https://www.cobaltss.net/gallery/sho...php?i=2574&c=3


This is a dyno from a 2.2L ecotec. Mods include: AEM Cold Air Intake, Airaid Throttle Body Spacer, DC Sports Ceramic Headers, Dual 3" NOPI Carbon Fiber Exahust, lowered 2" sitting on 18" rims. I also have N2O, but this is without it. The crank was dynoed at 191.8.

 

Nice. The TB spacer does nothing for you since the Ecotec uses a dry plenum. A replacement header helps quite a bit, especially when its ceramic coated. My big question is, how much of a restriction is the stock throttle body assembly?

Earlier tonight I removed my intake ducting just to peek around and saw that the stock TB looks to be close to 42 - 46mm in diameter. Considering the intake/head design and overall specs of the motor this seems like a huge restriction to me. This will be third on my list of upgrades as soon as a larger unit is available.

 

whats with the 3 inch exhaust thats a bit big for this car 2.5 would net you more hp

 

where did u buy the ceramic coated headers?

 

I've seen 58 & 62mm tb replacements at rsmracing.com and other sites. Although the stock intake manifold is even with the stock tb so it's kinda pointless to change until that can be made bigger. And with N2O, I'm not gonna do that. That's why I raised the tb instead. My exhaust is 2.5 until the mufflers. They enter as 2.5 then exit as 3". Mainly for sound reasons, that's also why I went with 2. You can buy the Ceramic Headers at Summit racing. They were 425 when i bought them. Also, this is an 05 cavalier that stock is 140 and I know the cobalts said 145 so maybe could have 196 or 200, not sure.

 

so headesr are useless at this point?

 

ok as long as its not a full 3 inch exhaust

 

nice dyno, impressive numbers. is that a 5 spd tranny too? or auto?

 

3 inch is good for the SS S/C or is my info on this wrong?

 

Not sure about the ss exhaust size...mine is an automatic, and he told the machine to read only between 3550 and 6000 rpm. That's why it looks like I'm not moving until 3550. He did it in 3rd gear starting at 65 mph. When it began to shift into 4th around 95, he threw it in Neutral. That's why the line dies to nothing all of a sudden.

 

When I run full throttle all of the way through the gears, it never shifts itself until 6500. So If this was possible to do, I might have gotten an extra 2 or 3 around 5800, because he went though 1'st and 2nd without hitting the 3550 mark so that he could get the reading in 3rd. He said there is a lockout thing to get that you can put on it so that it doesnt downshift, but I don't care enough about it to buy that for at most 5 extra horses to display.

 

3 inch on a ss/sc is pushing it. one way to tell you went to big is that if you rev the engine and then let it decellerate and the exhuast pops, to big.

 

A stock 2.2 exhaust does this. Its called unburned air-fuel charge hitting a hot exhaust manifold and igniting outside of the combustion chamber.

2.5" for the SS unless you're running ALOT of boost.

 

2.5 has been tested at close to 600hp on the corsa 2.5 exhaust so it should be fine

 

So, the dyno dosent show the crank HP i take it?

You say you got 191.8 at the crank, based on that and looking at the Dyno sheet, the cavalier loses 40HP to the wheels?

That seems a bit excesive. Or is that pretty standard?

 

on an automatic 40 hp should be expected to be lost to the wheels. You usally lose about 20% with an automatic so that sounds about right. I think manuals lose 13%. These were numbers for my old car at least cobalt might be different.

-Ryan

 

Can you explain why it pops if the exhaust is to big???

 

He doesn't know what he's saying. The stock srt4 pops like none other. It pops more than my aftermarket magnaflow catback exhaust. And when you put 3" on the srt4 you can get 15 to 20 whp and that thing pops like popping pop corn. 3" for the ss/sc could be good and bad. If you want hp demon, then the 3" would be suitable, but making up to like 300whp all you need is a 2.5

 

Yea' my 3" pop's not a crap load but it pop's enough.

 

The dyno tech did a bunch of "figirn" after the run with the enviromental numbers and what not, and said that if I had a 5 speed, my whp would have been 166.7. I went with automatic because 1. Better shift consistency on an 1/8 mile track, and 2. Girls like to drive it and feel cute.

 

Travis that is sooooo wrong, i have been seeing my GF for 6 yrs now and i dont even like her touching the radio.
This depresses me, you have great numbers but you are letting girls drive your car....

 

roadrunner im the same way. i dont even like my wife in my cobalt!

 

me too she gets in but not driving it

 

Header . And look at rsm's site i though they had an intake manifold for the eco's like the ld9's that match the 62mm tb. Honesly you could easily port your stock manifold and it would work just as good as rsm's.

 

Yeah...it makes them feel sexy then they want to be taken, reverse psychology....sorry to any females that may be reading this, but it's true.