originaladrian

So i was basically a few minutes away from buying new headers but some people were saying that there is a loss in back pressure so therefore its not even worth it to do this. I need the 2.2 army to give me some answers , thanks guys

D4u2s0t

only if there's a leak

originaladrian

so the loss in back pressure wont cause my car the accelerate slower? Also do u think this is worth it?

D4u2s0t

yep. you don't need back pressure. it's all about flow and velocity.

xpod666

headers would improve acceleration and keep the engine cooler

joeworkstoohard

backpressure is a myth.

basically, as long as it flows fast and clear, it'll allow the engine to run more efficiently.

REIGN SS

with the 2.2 i would go with the 2.5" header... The 3" is more for boosted cars or HIGH horsepower applications.

joeworkstoohard

well, too big is as bad as too small, it hurts air speed (air, in this case being exhaust, but could apply to an intake as well).

are those panties on a shifter?

REIGN SS

yes they are...

Red2.4SS/SC

header not headers

HunterKiller89

iTrader: (1)

he's got it right...youll loose a little low end power, but you'll more than make up for it in high end power....if you went with a 3" however, you would loose so much low end it wouldnt be worth the gains at the high end

bigrroberto

Iliked your picture of Hayden better...

hobbie2k

Backpressure is not a myth, the idea that a car needs some backpressure is the myth. It's a misconception grown from the realization that overly large exhausts and intakes often result in a loss of low-end grunt. The real issue is gas velocity vs volume. There is a good thread somewhere on this site by NJHK that explains it well, https://www.cobaltss.net/forums/general-cobalt-68/simple-explaination-intake-exhaust-resonating-camshafts-operation-68523/

Novajoe

anything higher flowing is going to gain hp, however it might shift it up high enough to where you might not be able to use it. Now you can go TOO big and lose power, but good luck finding a set of headers that'll be that large.

jigyflyuk07

i agree.

joeworkstoohard

well, that is what i meant.

yeah, who is that, exactly?

SilverBalt

just make sure you dont have SAI, than you will be headerless like me :-) it sucks !

Asphalt Assault

Most important thing for a NA header is equal tube length. as one cylider exhausts it can create a vacuum for the the next cylinder exhausting. important for SC cars but less important. ZZP midlength header is a great choice. and if you were planning on keeping the Catalytic then you will have too much back pressure always....LOL

HunterKiller89

iTrader: (1)

cats are pretty free-flowing....i dont understand everyones urge to remove their cats...thats like 1-2 HP....i'd rather pass my smog test than gain 2HP

Old Man

Lets clear some things up here.

First is the fact and no myth, you need some back pressure, emphasizing street engines, not applying to race engines. That amount is .75 to 1.5 PSI.

You cant run open headered on the street legally so a exhaust system is needed.
Vehicles are engineered to run a exhaust on the street.

For proper velocity,scavenging effects, cam designs, 02 sensor operation and I could make quite a long list of why minimal amounts are needed.

The point people use to defend with, the too large a exhaust means that some back pressure is required. That closes the case of back pressure required on street engines in some amount without going further.

High flow cats, HAHHAHHAHHAHHHAHAHA!!

There is no longer such a thing, there are NO GAINS TO BE HAD, NADA, ZILCH,ZIPPO, NOTHING.

Once upon a time when the term high flow cat was real, the cats at that time had pellets in them.The pellets were fairly well packed into a chamber and as they did there job, carbon would build up between the pellets clogging cats. Then someone came along with a plate style, honeycombed design that was truely a high flow cat versus what was being used.

You can bench flow all the cats of the same inlet/outlet that actually do the job as intended and find absolutely no difference in flow. Now going further, there are cats out there that are not legal, glass pack style, straight through in design that offer minimal differences in flow versus a true cat converter, but they dont work as a cat was intended.

Asphalt Assault

I am just speechless. there more restriction in the cat than a K&N filter. and as you drive your car it will get worse due to corrossion and carbon. there have been more than one cobalt (mainly SS SC) with clogged cats replaced under warranty. believe in what you believe. I dont recommend removal of the cat due the environment but I have to tell the truth on a NA 2.2L it will be good for 5 to 7 HP (more at the top end). on a SS/SC it is even more. (I know this a 2.2L thread)

Kennyspec

My turbo will give me all the back pressure i ever wanted. OPEN DUMP FOR ME!!!!!

Asphalt Assault

Good post but there is one point I would like to make. a 2" cat will flow less than a 3" cat. now I am not suggesting you run a 3"exhaust on a cobalt 2.2L but your could be doing really fine with a 2.5" downpipe with cat and then reduce to 2.25" replace those down pipes and header first then the rest of the exhaust. you could finish the exhaust later with 2.5" if you want. but if you plan for Garrett Turbo than hold off on any exhaust as the kit comes with exhaust changes for your car.

YellowLT

You lost torque but gained top end your power band now starts around 3200 rpm's Mine did the same thing.

Novajoe

Most good headers will give you an increase in both tq and hp, but they're both shifted higher in the powerband