well i have a sti and this car needs to just be a tad faster, have some questions seeing if you guys have answers

1) is there a smaller pully you can put on the supercharger. bring boost up to 10 psi i dont mind mixing race gas in the tank to avoid detonation.
2) i was planning to do a single 3 inch exhaust from exhaust manifolds back with no cat. or would 2.5 pipe be better
3) does anyone sell a complete exhaust manifold back set up
4) Does anyone make headers for the car
5) cold air intake anyone
6) computer set up

way i see it car is 205 now. if i can get 10 psi i can get extra 40 easy there, exhaust with no cat 3 inch from the exhaust manifolds prob 20 wiht no cat, headers 15 hp, air intake 10hp, computer like hypertech prob 20 hp.

any help woulbe appreciated.

http://www.scdyne.com/ makes a header for the redline, which uses the same 2.0 litre motor as the cobalt. There's not too many parts out for the car yet, but companys like http://www.psifimotorsports.com are sure to have some good things out soon :)

First never run it without a cat. Unless your a full race car you will have very small benifits of not having one. Get a hi flo cat 3" inlet and out. Cats have come along way in the last few years and the HP loss is not worth the dammage to the enviroment. Not that I'm a tree hugger, but come on their there for a reason.and it is possible to crack your exhaust manifold and valves by cooling them too fast. the converter holds a bit of heat and keeps the air from out side from cooling them too fast. Also choose a good wheel. find out what the stock rims weigh. then get some aftermarket wheels that weigh a few pounds less. 1LB of rotating weight is like 10LB of static weight. So if you can shave 2LB per wheel thats like 80LB of interior weight.... and it will handle quicker...

for 1 or 2 hp it isnt worth getting popped for having no cats. around here, no cats will set you back $1000 for your first offence, and you win a no-expense paid trip to the smog referee. that means that you will have to pay to put it all back to stock inorder to pass! thats a whole heck of a lot of money for a handful of horses. heck even 10hp isnt worth that cost! there will be lots of ways to make real power, just be patient.

i bought one of the first SRT4's in teh market. and it took a while for parts to come out, a long while. but now that its been a year or 2, there are a TON of parts floating around. just be patient and you will be able to go as fast as you could ever want too

on my sti 3 inch dp with 3 inch highflow cat i had 8 less hp at wheels than without the cat

well ill prob have sanderson headers out here do a 3 inch header back set up for me this week see how that works out

on my sti 3 inch dp with 3 inch highflow cat i had 8 less hp at wheels than without the cat

well ill prob have sanderson headers out here do a 3 inch header back set up for me this week see how that works out

So you have a Cobalt SS? Or do you drive an Sti or is it both?

well i have a sti and this car needs to just be a tad faster, have some questions seeing if you guys have answers

1) is there a smaller pully you can put on the supercharger. bring boost up to 10 psi i dont mind mixing race gas in the tank to avoid detonation.
2) i was planning to do a single 3 inch exhaust from exhaust manifolds back with no cat. or would 2.5 pipe be better
3) does anyone sell a complete exhaust manifold back set up
4) Does anyone make headers for the car
5) cold air intake anyone
6) computer set up

way i see it car is 205 now. if i can get 10 psi i can get extra 40 easy there, exhaust with no cat 3 inch from the exhaust manifolds prob 20 wiht no cat, headers 15 hp, air intake 10hp, computer like hypertech prob 20 hp.

any help woulbe appreciated.


The STi is rated at 300Hp is it not, secondly its turbocharged not supercharged thus there is no pulley. You only have one header as its a 4 cylinder, and with the smaller engine 3" may be a bit big as one person said.

Unless you have an SS cobalt which is a different car.

Ok so I'm not the only one htat got confused by his post, judging from his other thread I think he has an Sti and now bought a cobalt SS and is looking to make it faster?

negitive my colbalt friends. 3" is the ideal set up on a 4 banger turbo. thinkn of the standard for V8 cars..... 4 cylenders per side with dual exhaust....on a standard 350 5.7L chevy you get a 2" 3/4 for a good hi po motor. NOT forced induction... thats 2.85L per side now force feed it and a 3" almost seems small. but in the real world with the price of larger pipe and the nessary room to put that big of a pipe under a car and still get over a speed bump a 3" is the perfice size. i worked great for years on a 2.2L 20psi daytona shelby.....

negitive my colbalt friends. 3" is the ideal set up on a 4 banger turbo. thinkn of the standard for V8 cars..... 4 cylenders per side with dual exhaust....on a standard 350 5.7L chevy you get a 2" 3/4 for a good hi po motor. NOT forced induction... thats 2.85L per side now force feed it and a 3" almost seems small. but in the real world with the price of larger pipe and the nessary room to put that big of a pipe under a car and still get over a speed bump a 3" is the perfice size. i worked great for years on a 2.2L 20psi daytona shelby.....

Well it actually depeds on the hp you'll be putting down, we dynoyed our 92 Daytona with the super 60 turbo at 212WHP with a 2.5inch exhaust, then we put in a 3inch and the power never changed. On our 86 Shelby charger with a t3/t4 hybrid though the car picked up 8who going from a 2.5 to 3inch exhaust but the car was alreay making 300WHP+

Well it actually depeds on the hp you'll be putting down, we dynoyed our 92 Daytona with the super 60 turbo at 212WHP with a 2.5inch exhaust, then we put in a 3inch and the power never changed. On our 86 Shelby charger with a t3/t4 hybrid though the car picked up 8who going from a 2.5 to 3inch exhaust but the car was alreay making 300WHP+

Agreed, 3" is not always the ideal set up. Exhaust is often made to big for the car, and you also need to remember that a supercharger acts differently with exhaust than a turbo does, on a turboed car the exhaust already has backpreassure in it so there free'er flowing the better, but on a SC car going to large can cost you power. It also depends on if you have dual or single exhaust.

I would say plan for your long term goals, if your going to make a 300+ HP car then go 3" as its probably going to be significantly modded, but if you just want the car a bit quicker, say into the 13's, then I think 2.5 or 2.75 would be better.

Backpressure in your exhaust system is _never_ good, under any circumstances.

N/A
Turbocharger
Supercharged

Doesnt matter... your engine is an air pump. More air in + more air out == more power. Period.

Backpressure in your exhaust system is _never_ good, under any circumstances.

N/A
Turbocharger
Supercharged

Doesnt matter... your engine is an air pump. More air in + more air out == more power. Period.

True, but going to large can cost you power, as the exhaust leaves the engine the temperature cools significantly, and the exhaust then expands and slows down. This slower moving exhaust can cause backpreassure on the exhaust as it exits the pipes. This can be solved by going with smaller pipes the farther back from the engine you go. For example, you can go with a 3" primary, to a 2.75" intermediate pipe, to 2.5" cat back. This way the cooling exhaust can't expand as much and doesn't cool down as fast, thus keeping the exhaust free'er flowing.

Backpreassure gives you torque, so a little isn't a bad thing. Thats not saying you should go stick in non mandrel bent pipes or more cats or anything.

sorry i bought a cobalt ss but i know its not going to be as fast as a iwant im still waiting for it

i was thinking
pulley
slicks
ecu
cold air intake
nx 50 shot
header and full exhaust

that should get me into 12s with the jug im thinkin

i was thinking
pulley
slicks
ecu
cold air intake
nx 50 shot
header and full exhaust

that should get me into 12s with the jug im thinkin

Tat should make for a hella lot of fun, should be good for 110+trap sppeds.

Definitely some potential in the Cobalt SS. I keep pressuring my brother into getting one. :D

I'm not big into voiding my warranty but hopefully GM performance parts will be able to supply everything I need...ideally I want to do:

Whatever Stage systems they offer which should include a smaller pully, ECU reflash, etc.
Headers without a doubt
Possibly Cat-back exhaust
Cams
CAI
and maybe some lighter wheels with better grip down the line. If GM offers a stage increase for another 70hp at the wheels I think I'll be good. But if GM is listening MORE IS BETTER!

Stupid question, anyone on here actually have one of these things and taken it too the track,? dyno anything? I really don't see it being a huge assualt on alot of cars, maybe the SRT4, but the STI and EVO i dought.

Stupid question, anyone on here actually have one of these things and taken it too the track,? dyno anything? I really don't see it being a huge assualt on alot of cars, maybe the SRT4, but the STI and EVO i dought.

It isn't meant to compete with those cars, its meant to compete with the SRT4 and SVT focus. The car would be competitive if you dont factor in the AWD.

I found running without a cat in my dwn pipe I was running to rich. So you should run ths sti with a highflow dwnpipe to save yourself richness issues.

Stupid question, anyone on here actually have one of these things and taken it too the track,? dyno anything? I really don't see it being a huge assualt on alot of cars, maybe the SRT4, but the STI and EVO i dought.

How can you compare a $35k STi to a $21k SS? Thats like comparing the STi to the new Z06 vette.

Stupid question, anyone on here actually have one of these things and taken it too the track,? dyno anything? I really don't see it being a huge assualt on alot of cars, maybe the SRT4, but the STI and EVO i dought.

A better comparison would be the WRX to the SS. They are pretty close in price at that point. And as far as Dyno is concerned, GM is underrating the Redline @ 205HO. We've had several Redlines on our dyno and they have all put down about 215 to the wheels. So I would say they are probably in the 240hp range at the flywheel.

:confused: ok first off. i just read all the replys to this qwuestion and didn't see a damn person talk about how the cobalt ss runs 12 psi stock. so what the hell are you talking about with saying you want a pulley to make 10 psi. did anyone else notice this.

:confused: ok first off. i just read all the replys to this qwuestion and didn't see a damn person talk about how the cobalt ss runs 12 psi stock. so what the hell are you talking about with saying you want a pulley to make 10 psi. did anyone else notice this.
I did, but you beat me to the reply. Correct, 12 psi stock. No other parts are out yet, all are being developed, not yet for sale. SS owners will see aftermarket support much sooner than I have with my Red Line. It will be a year for me this June, and thats when most of the parts should start popping up. Just enough time for SS owners to break their cars in, up the power, and take them to the track.

Sticking to the exhaust topic....looking for info how a step up to a 2.5" pipe......but running a dual system instead of the singular one. What would be if any the pros and cons to air flow/back pressure...HP/torque gains or losses.....??????

Sticking to the exhaust topic....looking for info how a step up to a 2.5" pipe......but running a dual system instead of the singular one. What would be if any the pros and cons to air flow/back pressure...HP/torque gains or losses.....??????

Dual exhaust on an I4 is overkill, stick with a single pipe for ease, and that way you wont give the engine more pipe than it has exhaust for, doing so causes backpreassure.

I talked to the dealers and they said the cobalt was gonna be pushing 14pounds of boost i dont know were hes getting 10 if its just 10 that sucks

The Cobalt is pushing the same 12psi as the Redline. The motor has a control solenoid to bleed the boost after that. At this point, the engine also can only meter 14.7psi of boost with the Manifold Pressure sensor thats in there. So going above that boost level would be bad, the engine would never know it until it leaned out so far that BOOM. Bad results. We have been beating ourselves to death getting this info together. Well, this guy MotorMouth on our forum has gathered alot of the really technical info. So there are some electronic control issues to deal with first. On the plus side, who didn't see the Cobalt 272? Makes me real hopeful for the power gains for the Ion and the Cobalt.

As far as the exhaust goes, we have a couple of people with dual 3" tubes from the header. I agree that this is a little bit of overkill, but forced induction engines GREATLY benefit from a very open exhaust. Particuarly in the header area, in the header area you would go into overkill mode, there really isn't a header tube that is too big for a supercharged car. If you wanna go dual, there is a few people on the Redline Forums that have it done, and I'm sure would give you the info you need. They even have some pics up of how the pipes were run under the car. Should be about the same, it's all the same under the Ion and the Cobalt.

True, but going to large can cost you power, as the exhaust leaves the engine the temperature cools significantly, and the exhaust then expands and slows down. This slower moving exhaust can cause backpreassure on the exhaust as it exits the pipes. This can be solved by going with smaller pipes the farther back from the engine you go. For example, you can go with a 3" primary, to a 2.75" intermediate pipe, to 2.5" cat back. This way the cooling exhaust can't expand as much and doesn't cool down as fast, thus keeping the exhaust free'er flowing.

Backpreassure gives you torque, so a little isn't a bad thing. Thats not saying you should go stick in non mandrel bent pipes or more cats or anything.

A gas does not expand as it cools, it cools because it expands. Under normal circumstances simply letting gas cool also contracts it. In your exhaust system, you have to dance the fine line of keeping the exhaust speed high enough, with a well bent, longer and skinnier tube, and providing enough volume of pipe to get the gas out. In a N/A car, the trade off is low rpm torque vs. high rpm horsepower. A smaller tube helps get the gas out of the system at lower rpms, while at higher rpms a larger tube increases the systems ability to move large volumes at higher rpms. In the forced induction system, the blower at the front takes care of most of those issues all the way to the header. The header actually catches the 'poof' of still pressurized air coming out of the cyl as the next charge blasts in. ANY backpressure in the exhaust port or the inital header tube will reduce the power generated in the system. This also means that if the exhaust behind the header cannot get the gas out of the header correctly, it will introduce backpressure, and backpressure is the WORST thing for your blower efficiencey.

The Cobalt has one exhaust, I saw a picture of a cobalt with dual, is there a part that put on dual exhaust??

Has ne 1 seen that black concept cobalt, it has 270 hp but i dno what they did to get that, diff air induction it has a functional hood scoop. And it has quad exhaust i believe coming out the centre like the corvette. I think that car is sexy and i could deal with 270hp stock. And plz stop comparing awd cars to fwd cars its a diff class, the ss competes with the svt focus which they dont even make ne more and the rsx and stuff and i think it competes rather well with them. altho we wont see til they r on the street i think ne way u can look at hp and shit but i wanna see them race head to head.

Dual exhausts on 4 cylinders aren't always overkill. Honda s2000s handle them just fine.

Is your dealer mod friendly?

Dual exhausts on 4 cylinders aren't always overkill. Honda s2000s handle them just fine.

Is your dealer mod friendly?
It is when its 3" all the way back :) My 6.6L uses 3" duals...a 2.0(approx) has no need for anything remotely close to that size.

Dual exhausts on 4 cylinders aren't always overkill. Honda s2000s handle them just fine.

Is your dealer mod friendly?

S2000's don't have dual exhaust, they have dual mufflers branched off a single exhaust pipe.

S2000's are badass.. but arent they expensive to mod? :confused:

It is when its 3" all the way back :) My 6.6L uses 3" duals...a 2.0(approx) has no need for anything remotely close to that size.

There is no such thing as too much exhaust for a forced induction car. Both a turbo or supercharger benefit from the absolute least amount of backpressure possible. In a non FI application, the exhaust speed would be so slow that it would not clear out of the header by the time the next charge is pushing out, that would mix exhaust charge and the fresh charge to some degree, with the blower though, there is enough air pressure to force the charge out and into the header. You also don't get even close to the Rpms of some of these little I4 engines. That's where the fatty pipes come in, large cross-section = high rpms, small-cross section = low rpms. I had a '76 TA that made better power with 2.5" pipes than 3" pipes, but it wasn't blown or turbo. The more I read about a forced induction car, the more it repeats: "You cannot put too much exhaust behind a supercharger". I would concentrate mainly on the header part of that equation, and optimize the rest of the exhaust for your RPM range. The Cobalt (I assume) and the Ion actually have a 2.5" setup all the way back, except for one short length of pipe that is 2.25". Just pop it out and you've got a 2.5" system for $60.

There is no such thing as too much exhaust for a forced induction car. Both a turbo or supercharger benefit from the absolute least amount of backpressure possible. In a non FI application, the exhaust speed would be so slow that it would not clear out of the header by the time the next charge is pushing out, that would mix exhaust charge and the fresh charge to some degree, with the blower though, there is enough air pressure to force the charge out and into the header. You also don't get even close to the Rpms of some of these little I4 engines. That's where the fatty pipes come in, large cross-section = high rpms, small-cross section = low rpms. I had a '76 TA that made better power with 2.5" pipes than 3" pipes, but it wasn't blown or turbo. The more I read about a forced induction car, the more it repeats: "You cannot put too much exhaust behind a supercharger". I would concentrate mainly on the header part of that equation, and optimize the rest of the exhaust for your RPM range. The Cobalt (I assume) and the Ion actually have a 2.5" setup all the way back, except for one short length of pipe that is 2.25". Just pop it out and you've got a 2.5" system for $60.

i hear what your saying, and i must agree ;)

You really cant have too much exhaust flow on a forced induction car BUT once you get to a certain size you will be wasting time and money and yielding no power benefits. Like a 4" would just be ignorantly rediculous.

True, but going to large can cost you power, as the exhaust leaves the engine the temperature cools significantly, and the exhaust then expands and slows down. This slower moving exhaust can cause backpreassure on the exhaust as it exits the pipes. This can be solved by going with smaller pipes the farther back from the engine you go. For example, you can go with a 3" primary, to a 2.75" intermediate pipe, to 2.5" cat back. This way the cooling exhaust can't expand as much and doesn't cool down as fast, thus keeping the exhaust free'er flowing.

Backpreassure gives you torque, so a little isn't a bad thing. Thats not saying you should go stick in non mandrel bent pipes or more cats or anything. You're wrong. Backpressure kills power period. You never want any "backpressure". Very bad wives tale. Poor wording at the very least.

What you DO WANT IS HIGH EXHAUST EXIT VELOCITY.

Maintaining a good exit velocity has several benefits, first scavenging, it helps pull out the exhaust from the cylinder, second, during overlap it helps the intake charge to be pulled in, third, as you alluded to you don't want the exiting exhaust gasses to cool, this results in a denser exhaust charge which is harder to be pushed out.

Velocity is maintained by proper sizing of pipes, therrmal wraps and coatings, smooth bends and transitions just to name a few things.

This is more important in a street car than an all out drag car where the motor is usually operating at WOT, high RPM's, a bit of low end can be sacrificed for max peak HP.

I agree especially on force fed engines, but I think you can go too big on NA engines sometimes, Ive seen dyno sheets showin somebody puttin on a system w/ smaller pipes and gaining horsepower. Mainly because if its too big then the air doesn't flow in a striaght line for the exit because it has more space to move in which can create a sort of "turbulence effect" especially around bends in the pipe, sorry for the stupid terminology, its all I could think of to get across my point...

I agree especially on force fed engines, but I think you can go too big on NA engines sometimes, Ive seen dyno sheets showin somebody puttin on a system w/ smaller pipes and gaining horsepower. Mainly because if its too big then the air doesn't flow in a striaght line for the exit because it has more space to move in which can create a sort of "turbulence effect" especially around bends in the pipe, sorry for the stupid terminology, its all I could think of to get across my point...Although low to mid range gains can be seen when changing from a "too large" to smaller size primary pipes on headers and smaller diameter collectors and exhaust pipes it's a rare thing that WOT peak HP at redline sees any gains and sometimes suffers a bit when downsizing to a more suitable size for street type applications.

In all out drag high HP the rule is no exhaust system is the best, thus witness the short "zoomies" exhaust pipes on mega HP motors coming off the motor and ending within several inches.

Yeah i guess,but I kinda meant just regular street driven (reliably) cars.
But I understand what youre sayin.

The STi is rated at 300Hp is it not, secondly its turbocharged not supercharged thus there is no pulley. You only have one header as its a 4 cylinder, and with the smaller engine 3" may be a bit big as one person said.

Unless you have an SS cobalt which is a different car.

STi is an flat 4 so it has two heads.

STi is an flat 4 so it has two heads.
Yeah he's right (boxer 4) and thus header"s"

The header on the STI's is crazy. The header has so many twist's and turn's.

well i have a sti and this car needs to just be a tad faster, have some questions seeing if you guys have answers

1) is there a smaller pully you can put on the supercharger. bring boost up to 10 psi i dont mind mixing race gas in the tank to avoid detonation.


any help woulbe appreciated.NORCALSTI, yes there is a Pulley for these Cobalt SS's , as well as the Saturn Ion Redline vehicles. We here at South Florida Pulley HQ have these DUB (Dial_Ur_Boost) Interchangeable Supercharger Pulley Units in stock, to give you the added boost and horsepower the average performance enthusiast is looking for in the Boost area.

Of course when running higher levels of boost, certain things need to be taken into careful consideration and that is running a good Octane Fuel, such as Sunoco/Amoco/Mobil 93 octane.

We recommend starting off with our DUB 3.25" Pulley Unit, which will net you an additional 2 lbs. boost over the factory and regapping your Sparkplugs down .005.

Also, any pulley size smaller than our 3.25" , we highly suggest changing to One range colder sparkplug and regapping those new sparkplugs down at least .005 , to help lower the cylinder temperatures, associated with running higher boost levels over 2 more lbs. at wide open throttle.

Also with running a pulley smaller than a 3.25", we recommend PCM reprogramming, as well as using One range colder sparkplugs. Hope this helps, as we are in the midst of updating our website for the Saturn Ion Redline/Chevy Cobalt SS sections for our DUB Pulley Units. You can check out these DUB Pulley Units at this link provided.

http://www.southfloridapulleyhq.com/SFPH/wbody/ps_dub_system.htm

you can trust the computer geeks at hypertech (http://www.racepages.com/brand/hypertech.html) to unleash the power hidden in your engine.