oils aint oils

[powered by wattard]

Any other teams experiencing clutch slipage on the dyne using Penrite 10 tenths COMP ENG OIL. It is recomended for racing in cars and high performance bikes but i suspect it has got some friction modifiers present in the oil. With Shell motorbike oil, it is not as evident but still there no matter what the condition of the clutch as we have changed the plates.

Is the purpose of oil in a wet clutch to keep the plates cool or to help increase the stiction of the plates.

Were running a dry sump and clucth slippage is much worse when oil is fed up through the centre of the shaft through the pin. When oil is disconnected, there is no slipage but I suspect the plates get hot.

Any ideas. Any teams run stiffer springs, if so how much stiffer.

Thanks

Will
MUR Motorsports

[Angry Joe]

For our Yamaha R6, we could use any oil that did not have an "energy conserving" rating on the API seal. I don't know if you have the same sort of standards in Australia but it usually meant heavier weight motor oils. We used Mobile One 15W-50.

[Ben Beacock]

We're using Mobil1 15W-50 and haven't had any problems with our GSXR clutch. That's with many high rpm launches and the AWD adding extra abuse.

[Chris Boyden]

How could you tell that the clutch was slipping?

Do you measure the % difference between the output speed should be based on gearing and rpm and the measured output speed?

[Colin]

we get a bit of slip towards the end of the clutch's life and we usually go through 2 clutches in a year doesn't seem to matter what oil we use though we used the recommended oil one year and penrite oil the next with no obvious change. one little trick we used on the CBR was to put some washers under the spring bolts to increase the force, helped out a little bit.

[The guru of guru's]

One way to tell if your clutch is slipping... Put you car in gear and see if you can push it easily, then you will know if you have clutch slipping problems.

[JonBoy]

what about clutch lockouts? I know they're useful on buggies, has anyone used one on these engines?

[Chris Clarke]

The purpose of oil in a wet clutch is for cooling only. Not to increase the friction of the plates. You have to ensure that you use a motorcycle oil with no friction modifiers in it. Check out some motorcycle pages, this is a very common problem with people who put car fluids in their bikes.

[Chris Davin]

We, too, have traditionally used Mobil 1 15W-50, and it works well. Mobil 1 MX4T is a 10W-40 motorcycle oil that is supposedly designed for motorcycle engines with wet clutches. The MX4T oil is at least 50% more expensive than the 15W-50, and I couldn't notice a difference. We used MX4T in our competition motor, not to take any chances, but throughout most of the year we used 15W-50 just to save money.

We run stiffer springs because of the extra torque the turbo delivers. I'm not sure how much stiffer they are but it's something like 30%.