so i noticed the torque loss after i installed my 2.4 int mani last summer. well i got around to installing the 2.4tb and tune over the weekend and i'm happiy with the results. the torque loss in the low rpm is not as pronounced as it was if it's still there at all. any other 2.2's with a similar experience?

 

Were you tuned before the 2.4l TB? Did you do any other upgrades at the same time as the 2.4l tb?

 

i was tuned before the tb but not with the 7100rpm redline. the int mani was installed after i received my first ecm/tcm tune.

no other upgrades with the 2.4tb.

 

Hmmm... That's interesting...

 

What year are you spanky?

 

'06 and i'm trying to tune for a set of 33# injectors. the ratings over kill but it's the next best thing considering there's not real option for the 2.2.

 

Do you know if they make a 6 pin 2.4 TB?

 

someone posted a really good thread about throttle bodies and intake manifolds on another forum which i stumbled upon which included some actual mathematical equations dictating the amount of overkill bigger bore throttle bodies create. and through this persons findings he pronounced that after a certain point a throttle body no longer gives performance but rather takes away from it.

now he could be full of **** and he could be right but from what i gathered and he worked it out for the 2.2s the stock throttle body is more than sufficient for use with minor bolt ons, which you have spank seeing that you no longer run nitrous. amiright?

iirc he was saying that the only modifications that would require even the larger 2.4TB would be something along the lines of forced induction or stage 2 and 3 cams.

now i could be wrong and i could be right. maybe someone else can come in here and prove me wrong or right.

cause what im trying to get at is that the difference you feel may be in your head, or it may not. i just want to clear this up for myself.

 

all bullshit aside i know my car and there's something there. that dude could be right but i'll hang my hat on my experince not his equations. i'll do you a favor. ride out and we'll test out both. just be a matter of swapping parts and tunes.

 

here you go...

http://www.ecotecforum.com/forums/showthread.php?t=5089

 

hmmm I don't know if i believe this guy or not..

 

ive noticed tons more throttle responce and seems to like the TB more.

 

Im trying to get a throttle body right now can't seem to find a 6 pin though only 8 pins :/

 

2008 cobalt 2.4 has a 6 pin TB, I have one and it worked great on my 2007 cobalt, I feel like there is more tq than stock but then again I am tuned and fully bolted making 176 hp

 

Yeah that's probably where I'm at too. just got the 39 injectors and am planning on getting the TB at the same time and retuning.

 

blackbalt was referring to my thread...

To the OP, it makes perfect sense why you lost torque, takes air velocity longer to build up and resonating effects are slowed down until you reach higher RPMs. Your tune could have easily helped you in the fact that it can lean out your fuel mixture at certain points or even changed your spark timing in the lower RPMs to help increase performance...thats all.

When you put larger intake and exhaust components on your type of vehicle, thats what you're doing, you're changing where your powerband lies...making it wider is what you ultimately want to do, not making it narrower.

As far as needing newer/bigger injectors, you should only need new fuel injectors if your duty cycle is being maxed out. You can find out with devices like an Interceptor for example (not sure if you can use it for your application).

 

i run an interceptor now and it won't display the idc's. been talking to aeroforce about that.

 

Yeah I heard some vehicles it won't show the pulse width (which you can translate into duty cycle %).

 

well either way it sucks but i'm past that now. i'd like to get e85 on those 33# inj if its possible.

 

Thats a pretty standard calculation that has probably 100 different nline calculators using it for picking the proper sized carb. Which is all good and well if you plan on putting a carb on your Cobalt. The reaon its wrong is because it bases the amount of flow on a very high level of vacuum(suction), in this case he's using 25"Hg, our engines dont make 25" vacuum under any normal condition where the throttle is opened, so there is no way it will ever be able to pull as much air thorugh as these calcs claim. That is why if you were to put a 50mm TB on like the numbers seem to make it look like you need you would be strangling your engine, theres a reason the Delta L61s make more power than the Jbody L61s, and guess what they have a bigger TB............

 

this.. lol ..

not to mention alot of things play into affect like intake runner length and diameter, intake pipe diameter head flow .. its not just the TB thats going to change everything in the world