Exhaust Note

[bNasty]

ok so i was looking at DSM exhaust for my GS-T and i saw this vid

YouTube - 1999 gsx eclipse with apexi n1 cat back and down pipe

i was wondering how i would get this exhaust note is it headers or wht? because i know that the apexi turbo back does not sound lik this by itself anyway

 

[knochgoon24]

That sound would be cams and a 3" exhaust. Might not have a cat, only a muffler. He also has the idle nice, low, and steady.

 

[Spln_Hrd]

I wish my car still idled so nice. Damn 280's.

 

[bNasty]

i dont think its cams though because the idle isnt really that lopey... could it Be an o2 housing and manifold and turbo back?

 

[TunaTalon]

To get the lower exhaust tone just do everything to reduce back pressure; as for the best performance.

That exhaust is similar to my Talon with:
3 inch fabricated O2 housing
3 inch down pipe
High flow cat with 3 inch in and out
3 inch mandrel bent cat back
Straight through muffler.

It runs good and sounds good but I have to stay off boost through the manned speed traps.

 

[bNasty]

i dont really understand o2 housings. What are they and wht is the function? i see that u can get one vented or recirculated? which one should i go with? Which are the best ones?

 

[1gDSM4g63]

Recirculation o2:

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Vented o2:

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A vented relieves the exhaust which one may say is better, but without a dump pipe it heats up you engine bay coming out of the turbo a lot.

 

[bNasty]

can u buy a dump pipe or does that part need to be fabricated? Heres wht im thinking that ill get the full N1 turbo back then the vented or recirc o2 housing and i should get close to that sound?

 

[knochgoon24]

Venting the wategate gasses (aka. o2 dump) can be very loud, so remember this in your decision whether to recirc or dump.

 

[bNasty]

Which is better performance wise dump or recirc

 

[Boost92awd]

There both pretty close. o2 dump seems to help boost creep more than recirculated.

If you like to here your turbo spool get the reciculated.

 

[EvilutionaryTSi]

small turbo i suggest not dumping, can be annoying, because of fast spool up and wastegate opening when your just messing around a bit. bigger turbo def!

 

[bNasty]

whats bad or annoying about the fast spooling

 

[knochgoon24]

whats bad or annoying about the fast spooling

It's not the fast spooling, it's just that the turbo hits full boost quickly, then the wastegate opens. You wastegate will be opening as you accelerate from a stop light, or when you pass a car on the highway.

 

[bNasty]

i know its a newb question but lik is that bad because of the noise or because it causes damage or jus because... i dont know?

 

[Colt4G63 also]

Because it's super loud, your exhaust will be dumping out basically right after the turbo.

 

[talonDSMerr]

If your dump tube doesn't extend down far enough through the engine bay, it could heat up the air near your alternator and cause it to have a very short lifespan. Also if it's not long enough, it could heat up engine bay temps, lowering overall performance. So if you go o2 dump, definitely make sure it's clear of the bay. A lot of people choose dump over recirculated because they don't like the fact of rerouting gas to the exhaust and creating turbulence, and thus, backpressure.

 

[bNasty]

ok it makes sence to me now... how long should the dump tube be is the one in the pic above enough or does it need to be longer?

 

[1gDSM4g63]

Dump tube is just like a downpipe pointing down releasing the exhaust no where near anything. I really don't feel there's any for a vented o2 housing just some people kick of the sound. It really doesn't help spool especially on stock turbos and it maybe cause situation with emission test. And normally people only do vented o2 housing with dump tubes is if they use a t3 or t4 manifold with an external wastegate because it is the easy way to go instead of fabricating o2 housings.

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[TunaTalon]

Venting the bypass is against the law in all fifty states. When the waste gate opens some of the exhaust gasses go directly to the atmosphere bypassing the cat.

Venting the bypass will have little effect on performance because the bypass is only open when the turbo is already at full boost and some energy has to be wasted anyway.

Venting the bypass will have zero effect on the exhaust tone at idle because the waste gate is closed and the vent tube is not in use.

Venting the bypass will have no effect on spool up time because it is not in use until after the turbo is fully spooled.

The size of the O2 housing will have more effect on performance than exhaust note because most of the exhaust system volume is downstream of the housing.

But if you're dead set on making a lot of exhaust noise at full boost and don't have to worry about passing smog laws, go for the vent.

 

[loba]

+1 on the illegal part. You don't want to accidentally open your waste gate right next to a cop or near a speed trap. I guarantee the cop will get you for it.