Hilliard Flame Clutch Setup for Standing Start

4 Stroke Kart Engine Forum
1

My club does standing starts for LO206 Sr. Last weekend, I got completely smoked off the line by the entire field even though I qualified P3. I want to make sure my clutch is setup optimally for standing starts to help me maintain pace off the line and not get shuffled to the back before the first corner.

My clutch is currently setup with two black springs and two white springs with the shoes in the “leading” direction. I have heard this configuration recommended by a lot of people with Flames, but I don’t think many people in 206 have to do standing starts where the clutch lockup is more important. Two whites and two blacks without any weights seems to put the engagement speed at ~3400 RPMs.

I have read that adding weights to the shoes can help with standing starts. Is there anyone with experience doing standing starts in a LO206 that could help me optimize my setup?

Before the bathroom scale idea is brought up again, while clever, I can’t do this given my shop / living situation unfortunately.

2

If it’s a standing start and you’re getting beat off the line maybe lower the engagement rpm? I have always ran 2 white 2 black no weights. Only experience standing start 206s would be the 24hrs of Orlando and NOLA but obviously in that case its not really something we looked into

One thing I saw by a teammate which I also tried to some success at Wilmington was flipping the direction of the shoes to make 2 bigger patches instead of 4. Not even sure if this works or if I just drove better

3

We run 2 black and 2 white, no weights, standing starts while street racing.

Got a video so I can hear what you did?

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4

I should have the videos ready sometime later this week! Doesnt sound like I am too far off.

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5

I have been on the same boat. This is what I have tried and I race heavy at 390 lbs. We have a long straight till first break zone.
2 black + 2 white shoes leading — always got smoked
2 black + 2 white shoes pointing to each other — about the same, the clutch engaged really aggressive
2 black + 2 yellow shoes leading — better, still got smoked
2 black + 2 yellow shoes leading with 1 heavy shoes pointing each other — even better, but slow when clutch is slipping
2 black + 2 yellow shoes leading with 1 heavy and 1 light weight— Best so far, I can smoke most of grid

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6

What is your stall speed on standing start? Does your clutch disengage at all on a normal lap?

@Spenny - In theory, you want the heaviest shoes with the heaviest springs that give you peak torque (3200-3400 rpm on a 206) at the start. If the clutch is holding the engine at peak torque, it is doing everything you need it to do.

In real life, a standing start depends on a billion other things besides the clutch. Gear ratio, weight distribution, Kart angle placement, steering wheel angle, timing on flag man, etc. Share some video and we will gladly critique and help. @CrocIndy and i have probably done 150 standing starts between the 2 of us. Some really good and some really bad.

7

So what’s the issue with this one?

8

Clutch stay engaged entire lap. Clutch engage should be just below 3000RPM. Also we are running 18x70ish gearing.

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That’s what I used now, the issue is you will need to change spring quite often. Yellow spring does not hold up very long.

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10

If you are locking your clutch at 3000, you are giving up speed. What is your lowest RPM on a normal lap?

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3000RPM should be my engage RPM, not sure the full lock RPM, my guess will be 3200-3500ish?
Lowest RPM on a lap is about 3400RPM.

12

When preparing to launch from a standing start, does one hold the throttle and brake at the same time to bring up engine RPM?

Is this the answer the same for a rolling start?

(LO206-specific question)

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NO!

Unless you like glazed shoes and hot/sticky bearings.

Keep the clutch as cool as possible. Start your engine as late as possible.

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14

Sounds like a pretty emphatic answer :slight_smile: Thank you.

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15

It really doesn’t matter what clutch or what it’s in (car, kart, truck, bus motorcycle…), a clutch that is allowed to “slip” is only generating heat and damaging the friction material.

I am a little puzzled by standing starts in classes like 206. Why is this done?

16

So that nobody will think they can win the race at turn 1

17

Wait, you guys don’t just send it in T1 anyways?

Comin thru.

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18

We do street racing on standing starts. Just ask @fatboy1dh

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19

A squirt of water between the clutch shoes and drum will give you one high-stall launch before it boils

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I am not sure to be honest. It is just something the Oregon State Karting Championship Series (OSKCS) does for the 4 stroke classes (LO206 and World Formula).