I was on modernperformance and found these high flow cats..

http://www.modernperformance.com/gm/oncobalt.shtml

Is this going to make a differance or show any gains at all, and how hard is the install, im suprised noone has bought them yet.

 

I am not really sure, but on the RL someone said how we have the cat of a GM truck. It is literally, I am not joking, 2.5 to 3 feet long. I don't see how much more free flowing it can get.

 

anybody that knows thier **** can you shed some here thanks

 

a high flow cat is just a cat for a higher displacement motor. there is no "special" cat that flows more than another. the best you can do is get an all metal cat that'll last longer.

the cat on these cars is GM's biggest cat, for their biggest engines made for towing. so essentially it is a high flow cat. the aftermarket world would not want you to know that. you could get rid of it, but that's a federal offense, and any high flow cat you'll find is unlikely to give you ANY gain in performance, period. sorry

 

Roger That.

 

go with a ful new cat back exahuast you will get some hp out of that.

 

so your trying to tell me a catco or random technologies catalytic converter doesnt flow better than a stock, quiet GM one
we may have really good exhaust from the factory but that doesnt mean it is the greatest
ive put FULL EXHAUST (header downpipe hi flow cat bigger piping and flex pipe to straight thru muffler ) on 3 cars i have owned and all of them flowed better, you can feel it in the rpms and you can hearit in the engine

im prolly not putting exhaust on here because it doesnt need it yet

 

Are you putting three inch exhaust pipes on your cobalt, because that'd be a waste, especially with duals. A three inch exhaust is really only needed for a large displacement engine, I'm talking like 5.7 liters and up, which would be....sports cars and big ass trucks.

The small engines in cobalts aren't going to benefit from larger exhaust tubes, it'd be a waste of money. Save it and get a borla exhaust when those come out.

 

Orangepower,

Nice to see another Okie on the boards....I was in Stillwater yesterday for work, I live south of OKC. I did get to eat at Eskimo Joe's though (chicken cheese fries ). I am assuming you have an Orange SS....we need to get a OK chapter started.

 

Sorry but toyota supras often use a 4" exhaust system. With a forced induction car backpressure is not an issue. Its all about getting the exhaust out as fast as possible.

 

is it 4" pipe all the way from the headers back, or is it just a 4" tip?

 

whoever told you that is an idiot

the cat looks like a big coffee can right below the manifold. the 3 ft long device is a resonator. it looks just like one of those old, long cherry bombs. then in the back is the muffler

 

Cat back.

 

well burns, i dunno then. But i bet if it's 4" on a supra then maybe the size is related to the amount of horsepower that the engine is rated for. I guess I just have bad info.

 

they mainly use 4" when they have a big turbo on the car and are pushing 500+hp. Its the fact that it is forced induction though, not the fact that it is a high displacement motor.

 

I am not sure if it will make a huge difference, but it's a good supporting mod. Also remember if your going to get one your gonna need someone to weld it in place. They are not bolt on

 

I thought that a small diameter exhaust promoted faster exhaust movement?

4 inch is a HUGE exhaust. It's almost twice the size of a 3 inch (7"^2 versus 12.5"^2 )

But some of those supras put out a ton of power.

 

seen one on ebay a while back that did 730 hp.. insane

 

HEY I'M IN LAWTON...WE HAVE 4 SS/SC'S HERE AND WE ARE TRYING TO START SOME SORT OF COBALT CLUB,ORG,OR WHATEVER.INTRESTED?mech6929550@yahoo.com for details.Also check out (Domesticturbulence.com)I Started Team Shockwave Racing.We have different types of cars,but the more ss's the better.....

 

im in texas, you guys willing to travel south?

 

YEAH I;M WILLING TO GO TO TEXAS

 

How on earth is that post on topic. Your posts belong in the regional forums.

Lay off the caps and don't post off topic ppl.

 

Yah id say if your putting out less that 300HP you really dont need a 3 inch exhaust but if you plan on modding your car so that you'll be pushing 325-400HP range then go with the 3 inch exhaust now and take the loss in TQ but as soon as you do a little more modding you wont even know cause you will have already made up the loss in TQ

 

Say if I was planning to push that 325-400HP range, exactly what kinda mods would I be looking at on my SS/SC?

 

i am constantly amazed how few people understand exhaust tuning. "backpressure" is never a good thing, you always want the highest flow numbers you can get. but after a certain point you get no gain form more flow, this is why a 900 hp supra NEEDs a full 4 inch and we are fine with a 2.5 all the way up to 300 hp. so more flow is never bad but noise is. also (and this is the important part) exhaust volume is very important. incorrectly sized exhaust, espically at the headers and collectors will lose hp, even if they are too big. you hear about guys with wrxs that get full 3 inch and dyno LESS. and then some moron ricer say "yo dog you got too much flow"

a properly tuned streetlegal (not california) exhaust system will dyno within 1% of the same car with open headers. factory exhausts are getting better all the time and there is less and less return to be had if a part is already flowing enough.