John F. Russo
Senior Member
BillyGman said:
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
Contributing Member
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.John F. Russo said:
Constable
North East Marauder Member
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.
I'm not sayign the difference is even worth it on a Trilogy MM, but this hypothesis seems (to me) to be correct.
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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
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
New member
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.Constable said:
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.
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Constable
North East Marauder Member
BillyGman said:
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...
Constable
North East Marauder Member
Constable said:
^^^ 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.
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BillyGman
New member
You really have been taking me all wrong. I'm really not angry w/you at all, nor opposed to you being here. When we met at the track, I thought you were a great guy, and I've never had any problem w/you. I was just trying to offer some personal observations of mine from my forced induction experience w/my Marauder thus far. That's all. Sometimes some facets of communication can get lossed through the written word. Perhaps this is merely one of those times. I DO hope that you stick around. Peace. :wflag:
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