I have a 90 camaro RS with 305 tbi and i am thinking of getting a 3" catback exhaust and a 3" high flow cat. It is basically stock for now. I have a feeling this would be way to big but i would just like to now if a 2 1/2" would be better?

 

I'd say go for the 3 inch, but that's my opinion.

 

3" mandrel bend I pipe, dual 2 1/2" tail pipes, and no cat, works great for me, and you have basically the same car

 

You'll be fine with it, plus it will be there for future mods.

 

Thanks alot for the info
but one thing
would I have a problem with lack of back pressure

 

if you dont care about your egr circulating exaust gasses (who does?) you wont have any problem. But IMHO i think there will be more than enough pressure for it to work, expecially considering the egr exausts into a partial vacuum in the intake.

 

this is probobly gonna be a dumb question but what do u mean by egr circulating exaust gasses?
My friend has a 350 with 3" and higflow cat i know it wont sound as good as his but i assume the popping he has when he lets off the gas. I would assume because i would have even less back pressure i would have even more popping not that i am saying it is a good thing. that what i am not totally sure of.

 

the egr (that circular thing ont he back of the pass. side of the intake) is there to reduce emmisions by putting some of the exaust back into the intake to be reburned by the engine. I seriously doubt youll have any problems with reduced back pressure. In fact the less back pressure, the better. The engine will do less work ridding itself of exaust gasses and that frees up more power.
Im not totaly sure about what causes that but i beleive its some of the exaust gasses igniting after they exit the cylinder. As with any free flowing exaust, those will become more audible because of the reduced muffling effect (i assume your getting a high flow muffler). Personally, that popping never really bothered me and i kinda like it in a way.

 

Thanks alot for the info. I am defiantly going for 3" exaust now that i know it won't do any harm having to little back pressure.

I am getting a ravin R-33 muffler and high flow cat my friend has the same set up but he has a 350 tpi i know mine wont come close to his but it will be good enough for me.

 

I have a 3in system on my car with a cut-out. Get that popping when I let go of the gas. Sounds nice though and is very loud. The system gave me a nice improvement performance wise. I defiently felt a difference with it.

 

hey trans

tell me bout that cutout
I want one really bad.... I found one from Mr. Gasket ( i think ) and it is driven by a cable and can be opened from the inside the car.... are these reliable... do they seal good????

thanks guys

 

I had bought a similar one, is it in Jegs, mine only fit up to 2.25" piping and was cast iron and had to be brazed on, good luck finding someone that still brazes.

 

i had one it was good for loudness but it broke and sucked overall. if you want one get a wingnut one.

 

Mine cut-out is a 3 in one. I had the local muffler shop fab it up for me. They did it for $50. Uses three wing nuts to bolt the cover on when I don't want it open (when is that ) I have never dealt with the cable ones so I don't know too much about them. I placed mine right before the rear axle. The thing is loud but not cop chase you everytime loud. Just don't push the car when a cop is around because it is VERY loud then. I heard my friend across his neighborhood which is about 6 streets when he pushed on it. I set off my neighbors car alarm when I go down the street using more than 1/4 throttle. I love the thing and am very satisfied with it. It thumps in the morning and has that nice raspy tone on taking off from stops. A few guys on these boards have heard it. myHo, ponykiller, and Jason92z have heard it. myHo one sounds awesome with his 350. Deep as hell. I am waiting to hear it with the gutted cat. If you anymore questions about it I will answer them.