Looking for approximate HP gains from a TBE on a mildly modified Evo IX.

I've searched through hundreds of posts, some saying 30+ hp to the wheels, and others saying less than 10.

My reason for asking this question is I have an IX with a WORKS P2R flashed for a HFC and RS*R 3" cat back exhaust.

The noise on long trips was starting to get old (or perhaps I am the one getting old Nevertheless, I put the 100% stock exhaust back on, and had the P2R reflashed for this 'reverse' modification.

Seat of the pants it doesn't feel any different than with the 3" exhaust. So I wonder how much HP I left on the table by putting my stock exhaust back on. To me, it doesn't feel like many at all.

I have a theory that aftermarket manufacturers sell SO MANY exhausts to Evo owners that the benefits may be exaggerated.

Anybody with objective data to share?

 

Exaggerated? Isn't that like lying? Tell me it ain't so?

Doing front-to-back Mustang dyno runs on my X with a Buchur Cat-back versus stock exhaust did not show any definite gains at all. The pulls before/after were within 3 HP overall - probably less than the repeatability of the dyno.

Most X Cat-back mfgrs claim "up to 15HP" gains.

 

Thanks for sharing, Q15H.

That's exactly my point. These manufacturers make plenty of 'claims', that are really just that.

I've seen 'claims' of 20hp from a downpipe, 80hp from a reflash, 20hp from a LICP, and the list goes on.

 

I'm running an apexi it's damn loud but when I add the silencer it quiets down but you can feel the power losses and it feels
sluggish

 

I think the "up to" part keeps them covered. On a mildly modified evo, the stock exhaust is only minimally limiting, therefore replacing it, will only be a minimal gain.

Different story on a big cam, big turbo evo that needs that flow. These are the cars picking up that 15hp on that exhaust.

 

80 hp from a reflash lol I want that one hahahahaha.. When I was stock and got retuned I got an extra 24hp on a mustang dyno. And I felt a world of difference in how the car drove..

 

isnt the real purpose of having the 3'' exhaust, just for simple less restrictive more exhaust gas flow? Allow quicker respons. Which in the long run would work out. Less restrictive more power more faster spool. restrictive less power laggier spool.

Edit: but i mean from seeing some graphs there is usually a 15-30 hp gain.

 

Remember tuning is your friend. Gains with any mod will probably be very minimal until the car is re-tuned to make better power out of them. And IMO people are wasting their time with just a cat-back anyways. On a car like the evo, its full TB or you might as well just leave the thing alone.

 

I picked up 29 WHP and 21 WTQ with the buschur turbo back. I would say, you lost some power! Check this out! It's quiet now! And I still have NO cat!

https://www.evolutionm.net/forums/ev...t-exhaust.html

 

I've looked at other OEM exhausts...........take the Nissan GT-R for example. I havent seen too many guys posting big gains when upgrading the stock 3" center pipe to a 3.5" center pipe. This is a 500hp car, mind you.

I just don't think the stock Evo IX exhaust is as bad as everybody says it is.

 

I can definitely feel the power loss from TBE to stock exhaust. I have a QTP right now, but I've yet to get it tuned, so that should yield even better power.

 

its been noted on several occasions that most of the restriction occurs before the cat, so dp, o2 housing etc are going to yield more immediate gains. Opening up the dp and o2 housing is also complementary to a CBE at which point, so you're free flowing all the way back.

There have been a number of dyno pulls back to back illustrating the difference between a stock, and tbe + retuned evo. The difference is significant in quite a few cases. It's also been mentioned in a few cases (and magazine articles) that the CBE section gets you very little but sound if you don't upgrade the rest of it.

I'm also confused about your question. At first, it seems like your asking how much power one can expect to gain from a TBE, but as the thread progresses, it seems more and more like you're actually trying to say that an exhaust doesn't help that much. If that is your stance, I disagree. There are about a billion posts, and articles that explain the benefits of a more free flowing exhaust. Not many of them have actually been published by the exhaust manufacturers.

 

alot of those estimates include the gains you'll get after a tune.

I have mixed feelings about the morality of that.

 

"its been noted on several occasions that most of the restriction occurs before the cat, so dp, o2 housing etc are going to yield more immediate gains. Opening up the dp and o2 housing is also complementary to a CBE at which point, so you're free flowing all the way back. "

My research on the forum tells just the opposite...............the stock DP is very good, and perhaps a 3" will help spool a bit, but the major restriction is the stock muffler and converter.

Again, this is just what I've gathered. I thought the 'rule of thumb' was to work from the back of the car forward when eliminating exhaust restriction in an Evo VIII / IX. Meaning the biggest bang for the buck would be the cat-back/muffler.

Cat back..............HFC.............downpipe........ .........O2 housing.

 

why is that? a tune should be included when upgrading, because it is important, so why can't companies make claims based off a tune. Besides, if one company is claiming 20whp with a tune with their exhaust and another is claiming 30whp with a tune, you can still get an idea of which one may end up giving you more power.