Hi - new here, so excuse my basic knowledge. I came accross a AP1 with a GT3076r turbo kit from Evans Tuning. I must say... WOW this car is rediculously fast. The guy wanted 15k for it and he had just done a bunch of maintenance. I am sure he is one this forum somewhere reading this

Basic Question: Do any changes to the exhaust require software re-tune? The car came with a 3" straite pipe and custom catback from Evans Tuning (as it was explained to me). The car sounds amazing on WOT, but I cannot handle the drone when cruising. Any quick fixes for this? I was thinking of going as far as a factory catback and adding a pipe with a cat on it as well. I figure I could sell the one on the car for a couple hundred bucks.

Cannot add any pics but here is a link to the craigslist post (may not be up for much longer):
https://philadelphia.craigslist.org/cto/6024364891.html

 

Any change to the exhaust will likely have SOME effect on the tune, change in flow dynamics will change the AFRs, this could be minimal, or it could danger the engine. If you went to something less free flowing, you'll probably make it run a bit richer. If I were you, I would look for an exhaust that is the similar in shape (dual, vs single) and one of the same diameter. (its probably 70mm).

However, I cannot stress enough on how much you need to keep the cat off of it. Putting the cat back on will do many things; A) It will disrupt the tune. B) The exhaust will be much more restricted, the AFRs will be significantly richer, and you will lose power. C) The cat will probably fail in under 10k miles or so. Cats with boost on these cars do not end well. Just put / leave the test pipe on (straight pipe that replaces the cat), find another catback exhaust that has reviews of being quiet that is of similar diameter and you should be okay. Keep an eye on the AFRs after you replace it though, and if you're super worried about it, just go get it retuned by Evans.

If the exhaust is 70mm dual, a good option is the Invidia Q300. Greddy also makes one, T1R is another option, etc.

 

Using "reviews for being quiet" in one paragraph and "Invidia Q300" in the next still qualifies as an oxymoron.

-- Chuck

 

Can you guys recommend a few quiet exhaust options that I can research?

I found the below - what do you guys think?

"Invidia V4 - $600
This is a fairly new system. 70mm piping diameter. This is the quietest system available from Invidia. If your looking to just get a little more sound from your exhaust then this may be for you. Being 70mm this should perform well, but there is no real information other then this at this time. " (source: https://www.s2ki.com/forums/s2000-na...%2A%2A-634543/)

 

Drone is different then loud. A turbo actually quiets the exhaust. What you are trying to address is the drone when cruising. A 3" probably isn't helping that. You will probably have to sacrifice some flow/power to mitigate the drone. The standard oem 60mm cat back style will help. My exhaust (Tanabe Concept G) is one of the few that do not drone and is run with a TP. You will likely lose a little power though and run rich without a tune.

 

Mate, take your car to an exhaust shop first and ask them if they can fit one or even two resonators on your current exhaust to help with the drone. (1 of those resonators replaces the Test Pipe position.
If that fails (which I doubt) either buy a 70mm T1R Dual or 70mm Greddy Spectrum Elite Dual.
Other guys on here have a 3inch single with 2 resonators and have been happy enough.

 

Add the biggest resonator you can and it wont have an effect on the performance and should help quite a bit.

 

Can you guys recommend a test pipe with a built in resonator? Or should I just let my mechanic hack/weld anything he has laying around onto my test pipe?

 

But a Vibrant Ultra Quiet resonator or two!

 

Thanks to all the excellent/prompt advice here!

I bought a Vibrant Ultra Quiet resonator - will install and let you know how it turned out.

ALSO - I spoke to Evans Tuning. They said that NO retune is required if:
1. adding a resonator
2. replacing my current 70mm catback with another 70mm system