Clutch Porn

The part I like about astick car is when the local hot shot deliberately pulls into the lane beside you because you are running a stick car . You dial a 12.00 and run a 12.01 and put him on the trailer . The next weekend he makes sure he don't pick you in the first round . From my experience if a set up is consistent it will work with a stick or a slush box . About being old I am from a time when every body run stick cars , I still think they make a guy pay attention to what he is doing.

UPDATE: I've received my rebuilt PP back from Ram--total turnaround time was 2 weeks. Cost to rebuild and modify it for counterweights was half of a new PP.





Note the arm above with the hole in it--this gives a place to hang the counterweights, which are actually bolts, nuts, and (if desired) washers. The head of the bolt faces the direction of rotation:



The arms themselves should also act as a CW, whose purpose is to assist the lock up the PP in higher RPM's. The CW's can be made out of steel or aluminum and you can use different lengths. You can also mix the 2 materials. A gram scale is required to determine the differences in the parts. Equal weight must be applied to all 3 PP arms.

Note that RAM re-certified the PP as meeting SFI 1.2. They etched over the old markings and applied a new sticker.

The flywheel was re-ground on a blanchard grinder:



Although the disc looked OK and just glazed, I decided to buy a new one to match the resurfaced parts:



Assembly bolted to back of motor. All 3 arms shown will have a 3/4" bolt and nut installed:



To make it easier to swap CW's. I decided to punch a window in the bottom of my Lakewood scattershield.



This is not NHRA approved as you cannot modify the scattershield in any way. My home track does not check such things at my level of competition. My scattershield is over 10 years old (which makes it out of date by over 8 years) and has already been modified for the base pressure adjustment. I also added a small hole on the bottom to check air gap. It can be seen just in front of the new rectangular access hole shown above. The other rectangular hole is for the clutch fork.





Here is a pic of the throwout bearing that I used. It is a HD stock replacement part. Note the grease zerk on the right.

A few other things that I've learned from some experienced and national record holding class racers since my "prior" experience.

There is a procedure for bedding the clutch (although ram calls for no breakin.) One should start making runs using maximum base pressure (and some counterweight) to prevent slipping in any gear. Race the car as normal for 2-3 runs THEN back off one full turn (decrease base pressure) and then run it again. Repeat until ET's start to increase, which is a sign of excessive slippage. This was one of my downfalls the first time out.

Controlled clutch slippage off the line will limit bogging and lower ET's. Counterweights help lockup the clutch at higher RPM's. Launch RPM's will be less than shifting RPM's.

Although one can work with trial and error, the best route is to use some type of data collection that records the motor and driveshaft RPM's to determine slippage. I will probably be adding this dual playback tach prior to getting aggressive with my clutch adjustments. It comes complete with a driveshaft sensor:

http://static.summitracing.com/globa...e/atm-6881.jpg

Can't wait to hear how it turns out this time...Hopefully those counter wieghts will do the trick..