Just how much does GM hold back on the out put and tuning of the 2.4L?

From some posts, talking about air/fuel ratios ect--it seems like quite alot.

Anyone else think so or have any other thoughts on this subject?

What mods bring the biggest changes? (while keeping it NA)

 

id say that the actuall hp and torque can be atleast 200 hp and 180 torque from factory but thats just me.

ryan.

 

Personally, I don't think Chevy is purposely holding back performance. They have to abide by Government emissions regulations and sell cars that are able to use fuels that are available to the public.
On the same note -- I talked to some Buick electrical engineers about this back when the Grand Nationals were being made. They pointed out that they could provide performance PROMs from the engineering they had accomplished for the Indy cars but their hands were tied because of emissions and fuel regulations. Aftermarket can get by this by selling items as "off road use only". Chevy could sell items as "off road use only" but their engineering costs are higher and they cannot compete with the lower cost aftermarket companies -- which is THE reason they have not provided an intake for the SS/SC cars. Proof of this is the 2.2/2.4 intake -- the GMPP looks sharp and performs well but it appears most Cobalt owners want the Injen. One would have to wonder what GMPP could/would do if Cobalt owners supported GMPP 100%. I can only imagine what GMPP would provide if we supported them totally.

 

Doubtful without CAI and Exhaust. But I'd say it's wholly reachable within $1,000 of parts and tuning. That's my goal anyway. 200hp.

 

I do wonder what you are saying, we have people who are claiming 12whp and 12whtq with simple tunes and then the new 07 HHR has 175hp must be just in the tune. I am waiting on sushi to dyno with his injectors and tune.

 

gm adds tq management, to help keeping the car together. they take away timing and run them rich, to play it safe. they pay for warranty after all. i call it detuning.
ever hear of a rumor that the computers hold back extra when a car is new, and one day it comes more alive? personally i dont see how that could be without everyone knowing about it, must be vicious rumours. regardless, running motors with less stress lets them last longer.

 

not happening. There are quite a few stock dynos--and even when you calculate back to crank hp--it not close to 200. Remember 2007 2.2/2.4L are uinder the new SAE hp ratings..they are pretty much spot on.

Yeah I wonder with injectors/tune/header/CA/dwon pipe if I could get 25 hp....my car needs it!!

 

you and me both, makes me want to get a small loan then sign for another 4 years in the military to pay it off. LOL i am not american with out debt damnit

 

Quote: Originally Posted by rlinden86id say that the actuall hp and torque can be atleast 200 hp and 180 torque from factory but thats just me.

ryan.

not happening. There are quite a few stock dynos--and even when you calculate back to crank hp--it not close to 200. Remember 2007 2.2/2.4L are uinder the new SAE hp ratings..they are pretty much spot on.

hes saying that if gm were to completely retune the ecm and squeeze some more juice out of the 2.4.....that it would make 200 hp and 180 tq......which i believe is very achievable....but like you say its gm and they are gonna tune it to be efficient...

 

yes it is,all nissan did with there new spec was give it an aggressive cam profile and they got NA 205hp

 

ah right..sorry mis read the post.

higher compression are among the changes Nissan did--not jsut a cam. Probably exhaust, intake, head design, exhaust ect

 

the 2.4 could make well over 200hp in stock trim, but there are a few hold backs.

on the tuning side, the engine would make a good deal more power if it was allowed to have another 500-1000 RPM. in other words, better springs and a good tune and a 7200rpm redline would probably get you there.

also, the intake and exhaust manifold and downtube are all (so i hear) restrictive. every IHE 2.4 driver says that it really wakes up the car, which is rare on a modern 4 banger. hell, i'm convinced that it got stronger once i put in the +4 spark plugs.

 

Who is in the lead for most mods done and who will dyno soon i want to know where we all stand and with what (time's from the 1/4 mile are way better then dyno but its winter so ta hell wit it)

Also not to steal the thred but can some one answer this.
1.What valve springs and retainer should we get (best bang for buck w/ customer service)
2.I know we need retainers what about Push Rods or anything else?
3.My Chevy HHR only has a rev limitor to 7000rpm how would i know can hptuners just have the light come on past 7000 or should i look at changing face display with a cobalts?
I think the injectors and basic bolt on's with tune can get us this 200hp 185whp maybe?

 

You will know where you new redline is...just **** at that...the rev limiter will be just a wee bit higher then that---still there. Custome guages witha new higher redline sounds neat but where are you gonna get that done? A Coblats redline is 6750 rpm so thats not good either.

 

get an aeroforce interceptor, a program the shift light, if your going thru the gears, you shouldn't be looking at an instrument cluster.

 

like i said b4 the 2.4 cobalt i do believe can achieve 200 hp from factory but would lose the milage if they tuned the ecm and made some minor adjustments. the compression is very high i think for anything else. but as far as if you want to turbo or super it id think youd have to change out the piston rings cams and crank not to sure but maybe get better pistons aswell but could be wrong. but thats alot of money too. im looking at a turbo but it needs more than just turbo and stuff internals have to be rudone alittle.

ryan.

 

Believe me, they run them rich on WOT and higher RMP. I have dyno charts with F/A Ratios to prove it. And, when we reduced the F/A ratio just 4 percent using a MAF corrector box, we picked up almost 2 HP. Not much, but the change was not much, either. There's room for improvement using HPTune, for sure.

I was told just today that the richness may be to protect the cat. They are prone to melt-down with lean mixtures. So, it's true - GM has to make all the parts last (from the cat to the tranny), meet internal GM durability standards, meet government emission and noise standards, keep warranty claims down, and still produce power.

Considering that a Chrysler 2.2 in 1989 with a turbo and intercooler was rated at 175 HP (and it was fast in its day), current technology ain't bad at all! If we want more performance, we need to get GM to reduce the weight of the Cobalt about 800 pounds. That would do more for us than anything! Those 1990's Chryslers were fast because they were LIGHT!

 

And a W41 Quad 4 was rated at 195hp about 15 years ago. OF course our engines have some more TQ (much flatter curve too) and are Reliable! Still to bad GM can't push this engine from the factory a bit harder--Nissans gettting 200hp now and we have that Civic Si Sedan...who kknows what a next gen raliart will be running.

Weight reduction would be great but its not cheap. All the safety features these days add weight--and aluminum is $$

 

I mean my RPM guage only goes up to 7000 what does the cobalt's go up to?

 

im sorry but decreasing the weight is not the answer. the car is light enough as it is. i just do 55 in the rain and i have to worry about hydroplaning. ever thought of the reasons why the cobalt is frontwheel drive besides making it cheaper to buy?

 

If that is true, which it is, then think of a I/H/E and tune. That would really open up. I don't want to throw numbers out there but it should do a damn good bit with those 4 mods. Think about it, you're opening the main passageways of air-flow which is very restricted on the Cobalt which alone makes it wake up and then throwing on better mixtures and tunes including the higher rev-limit. Pure ownage.

 

i don't think that they're THAT restrictive, but i'm under the impression that it never hurts.

guess it shows that after all these years, the old ways of hot rodding are still the best.

 

I know what you meant--sry I was not too clear.

Post a pic of your gauges--I am sure your redline is 6750 like the Cobalts. Look very carefully at your guages.

 

2.4L held back?? HELL YA, sons a bitches manufacturers I say give the car 6th gear for cruizin on the highway..

 

Hmm, I don't know about 6th gear, but I do wish 1st gear was a little longer.