Newbeetle, 1Bearman told us the 360 belt would make more speed. Someone else told me it is longer. If it is longer it will give us less speed. If it is the same length and wider it should help us except for that top speed CDI limiting issue.

Important The belt does not go anywhere near the bottom of the driven pulley. You look at your driven sheeves, you will see the belt has never been down inside more than 2/3 from the top or so.

Most of our belts can stand to go up the drive pulley a little higher. When the drive pulley is closed all the way, the belt is 1/4 or so from the top. If your belt could go up the driven higher, I do not believe it would be any less safe than it is now, since you have to stop the rear tires at almost top speed to get it to loosen up n order to be able to jump off. Otherwise it is under extreme tension and couldn't dream of coming off. Snowmobiles sometimes have their belts go all the way. Why can ours. It would pull the belt lower into the driven quite a bit more.

So, why don't we machine the drive pulley to get a little more ratio out of it.

I unplugged my KEBC motor and ran the engine in neutral to see if it shifts out all the way and it does. But the belt could go a lot higher if it closed further. I might mess a little to see if it can be done.

 

NYROC... why would the longer belt slow it down, if the deflection was adjusted ???...

if the belt is not going all the way to the bottom of the driven clutch, what is stopping it???is the belt too wide to fit any futher down the secondary, or is it not drawn down far enough by the primary... if it's too wide, what stops it???... helixes too short etc...

this will probably be my starting point, maximum gear ratio advantage can't be achieved if the belt doesn't reach either the top of the primary, or the bottom of the secondary...

in talking with SHOTGUN about lightening the front clutch, he commented that he still had unused pulley at the top of the primary, that the belt doesn't travel to... if machining the primary, so that the sheeves won't touch, & lightening it to a point of adding heavier weights, what keeps the belt from finishing going to the top of the primary ???

there are alot of questions left to answer here... I too have pulled my K-BEC fuse & watched my CVT cycle... the bad news is that that was before installing the new secondary, & in nuetral, it cycled perfectly...

even though the springs are interesting, I think that part should fall under tuning, & isn't relivant until we max out at least one of the pulleys

 

The mighty ALLTOY's keeps telling us what we need to do, but we just won't listen...

"Some clutch stuff.
Like most of you I revamped the clutch on the V700 maybe a little more drastic but it works. I posted times of 4.74 - 5.19 in 350 feet with rpms hitting 8000 - 8200 not sure of the total speed.

Spider was milled between cross sections eliminating excess material. Sheaves were machined to a total 0.100, 0.050 inchs per side then blended in by machining. Vanes on the rear of the front sheave were milled every second small vane was milled flat to 0.030 inchs above base sheave. What will happen now is the sheaves will come closer so the belt will move to the top of the sheaves produceing more speed all that is required is the horsepower to get it there. The rear bearing in the bottom of the sheaves was machined 0.040 smaller allowing the belt to reach bottom on the back and top on the front. I found the 700 belt was thinner than the 360 belt just my observation you may have to machine more or less to accomodate the belt being used. I also found the front basket of the moveable sheave is different than the 02 650 as it is hard to get the weights of the 650 where it is easy on the V700....more space for the socket. A major point is to gap the face plate to the basket the same as the distance machined on the sheaves...... 0.100 for sheaves / 0.100 for spacing or sheaves will not bottom out.

I also drilled holes in the V700 weights to lighten them up total weight savings was in around 700 grams. I left in the stock springs but took out most of the temper in the front spring allows weights to operate to full extent. All pieces were balanced separate then balanced when assembled. "

of course this was on the V Force project, but as most of the parts are the same or similar, this looks like a good place to start, with the primary & secondaries...Thanks Gary

 

I dont want to sound bad here, but the mighty alltoys might be blowing some allmighty BS. When stretched alky burning Banshee only run strong at 4.7's give or take in 300ft, a 4.7 in 350 feet would be a rocket in comparison. I would like to see that run. Even a modded one on nitrous would not run that fsat.Bubba

 

The highest gear ratio occurs when the belt is furthest OUT on the drive pulley, and furthest IN on the driven. A longer belt is not pulled as far into the driven pulley as a shorter one if you have the exact same drive pulley closure.

Longer = Bad for top speed.

Yeah, what alltoys said sounds good - a little difficult to follow. I wish he had a camera or a diagram. I am going to print what he said and look at the clutch and see if I can interpret it.

 

Ooops, my mistake. The drive pulley closes all the way.

The mod that alltoys described that you quoted is not recommended, not even by alltoys. In order to close more, he had to change the angle of the v in the sheeves. That made the belt drive not work so good. He said that to me in an email and also in one of the clutch discussion topics.

Wider belt, or more RPMs.

I have my pulley apart right now looking at it. The belt only comes within 1/2" of the top of the drive pulley. It starts at the very top of the driven.

It could stand to be a little shorter to pull it down into the driven more. Or wider to force it up out of the drive pulley more.

 

Don't mill your clutch sheaves. if the angle isn't exact you'll have no grip on take off. I posted a year ago that we did this. we got alot of speed, but it really hurt take off and belt wear.

I said this many times, we need a wider and slightly longer belt. it has to be wider so it will work in the primary. now the angle of the sheaves leave the belt about 1/2 to 3/4 from the top.

Why does it need to be slightly longer, if you took the spring out of the driven and the spring out of the primary and put both back on the machine, installed the belt and manually pulled it down to the bottom of the driven, it wouldn't go out to the very top of the primary.

Granted, it would be a loose belt and we might have to do away with the belt switch, and the engage would be higher, but there about 10 MPH more to be had or more.
I'm only talking slightly longer.

This is what I'm going to try. I going to stretch an old belt. Then I'm going to take it to my son in law, who own a spray on bed liner shop. I going to grease the top and bottom of the belt and have him spray 1/4 " of bed liner on the sides, I'm going to bring it home and cut it back to angle in a ban saw and remove any that got on the top and sides. No I don't drink.

We've got some great mines on here, everyone think out of the box and post an idea, doesn't matter how foolish it seems, it might work.

We can sit here forever and hash over things that we knew a year and a half ago or we can come up with ideas that might help us.

 

I wonder how much drag is generated by the cooling vanes on the back of the primary? Any sort of a fan requires substantial horsepower to turn at 8000 RPM. Maybe they should all be milled off and a 12 volt blower installed to provide cooling air for the clutches and belt. [img]i/expressions/face-icon-small-confused.gif[/img]

 

I wish someone had a spare 360 belt to loan me so I could check it out.

Nova, that kind of thinking works for people that race alot, I will stick with the simplistic.

I took the fan off my truck and installed an electric fan (only needed for AC). I got a little better fuel economy and better takeoff. Sortof the same principle, but I don't think my 650 wants to have that done to it.

Shotgun, those two dimensions work together to result in the starting and final ratio.

Wider alone would make my 650 have a higher final ratio, since my primary always closes around 50mph, and I go faster than that.
Longer alone would make my 650 have a lower final ratio.
Shorter alone would make my 650 have a higher final ratio.

Depending on your wide vs long thinking, you might speed my machine up by giving me a little more wide than long. I took my springs out and moved the primary closed all the way, and a longer belt alone would result in a lower ratio (slower quad) since it would not go into the driven as far. Longer and wider, like you say, might make the belt go a little higher up the drive pulley - but with less effect than a wide belt by itself. However wider by itself would do even better than that by going higher in the primary and lower in the secondary at the same time. More effective.

The reason this is the case is that the belts never go down into the secondary all the way. We have a lot of room there to play with. Simply a wider belt should do a lot for us (as long as it isn't also longer, it will defeat the benefit of being wider). I think our timing limitations are the biggest thing slowing us down.

 

I'm personnally really happy with what I'm seeing here... there are alot of Ideas... please keep them coming...we are all opinionated & I hope we all really don't care who solves this puzzle with the easiest solution, as long as it happens... I had another ( too short a meeting ) with my tool & die buddy... there are a few possible solutions, unfortunately they do require machining... we can all hope for a more practical solution, if THEROCK, or someone else could find that magic belt...Good luck...WAM