Yea, the more mods / boost you are running, the more that exhaust flow will count. I say go for the Turbo-Back Exhaust, but that may be too loud for your tastes.

 

logical. it would seem. Meaning a bottle neck further down the line will still bottle neck the entire system. however, in looking at the information i've gathered from reading over everyones experiences, you can expect minimum gains from any one of these, but HUGE gains from them all together, moreso than just the gains from each added together. Saying for example, each part in the exhaust gave you 5hp if changed on its own, however changing out all 4 would give you substantially more than 20hp.

 

I would recommend an O2 housing, 3" dp, test pipe or hfc and stock cat back.
I ran my last evo with that and went 11.5 at the track. Ive seen a IX go 11.4 with that same exhaust setup as well.
Almost as quiet as stock but frees up the major part of the restriction at the dp and cat.

 

There is a big difference from a 3in tbe and a stock tbe.

 

is 1/2" at ~300whp going to make that much of a difference?

 

When I first got the car in 2006, I wanted to go the route 1slowevo recommended: 3" DP, 3" HFC, and stock catback.

However, the consensus was (at that time) I was going to be leaving the most restrictive part in the system (muffler/cat-back) on the car, and would likely not see any gains.

I'm not saying a full TBE is a bad idea............just questioning how much of an improvement it is on let's say, an IX with simply a flash + MBC.

I've also read magazine tests that say a TBE on an IX is not worth much HP on it's own, but then when you add tuning into the equation, it really wakes up.

Which begs the question, are manufacturers who are claiming 'big' gains (30hp) from a TBE also factoring in the tuning portion? How much of that is in just the tuning?

Thanks for the feedback!

 

Well the new owner of my old evo had just gotten the car dyno'd, and based on that, im surprised.

The car has a TBE, full 3", and a ETS Intake.
He made 319HP.

No tune, just a dyno, and the fuel cut moved up.

Don't they make like 240 stock?

Insane, isn't it?

 

There are soooo many variables between dynos and correction factors it's hard to estimate.

That's why I was looking for anybody with a single-variable, A to B comparison on the exhaust, preferably with dyno plots or backpressure measurements.

My goal of starting this thread wasn't to discredit anybody using a TBE............I simply had one, removed it (and had ECU reflashed again) and did not notice a performance difference, which I was surprised.

The problem I had (which probably most others have) is that I put on the exhaust and tune at the same time. Most people probably don't do it in stages.

 

^was this a mail-in flash or were you street/dyno tuned for both your aftermarket TBE and back to stock exhaust? I'm wondering if maybe you weren't ever getting the most out of your aftermarket TBE.

BTW - apologies if I missed that in the thread, my mind is wandering with only a couple hours o' sleep.

 

No worries - I had a basic mail-in flash from WORKS, that was configured for the 3" exhaust.

When I told them I wanted to put the stock exhaust back on, they recommend I send in my ECU for a reflash and I did.

When I got it back, coupled with the stock exhaust, I was pleasantly surprised at how fast the car was.

 

big differnece with different mods

 

While not a strict apples to apples comparison...

This article documents a stock MR vs. w/mods/street tune vs. mods/dyno tune...
http://www.roadraceengineering.com/evo/scc-mrstg1.htm


While they did not dyno the car with just the mods and no tuning...
It does show all those mods AND a street tune netted 50 whp increase (you can click on the jpeg to enlarge)

But obviously this doesn't answer the question of what just a TBE will gain...might just give some clues...

 

This article also goes over it pretty clearly:
http://www.motoiq.com/MagazineArticl...ne-Tweeks.aspx

There have also been members of these boards who have wanted a more stealthy look, so they've actually kept the stock CBE and upgraded the DP and gone to a testpipe or HFC, and put down some very respectable times.

*As I understand it*, you can run higher boost, spool more quickly, get better mileage, get more ladies, solve world hunger, stop global genocide, and prevent killer whales from eating their trainers by running an aftermarket TBE. These benefits far outweigh the drone!

Joking aside, I'm running the cobb AP and they recommend not doing their "stage 2" upgrade until you have an upgraded DP. They suggest you wont hit your target boost levels with the stock DP, and they also suggest your EGT's may go through the roof. My simple (and possibly not all too accurate) reverse engineering of that statement says to me that: a larger DP will allow you to boost more efficently, keep your egt's in check, and save you some weight. My understanding is also that although there are gains to be had in just going TBE, the real gains from tuning it after. Hope all this info helps.

 

Here are my results of adding 2.75" dp and tanabe exhaust. I already had a Perrin hfc installed so take that into consideration. This was all before tuning. For me it was about 13hp difference

Stock with Perrin HFC (AirFuel)


Post Exhaust & DP install


Overlay compare

 

Unless I've missed something, I was under the impression he doesn't have a TBE, just the CBE + retune.