I currenly have a 19% and I want to put in a crankpulley. is it ok to put in a 2% crank, equating to a 21% SC pulley?

 

It definitly isnt the most reliable, but I have seen it done. It really depends on what you want to risk. Not trying to put the idea down or anything. I have just heard that it can over work the SC and cause early wear...I say...

GO FOR IT!!!

 

Not very reliable and you run risk of overheating if you do AX or Track Days. Understand reliablity depens a great deal on other mods. Also other mods can gain you more power or get it to show up quicker, done any other changes (injectors, ECU,IC (probably should with 21% reduction), exhaust, VGS, TB, head, adjusted BPV)?

 

i just wonder if 2% is that much of a deal. i look at it as increasing my overall average driving speed by 2% as this will essentially cause the SC to spin 2% faster.

19% pulley = averaging hwy speed 70mph
21% pulley = averaging hwy speed 71.5 mph

doesnt hardly seem that it would cause a dramatic wear on the SC. maybe im seeing it all wrong.

 

If you only drove in 6th, your analysis would only be slightly incorrect. You overlook the effect of gearing on engine revolutions.
I'm no expert on it, but I think the main issue is that you're getting close to (past) the specs of the SC, depending on how often/long you hit redline.
The issue is not the last 2%, it's the first 19%.
According to this post, your (safe) redline would be reduced to something below 7K RPM. This one is even more precise. Max 6393 rpm to keep the SC below redline.

 

go to the Eaton web site, and look at the temp delta vs SC RPM. As it spins faster and faster, you loose efficiency. IF you don't live at red-line, who cares? But if you do, you're really starting to heat up the air charge, and issues with timing retard will rear their ugly head more and more....

But you will get more boost at a lower RPM....

Matt

 

i think alil Co2 on the IC will help that....We shall see being im doin the 2% crank

 

some that have used it found it made it's way into the intake...

That didn't help power at all...

Matt

 

def understand that....ive used nos so far which is expensive an a waste to just spray the IC so im switching to Co2