Trans tuning woes

[dv/dt]

Started the season with some upgears, a keli vari with three 6g and three 7g, stock clutch springs and stock center spring. I liked the setup a lot actually!

It had good street manners and revved out to about 9k where it held until terminal velocity. Then one day i drove around going WOT everywhere and i swear it began to feel weaker. Like something was slipping or wearing out. (the belt is only around 100 miles old fyi)

So, i had parts from VT sitting around that i had never touched. A 3 pack of center springs and a set of yellow clutch springs. I installed the weakest of the three center springs and also the yellow clutch springs. Fired it up and it would rev to the moon and barely move! The clutch springs engaged at about 6k rpms! =/

So i added 3g to my variator total, and it got a little better. added 3 again, better again. added 6g more and better still! So i left it.

What i hate the most is at about 40 the thing goes from about 9k rpm down to about 7500 and it feels AWFUL. I'm pretty sure its because the center spring is too weak and its shifting to the "small pulley" in the rear too soon.

So i think i'm going to remove those 6k clutch springs, because they seemed a bit too aggro for me and i'm going to try and go up one spring (1500 rpm.)

I'm still learning about how these scoot trans systems work, but does my thinking process seem sound?

If i end up going back to stock springs in the long run, i will feel very silly.

[eliteguy50]

If you hqve enough power on the bottom end, you don't need to change the triple springs. The center spring will be your shifting spring.

[dv/dt]

anyone else?

*crickets*

[bonesv]

This is what helped me the most: Only make one change at a time.
Write down what you did and keep trying patiently. Read more posts.
Happy Trails!

[JJ Joseph]

one day i drove around going WOT everywhere and i swear it began to feel weaker.

This is exactly what it feels like when it's overheating. These units will get like RED-hot when pushed at WOT for a long time, and then they'll feel like they're being strangled. Mine one time melted the plastic fan shroud around the cylinder, yet it was still running (barely). One of those nifty little LCD temperature gauges is useful if you like blasting along at WOT. I'm now older & wiser, so I now only cruise at part-throttle.

[kingkamehameha]

Sounds like you need a set of polini naturals and a 1000 or 1500 center. The heavier springs cause heat soak. Heavy springs need heavier weights. You will like the naturals. Trans tuning is a pain. What kind of pipe are you using?

[eliteguy50]

one day i drove around going WOT everywhere and i swear it began to feel weaker.

This is exactly what it feels like when it's overheating. These units will get like RED-hot when pushed at WOT for a long time, and then they'll feel like they're being strangled. Mine one time melted the plastic fan shroud around the cylinder, yet it was still running (barely). One of those nifty little LCD temperature gauges is useful if you like blasting along at WOT. I'm now older & wiser, so I now only cruise at part-throttle.

Sounds like someone needs to work on tuning their engine.

[dv/dt]

one day i drove around going WOT everywhere and i swear it began to feel weaker.

This is exactly what it feels like when it's overheating. These units will get like RED-hot when pushed at WOT for a long time, and then they'll feel like they're being strangled. Mine one time melted the plastic fan shroud around the cylinder, yet it was still running (barely). One of those nifty little LCD temperature gauges is useful if you like blasting along at WOT. I'm now older & wiser, so I now only cruise at part-throttle.

I do indeed use a CHT guage. It did not overheat.

[dv/dt]

Sounds like you need a set of polini naturals and a 1000 or 1500 center. The heavier springs cause heat soak. Heavy springs need heavier weights. You will like the naturals. Trans tuning is a pain. What kind of pipe are you using?

Excuse me for being a noob, but which springs are the naturals?

Pipe is a pg short.

[Wheelman-111]

Greetings:

The triplet springs control the clutch engagement RPM, period. They don't fight the variator rollers, so they don't have any effect on your premature "upshift" issue. If you don't like launching like Don Garlits, swap to the unpainted ("Natural") Polini springs or your stockers. Slamming into Drive is over-rated

It sounds like your rollers are simply too heavy for your yellow Center spring. Go back down 3 grams at a time and your issue should improve. The only connection to your launch issue is that sometimes the vario starts to "shift" before the clutch engages. For sure you have to correct this for streetability. Anyway my point is that the Contra and Triplet springs have very different functions. Think it over.

[dv/dt]

Greetings:

The triplet springs control the clutch engagement RPM, period. They don't fight the variator rollers, so they don't have any effect on your premature "upshift" issue. If you don't like launching like Don Garlits, swap to the unpainted ("Natural") Polini springs or your stockers. Slamming into Drive is over-rated

It sounds like your rollers are simply too heavy for your yellow Center spring. Go back down 3 grams at a time and your issue should improve. The only connection to your launch issue is that sometimes the vario starts to "shift" before the clutch engages. For sure you have to correct this for streetability. Anyway my point is that the Contra and Triplet springs have very different functions. Think it over.

I may not have given the impression, but i do quite clearly understand the differences between the clutch and center springs.

As far as variator weights, i started much lighter and incrementally crept up to the weight i have now. With less weight it revved to the moon and went nowhere, it was so sad!

Anyway, i dont see how anyone can enjoy using such aggressive clutch springs.

[Wheelman-111]

Greetings:

Sorry if I didn't read carefully. You're on the right track going up a spring size, but it's a lot easier just to downsize the rollers. Less work.

Here's where I got the wrong idea:

So i added 3g to my variator total, and it got a little better. added 3 again, better again. added 6g more and better still! So i left it.

Six grams in one go is a big jump. It can be enought to "overshoot" the ideal. Then again, cheap center springs do tend to become floppy pretty quick, especially ensconced in a transmission cavity without adequate ventilation. Heat and repeated compression causes the spring to lose its spunk. That may be part of it, or all of it. By all means replace the spring, but be prepared for it to "rev to the moon" again, because now you have to re-think the variator load all over again.

Before you reassemble, wash your hands thoroughly and clean all the pulley sheaves carefully with acetone. Lightly go over the belt if you like, too. A slippery belt (or a weak spring) can cause the "weak" performance behavior you describe.
Overheating is a remote possibility, but wouldn't hurt to check your compression while you have the plastics off.