Clutch engagement

has anyone done any testing with a hilliard clutch as far a different spring combos and adding weights to shoes.

I’ve done a few different combos, but you really just want the clutch to engage at/just before peak torque.

Most tracks are always locked up anyway, so it doesn’t really matter.


At least in senior class, what I’d call the “standard” setup is 2 black springs and 2 white springs, no weights.

2 black and 2 white is what we used in senior and heavy as well.

Otherwise here is the setup chart.

Keep in mind that this is engagement speed, not lock up speed. Lock up speed, which is what I believe matters more for tuning, is about 200RPM higher.

Thanks for sharing this!

What’s the school of thought on running the shoes “leading” vs “trailing”? Has anyone done any trials with this?

50rpm early on average harder engagement in leading (largest leverage). Both weights are a even stronger engagement though and another 50rpm or so.

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Unless your track has both a really long straight away AND a really sharp hairpin there is no time in clutches. 90% of the sprint track in the country, you never come off the clutch. And the ones you do come off the clutch have such high gear ratios that it doesnt matter.

I run weights, but a baseline white and black leading shoe flame set up is good enough to win anywhere.

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OVRP comes to mind. :sunglasses:

Isnt that straightaway only like 600 feet long? Think more like the Battle at the brickyard. 2.9 gear ratio and a hairpin with a radius of about 20 feet.

It’s a good length straightaway but the switchback is tiny!

Where is this track?

Cuddebackville, NY, about 2 hrs from central Jersey


Like a boss!

This is our track in Jacksonville, Florida

That’s a straightaway!

It’s close to 1000ft!

Wilmington seems hard on clutches, couldnt do more then 6 laps without getting chunking on the Hillard Flame. One of the main reasons I have switched clutch manufactures.

Wilmington was tough! How do you think that endurance race there will go?!?! Better have a stack of clutches.

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I think fine if your on a stinger.