i got a front end alignment today and right when i left the shop, both my belts just shredded to pieces!!!! so now that i have to replace them, i am gonna upgrade the pulley.... if i go 3.25 or 3.125, will i still have to upgrade the fmu to a 8:1 disc, even with the 3.25? i know i have to with the 3.125, but not sure with the 3.25..... and also what belt sizes do i need? thanks

 

I have a 3.25" pulley, and I was definitely running a little lean with the 6:1. The 8:1 seems a little too rich, but not by too much.

 

if you are running too rich with the 8:1....maybe you could test my theory few threads down there, "a cheap way to lower my fuel pressure"

but it is better to run rich than lean, stay with the 8:1 and get an S-AFC or just get the adjstable FMU.

belt size? have you checked the stickie in this forum, hooktup98SE?

 

I have a safc, but I don't want to lean it out more than about 10% at high rpm without it being on a dyno.

By the way, Mardigrasmax went with a boost bleeder valve along with a 3:1 fmu, adjustable fpr and fields afc when he went to the 370 cc/min injectors. How he managed to juggle all that in getting to 12's is beyond me.

 

so if the 3.25" is running alittle rich, than is it safe to just go with the 3.125"? what do you all think is better? or should i say, safer.... thanks all... (this is hooktup98se by the way on someone else's account)

 

Yeah, if I had to do it over from the beginning, I'd just go with the 3.125" pulley. Craig Mack is running a 3.125 and 8:1, and he thinks he is too rich. So you should be safe. I should mention I also have a variable intake, so I'm getting more air at high rpm. So a little rich for me with the 3.25 and 8:1 and mevi might be way rich for somebody with a 3.25, 8:1 and stock intake.

 

thx Stephen...I just PM'ed him

 

if your injectors can handle it....increase boost will make your car even more rich. the best way to know is to get a baseline dyno after you drop in the new pulley. have fun~ be careful when you remove those hex bolts and make sure to use some antiseize on the bolts when putting them back.

 

I got a new 8:1 FMU disk and gasket if you are interested.

 

Do what I did, go to a turbo set up