09-06-2008, 12:04 AM
Hey tom, I got another ? for you!! since the JRSC is a roots blower, it is based off of rpm since it runs off the surpentine belt. since the JRSC makes 9-10 psi @ 6500 rpm w/ BBK, what about at 7600 rpm??? I just realized that I will prolly be at 11-12 psi. so an OD crank pulley would put me around 14 psi which would be too much for the stock bottom end. so my question is sort of a follow my thinking/logic and tell me if its right question. I guess what I am getting at is there is no need for the OD crank pulley right?
09-06-2008, 07:50 AM
First I wouldnt turn the stock Zetec engine past 7000 and your starting to get into the over spinning of that SC
09-06-2008, 11:35 AM
I'll have to put the rev limiter back in, looks like i will be going w/ The OD pulley then. do i need a new serpentine belt?
09-09-2008, 12:57 PM
I wouldn't go with the OD crank pulley on a jrsc that already has a bbk, Tom just said how you are leaning toward over spinning the blower, which has a max of 13000 revolutions before its over spinning and not producing any power. you must also keep in mind that this blower isn't intercooled and you can really do some damage to your engine running it hard. From what i recall i believe it is 10psi at the most you can run before having to drop in an intercooler, the only downfall about the jrsc is that you can't put an intercooler in it because there is no room for one. So what im saying is, DON'T run your jrsc/bbk with an OD crank pulley, you'll mess something up, no doubt!
The jrsc only has a powerband that falls after 10psi for some reason, its dealing with the efficiency of the rotors being able to push air into the head while spinning at high rpms, when the blower is overspun there is no power there anymore just a spinning/whining blower that is about to overheat and cause engine knock. Keep it at 10psi, otherwise if you want more power, buy a turbo, or a centrifugal supercharger
09-09-2008, 06:01 PM
I know how the sc works, but there are guys running 14 psi over on the jet w/ wmi. I want about 12, and w/ my wmi kit, I don't have to worry as much w/ the wmi kit, at least, no more than 10 psi w/o. and of course all proper tuning through tom.
09-09-2008, 06:10 PM
There is a guy on FJ in the regionals (north west) named "Stolle" you should check out his thread he's been doimg regaurding the WMI kit through dataloging pertty interesting stuff.. just a heads up.
09-09-2008, 06:33 PM
ya, i think he's the guy making 220 whp with IAT temps still in the 1xx's !!