I'm not looking for opinions on which pulley is safer / preferred but rather which would give the best quarter mile time. I'm looking for things like... would the 2.8 knock the timing back giving the 2.9 a better time, etc...

All mods are in my sig line.

 

i think the 2.9 will make more power just because you dont have any cooling mods and you are getting heat soak by the time you are half way don the track

 

agreed...

i wouldnt run a stage 2 tune with a 2.8 anyway.. bad bad...

If you get a custom tune and lean out a touch, youll have better times with the 2.8..

Stage 2 tune, i wouldnt venture far from the stage 2 pulley..

 

Agreed...if you can find someone with HPtuners...you can really change some things with the GM tune. I am waiting on my tuner to get a wideband o2 so that we can change the timing, afr..etc

 

I have read hundreds of posts here about that topic and totally understand. I'm looking for opinions on which pulley would give the best 1/4 mile track time, and why ?

 

2.9 you will make more power up top because of less heat if you want to run a 2.8 on the gm tune i would at least get a new heat exchanger and maybe a dual pass

 

Okay then..

Theoretically, the 2.8 SHOULD be faster, higher boost, higher hp..
remember though higher boost doesnt always mean higher hp, but for the most part, its true..

Depending on the day, you might not get knock (try to use 93 octane) with the 2.8... But from what i hear, people were knocking from about 6500 rpms and up, so thats 500 rpms of reduced power.. But im not sure how that would balance out, nor noticable or not.

since the gm tune is rich, and the 2.8 will be pushing more power (theoretically), its gonna be dumping more gas... proof the 2.8 is pushing more power is the injector idc. An already rich tune + more power (more gas) = higher idc..

 

Any more opinions

 

There was a thread where someone went to a dyno and proved a 2.8 made less power than a 2.9 on GM STG 2 tune.

 

I hate these threads so much. I just stated it in another thread that the IDC's will be through the roof with a 2.9 let alone a 2.8 on a stage 2 tune.

When you run your motor to 7grand and have a 2.8 on a stage 2 tune, you are robbing your engine of A LOT of fuel that it needs. This is very very bad.

I would recommend either grabbing 60lbers and hptuners, or simply running the stock stage 2 pulley.

To answer the question though, the 2.9 would make more power than the 2.8. The 2.8 will heat soak quicker, and will have the idc's to high to make power. In the lower end the 2.8 would have more tq and power, but in the higher end the 2.9 would win.