If staying emissions legal is important to you, note that many turbo-back exhaust packages use a test pipe to replace the catalytic converter. Such a car will never pass any emissions inspection in any state.

If you want to stay legal, you'll need to get a turbo-back which has a high flow catalytic converter rather than a test pipe -- and a high flow cat is definitely going to jack the price up compared to a test pipe.

Whether to stay legal depends on your own comfort level with bending the rules, and whether your area requires periodic emissions inspections.

 

That is a bias and extremely broad statement ... I'm ashamed of you SilverEV08. For the most part ... there is NOTHING WRONG with mixing components. For instance, Thermal R&D ONLY MAKES cat-back systems ... yet they are high quality and frequently test very well on a dyno. Therefore, one would be forced to go with a downpipe and highflow cat or test pipe from a different manufacturer. My evo exhaust system will most likely be:

HKS Downpipe 2.55"
RMR test pipe 3"
Thermal R&D or HKS Carbon TI cat-back (when available) 3"

I like the HKS idea of a slightly smaller downpipe to elliminate the possibility low end torque loss ... I plan to stay with the stock turbo so there is no need for me to install a 3" downpipe.

 

but does the turbo lose compression because the cat is gone??

 

Whoa, hold on there.... There is plenty wrong with mixing components from different manufacturers. There is absolutely no assurance that they'll bolt on to one another. You may not know this but there was lots of grief in the WRX crowd when several manufacturers stuff would not fit so well even when it was all their design and manufacture.... People make their own stuff in their own way, they make their parts to fit with one another and not necessarily with their competitors...
What are you gonna do when you have a bunch of different parts and they don't fit right? Who are you going to ask to make it good? They all going to say that the other guy's stuff is the problem, and they are right, I would not want to take care of stuff I did not make or design.
If you want stuff to fit right, you are much better off to go with a complete set up from one manufacturer. Generally all the exhaust systems are pretty much the same anyway. Basically a bunch of tubes... The biggest difference is the quality of materials and care of construction (and the price of course). I stand by my opinion. It's better to deal witha single source when dealing with these types of things.

 

No. Basically, the freer flowing the system is after the turbo, the better, period. A test pipe (straight pipe that replaces the cat) will flow better than the stock cat, and flow better than many aftermarket cats too, but is not emissions legal. ALL (repeat: ALL) a catalytic converter does is clean the exhaust gasses before getting pumped into the atmosphere and it tends to create a little resistance to flow in the process (which is bad), but there are some high-flow cats that basically flow just as free as a test pipe , and there you have the best of both worlds, though at a higher cost. So as a final answer to your question, the turbo compresses more efficiently (less spool-up time, etc.) with whichever system gives you the best flow and turbocharged cars do not want backpressure; that's more of a N/A thing (meaning naturally aspirited or non-turbocharged). This is in response to a previous question of yours about back pressure that didn't get answered).

 

So in effect, more money lets you have your cake and eat it too. Good to hear for a liberal speed-freak tree hugger like myself who wants to go fast and save the environment. I think I remember reading that the LEV1 standard that the evo adheres to stock is actually cleaner at the tailpipe than ambient London air..

 

I just got my JIC ti exhaust today it does not have a bung for my O2 sen which i knew, Does anyone know where i can get a MIL Eliminators and or are they all the same



(Evo mods:HKS downpipe,K&N Drop in filter,JIC TI exhaust, Just ordered a set of Racing Hart CPO-35R 18x8,Can't decide between TEIN coilovers or JIC??????????

 

Well ok, to end these questions.....whats the best set up you think i should get...

 

Depends on how much you want to spend... Turbo back w/ cat cost more but you'll yield more power and compatability than the cat back put together system.. at least compatability wise.. so its really your choice

BTW, can you post a pic of urself and your car?

 

is anyone else getting tired of the ?

this, that,

 

i can't beleive you own and evo and don't know the difference between a cat back and a turbo back, i mean i know you are a newbie and trying to learn and all but holy crap, you're in one hell of a car not to know much about it!

 

What???

I would guess that less than half of the Evo owners out there are even considering installing an exhaust upgrade... In case you haven't noticed, the car is pretty damn fast in its stock configuration.

I don't remember Car & Driver mentioning in their Evo review anything about how the car is great, but could really use a cat-back upgrade.

The fact is that only people who are actually in the tuning scene should be expected to know the difference between a turbo-back and a cat-back. And even though the Evo is a car which appeals to those people, it also appeals to people who have never bolted on a single upgrade -- it appeals to them because they can own a car which is basically already a tuner special (with a dealer-backed warranty, no less).

 

yea that might have come out a bit harsh, but the EVO, like the STi, will mostly be bought by "those-in-the-know" plus it is a pretty expensive car also, guess i just figured that if you are gonna drop 30k on a performance machine you would know a little bit more about it. again didn't mean to be to harsh and i know the evo is a great performer stock. but most people who know anything about cars know what a cat is and what a turbo is. one is a "cat-back" the other is a "turbo-back" pretty self explanatory as it is. again, this is by no means make a rude comment on age or whatever, i don't care if you are 50, or if your parents bought you the car and your 16 (cool parents!), i spose it just caught me off guard, but then again, i'm a motorhead so... sorry if it seemed rude.
harrison

 

Knowing about it versus knowing how/what to upgrade is a bit different in my opinion. I could read all day on the internet and magazines about the specs and capabilities of this car and I'm willing to bet that they'd never mention either of these terms. They would if it were a tuner mag but that's about it. Imagine how many people own an M3 but never touched a wrench for anything car related in their life. Same with many other much more expensive sports cars. Just because one guy eats/sleeps/breathes car parts all day doesn't mean everyone in the world does...but those two people could have the same interest in upgrading their recently purchased sports car.

 

Okay .... I see what are you are claiming' however, it's more of a personal preference to ensure a "play it safe" approach, opposed to the reality based on the fact that one can find out if the pieces fit before purchasing. On evo, most of the aftermarket exhaust parts are being designed to fit with other systems and/or the stock system. For example, HKS does NOT make a test pipe but its downpipe will work with the RMR test pipe. I've also been told by HKS that the HKS Carbon TI will also be designed to work with just about any 3" test pipe, just like the JIC (among others) does. Thermal R&D builds an awesome cat-back, yet they do not offer a downpipe, highflow cat, or cat-delete pipe as of yet. However, the Thermal system for the evo WILL WORK with the RMR test pipe or the stock cat. So I do see your point .... but there is no reason for one to stay with one manufactuer just for the fitment reason alone; rather, one sould find out IN ADVANCE if the parts will work together .... and the manufacturer (s) can easily provide that info.