pianoprodigy

iTrader: (1)

I recently acquired a 3-series BMW with a F1R-procharged 410 ci SBC transplanted inside. The car does not feel all that fast, and though I have no boost gauge hooked up, I have a feeling belt slip is the culprit. I took a video of the movement of the belt. Can I get a confirmation that the belt is WAY too loose? The crank pulley is 7" and the blower pulley is 4.25", so it should be turning 50,000 RPM at 5500 engine RPM at full tilt making some pretty good power.

Also, does someone sell an upgraded 12-rib tensioner that I could add to that bracket since the one on there looks kinda shot as is?

Link to video:
View My Video

Photo of engine bay:

9sectruck

iTrader: (9)

yes your belt is to loose, it should not be flopping around like that at idle,
you need to be careful though, the manual tensioner can put a **** ton of stress on the snout of that crank causing bearing issues or snapping the end of the crank off, if you crank down to hard on it.
you need to convert it to cog as the belts are the same width as the 12 rib it will fit everything you have already.
I have a 41 tooth blower pulley and a cog idler if you are wanting to switch.
pm if interested

Bob@BruteSpeed

iTrader: (16)

I agree, the belt is way too loose.

Alan, that belt has slipped enough that I would start with a new belt. After the new belt has been installed, tighten it down tighter than you normally tighten a belt. Then take it easy on the new belt for about an hour to let it break in and stretch, then tighten it back down. I'd also wipe the blower off and keep an eye on it for signs of black dust appearing, which will tell you if the belt is slipping. A boost gauge would also help you to keep an eye on it.
Keeping an F-1R from slipping with a serpentine belt is going to be hard to do though, if you keep having belt slippage problems then I would convert it over to a cog belt as 9sectruck has suggested. Bob

pianoprodigy

iTrader: (1)

The pulleys do not really seem to be adjustable, which is odd to me. I think I also need to get a larger pulley closest to the crank on the top side of the belt at a minimum. Bob, do you sell those idler pulleys? Do you sell the belt? Is it possible to add a tensioner of some sort to my bracket?

Also, the blower seems to make a good bit of noise when running. I'm sure some is normal and some might be from a loose bolt on the bracket that seems to serve no purpose other than rattle. However, when the car is off and I tap the belt next to the blower pulley, it makes a noise that seems to emanate from the inlet of the blower and out through the elbow and the filter.

Should I be concerned? Video below:

View My Video

Of course, the secondary question is that depending on how much work and cost that all is, what would be the cost to just convert to a cog setup?

93formto98T/A

iTrader: (28)

The whistle sounds is normal. The grinding bearing sound isn't. I've run an F1R and F2 in the past and would highly recommend a 30mm cog drive. Your idler pulley should have a slot that allows you to loosen it and adjust the belt tension.

9sectruck

iTrader: (9)

F seires blowers are load a clunky,

The Alchemist

iTrader: (19)

That tapping sound almost sounds like the lash between the gears. It's funny the way sounds can be amplified sometimes.
I have a D1 and it is pretty loud as well, but you get used to it. It's great for scaring away deer.

Here's what my car sounds like.

http://www.youtube.com/watch?v=zb2H-QL6NeQ