206 Gearing low vs high

[SpeedFreak]

I rub a 1/5 mile track, momentum banked track similar to dnq series track. I ran a 14-62 but everyone pulls away from me at the start. I moved to a 12-53 and am always towards the top. Is there ways to moves up drivers but have a quicker start? I want more top speed.

 

[gary10]

What rpm are your min and max rpm right now?

 

[Dav]

There was a difference between 4.43 and 4.42 gearing?

 

["J'-remy]

your clutch needs to be set to torque peak. what class what clutch? that's take off. the gear needs to be set to run in the peak of the cam. two completely different areas to focus on. both need to be set to win

 

[CarlsonMotorsports]

Like Gary asked, what are your drops now? That will help determine what direction to go on gearing.


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Carlson Racing Engines
Vector Cutz
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[SpeedFreak]

We are hitting around 6000 to 6050 and dropping down to about 5100.

Also yes there was a difference. When I would be on the 14-62, everyone was pulling off of the starts way faster and losing spots. When I switched to the 12-53 I kept on the back of the leaders and could still keep on them towards the end of the race.

 

[Colt sr]

Is your setup and tires good? That's quite a bit to drop on rpm.

 

[gary10]

Can you hear the engine hitting the rev limiter at the end of the straight at all? Sounds like you are right at or under it

 

[SpeedFreak]

Set up Wise its pretty good and and tires are good. I do not hear it hit the rev limiter I am right under it.

 

[gary10]

If you felt you liked the 12 on the clutch better then stick with that and just add 2 to the rear for a 12/55. You’ll probably need to go back to a 12/54 but I would see how you like the 55 first. If you can pull under them out of the corner and get next to them it won’t matter what happens right before the corner. It will likely give you the acceleration you’re looking for. From there just make sure your clutch is setup properly and at peak torque

Gary Lawson
Lawsonspeedshop.com

 

[SpeedFreak]

I see some people state that the peak torque for black slide is 4000 rpm but what briggs shows is at 3500.

 

[gary10]

When you start reading too many opinions someone is going to be wrong. Get with an engine guy with a good reputation and put your trust in them.

 

[Dav]

My local shop‘s dyno sheet lo206. shows 3250@ 11.4, 3500@ 11.3, 3750@ 11.3, 4000@ 11.2, 4250@ 10.9. Tq.

 

[CarlsonMotorsports]

I see some people state that the peak torque for black slide is 4000 rpm but what briggs shows is at 3500.View attachment 28715

Peak torque will be 34-3600 rpm for adult black slide. There is a little variance from one engine to the next, mostly caused by the carb set-up. The torque curve is so flat in these engines that if you're even close to that, you'll be alright. Definitely NOT 4000 rpm though!