powerdyne guys help

[99BlackW68]

how long does your guy's impellar shaft bearings last before you have to replace them usually? im about to go on my third set of impellar shaft bearings...first set i had to replace after having the blower on my car for about 800 miles, but that was with the standard bearings and it was bought used then. i then replaced them with the ceramic bearings from 928 motorsports and thought my troubles would be over for a while...but no, they are going out again with less that 600 miles on them. they both make noise when i spin them, and one looks like it has leaked its grease out inside the housing. so how many miles do you guys usually get between replacing bearings? i know it depends on how much you beat on your car...drag strip time...ect. just asking for your own personal experiences.

[johns00c]

Re: powerdyne guys help

Did you do the bearings yourself or did you send it off. I think Tpunk tried to do the bearings and had the same problem.

[redfbird99]

Re: powerdyne guys help

havent had a problem at all and I think ive got about 1000 miles on my powerdyne, I bought it supposedly rebuilt off ebay.

[ssms5411]

Re: powerdyne guys help

The more PSI you try to run on the PD, the more troubles you will have, if you keep it at around 6-7 psi it will last longer and the less problems you will have. 928 runs high PSI #'s on their powerdynes in events then rebuilds them after for the next event. So unless you want to rebuild it now and then, I would just stick to 6-7 psi. That is the trouble I experienced with mine trying to run high PSI #'s. Got me about $2500 total in 928 racing rebuild , venting/ shimming and swaping out internal belts and bearings now and then. I think I had with the $3400 Rksport price tag and the extra pulleys and upgrades around $6000. I wish I would of went with nitrous alot sooner or a good FFF kit or even the Mach kit would of been sweet. Either the FFF kit or MACH kit will be the next mod to help the nitrous.LOL

[99BlackW68]

Re: powerdyne guys help

yeah i pressed them on myself. it was fairly simple...pulled them off, then pressed them on with a hydraulic press and a piece of piping that fit the bearing well.

do you think theres a certain way you have to press them on so they seat well? or something like that?

[ssms5411]

Re: powerdyne guys help

I used to use a socket and tap them in, with a rubber mallet. As long as there seated all the way down, they should be correctly seated. Which it sounds like your doing.

[99BlackW68]

Re: powerdyne guys help

yeah, they were definately seated all the way down. how much psi are you running? how long have your bearings lasted between replacements?

[ssms5411]

Re: powerdyne guys help

I sold mine a couple of years back, but after I started running a 2.6" grooved pulley, I was running peak 11PSI and would bleed off down to around 9 psi. This was with the VS cam. I had it for about 4 years total. I lost off the boost gauge 2 psi after the engine rebuild with the VS cam. I think I had to rebuild it the first time about maybe 2 years after I had it but I always ran the 3.12 grooved pulley which gave me a solid 6 psi with the stock cam. Then went to a 2.8" or a 2.9" grooved pulley after the engine rebuild which was giving me the same around 6-7 psi. I then went with the 2.6" that gave me the 9-11 psi, sometimes 8 if it was getting hot. I even tried a 2.25" that spun up quick but bleed off just as quick. So back to the rebuilds, I did my first one after switching to the 2.8 or 2.9 pulley, then another one when I switched to the 2.6". Had 928 do the racing rebuild, venting and shimming. Got that one back from them and they didn't put the retaining cover back on the output shaft so it was slipping internal belts and I also needed a new shaft since it was dinged up a little. So I ordered and installed the new output shaft which came with the new belt retainer clip and ran it for a couple of months with the 2.6" pulley without any internal belts popping off and had to sell it at the time due to the wife with no job. The ceramic bearings appeared to hold up pretty good considering the AZ heat, my IAT temps would be around 230 degrees so it took a beating. So in total I rebuilt it probably 3 times and 928 once. But I replaced the internal belt about 5-8 times with a kevlar one, eveytime. The most I got out of it with around 8 psi was 288 hp and 330 tq, this was with the VS cam. This was on stock springs(I have Comp 105's now), I was getting alot of valve float when I dynoed. I did have hptuners and 36lb injectors, way better than the FMU. I never got a chance to dyno after the racing rebuild ran into all those problems, then had to sell it due to finacial reasons at that time.

[Mighty Thor]

Re: powerdyne guys help

I never had any problems with mine. I've had my SC since '98 and then upgraded to ceramics in 2002 and still doing fine. "Knock on Wood."


Buy the bearings and Try replacing it yourself. If not you can take it to a machine shop and have them do it. I know those particular bearings can be difficult to pull out.

[99BlackW68]

Re: powerdyne guys help

well thats good to hear. yeah ill get these taken off and pressed on and hope they dont crap out soon like the last ones haha

how much boost are you running?

[grayman]

Re: powerdyne guys help

30,000 miles on my original bearings at 6psi and still going strong.

what i dont quite understand is WHY the bearings seem to start to pretty much fail immediatly (cuz 1000 or even 5000 miles is immediate to me) upon going to smaller pulley and raising the psi. Other blowers use bearings and run higher than 6 psi. is the powerdyn just a substandard quality blower in that respect? the fact that the bd11a uses an internal belt rather direct gearing seems to me that the internal bearing stress would be LESS than a similar geared blower... unless the quality and design of the bd11a is the root of the problem. the bd11a is still used in many popular aftermarket kits such as the mustang. im going to make a point to research some of those performance forums and see whats up with the bd11a in other circles.

I cant seem to think of any members here who have ran a 9psi or higher powerdyne on a daily driver for very long. seems like the kits get sold off, cars get wrecked or the bearings melt down over and over.

So, question to the FI forum: how many powerdyne peeps have been running a 9psi (or higher) powerdyne for 20,000 miles or more on one set of bearings?

[99BlackW68]

Re: powerdyne guys help

agreed, id like to have that question answered

[grayman]

Re: powerdyne guys help

I am kinda asnwering my own question, but just putting it in this thread so i dont forget myself. :-)

Problem with the BD11a is that it has no internal oil to continualy lube/cool the bearings. The smaller the pulley the faster the impeller, cogs, belt and bearings spin. That amount of heat and stress is too much for the bearings/shaft. Even if the bearings are upgraded they still dont have a feed and return line of oil. It is not so much the back pressure from increasing the PSI output of the pulley over 6 psi as it is the stress on the bearings from the greatly increased rpm's of the internal gears/cogs in the blower.
Consensus from other sources seems to be that even at 6psi you can get accelerated wear from continuos high rpms... aka... several back to back track runs would be better served by turning off the engine or even just idling for 10 minutes or so between runs in order to allow some cooling of the bd11a. Daily driving the bd11a with 6 psi and zipping around or freeway on-ramping is no problem at all and people can expect 30k miles or more before internal belt or bearing replace is needed. Bump to 9 psi and drive hard and dependability basicaly goes out the window.

[99BlackW68]

Re: powerdyne guys help

yeah i knew it was based on rpms and not psi...but thats the gauge im using for how fast their S/C is spinning based on their psi. but yeah, that makes perfect sense...if at the track, let the S/C cool down in between runs.

[Chris Stone]

Re: powerdyne guys help

Could you tap an oil feed and return and maybe attach a small scavange pump to it?