The adventures of JK superchargers... Here's a narrative on where I'm at and what I think about the Sprintex system.
First I went through installation. I'll actually give Sprintex a 9/10 on overall fit-and-finish of the product. Exceptional instructions, includes literally everything you need, every hose is perfectly bent to fit, every bracket is thought about. There's almost nothing I would improve. My main gripe with the overall mechanical design is that there's only about 5mm of clearance between the top of the supercharger and the firewall. I'm afraid it's going to hit at the dunes and crack, but we'll see.
I had to get creative on installation. Due to my under-hood modifications, I had to do some custom brackets for the intercooler, the water pump didn't fit where they wanted requiring some more bracket work and a lot of custom heater-hose work, and the intake was the biggest project requiring a structural intake tube to act as a strut brace. Took a few days but eventually I got everything built up.
Now things got a bit interesting... I start it up the first time and it generates just an unbelievable amount of smoke. I figured it must just be manufacturing oil work out or something. So much smoke that driving down the road at 25MPH I'm producing huge visible clouds of smoke behind. Clearly something is not good, but 10 minutes later the smoke is all gone.
Next day I check the intercooler fluid and it's basically run dry (the intercooler design is poor, it's very challenging to bleed because there's no reservoir just a little cap with maybe a 3/8" diameter hole into the system). I figure it's just been working out air, so I bleed it again and fill it up and run the pump for a bit to be sure. Start it up and the starter turns a few times then bang and it's seized. Try to turn it over with no spark and the starter just locks up. I just call it quits for the night but right before bed I gave it one last try cranking and it started up somehow, and worked perfectly but again huge clouds of smoke.
Once again, back in the shop the intercooler pump is running dry. At this point it hits me what's going on so I do a vacuum test on the intercooler loop and it doesn't hold any vacuum just hisses from inside when I try to pull. I took off the supercharger and the whole intake is full of coolant and I had hydrolocked the engine.
By some small miracle the engine seems fine. One of the output-flange o-rings was not properly seated from the factory so I just popped the part out and put it back in with some oil and the o-ring slid into place and no leaks anymore. Pretty pathetic QC on Sprintex part and almost cost me my engine.
With no intercooler leaks, I got to really discover just how bad the Sprintex tune really is. It blows my mind that over the last 5 years they still haven't made the tune good. It really is as bad as people say. It has almost continuous LT knock retard, poor power, and my fuel economy cruising at 60 dropped to under 11. I imagine you would wreck your engine if you actually tried to use their tune for very long.
Since it came with a Diablo tuner and the company doesn't trust customers with the tuning software, I begrudgingly picked a very well known forum tuner, sent $300 on Paypal, and watched what would happen. He immediately made the knock go away, but fuel economy still sucked and drive-ability had issues. By tune #6 fuel economy was back up to 14.5 highway. We went back and forth on throttle-response settings and I just couldn't get him to give me what I want, so now I have an HPTuners coming in the mail tomorrow and I'll take it over from there to really make it drive how I want. The trans also needs shift point updates.
I found a major boost delay (about 1-2 seconds) that wasn't tuning out, eventually I found that Sprintex put a restrictor in the vacuum line to the bypass valve so it took forever for the valve to close under high throttle. I have no idea why they did this, perhaps customers are so used to turbo setups that they wanted to introduce emulated turbo lag. I took the restrictor out of the vacuum line and now there's basically no boost delay.
Another installation modification I made is I run the intercooler pump directly off an ignition-switched 12V line so it's always on. The instructions have you plug the pump directly into a Y-harness that goes to a fuel injector (not even for a PWM-speed signal... it's just a 2-wire DC pump red wire to injector +, black wire to injector -). This is cringe-worthy to me. It seems like a bad idea in so many ways, both thermally and electrically. I guess they are trying to save energy by not running the intercooler when not in boost, but that seems like a recipe for heat soak. I want it to cool down when I'm not in boost to get ready for the next time I am in boost.
Overall at this point although I have a bit more fine-tuning to do, it's an unbelievably awesome setup. The power is incredible, and the low-end torque completely exceeds my expectations. It looks like it produces flat boost from well below 2000RPM up to redline. About 4PSI in normal throttle ranges and 8PSI at WOT (I need to do some throttle-response tuning to make it smoothly approach WOT, I couldn't get my tuner person to get it right hence the HPTuners purchase).
Overall it's far better than I expected on power boosts and is so much fun to drive around. I'd completely recommend one, so long as you're willing to deal with crap QC and figure out tuning on your own.
I will give Sprintex customer support a 5/10. They actually do respond pretty quick for installation questions. For me, they will just ignore questions about tuning and drive-ability (literally they don't even respond to the emails).
You do hear it, but it's a lot quieter than I expected. It's fun, not annoying, at least to me although I know some people can't stand it.