You will loose all of your power from 2k rpm to about 300rpm before redline. These aren't high winding Honda engines. They simply don't move enough air to ever need 3" n/a. Even if you had a cnc ported head, short runner intake, kickass lt header like an ottp, stg2 cams, you still won't benefit from 3" pipe. LS1 f-bodies use 3" pipe........they have more than twice the engine you have. You gonna go race them now?

 

You live in San Antonio, I live in Victoria. I plan on going to the next midnight madness at SAR, either at the end of this month or the one next month. I'll race you with my stock exhaust and be glad to hand you a quick ass kicking. LOL What was the trap speed and other details of your last run? What was the d/a that run? I trapped 89 in an awesome negative 775 d/a before the Cai and 2nd cat removal iirc. After, in a worse d/a of 2434, I trapped 91 mph. Still using stock exhaust. So, post up that slip bud.

 

Or, if you feel that confident, you can drive down here and I can have a friend record our runs. Looser buys gas.

 

Hrmmm this again eh?

Backpressure = Myth...you don't want any backpressure

Scavenging has more to do with the manifold runners and collector than anything post collector.

My car made an extra 9whp and 14wtq running it open header (over my full 2.25" exhaust), dyno'd back to back...so its 100% proven and it is all-motor....HP and TQ listed in Sig.


Will he see a gain from running a 3" downpipe over a 2.5" downpipe...probably not...will it hurt it....no.

Think about it....people put 3" true dual full exhaust on V8 cars all the time that make 300-400, half of 300 is 150 If it didn't make power people wouldn't be doing it.

 

most V8 cars i know of run 2.5 or 2.25 exhaust

but you also gotta remember, V8s have more displacement then the dinky 2.2 motors

 

Right.

but....

Exhaust gas velocity has to do with the entire exhaust system. He can have a great scavenging manifold or header, but if he is dumping into too large of a pipe it will cause eddies and slow the exhaust flow down. You cant compare your car to his car. You have more done to yours I'm sure. A basically stock N/A 2.2L Cobalt should run no larger than a 2.5" downpipe or catback for optimum flow and exhaust gas velocity.

I don't know why I waste my time trying to help kids on this site anymore. Everyone always thinks bigger is better on here. Ohh well....

 

I agree backpressure is bad, but cutout vs 3inch dp to stock/2.5 exhaust will create more backpressure because due to the gases not escaping at maximum velocity (eddy currents edubs was talking about). Although it would be interesting if some did dyno numbers compairing 2.5 dp to 3.0 dp to stock, but I doubt anyone on here would/will

 

The 15.5 was just Sri and lowered. Next time will be with the downpipe and catback. I'll def post slips prob gonna be a bit though before I get out there

 

Mobile site won't let me edit my post, it was staged07ss who mentioned the eddy currents not edubs

 

why are you so quick to jump down my throat and boast that your faster? I don't care if your faster than my car.

 

If you don't care how fast your car is, then why even add performance mods to it? Seems kinda couterproductive if you ask me. I'm just trying to prove a point dude. Huge exhaust will slow you down, considerably.

 

He didn't say his car was faster than yours. A 5 speed cobalt should beat an auto one anyway. Your comment was kind of uncalled for lol.

 

-grabs my chair and popcorn and enjoys the show-

 

 

this is gettin interesting lol

 

me too

 

Man, trying to help out, and just get **** on. I'm sick of trying to help whiners and crybabies. We all try to give helpful advice and the people who ask for it don't use it. Seems kinda pointless to me. When I ask for help and advice, I listen and take heed to what's given to me. If you're not worried about how fast your car is, then why even bother adding performance mods? The whole point to adding performance mods, is to improve your cars performance.

 

4" out the hood!

 

Stack through the hood ftw!!

 

ok im not whinning, you are being the crybaby about a car that doesnt even pertain to you. yes i appreciate all the comments and advice but no one is shitting on you. i mod my car for my own personal enjoyment, if your faster than i am, cool. there are alot of cars faster than you and me and it doesnt bother me. like i said i will see how this 3" does for my performance and track time until then stop talking **** and chill out its not your car.

 

https://www.cobaltss.net/gallery/sho...hp?i=82097&c=3
there is the slip of my best run with just sri and lowering springs

 

i wish i coulda got more seat time in my cobalt when it was stock. i ran a 15.9 @ 88 mph with a 2.2 60' with a K&N drop in filter. best was a 13.4@111 2.4 60' and 14.6 @ 115 2.9 60' lol. good luck to ya homie

 

What mods did you have when you ran 13.4 that's impressive from a 2.2

 

i was turbo'd lol

i forgot to mention that in the first post. the purpose of the post was me sayin i wish i coulda saw what i could do with bolts then had more time to dial it in with the turbo

 

Ah Ok lol still a good time though