Mine was really a freaky stupid issue. I had a local shop install the billet wheel. Matter of fact they did it while I waited and was able to watch the whole process. They de-burred the landing surface on the crankshaft to make sure there were no high spots. Heated the new billet wheel and installed with the correct tool. chucked it up in the lathe and the fucking thing had 0.040" of run out. The dude acted like he didn't know why it was fucked so I pointed out that heating the wheel with an acetylene/oxygen rig might not have been the best choice especially since he barley moved the flame around and just heated the fuck out of one local area. When I saw him doing this I kept my mouth shut. I'm not the kind of guy to show up with parts and instruct the shop on how to install them. That is their business and should know best. Well, it was so fucked, he pulled that wheel off and started off with another new one. He was a little better with the cutting torch to warm it up this time. Chucked it up and it still had about 0.025" runout. He assured me that 0.025" run out was well within spec and that they have never had any issues with other wheels with this much runout. This lead me on a 6 month quest to figure out why my new Holley EFI system would freak out and completely shut off around 6000 rpm when the blower was hooked up. There is a ton of info I wrote about on this site looking for help and no matter what was recommended (I tried everything) and could never get it to act better or even different. I was able to even get Holley involved in the matter and they couldn't see anything wrong with my tune up. It's impossible for me to constantly drive this thing around the block to test and get data logs as this is a race car with a solid roller cam, an F2 Procharger and open headers. so I decided to pull the motor and put the thing on an engine dyno. I didn't run the motor with the blower on the engine dyno and boom first pull.....clean to 7500 rpm with no issues. So, I took the motor home, slammed it back in and ran it around the block with the blower belt off and it ran perfect. There the belt on and bam, dead at 6000 rpm.
Completely fed up with the whole situation, I decided to install an external MSD 4-magnet wheel on the front of the motor with one of Holley's hall effect sensor. Took the truck out with the blower belt on it....and bam clean pulls to 8000 rpm.
My final opinion on the problem is this. .025" run out on the internal wheel might be fine in something that doesn't make a ton of power. However, when I had the blower hooked up, it was making enough power to start flexing the crank (turning it into a wet noodle). This minor flexing with a wheel that was already on the edge of too much run out was just enough to create a situation where the run out was suddenly being "flexed" outside of the workable specs.
