Well, I've been noticing that my SN89 is making an intermittent rattle at idle (can't tell if happens all the time due to the exhaust of the car). It is just a random rattling sound. It is not constant in its rhythm. I do not have a fluid cooler on the supercharger yet, but I plan on installing it tonight. It seems to be working properly otherwise. What could this noise be?
FD: T66 - 425 whp - Click Here for Pics - Sold! 9/05
FC: Supercharged Drop Top - 230 whp - For Sale!
Z06: TRAP, Hurst - Picking up 10/05!
Nope! Stop running the unit. Your balls in the ball drive are out of round. If you continue to run the unit, it will dammage the impeller shaft and possibly the races. Get some new balls. They cost $50 bucks for five from paradise or you can try and find the correct ballbearings from a local bearing shop. I did! The balls you need are a grade 25 and are 1 1/16 diameter.
Good luck, let me know if ya need any help
Crap. I was afraid this would be the response. So, how much of a PITA is it to do this rebuild? I'm leaning towards just running it until it breaks then just buying an SN2000 from Paradise.Originally Posted by Dirk Diggler
FD: T66 - 425 whp - Click Here for Pics - Sold! 9/05
FC: Supercharged Drop Top - 230 whp - For Sale!
Z06: TRAP, Hurst - Picking up 10/05!
Don't waste your money! Sn2000's are prone to the same type of problems. Just rebuild it your self. Super easy, and plenty here who will help you through the process. Replacing the balls will cost a max of $50 bucks and a little time. A new SN2000 will run you $1200! You can rebuild your entire unit and add my VR4 for way under that price tag:D
Well, I just called a local bearing shop and ordered 10 bearings for $2.42 each. I figured I'd get 2 sets in case I need them later. They had to order them from their Orlando branch, so I'll have them tomorrow. He did say they would be a "better" grade (around 100). I asked if that would be a problem, and he didn't seem to think so. Will that be a problem?
FD: T66 - 425 whp - Click Here for Pics - Sold! 9/05
FC: Supercharged Drop Top - 230 whp - For Sale!
Z06: TRAP, Hurst - Picking up 10/05!
Am I going to need any uncommon tools to do this job? I really don't want the car to be down for more than a day. I'm planning on taking off the blower tonight and getting it opened up and ready so that when I get the balls tomorrow, I can just put them in and be back running.
What are the torque specs for each of the different bolts? When I talked to Paradise Craig about buying an SN2000 and the desire to rev to 50k, he said he could do something to tighten everything up and allow a greater RPM; however, he said that there would be no warranty on the supercharger then. Can I do something similar with my current supercharger? I'm not looking to go crazy or anything, but if I could eek a bit more power out of the SN89 as it is, I'll probably be satisified for awhile.
Also, what do you think caused my balls to get "out of round"?
FD: T66 - 425 whp - Click Here for Pics - Sold! 9/05
FC: Supercharged Drop Top - 230 whp - For Sale!
Z06: TRAP, Hurst - Picking up 10/05!
Really, really easy. No special tools req'd, save an inch-pound torque wrench.
Balls go out of round because there's 100,000 lbs per sq. in. pressure on them in this thing.
Check the multiple supercharger rebuild threads in this forum for the #s you need.
F=MA
Hmm, I don't have an in/lb wrench and they're quite expensive it seems. I guess I'll ask around. I know some tool stores will rent their tools.
"Out of round" meaning that they aren't perfectly round anymore then?
I read every thread under "rebuild" and "torque" searches (separately). These are the figures I came up with:
Allens on case - 120 In/lbs
Impeller/Ball Drive Bolt - One thread said 150 in/lbs another said 15-20 ft/lbs (180-240 in/lbs)
Force to turn unit over - One thread said 47-52 in/lbs another said 35 min/45 after a tight rebuild
Are those all the figures I need to know? By taking this thing apart, I'm not going to need any seals or anything to reseal it, am I?
FD: T66 - 425 whp - Click Here for Pics - Sold! 9/05
FC: Supercharged Drop Top - 230 whp - For Sale!
Z06: TRAP, Hurst - Picking up 10/05!
The balls are the most common thing to go bad on the ball drive units. The races could be pitted and/or hte impeller shaft could be out of round, but the balls are much softer than the impeller shaft..I think...SPeedytang? 9% of the time, its the balls. Using harder balls could be a good idea or a bad idea. I've considered using harder ones. The only thing is that if the balls are harder than the impeller shaft and the balls do go bad, they will tear up your impeller shaft, which cost about 150$.
Measure the torque on the ball drive with the unit assembled from the pulley. Should measure between 22-44 inch/lbs standard ball drive is 22 inch/lbs, VR4 is 44 inch/lbs. However, many here run our units @ 52inch/lbs and have had good luck wiht them.
Your noise could also be the oil pickup inside the unit hitting the case. I have seen this before also.
Nice. I'm going to install the oil cooler now. I've decided not to screw with it right now. If it breaks, it breaks. I'll deal with it then.
FD: T66 - 425 whp - Click Here for Pics - Sold! 9/05
FC: Supercharged Drop Top - 230 whp - For Sale!
Z06: TRAP, Hurst - Picking up 10/05!
FWIW, my SN89 has had a slight rattle at idle since I got the car 3 years ago. I was told at the time by another SN owner who heard my car, "that's normal for the ball drives". Not sure if that was good advice or not.
I've had it apart once to reseal it and noticed no unusal wear. I keep up with my fluid changes and it's still going strong. I have an oil cooler also.
You can buy a beam type inch pound wrench for $15 or so and that will get the job done, if you're observant and careful.
FWIW, I raced my car at the track with a ball drive that had a pit in one race about a 1/4 inch long and several thousandths deep. It made a horrible racket but ran fine. I replaced the races with used ones from Paradise and left everything else, including the balls, in the unit. A-ok, no problemo, silent as it should be and full boost, too.
F=MA
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