General Polar Clutch Tuning Tips

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General Polar Clutch Tuning Tips

Postby Honey » Sat Jan 10, 2009 9:58 pm

General Polar Tuning Tips

Heavier Weights= Less top end RPM's.
Smaller Weights= More top end RPM's.

Heavier Weights = Loads Motor more on the launch and makes it shift sooner. A bigger motor (stroker) requires more weight to load the motor for better 60' times.

Smaller Weights = More (Quicker- RPM) off line (lighter car-driver combo) allows motor to RPM more before shifting, therefore letting it shift farther down track.

TIP: More weight on roller arms and/or steeper ramp angles loads up engine more (I.E. slows down rpms) less weight or shallower angles speeds up the engine.

The purple spring in the drive unit (front half) with an 18° ramp angle will raise stall speed to about 5200 RPMS - the stiffer black & yellow spring will take you to about 6000 RPM stall.

The drive unit uses the amount of weight on the roller arms to raise or lower the shifting point of the motor (more weight shifts faster centrifugal force). Most cars with (good) motors - bigger stroke good porting etc. will use the 18/28/22 ramps with a purple spring and number 5 or number 6 weights.

Driven Unit (Rear) - The spring in the rear can be used to control how quickly the clutch shifts. (Small effect) If your engine is basically stock I recommend placing the spring in the fourth hole in the cam modified engines use the fifth hole. The driven unit uses a cam angle also to control the shift. (Big Effect) (Stock is 34°) Light car (combo) - 38° to 42° cam (quicker et)

Light car (combo) - high revving motor (46° cam) I recommend 42° for light combos

I tune by launching car and making a 250' - 300' pass then slow down and drive to end slowly or shut off. (Read max recall on tach) Should be 7500 - 8000 RPM (or in your cams may power zone) because that's where you want it to shift at, so the torque stays up. (It will have already shifted by 300') if tach reads much less it means it shifted too soon and is lugging your motor - wind rear spring tighter - or change rear helix to attain your proper shift RPM. (Remember steeper helix angle for light cars that need less torque to move, less angle for heavy cars for more torque to get going.

Steep - shifts quickly,

Shallow angles - shift slower

Take front drive unit apart by using two bolts in the threaded holes in cover - turn each a little at a time.

The clutch bushing (square gray plastic) MUST be clearanced for proper engagement & release & consistency - use a feeler gauge to check clearance between the bushing and the square hub - 0.007 to 0.10 clearances.

** Scrape with a sharp knife till all sides are OK everything should slide freely on its own weight.

1. Use a 12" piece of 5/16" square stock to set the offset (front to rear) see diagram) (rear sites outside front by 5/16')

2. 2. Set centerline to centerline of crank to jackshaft 1/16" less than belt 8 15/16" or 9 5/16"
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