Cog belt system verified and works like a charm!(vids/sample sounds added)

suutari

Registered User
Hi!
It´s a long time I have not been posting.

I have a cog belt setup that´s really nice.

I bought 1 1/2" wide gates polychain carbon belt+pulleys and machined them to fit and it was the best thing ever..

slight nice whine..no biggies on the sound dep. sounds really cool. Little bit like turbo whistling :). Not a big sound at all.

Set up:

Bmw 2.5L engine m20
eaton m90 ported ( now coming with teflon rotors...hmm should have tought that before..maybe have to peel the coating off so it´s not in my cooler)

drive ratio 2.82

you might call this the old 25% overdrive

max boost in 2.5L engine aprox. 20psi ( turbo coming also so the blower alone is overdriven too hard)
aprox. 315hp at wheels.

This kicks ~~~!!

sized the blower because engine got too hot and did not see it. under hood temps+blower temps shot high--> one sized blower..and the cog belt system..

NOT A SCRATCH!!!!! stopped the engine when sized the blower!!!

So you could get off with a narrover belt too!!!

No more belt slip for me!

Tomorrow rebuild blower going back and taking it easy(I hope) untill the turbo will be under hood also to put the blower at rest on higher rpms..

Just let you guys know that THERE IS A NICE COG BELTS AVAILABLE!!!

just a little machining to do to the pulleys..I used only the outer belt profiles attached to aluminium centers on my car.

cheers, Sami
Finland

PS: I think this is THE last belt I will ever have to buy :D, I battled with the 8 rib for two years since no room for bigger..and Now I´m happy. Just my two cents!
 

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The gates polychain is used alot in the machine tool industry to turn lathe spindles; no doubt about their ability to transfer power. Seems like they are speed limited though. How long has the belt been on there?

Mike
 
I use the Gates Polychain GT2 as a timing belt for my cam drive and it works well. I only spin it to 10k, though, but the spring pressures should make up for the difference in RPM the M90s use.
 
Got any better pix of the engine? I want to see the idler/nose mount you have. Did you have it made specially or did you use somethin' from another kit.

SWS
 
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