Fire Clutch Engagement RPMS for Senior 206 weighing 365

I am running 2 black and 2 white springs with no weights. My engagement RPMs is 3400. I am wondering if I should run other springs to lower clutch engagement for the 206.
You're fine right there. You can fine tune with the weights if you'd like. If you've got a hair pin turn, you might consider adding weights to lower the engagement so that your clutch stays engaged in the slower/technical parts of the track, otherwise leave it as you have it.


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🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
32 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
A senior 206 has a very consistent / level torque band from 3000 to 3700 RPMS with the peak torque at 3400 rpms.
 
You're fine right there. You can fine tune with the weights if you'd like. If you've got a hair pin turn, you might consider adding weights to lower the engagement so that your clutch stays engaged in the slower/technical parts of the track, otherwise leave it as you have it.


-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
32 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
I race at 103rd in Jacksonville Florida.
 
I would want to get that down to 2900 - 3000 for 103rd and it's better to do it with more weights.
 
Kid Kart engine that never gets to 5252 rpms VS a modified engine with peak rpm of 9000.
Peak torque and clutch engagement should obviously be considerably different.


KID KART.png


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While the clutch is slipping, the horsepower at the engine, and the horsepower at the axle, are different. Slipping the clutch, at peak torque, means there's maximum torque at the axle. Look at the formula!
RPM X torque / 5252.1 = HP. So, with maximum torque at the rear axle, you have maximum HP at the axle. There's just no way to get around this.
 
Slipping the clutch at peak torque does not necessarily guarantee the fastest acceleration (or the best lap time).

Since the amount of torque going to the rear axle is a function of what the engine is producing, minus the amount of heat being created... it is entirely possible that slipping the clutch at a slightly lower rpm (putting out a bit less torque) could still produce as much or more torque to the rear axle if the clutch friction surfaces are operating in a more optimal range. (dynamic friction can be very fickle)! I have found that lap times are often faster when the clutch engagement is slightly below peak torque. Not only that, but it typically saves a lot of wear/abuse on the clutch, and generally the end result will be faster over race distance.

Of course the the setup within the clutch (primarily how much spring and weight are used to get to a certain rpm of clutch slip) can dramatically change how the clutch "acts" below and above the actual stall rpm (which also can effect the start, in the case of LTO racing).

Ultimately, the stopwatch should be what determines clutch slip, not the tach... especially when seeing the relatively flat torque curves the 4-cycle engines produce.

PM
 
"Ultimately, the stopwatch should be what determines clutch slip, not the tach... especially when seeing the relatively flat torque curves the 4-cycle engines produce" (y)

The way I see it is if you have a start that is above clutch engagement and you never slow down enough in one or more corners to disengage the clutch on the track clutch engagement is a non factor.
If you have a Le Mans start, a standing start or a very slow start clutch engagement is much more important.
 
Jimbo,

Quite true, however if the corners drag the revs down to a bit above clutch slip, then there "may" be something to gain by increasing both the spring and the weight in the clutch (still keeping the same stall rpm), as that makes the force (of the shoes against the drum) rise more rapidly above the point of engagement.

PM
 
“Clutch lives don’t matter!”
Seriously though this seems to be the most active topic for 206 sprint racers to discuss and it has little to no effect on performance. It’s simply something easy enough for a racer to change and feel they’re making a difference. The same reason parents in cadet/sportsman classes change gears more than every other class combined. Clutch performance is way down on my list of concerns when at an event.
I’ve probably said something similar to this post a dozen times by now but if I can help one person not waste their time on a stupid clutch and focus on working on driving technique then it’s worth it😊
 
I do it because I love to tinker. I'm old enough I've seen the quick ones change nothing and get in and drive away,
but for me its just part of the hobby I like. I know that 90% of the stuff I get and put on has no effect because I'm trying to change a big problem (driving, seat placement ) with items at best would give me a sliver less lap time, out 8 places to the right of the decimal. The pop can theory.
If the quick guys show up with a pop can taped to the front fairing, you'd better do the same. Why ? Because the quick ones have it.
 
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