Okay I have a 94 camaro z28 m6. All bolt ons edlebrock shorty headers going into a offroad pipe into the loudmouth exhaust. Next summer I plan to have A.P.E - A really good performance shop build me a 355 with a sts turbo kit. Now This sts turbo kit mounts in the rear. I mean do I even need my loudmouth or a cat with this turbo - with my mods I have listed what do I need / dont need. Also its the garrett 67mm turbo - Should get 600rwhp at 10psi crazy power. When do these turbos kick on/off usually. It's strange with a rear mount like that. Also would I need a intercooler or is it built in or something like that - Mike

 

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since noone else replied I thought I would throw in my thoughts which may not be much help. I dont think you need a muffler because the turbo acts as a muffler. I think the sts uses regular headers/manifolds. When the turbo starts boosting is different for each turbo one and probably engine as well. The sts people say a intercooler isnt needed because the length of the tubing from the turbo into engine is so long it acts as a intercooler. but i bet if you had one it could make more power.

 

The turbo sits where your muffler currently is, so there will be no need for one. You can use whatever exhaust you have on there, I have heard longtubes and the STS kit work well together. You won't need an intercooler unless you are gonna run more than 5-7 psi. If you are forged then you can handle some more.

 

No, you don't need a muffler, there isn't really room for one with an STS kit. As far as spool time goes, that depends on the exact specs of the turbo. Most STS guys have been reporting full boost around 3500 RPM or so.

 

It wouldn't seem as though a turbo would make a very good muffler. How loud are the STS cars? It doesn't make much sense to have a street car without a muffler, as I'd get a ticket in no time.

 

A muffler is just a series of baffles designed to reduce sound. The blades on the exhaust wheel of the turbo will have a simlar effect. You won't get a ticket (not for noise anyway).

 

Full spool on a GT67 with a 350ci motor will probably be around 3500 or so. Bigger cubes and it will spool faster. Just depends on which A/R you choose. Mine with the same turbo and .81 A/R doesn't spool till after 4k. Doesn't hurt me in a race though it sucks having to wait that long for FULL boost (13psi).

You're going to need either methanol injection or an intercooler. If you like to mash around a lot I prefer the intcercooler but it's a toss up otherwise because the methnaol also adds much needed octane. You're call. IMO do both. Works awesome

The STS cars are not really that loud. My truck on theotherhand is. With a beefy cam, no cats and no muffler it's a bit too loud on the street and could very easily lead to a ticket. I think youy'll be fine as long as you either keep your cats or run high flow cats.. STS as well as some of the dealers say they loudness is generally only with trucks, the cars are much quieter. I've only heard 2 STS LS1s in person and they were MUCH quieter than my truck.