD system and gonna start rounding up the parts for a Mass air swap. If any of ya'll know where I can find a nice A9L computer, let me know. Also, I think I am going to bump up to 24lb injectors too. Might as well, it's all apart now.:rolleyes:
Plus, I read several threads where guys have had to turn UP the fuel pressure like 4 PSI to even get the car to run right with the 19lb'rs on a SD setup. That tells me I am running lean. I was kinda suspecting that based on how the car was acting.
Thanks again for everyone's input. :beer:

[ROCOB]

Might want to look at MPS.

http://www.ebay.com/itm/FORD-MUSTANG-MASS-AIR-CONVERSION-KIT-METER-ECU-5-0-87-88-A9L-JUMPER-HARNESS-/140763023767?pt=Motors_Car_Tru ck_Parts_Accessories&hash=item20c6214997&vxp=mtr

[martyo]

I just sold a bunch of the parts you need. Let me see if I have more in stock.

[martyo]

I just sold a bunch of the parts you need. Let me see if I have more in stock.

We do not have any A9Ls in stock.

The harness you can get from the Auto Part store.

[Vortech347]

Right. So, now I am officially throwing in the towel on the SD system and gonna start rounding up the parts for a Mass air swap. If any of ya'll know where I can find a nice A9L computer, let me know. Also, I think I am going to bump up to 24lb injectors too. Might as well, it's all apart now.:rolleyes:
Plus, I read several threads where guys have had to turn UP the fuel pressure like 4 PSI to even get the car to run right with the 19lb'rs on a SD setup. That tells me I am running lean. I was kinda suspecting that based on how the car was acting.
Thanks again for everyone's input. :beer:

Changing the fuel pressure will screw with a ton of stuff. Adaptive will correct it and cause other issues.

You can get an A9L from part stores for $100 with a warranty. Don't pay $200 for a old used one. (I just replaced my fox computer last year)

When you do the 24lb injectors you'll need a matching calibrated MAF. My suggestion is Pro-M.

Short of that if you want to make it run like a top you'll want to get a quarterhorse and binary editor for the computer. Its cheap and you'll have full control/datalog ability. I have my high HP fox running like a kitty cat. Its so nice.

[LSCR351]

It is old technology but our shop still handles quiet a few of these cars.
Modifyed speed-density Mustangs? If so I will probubly need to buy some help. I am running a Vortech'd 351 on a DA1 with an FMU. For the 30# injectors to work, the fuel pressure is turned down to 20psi. and that makes it hard to start (lean). But just this week I ordered the Quarterhorse & BE. My problem is I know nothing about computor tuning!

To the OP, you can make SD work fine with that mild combo if you wanted to. I was at 290/359 at the wheels and ran 100% as good as stock. Then I threw a Vortech into the clockworks! Now it needs to be tuned, but so would a A9L/A9P.

[bigcowl-imp]

....... I have my high HP fox running like a kitty cat. Its so nice.

Whats the motor and hp ?


sflrainmaker01......i might still have a A9Ls that you can have.??? i will check later today.

[sflrainmaker01]

Modifyed speed-density Mustangs? If so I will probubly need to buy some help. I am running a Vortech'd 351 on a DA1 with an FMU. For the 30# injectors to work, the fuel pressure is turned down to 20psi. and that makes it hard to start (lean). But just this week I ordered the Quarterhorse & BE. My problem is I know nothing about computor tuning!

To the OP, you can make SD work fine with that mild combo if you wanted to. I was at 290/359 at the wheels and ran 100% as good as stock. Then I threw a Vortech into the clockworks! Now it needs to be tuned, but so would a A9L/A9P.

Were you running the DA1? It seems the stock 86 computer is different than the 87-88 ones. These modifications seem to work better on that computer. .



Changing the fuel pressure will screw with a ton of stuff. Adaptive will correct it and cause other issues.

You can get an A9L from part stores for $100 with a warranty. Don't pay $200 for a old used one. (I just replaced my fox computer last year)

When you do the 24lb injectors you'll need a matching calibrated MAF. My suggestion is Pro-M.

Short of that if you want to make it run like a top you'll want to get a quarterhorse and binary editor for the computer. Its cheap and you'll have full control/datalog ability. I have my high HP fox running like a kitty cat. Its so nice.


Someone on Corral.net said he turned UP the fuel pressure to like 43psi with the stock 19lb'rs and got some decent results. But in the end, switched to Mass Air.

Big Cowl, thanks!

Martyo, thanks for checking!

One last question.... Would an A9P work just the same?

[Vortech347]

Modifyed speed-density Mustangs? If so I will probubly need to buy some help. I am running a Vortech'd 351 on a DA1 with an FMU. For the 30# injectors to work, the fuel pressure is turned down to 20psi. and that makes it hard to start (lean). But just this week I ordered the Quarterhorse & BE. My problem is I know nothing about computor tuning!

To the OP, you can make SD work fine with that mild combo if you wanted to. I was at 290/359 at the wheels and ran 100% as good as stock. Then I threw a Vortech into the clockworks! Now it needs to be tuned, but so would a A9L/A9P.

Running 20psi is a horrible band aid for bigger injectors. FMU's are also a thing of the past. eectuning.org will be a great resource for you. While you made that power with SD I'll bet whatever the combo was a correctly tuned MAF'd would have made more and driven much better.



Whats the motor and hp ?



sflrainmaker01......i might still have a A9Ls that you can have.??? i will check later today.

347ci, ported Edelbrock heads, Super Victor Jr. EFI intake, Vortech S-trim (at Vortech right now getting the Si Upgrade), B31 Cam, 60lb EV14 Injectors, to much stuff to list. Dynosheet "cool down" pull was 570+rwhp. Heat soaked Street/Open track tune is 550rwhp. Idles at 800rpm, I can cruise at any RPM with 0 surging. Would love to go beyond the current 11psi but the stock block will split its ass into two pieces. All tuning done on 91 so I can drive it where ever the hell I want. :)

[LSCR351]

Were you running the DA1? It seems the stock 86 computer is different than the 87-88 ones. These modifications seem to work better on that computer. .





Actually I was running a 1986 VL1 most of the time. The DA1 was good for .05 better 1/4 mi. ET but would die sometimes after running it hard and then mashing the clutch. When it was dyno'd it was with the VL1. Quarterhorse does not support the VL1 though.

[bigcowl-imp]

sflrainmaker01....all i could find where harnesses, trim, etc etc ....i did find a pair of black a pillar moldings for a convert..... and no computor...sorry

Vortech347.......sounds nice lets see a pic or 2..

[sflrainmaker01]

Actually I was running a 1986 VL1 most of the time. The DA1 was good for .05 better 1/4 mi. ET but would die sometimes after running it hard and then mashing the clutch. When it was dyno'd it was with the VL1. Quarterhorse does not support the VL1 though.

Hmmmm... Interesting.:hmmm: So, much for the DA1 theory then...:banghead:

I found a local guy who has an A9P, Pro-M meter and 24lb'rs that is supposed to be in good working order. Should I try that for my Mass Air swap or keep looking for an A9L?

Bigcowl-imp, thanks for looking!;)

[Vortech347]

Hmmmm... Interesting.:hmmm: So, much for the DA1 theory then...:banghead:

I found a local guy who has an A9P, Pro-M meter and 24lb'rs that is supposed to be in good working order. Should I try that for my Mass Air swap or keep looking for an A9L?

Bigcowl-imp, thanks for looking!;)

You don't need to look for an A9L. You can get them at any part store for $100.

http://eectuning.org/forums/viewtopic.php?f=1&t=20284

You want an A9L to start with if your car is a manual. A9P can work but you'll need to immediately make some changes to the calibration.

[sflrainmaker01]

You don't need to look for an A9L. You can get them at any part store for $100.

http://eectuning.org/forums/viewtopic.php?f=1&t=20284

You want an A9L to start with if your car is a manual. A9P can work but you'll need to immediately make some changes to the calibration.

Thanks! I will check into that! I still might just buy it all. He only wants $175 for all three pieces. :eek: I know if it's to good to be true, then it usually is.

How can I tell if the injectors are in decent shape? I am pretty sure the 19's I am using now are probably not working at peek since the car sat for 7 years only being started and ran in the driveway with the same crappy gas until it started to run bad. Then, it was parked for three more years.:eek:
At that point the gas tank was shot, so I had to get a new, tank, fuel pump, filter and I re-conditioned the sending unit myself, since there are currently no remans available for the 86.

[LSCR351]

I found a local guy who has an A9P, Pro-M meter and 24lb'rs that is supposed to be in good working order. Should I try that for my Mass Air swap or keep looking for an A9L?

B!;)
The wiring is different between a A9L and a A9P. If you put an A9L where a A9P is suppost to be it WILL burn up the o2 Sensor part of the computer and from then on will only be in open-loop. I may have forgotten (reserch it to be sure) but I think it's the A9P that has the same basic wiring diagram as a Speed-Density car, other than the MAF and Thermacter.

[martyo]

Modifyed speed-density Mustangs? If so I will probubly need to buy some help. I am running a Vortech'd 351 on a DA1 with an FMU. For the 30# injectors to work, the fuel pressure is turned down to 20psi. and that makes it hard to start (lean). But just this week I ordered the Quarterhorse & BE. My problem is I know nothing about computor tuning!


My tuner said he personally likes the MAFwith a larger injector because of the extra tuning range the MAF gives. With that said, yes he can tune the da1 just not a big fan of the sd system. If you would like to speak with him, just let me know.

[LSCR351]

My tuner said he personally likes the MAFwith a larger injector because of the extra tuning range the MAF gives. With that said, yes he can tune the da1 just not a big fan of the sd system. If you would like to speak with him, just let me know.

Yes I am interested in tuning the DA1.

[martyo]

Yes I am interested in tuning the DA1.

We could set you up to tune the car at our shop if you want to come up this way.

I will set it up so that you get tuned when you arrive since you have a bit of a drive.

Let me know how I can help.

[Vortech347]

Seriously, don't waste ANY time with SD. There is no point at keeping it unless the car is stock.

[sflrainmaker01]

You don't need to look for an A9L. You can get them at any part store for $100.

http://eectuning.org/forums/viewtopic.php?f=1&t=20284

You want an A9L to start with if your car is a manual. A9P can work but you'll need to immediately make some changes to the calibration.

I checked at Auto zone, Advanced Auto parts and Rock Auto. All "out of stock". I have a couple guys hitting me up over at Corral.net. See how that works out.

How would I know if the Fuel Injectors are any good?

[LSCR351]

We could set you up to tune the car at our shop if you want to come up this way.

I will set it up so that you get tuned when you arrive since you have a bit of a drive.

Let me know how I can help.

I do come up that way from time to time.

I am waiting for my Quarterhorse & BE to come in now. I want to tinker with it for a month or two and see what I can learn first. Maybe I can bring it to tune shortly before the SSHS14!

Thank you.

[LSCR351]

Seriously, don't waste ANY time with SD. There is no point at keeping it unless the car is stock.
Everybody has an opinion. Some might say don't waste any time with a 4.6, Or with a 4000+ pound 4-door. But we still do it, And sometimes it comes out alright.!

[Vortech347]

Everybody has an opinion. Some might say don't waste any time with a 4.6, Or with a 4000+ pound 4-door. But we still do it, And sometimes it comes out alright.!

Yea, but there is a reason that Ford no longer uses SD since 1986.

Open the door to so much more control, power, drive ability, and most importantly, SUPPORT. Most good tuners won't even do SD stuff, they'll tell you to do a mass air swap.

Its pennies for what you gain!

[sflrainmaker01]

Yea, but there is a reason that Ford no longer uses SD since 1986.

Open the door to so much more control, power, drive ability, and most importantly, SUPPORT. Most good tuners won't even do SD stuff, they'll tell you to do a mass air swap.

Its pennies for what you gain!

FWIW, I am in the middle of rounding up Mass Air conversion parts for the Mustang instead of Eaton Swap stuff for the Merc. :mad: I will let you all know how it turns out. I will probably need a week or two to get all parts and install. Plus, I might splurge and take it over and have it tuned on the Dyno. After all this, might as well, right? :wflag::burn: