So I still have my full stock exhaust, but like most people here, once you make one or two small mods like I have, you have to make about 10 more before getting it tuned. I have the Perrin intake and a Hallman Pro RX MBC hooked up right now. My goal WHP is in the mid 300's (335-360ish i guess)

I'm not in to switching out the cams or using meth, or even upgrading the turbo or injectors.

Having said that, I think the last thing I really want to do is upgrade the exhaust, but knowing what my goal WHP is, which parts of the exhaust are really unnecessary? It seems like just the O2 housing, DP, and test pipe would be just fine, unless someone would like to explain why the cat-back is completely necessary. I'm definitely finding the cheapest way to my goal, but if I need to I'll spend the extra $400-600 on a cat-back. Of course I'd rather just spend less than $300 on the O2, DP, and Testpipe combined though. Thanks

 

Alot of people are happy with eBay exhaust. Never looked into them but I think a full TBE goes for around $280.

 

A free-flowing exhaust will help reduce backpressure which will in turn help you reach your power goals. I'd say the o2 housing is the least important part of the equation (if you're doing things on a cost basis). We usually suggest the Perrin DP since we feel it offers tremendous quality at a very nice price. As far as CBE goes, it's definitely a restriction. That being said, there are a few guys running a similar setup (retaining the stock CBE). I don't know what their numbers look like but I'm sure a search would help you find the answer.
-Alex@ECS

 

Yeah I was considering that one too. I like the looks and sound of the Perrin cat-back, so if I got one it would probably be that. Plus there is a shop within 10 miles of me that has one sitting there for $450 which is a good deal for a perrin. I just want to make sure that it is completely necessary for me to get a cat-back or not based on my WHP goals. i would think the O2, DP, and cat-delete would be good enough, and cheaper of course.

 

I've been doing a lot of searching lately and people say that the 02 dump makes a pretty big difference. Are they wrong, or do they just have supporting mods that make it so an O2 is necessary? I've never really heard of switching out this part before I had the EVO. 3S people never talked about this stuff so it's all new to me.

 

honestly, an exhaust is just piping with a fancy name on it. whatever u get make sure it is 3" mandrel bent 304 and ur good. a lot of exhaust companies don't even make their own, meaning, it is made for them and they slap a badge with their name on it. get 02 housing and a 3" tbe. you can stay with hfc to avoid emissions problems and still make good power.

 

I should have re-phrased that. Usually people do the o2 last. CBE-->TP/HFC-->DP. That being said, the o2 housing is quite a worthwhile modification. Again, there are always exceptions, and we've had customers start with the o2 and then move on etc.

 

While this is true, the only thing you have to worry about with the off-brand exhausts is fitment. When it comes down to it though, you're right, what's important is that the exhaust is 3" and SS. What name brands often offer is fitment, reduced weight, and various noise reduction measures.

 

So if I got an O2, DP, and TP, is it worth it to get the CBE on top of that, or are the performance gains not significant enough? For other cars I've owned, I was told that unless you're producing over XXX Whp, then certain things are useless. Is this not the case for the EVO CBE? Thanks

 

every component of the exhaust will yield gains on an evo


I have a buschur exhaust

o2 all the way back

high quality, fair pricing, and awesome performance

 

Thats what I was thinking.

I'm thinking of going with the Ebay O2 housing, perrin DP, TP, and Perrin CBE. So those along with the Perrin full intake and the boost at around 24-25PSI should get me in the 340-360whp range? This is about what I'm expecting after a few weeks of searching/research. Seems like the guys with the full exhaust, intake, and raised boost with a tune are mid 300's.

 

You should be around 310-320 WHP.

 

360whp with those mods? You're DEFIANTLY reaching for the stars You might be a little over 300whp. But it's hard to guess. Dyno's differ. Sometimes even day to day the same dyo will differ a little.

 

Yeah, 360whp was the higher end of what I was guessing, but I'm hoping low-mid 300's.

 

It's really tough to say since numbers are so variable. Everything from humidity to the type of dyno will affect the final numbers that are output. What's most important, other than the power curve, is the difference in numbers before and after modifications. Without a baseline, numbers are very tough to gauge.

For example, say a car puts down 360whp on dyno A but only put down ~300whp on dyno B. The same car could have baselined ~330whp on dyno A but ~200whp on dyno B. So while dyno A looks like a "faster" car, it only gained ~30whp while it gained ~100whp on dyno B. Obviously, this is a made up situation, but it's one that shows the main flaw with the whole numbers game.

-Alex@ECS