to 2.76 or not?

[markw351]

Quick run down of the mods:
Stage IV ported eaton
Stage II ported TB/Plenum
2.93 Billetflow non-slip pulley (seeing about 12lbs in the summer heat)
full set of idles
metco tensioner
JTL RAI
Mafia
Amazon tune via a predator (currently 11.4-11.9 AFR and 19* timing)
1 5/8 Full lengths
X-pipe (no cats)
Steeda cat-back

Fuel:
BAP
60's
91 Octane

Question is should i step up to a 2.76 pulley? After the ported blower install it felt like i might have lost a little torque and gained in the top end (normal results i guess). we just checked AFR with the wide band, so no dyno results to back it up just the feel in the pants. Will i be safe with 19* timing, a 2.76 and 91 octane? I figure with the full exhaust i won't see 15lbs unless its a cool night out. Probable more like 14lbs most the time. No dyno tuning will be done if i install the 2.76. Just another AFR check. The tune in the car is the same tune that has used with almost the identical set-up on the same car except with a stage III blower and better gas. Only thing we did was drop the timing to 19* for the 91 octane. I'm hoping to get that torque back.:loser:

 

[cobracide]

Add a 4# lower.

 

[lowflyn]

Going from a 2.93 to 2.76 I don't see you gaining anything except belt slip.

I'd put a 4# lower on and go from there. If a 4# seems like too much, add a 2# and still pick up the power without the slip.

If I could go back and change my setup it would be a 2.93/4# setup.

 

[wudy]

I added the 2.76 from the 2.93 with the ported blower and dyno results were 50 hp gain and lost 1 ft lb of torq. I agree with the above, get the 4 lb lower. That will get your torq back.

 

[markw351]

Thought about a 2lb lower. 4lb is too much for taste on crap Kansas 91 octane. The 2.76 will cost me $95 vs what about $400 for a metco lower set-up. I know belt slip could be an issue but with a full set of idlers and the metco tensioner i thought i might be ok. The car had a 2.8 pulley on it before with no slip issues. Thanks for the input guys.