Rennbay: Racing Timing Belts now available & 1 Day Sale
09-30-2009, 01:40 AM
#77
Three Wheelin'
Hi y'all,
No-one has mentioned the likely reason that the "ricers" are stripping timing belts: lightweight flywheels.
The torque impulses of a 4-cyl motor are severe and the more flywheel inertia to damp out the torque impulses the better. The torque impulses create torsional vibration at the crankshaft which is transmitted to the timing gear and any other drives attached to the crank.
The worst-case situation is with the car in neutral, since the drivetrain can only help damp out the impulses when it's coupled to the engine... So if you're running a lightened flywheel and plan to sit in the carpark (or in traffic) a lot, get the uprated belt.
I crewed for a racecar that had this exact problem, repeatedly, with the timing CHAIN. A heavier flywheel completely eliminated the problem, even when we raised the rev limit by 15%. Heard of (but not seen) other examples as well.
My $0.02!
Mike
No-one has mentioned the likely reason that the "ricers" are stripping timing belts: lightweight flywheels.
The torque impulses of a 4-cyl motor are severe and the more flywheel inertia to damp out the torque impulses the better. The torque impulses create torsional vibration at the crankshaft which is transmitted to the timing gear and any other drives attached to the crank.
The worst-case situation is with the car in neutral, since the drivetrain can only help damp out the impulses when it's coupled to the engine... So if you're running a lightened flywheel and plan to sit in the carpark (or in traffic) a lot, get the uprated belt.
I crewed for a racecar that had this exact problem, repeatedly, with the timing CHAIN. A heavier flywheel completely eliminated the problem, even when we raised the rev limit by 15%. Heard of (but not seen) other examples as well.
My $0.02!
Mike
11-07-2009, 02:11 PM
#78
Advanced
Join Date: Feb 2008
Location: San Jose, CA
Posts: 96
Likes: 0
Received 0 Likes
on
0 Posts
Just getting in on this convo..as I'm due for a t-belt.
Can you give a quick rundown as to what testing was done for the 944 app? Is the tensioning process/numbers the same? Was tension played with via the testing?
'86 951 here. Chipped and shimmed.
Can you give a quick rundown as to what testing was done for the 944 app? Is the tensioning process/numbers the same? Was tension played with via the testing?
'86 951 here. Chipped and shimmed.
11-07-2009, 03:03 PM
#79
Team Owner
Join Date: Oct 2009
Location: one thousand, five hundred miles north of Ft. Lauderdale for the summer.
Posts: 28,705
Received 212 Likes
on
153 Posts
"They will only be available for the 8 valve engines. Sorry S/S2/968 guys... "
since I am going to do a supercharger on my 968, i was hoping this could be the last belt i ever do and drive the car until something breaks finally, like maybe somewhere north of 200 k and follow up the little-engine-that-could with an LSx motor... and really screw things up royal.
since I am going to do a supercharger on my 968, i was hoping this could be the last belt i ever do and drive the car until something breaks finally, like maybe somewhere north of 200 k and follow up the little-engine-that-could with an LSx motor... and really screw things up royal.
11-07-2009, 06:01 PM
#80
Instructor
Join Date: Mar 2004
Location: Ashland, Ohio
Posts: 245
Likes: 0
Received 0 Likes
on
0 Posts
I ran one for the 24 hours of lemons without a single problem. Checked the tension after the 24 hours/1200ish miles with the 9201 tool and it was still perfectly within spec readings. I know gates makes good belts so I'm not surprised by my results at all. A great belt if you ask me but that's just my 2 cents.
11-08-2009, 01:13 AM
#82
Site Sponsor
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Thread Starter
Join Date: Aug 2002
Location: A great big building in the woods, FL.
Posts: 6,527
Likes: 0
Received 4 Likes
on
3 Posts
Also, they do not list us because we do not stock or sell any of their standard racing belts so... there is no point.
We do wholesale the belts from our stock to other companies so if you are interested in bulk quantities please let me know.
