cvt vs final drive ratio

[o4twinpeaks]

If you were to change the final drive ratio how does it affect the clutching? ex go from a 19 to 20 on the countershaft and staying with a 33 on the rear. Lower weights to rev harder to get full shift out as we are loading the clutches harder now?

We are doing 300' drag races and running a 19 33 right now turning 12900rpm. we were running 19 30 last week and turning 12400. Would like to see motor turn 13800 right at the end of our run. full overrange 4.5/4.75 sliders koso 1500. I'm going to start dropping roller weight to gain rpm and watch the ets.

Do many end up changing final drive ratios for tight vs open tracks and if you do what do you change in the clutching?

Thanks
Tom

[Hetrick Racing]

Why would you like to see the engine turn 13800 at the end?
Question
If the engine makes peak torque and HP at 12,200 why would you rev past that?


Not saying your engine does but thats the kind of question you ask yourself.


Each cvt is different some yes some no as far as changing gear vs roller weight.

If you have your quad at its best as far as the clutch goes(to engine hp and rpm),, a small gear change should only change top speed,within parameters set forth in previous testing

[fomospede]

theorize all you will
testing with exacting parameters and results charting
will take you where you want to go
hope you have patience!!

[o4twinpeaks]

Thats it. Peak torque at 12800 and peak hp at 13800.

[fomospede]

gearing up may give more top speed but will take from your launch
understanding that you want to get from A2B the fastest
away from the engine cvt and gearing is your machine dialed in ?
squared front to rear
toe in set
brakes releasing properly
does it squat and launch with minimal tire spin
tires balanced
im not trying to dog you these thing make minimal power so slight static losses equal alot !
so the cvt tuning is just the tip of the tuning

[denny1610]

JUST CURIOUS WHAT KIND OF ET YOU ARE SEEING WITH YOUR QUAD, MY SON RUNS A APEX 90 THATS HAD SOME WORK DONE. WE ARE RUNNING 19 / 35 WITH 19" TIRES. TURNING 12,500. OUR BEST ET SO FAR IN 300' IS 7.05@47.
SEEMS FAST BUT HAVE NOTHING TO COMPARE TO ,AS ALL THE OTHER KIDS RACING HAVE STOCK BIKES.

[o4twinpeaks]

12 passes all between 6.700 and mid 6.8 so far this year. That was with the 19/30 gearing and he is 160#. And he was only turning 12400 on those runs. No times yet since the gearing change bud did see an improvement. Will have times when we go to waren track on 6/22. last year he was 6.9 to 7.3 with old motor.

We are running and 18" x 10" tire that I cut. Took almost 5# of rotating mass off the rear tires.

[o4twinpeaks]

here is the one slip he red lighted on this run but was his quickest et.

[denny1610]

WOW ! thats awsome .
We can't get the thing to hook, are tires are shaved also. my kid only weighs 80lbs. the bike is like a rototiller spinning all the way down the track.
we have the rear as soft as we can, but doesn't seem to transfer any weight.

any idea's ?
thanks

[o4twinpeaks]

What kind of track? Ours is hard clay tractor pulling track.

Give me a shout 410 808 4658
Tom