kinda bringing this thread back to life here but if i do the GM dual pass option B is this enough to safely run a 2.5 pulley?( properly tuned ofcourse)

 

I went from a GM S2, 3.09 or wtv, to a 2.9 and frankly didnt feel a whole lot of difference. I was preatty disapointed actually

 

With my mods including the ported head from JBP, I found the best power HP&TQ came with the 2.8 pulley. My car achived 305whp and 292wtq
My final tune was set up at turbo technoligies. I pull 19lbs of boost and my hp/tq curve peaks at 6050rpms. Pushing more than that is loosing time in the 1/4 mile
Last year I had all my mods minus the ported head and I ran 13.8 all day long
with out the head, my balt was at 277whp and 242wtq
The JBP ported head made that big of a difference. Im hopeing to be in low to mid twelves. And maybe if I fart just right high 11's

 

The torque increase with the 2.6" pulley is nice. Especially in the mid range. The heat that comes along with it however is not so nice. Hence the reason why I went back to the 2.8" pulley until I get another HE to go with my freshly done dual pass mod!

 

Stop fighting its a frigg'in number spit out by a machine and if you took the same car to 10 different dyno's on the same day let alone on different days you would have different #'s for all.

I know someone with stage 2, 2.8 pulley, meth injection, stock everything else with a tune and he dynoed over 282 on a mustang dyno. I have the fastest cobalt time in my area even though I have GMS2 only so you guys can take the dyno #'s and shove it cause it means nothing.

setup and performance can only be seen at the track. that is the real thing you guys should be looking at. Dyno #s as just dumb. use the info for what it was meant to be used. see if your going in the right direction and rather than peak HP you should be tuning for usable power and learn how your motor is producing power to stategize your shift points for your passes at the track to get the best time possible.

so 2.6 will help mainly for torque and you want it to get a better feel out of your motor. but I think more of us should be looking at traction (tires) to decrease times, LSD as well if you dont have it, then look at full exhaust, head port and polish, blower port and polish, cams, cam gears, valves, and valve springs before going to a even smaller pulley, IMO. not as cheap as pulley but when you go to a smaller pulley finally you will get the most out of it.

rant done.

 

yes, good points, but the reason i brought this thread back up was to see what thoughts you guys have about a 2.5 and a dual pass and if thats enough?

 

what are your other mods?

 

tag tuned for a 2.7, gmmp sport, exhaust, gmpp manifold 2.5 CA dp, injen intake.

 

i would get a cobra heat exchanger as Laz and I saw that dropped IAT's alot and with the dual pass even more. The car runs better better with the 2.6 pulley with the HE.

 

Easiest question evar! Its .2 inches difference.

 

you bring up a few great points..

dyno's are mainly for tweaking before you road tune. Its a great way to get a tune in close, but not fine (make sense). I got great numbers for my tuning. I went from a 2.7 to a 2.5 and gained 20 hp and 20 ft/lbs....just the pulley swap. I tweaked the numbers a bit and lost a little hp but gained more torque in the mid-range.

Finding out where the optimal shifting points are is great. I was actually reading about it last night. I'll have to write up what I learned.

Also, without head work I am doing my motor a disservice. I can get much more out of it with some porting. The cams and valves would also make a huge difference. Then the pistons and rods. Without going into the motor, I've had good sucess. Once I get in there, I'll be well over 350hp & 300ft/lbs. Then comes the twincharge.

 

All I wanted to say is when i just had stage 2 aem intake and thats all i had my car dynoed and i hit about 257 whp.

 

ok guys if all goes as planned I am getting re hptuned and a dyno tune on sunday 04/01/07. The dyno is a mustang dyno i believe. So I would imagine the #'s will be lower than some of the other dynos people are using. My mods are in my vgarage. I am going to see if they will tune it with the 2.6 and tune it with the 2.5 as the ending pulley that I will leave on.

 

 

yellow cobalt i have a question.... the gmst2 pully is what size? 2.8? and im thinking of getting the intense stg3 pully... or should i just get the stg4? i dont want to change out the cams or headers ne time soon or do meth injections... okay maybe the headers ^.^... but what would u suggest?

 

the stage 2 pulley is 3" in diameter. I would go for you a 2.7" pulley and 60 lb injectors and a tune.

 

a 2.7 is stg3 intense?

 

I have a question what size pully comes with the stage 2 at cobalt addiction i wanna get a kit and wounder what size pully to get or what it comes with

 

try www.cobaltaddictionfaq's.com

 

That dont tell me nothing about the pully size or what size it comes with.

 

thats because its a fictious link...the ca site would be a great place to start.