First ATI dyno #'s , need pulley help
Teching In
Joined: Dec 2003
Posts: 9
Likes: 0
From: Hillsborough, NC
Hey guys, I had a couple of people want me to chime in here on this thread, and here's some feedback.....
- timing IS dropped up top, so that's no worry...
- fuel is perfect until we ran out of injector at 5600 revs, and we hit "170%" which is a calculated value that's just an indication of "fuel injectors turned ON" which they are...
A lot of the good advice given matches exactly what I've said already, and the warnings are the same. We're running lean up top, no doubt, and lots of warnings given. But I'm not going to play the game like a lot of places do and just try to sell everyone bigger injectors right off the bat. Settting the rev limit low, warning about keeping the revs low and planning on an upgrade in a methodical manner, rather than being all hysterical about it (but still serious for sure).
So, no worries, trust me, nothing would leave here with 12.5 on a blower car for any more than 100 rpm. (And my Dynojet is a high inertia model, 6600# total weight.) And this one didn't leave at 12.5:1 for more than 100 rpm, and where it was lean it was also low timing.
Back to the question.... Anyone with that size crank pulley with a 4.5" blower pulley, what are you making for boost? (And I agree with the comment that keeping the revs low and making the boost low will make it live longer...)
I'm back to the parking lot to party at the F-body National Event in Memphis,
see ya!!!
-jeff
- timing IS dropped up top, so that's no worry...
- fuel is perfect until we ran out of injector at 5600 revs, and we hit "170%" which is a calculated value that's just an indication of "fuel injectors turned ON" which they are...
A lot of the good advice given matches exactly what I've said already, and the warnings are the same. We're running lean up top, no doubt, and lots of warnings given. But I'm not going to play the game like a lot of places do and just try to sell everyone bigger injectors right off the bat. Settting the rev limit low, warning about keeping the revs low and planning on an upgrade in a methodical manner, rather than being all hysterical about it (but still serious for sure).
So, no worries, trust me, nothing would leave here with 12.5 on a blower car for any more than 100 rpm. (And my Dynojet is a high inertia model, 6600# total weight.) And this one didn't leave at 12.5:1 for more than 100 rpm, and where it was lean it was also low timing.
Back to the question.... Anyone with that size crank pulley with a 4.5" blower pulley, what are you making for boost? (And I agree with the comment that keeping the revs low and making the boost low will make it live longer...)
I'm back to the parking lot to party at the F-body National Event in Memphis,
see ya!!!
-jeff
Originally Posted by Milkman383
Back to the question.... Anyone with that size crank pulley with a 4.5" blower pulley, what are you making for boost? (And I agree with the comment that keeping the revs low and making the boost low will make it live longer...)
-jeff
-jeff
The thing is you can't compare boost levels like this.... U need to see what your car is making and then adjust the pulley size for what u want. Some cars might see 10psi with the same pulley combo i have if they are running stock exhaust and cam, but im only seeing 8psi because i have less restriction in my engine which is allowing more air to get in the engine.
So based on the boost levels u got now with the 4.00" pulley i say u would need somewhere between 4.30-4.40 to fix your problem. Good luck.
