[Frank]

Well my Cougar is all back together and let me tell you all something... it seems to run the same, if not better, with the stock Y-pipe and cat-back exhaust compared to having full 2.5 inch trubendz with a 2.5-inch test-pipe. It might have lost a tiny bit of power above 6K, but overall the difference is insignificant. Today I had a chance to get a few quick runs in, one against my friends 4.3L S-10 and another against my friends 2001 V6 Accord. The Accord used to destroy me when my car was stock (and when all I had was exhaust), but with all the mods I had we were finally pretty even. Well... with all my mods EXCEPT the exhaust, we were STILL even all the way from 0-120. This is a car that should run 16 flat in the 1/4 mile. The S-10 used to stay even with me until about 50-60, then I'd pull away decently. Well, I still beat him just about the same as I used to with the full 2.5-inch exhaust. His truck runs a consistent 16.2-16.4. If I had to do this all over again, I would never have even touched the exhaust... I would've just gotten the MSDS headers and SVT UIM and called it a day. And I would have still done the IAT mod because it makes me happy.

Just something to keep in mind if you're looking for horsepower on a budget... there's very little hiding in the exhaust (except for the stock manifolds, which suck). Do it for looks, do it for sound, don't do it for power. It might shift the power band up and give you higher peak numbers, but it did not make me faster at all.

Just thought I'd share... it's kinda neat having a car that basically looks and sounds like a stock ATX Cougar, but is roughly a full second faster... versus one that makes tons of noise and is still just as slow.

 

[Instigator]

I think your butt dyno is broken, you should have that checked out

 

[mindtrip1016]

You must be referring to the dual exit trubendz exhaust. I can agree with that. The shape of the "Y" near the exit does nothing better than slow down the exhaust gasses. Single exit is the way to go if one is performance oriented. Unless some one could find a better way to make the transition from the pipe to the U shaped bend.

 

[EternalOne]

I would've just gotten the MSDS headers and SVT UIM and called it a day.

And without an exhaust those would have been just as worthless. The intake/exhaust system of a performance car should be considered one system, because it really is all about moving air in and then out of the engine. Sure, you'll get some gains if you can take in more air, but what about the extra backpressure you're going to build up?

E1

 

[Russell]

i have a 3L hybrid, PnP heads with 3L valves, MSDS headers, SVT UIM, LIM, and cams, and stock single exhaust

my car is horribly choked up in the higher rpms, but has gobs of low end torque, the car feels better below 6K !!!

come spring i plan on doin true duals

 

[Frank]

Originally posted by: EternalOne

I would've just gotten the MSDS headers and SVT UIM and called it a day.

And without an exhaust those would have been just as worthless. The intake/exhaust system of a performance car should be considered one system, because it really is all about moving air in and then out of the engine. Sure, you'll get some gains if you can take in more air, but what about the extra backpressure you're going to build up? E1

Did you read the rest of my post? That's what's on the car now (actually see my sig for all the mods) and it's still just as quick as it was with full exhaust. I couldn't believe that I was neck and neck with that AV6 exactly the same as I was before putting the stock exhaust back on. I was making all that noise for nothing... lol.

 

[GrandMasterKhan]

oddly enough if you check out the CF2k2 dyno list...even peeps with more exhaust mods on there ATX didnt benefit very much if at all vs stock ATX....However the MTXs it was not so:shrug:

However I am also starting to think about ditching the quasi-duals for a single exhaust, or a custom true dual setup. :naughty:

 

[Frank]

GMK, that just made me think of something... while changes in engine power should be the same with either transmission, the ability to use the slightly increase in peak power from a big exhaust is almost non-existent with an ATX.

My car made 151.5 with Borla single and stock cat and 155.0 with TruBendz + test pipe (stock UIM)... but all the gains were above 6300RPM. With the ATX's gearing, the mid to upper 6K range is hardly used... the 1-2 shift drops the RPM's to mid 3s. and the 2-3 shift drops them to high 3's... that's where the ATX needs to make power for most of a race, and one of the only mods that boosts mid-range torque significantly is the headers (a chip would help too!).

If you have an MTX, then exhaust mods other than headers might be slightly useful... and slightly more useful with a raised rev limit.