Kooks on a Trilogy car

[Logan]

I echo both JET's and Lidio's comments... My Trilogy (Now Buckwheat's) car was in the same power range as theirs in both the 9.5 and 13 psi ranges...

Highly recommended mod on a blown car...

[Constable]

If a Trilogy car (bone stock aside from blower) starts off making 9.5 psi, what is the boost pressure after the Kooks system and exhaust is installed??? I've read that modifications AFTER the blower tend to decrease boost pressure, while mods ahead of the blower will slightly increase boost. This is a very general statement... I don't mean it to be taken as fact. I also am not saying that the difference in pressure is major or significant.

The thing is this: Say you guys start off making 10 psi and about 400 hp. You then add the Kooks setup and gain 30hp (now 430 hp), but drop to 9 psi of boost pressure. Now go and fiddle with it to get your boost pressure back up to the original 10 psi. You'd see that the new power is around 440-445 (from the same 10 psi and the added Kooks).

These are just numbers I made up off the top of my head for example purposes. Do you guys understand where I'm going with this?? The Kooks may be worth more power than you think on an SC car... you're just not seeing that extra 10 hp or so because of the drop in boost.

Check out "Mods for 4V Mods" in this last month's MM&FF for more on this subject.

[BillyGman]

Nope. my car is making 10PSI according to the gauge, and it has the 9.5 PSI pulley. So I've always assumed that the gauge is about one half PSI off. but either way, it definately is NOT making less boost because of the headers and free flowing exhaust.

[Constable]

Billy - you had your Kooks on the car PRIOR to SCing it. Your thought process is not scientific. If you had the car SCed and THEN installed the Kooks & exhaust, there'd be a slight difference. Plus, accurate measurements cannot be taken from the boost gauge. I'm talking about electronic measurements.

Again: the differences in pressure I'm talking about are very slight. I'd like Lidio to chime in on this. I'd just like to see if he's experienced this or not... and I'd like to see what his thoughts are.

[BillyGman]

Billy - you had your Kooks on the car PRIOR to SCing it. Your thought process is not scientific. If you had the car SCed and THEN installed the Kooks & exhaust, there'd be a slight difference. Plus, accurate measurements cannot be taken from the boost gauge. I'm talking about electronic measurements.

Again: the differences in pressure I'm talking about are very slight. I'd like Lidio to chime in on this. I'd just like to see if he's experienced this or not... and I'd like to see what his thoughts are.

Until Lidio can chime in, since I've never had my car dyno tuned EVER,then I don't see why it would make any difference which modification I had first. What I'm telling you is if a boost lowering of any signifigance resulted from the Kooks, then I don't think that I'd be showing more than 9.5 PSI on the gauge, infact if ther were any changes on the gauge, then I'd think that it would read less than 9.5 PSI, and certainly not 10 PSI. would it? I wouldn't dispute your claim if you are talking about a mere .5 PSI of boost, but then again, I don't really think that .5 PSI of boost is going to matter one way or the other anyway. Do you? I DO understand what you mean abou the boost gauge cannot be considered exceptionally accurate. But I'd like to think that it's within .5 PSI of accuracy. But maybe I'm wrong on that.

[FiveO]

I had my Kooks on before my Trilogy.

My car makes 10.5psi of boost (3.2 pulley).

Even showed it on the dyno.

Boost gauge shows 10.5 also.

[John F. Russo]

I would think that the best deal on a Kooks exhaust system can be had directly from Kooks, but I could be wrong. But since my car is only puting 400 HP to the wheels w/the Kooks system and the Trilogy set-up is intended to put 385 HP to the wheels w/an otherwise stock Marauder, then I'd say that I've only gained about 15 RWHP from the Kooks system once my car was S/Cered. But the Kooks system does make the car sound sooooo NICE!!!

I am considering an exhaust upgrade. I don't like the higher noise and am considering the Cobra system that SergntMac has. But if you only really get 15 hp from the Kooks, I'll even get less from the Cobra. Is it worth it?

Why did you get only 15 hp from the Kooks when they claim 50 hp. Is it a matter that you are using only single one dyno data points and it is not truly giving you the real difference or is it as someone else said that addding individual hp's from different mods will not be a 1 + 1 =2 but some smaller number.

Is it possible that the baseline for your car is not as high as 385 hp and the 400 hp is really less that the true hp and the real difference is 50 hp as Kooks' claims?

[FordNut]

I am considering an exhaust upgrade. I don't like the higher noise and am considering the Cobra system that SergntMac has. But if you only really get 15 hp from the Kooks, I'll even get less from the Cobra. Is it worth it?

Why did you get only 15 hp from the Kooks when they claim 50 hp. Is it a matter that you are using only single one dyno data points and it is not truly giving you the real difference or is it as someone else said that addding individual hp's from different mods will not be a 1 + 1 =2 but some smaller number.

Is it possible that the baseline for your car is not as high as 385 hp and the 400 hp is really less that the true hp and the real difference is 50 hp as Kooks' claims?

I believe Lidio has more accurate numbers, and he claims 20-30 rwhp gain. Why are his numbers more accurate? because his experience has been with cars that already had the blower so direct comparison of before and after header installation can be made. Billy already had the Kook's headers before the Trilogy was installed, so all he can do is compare his "after" power numbers with other cars' (without the Kook's) "after" numbers. And we know that 2 cars with identical mods will commonly produce different dyno numbers. Mac should be able to give you relatively accurate numbers on the Cobra manifolds, as his car was blown with stock exhaust, then converted to the Cobra manifolds and he did before and after dyno runs. Even though his car has a centrifugal blower instead of the Trilogy, the numbers should be fairly accurate.

[Constable]

Billy (and all others): My ideas about boost pressure changes are just that... ideas. But I want to make sure I convey them as clearly as possible. Now I saw that you are claiming 10 psi while FiveO is claiming 10.5 psi... I believe you're both using the same pulley. Hopefully the difference is not due to your gauges. My questions and ideas are best explained in that article I mentioned. In the 11-04 issue of MM&FF, there's a graph and large caption on page 160. The caption is titled "Exhaust Test: Stock vs. Cat Back vs. Headers". It shows a power improvement from each step, but also a decrese in boost pressure (measured on a '04 Cobra motor... Eaton M112). The pressure starts at 17.9, drops to 17.2 after the cat-back install, and then drops to 16.5 when the headers & open pipes are installed. The power increased dramatically 666/578 to 682/595) even though the pressure dropped. But now imagine if you went back and increased boost pressure to the original 17.9?? There'd be even more power present. Read the article... it's good.

I'm not sayign the difference is even worth it on a Trilogy MM, but this hypothesis seems (to me) to be correct.

[Lidio]

I don’t have any real scientific data at this time to fully explain the whole boost drop and better exhaust thing. I just don’t know it all in that department. I do know that on Trilogy MM’s they don’t seem to loose any or very little boost when you go to full 2.5” exhaust with kook’s? But yet they gain substantial power at the rear wheels. On paper certain things just don’t always equate to what we see in the real world.

Here’s another one we found too…. On supercharged ’03 Cobras weather they’re making the stock 8ish psi of boost or up to about 13ish. We found that once they already have a good 2.5” exhaust system + mufflers and then you at a later date add long tubes in favor of the factory cast manifolds, they only pick up about 5-10 RWHP!! Because of this we don’t even bother pushing much beyond the factory supplied cast manifolds on the ’03-04 Cobra’s now days. Unless the stock Eaton M-112 has been replaced with a Wipple or Kenne Bell and even then long tubes don’t seem to add what you’d think over the manifolds in term of HP.
This is why on my own personal ’04 Mach-1 shop project car, I choose to leave the factory cast manifolds, but make the rest of the exhaust 2.5” with two cat’s and delta-40 FloMaster mufflers. Plus since my Mach-1 is an automatic, it makes trans R&R much easier with shorty headers or stock cast manifolds. So far on my Mach-1 with a intercooled 2.2L Kenne Bell blower making 17psi of boost on 100 unleaded fuel, I’ve already made 565RWHP. This is pretty good RWHP for an auto trans and no headers what so ever.


Thanks

[BillyGman]

Billy (and all others): My ideas about boost pressure changes are just that... ideas. Now I saw that you are claiming 10 psi while FiveO is claiming 10.5 psi... I believe you're both using the same pulley.

NOPE. NOT true. Five0 has the 3.2" diameter pulley, and I have the standard 3.4" pulley which is the one that the Trilogy kit comes with. That's why FiveO's engine is pushing a little bit more boost pressure than mine is. At the time I purchased and installed the Trilogy kit, I had decided that I'm sticking w/the only pulley that Trilogy Motorsports offers their S/cer kit with. And that's the 9.5 PSI pulley which is 3.4". Your car is not S/Ced, so how the flow of the exhaust system effects the output of your engine is NOT neccessarily the same as it would a S/Ced engine. I've been told by a couple engine tuners that a free flowing exhaust doesn't have as much effect on a S/ced engine that's on most street cars. And that it's only when you start approaching power levels close to 600HP that a free flowing exhaust begins to make some major contributions in power levels.

But I don't regret having the Kooks headers, as well as their entire exhaust package, because it makes the car sound real mean!!! And it also drowns out most of the S/Cer whining noise. And I'm also happy about that too, because I don't particularly like the whining noise. And on my car, you can barely detect it, even at WOT.

[sailsmen]

To understand you have to realize that S/C or a Turbo does not significantly increase the peak max pressure that is in the cylinder. It only significantly increases the druation of the max pressure through out the cycle.

[Constable]

Your car is not S/Ced, so how the flow of the exhaust system effects the output of your engine is NOT neccessarily the same as it would a S/Ced engine.

I know my car isn't SC'd... thanks for pointing that out. Also, I never once made reference to my car... nothing I've said has anything to do with my car. All I did was bring up a possible scenario and say that there might be a few more ponies that are unaccounted for when you install a high-flowing exhaust and headers on an SC'd car. The info is backed up by dyno tests that were performed in a controlled environment on a 4V Eaton-blown motor. I've already made reference to the source.

Ya know, I haven't been posting much at all over the past 10 months. I think this is the reason why...

[BillyGman]

Ya know, I haven't been posting much at all over the past 10 months. I think this is the reason why...

LOL!!! Thankyou for writing such an emotionally mature reply.

BTW, you're welcome for the correction on your inaccurate statement about my car having the same blower pulley as FiveO's car.

[Constable]

I believe you're both using the same pulley.

^^^ All I said was "I believe..." I never said it was fact. I was anticipating that you or FiveO would KINDLY provide the correct answer.

Before this gets out-of-hand, Why does it seem like you keep taking "digs" at me on this thread? Have I insulted you? What, exactly, have I done to deserve the wrath of Billy G??

I was just trying to stimulate the minds of our membership with some information that I had acquired. Guess I'll just go back into hibernation from posting again... Out of respect for Logan and the other administrators, I'd rather not continue this e-confrontation.