Stock exhaust mod for higher boost

[miles556]

DSMers,
The goal is to push more boost about 20psi on the stock exhaust without running into major exhaust problems. I am new to California and the law on modifying cars here is very strict. Currently i push 15psi on stock exhaust with EVO316G + evo manifold and it seems to be fine so far. However manifold gets red quickly after just few pulls on the highway.

How about running straight pipe 2.25 from downpipe to muffler? (Deleting silencers that restrict flow) Any one tried this yet?

Also, some parts can be California legal (such as injen intake). What about exhaust? is there 2.5/3.0 California legal cat back exhaust?

Let me know
Thanks

 

[ENICKB]

Get a tubular manifold, a big o2 housing (port yours) and a 3" downpipe (megan racing is cheap)... And honestly, as long as you dont have a check engine light, and you have a catalytic converter, and stock catback, you should be great! (my cousin lives in cali and thats his setup, but he pushes 25psi on 16g)

 

[goodbuds]

just upgrade your exhaust, and don't get caught driving like an idiot.

 

[bboyalan]

If your goal is to maintain the factory exhaust, then a cut-out might be something worth considering - no compromises for an absolute win/win. The consequences can be severe if caught running around cat-less, so I cannot recommend that unless you make it appear otherwise or go HFC.

 

[miles556]

If your goal is to maintain the factory exhaust, then a cut-out might be something worth considering - no compromises for an absolute win/win. The consequences can be severe if caught running around cat-less, so I cannot recommend that unless you make it appear otherwise or go HFC.

Cat-less is not an option. I actually care enough about the environment to always run working cat. I don't mind dropping resonators or use straight through mufflers for more flow at the cost of extra noise. Now I am leaning towards the custom exhaust project. I don’t like how some pre-made exhaust hanging low under the rear GST suspension. For those running lowered DSMs (including me) that’s not a good idea.

 

[nicholasramos]

One good rule of thumb as far as exhaust is Post-Cat = Legal. Pre-Cat= Illegal. So that would mean that a catback exhaust is pretty much anything goes, (so long as you don't break local noise laws)However any mods to manifold, manifold o2, downpipe, turbo, is all illegal (technically). Things like porting are obviously not going to be checked, but just for your knowledge, TECHNICALLY, anything between the engine and the cat is illegal to touch.

 

[4G63_Attack]

Currently I'm running a Megan Down pipe, High Flow Cat, a Apexi N1 muffler and no silencer. So far no problems with the law.

just upgrade your exhaust, and don't get caught driving like an idiot.

Yes, as long as you don't drive like an idiot your all good. Couple times I have been followed by a cop car. I just drive normal, follow the speed limit and no tickets or been pull over (knock on wood). To top it of shinny front mount intercooler and muffler, to top it off no front plate to boot.