Superchargers in general are a reliable source for boost, however, I'm not really a big fan of JR. In retrospect I should have went with a turbo instead of the JRSC kit, but I got the blower kit for a really good price at the time, so I went ahead with it.
The eaton blower itself is only good up to 10psi, after that, the high IATs will not make you any more power. Like somebody mentioned above, the JR kit does not allow you to run an intercooler, which is a really big factor, furthermore, the blower placement doesnt give you any room to run nitrous. Running the nitrous before the blower would damage the coating on the rotors, and there are clearance issues with running the shot between the blower and baseplate. There are also clearance issues with running a wet shot... so in short, it has not been done with the JRSC kit yet. There are similar problems with running water injection, it HAS been done before, but we're still unclear as to how it will interact with the coating on the rotors (really hot rotors + cold mist of water could cause something to break).
My main gripe is with JR's customer service. Back in the day when they were still in the minor leagues they had an awesome reputation. They would send out parts that wore out for free etc. I recently had a pulley melt on me due to debris from the ABS lines getting into the bearings (yes, the belts WILL cut into your ABS lines if you dont protect them... clearance problems again). At the end of the day I had 2 melted pullies and I was stuck at work. The techs at JR (specifically keith) were talking to me like I was an idiot, and refused to send me new pullies at their cost or even giving me the specs for them so i can get them for MUCH cheaper at NAPA. Keep in mind that they USED to have great customer support, and something like a pulley wouldnt really "set them back" or anything like that. Anyways... enough of the rant...
In short... JR kits:
You're stuck with JR, you cant get parts for the blower anywhere else
You cannot swap out the blower for a different size, all repairs/replacements must be through Eaton/JR
The EMS is a piece of CRAP, basically a bandaid system (some call it a piggyback)
No intercooler
No boosting over 10Psi (keeping in mind you'll have to change the fuel system and EMS.. a good $1200)
Cannot support nitrous
Will not make over 270whp EVER
A properly sized turbo will not have any noticible boost lag, however the torque does not come on instantly. A JRSC lude will have about 180lbft tq at 3k RPM and remain constant, a turbo lude will be stock at 3k rpm, but might have a higher peak tq. Take a look at the dyno's i got my hands on, both at 6 psi:
Turbo setup:............................................ ...............SC setup:
(dyno's taken from a dyno library at
www.preludeonline.com, PM me if you want them taken down)
take note that at 6psi, the parasitic drag from the SC is neglegible in the dynos. Granted with much larger blowers (the M62 is a REALLY small blower) the parasitic loss would be a big factor. What I wanted everyone to see is that at 3k RPM the turbo at 6psi (not spooled) was making 70ft-lb, while the JRSC was making ~150ft-lb
Keep in mind, with a turbo you can always resize and get a larger one, with the JRSC, you're stuck with the M62. There is also a problem with vibration in the JRSC kit (specifically for the prelude), however JR is not willing to admit there is this problem... i experience a lot of audible vibration between 3.5k-5k, on the otherhand, turbo's have boost creep....
Hope this was helpful to some of you....