More Variator Questions / Observations

[jumpjunky]

I bought a new variator from Battlescooter and installed it on one of my Mets. Run it against my other Met and they are virtually the same - maybe with an edge to the stock one.

The variator I received is a 'Daytona'. Only got the moveable sheave of the primary along with new weights. I have (3) 5.5's and (3) 6's in it.

The fixed pin that the sheaves ride in are essentially the same length (stock to mod). With my calipers, the stock one is .3mm shorter.

What is the theory behond the variator mod changing the final gear ratio? The stock and mod sheaves have the same angle (the must for the v-belt to function properly). Is it that the rollers ride further in the primary? If so, isn't the secondary fully shifting out?

I understand that the shift profile can be much different due to the channel the roller runs in. (I tune snowmobile CVT's OFTEN).

Either setup hits the rev limiter at 38mph.

If I were tuning a snowmobile CVT, this would indicate I'm undergeared. (which is probably the case, but chagning gear sets is more than I want to do).

I look at the wear marks on both sheaves (stock and Daytona) and the belt isn't riding as high with the Daytona. I think I need to take some weight out to get full shift.

Question - is the Daytona a good variator sheave / shift profile?
Any suggestions to get 40+

Thanks!

[chanito]

Just shave the spacer down to 35mm

[timberwolfmadcat]

Try Bumping up the wieghts in the daytona before anything, try 6.5's, i found the 6's limited my top speed to around 38 MPH on my 05

[jumpjunky]

chanito said:

Just shave the spacer down to 35mm

Will this help my 'stock' one also? Or, is the variator already shifting out completely?

Guess no better way than to test

[jumpjunky]

timberwolfmadcat said:

Try Bumping up the wieghts in the daytona before anything, try 6.5's, i found the 6's limited my top speed to around 38 MPH on my 05

If anything, I was considering going lighter. As it is, the mod variator has a more aggressive shift profile. The weights I have in it pull the engine down pretty good - in fact, maybe too much. IF I lightened them up, it would allow my enging to get in its power band

Wish I have more weights/rollers to test.........

[Dandy Dan]

Aftermarket variators have a wider range of gearing because if you look at the ramps where the weights roll up and down you'll see these ramps are longer with the aftermarket variator. This allows the inner face to move further outward toward the fixed outer face. Because these faces come closer together the belt is pinched higher hence a taller top gear ratio. If you are finding that your top gear ratio didn't change it's likely because your roller weights are too light.

You're not confusing your max speed with your redline speed are you? The variator should gear you taller (if your weights are light enough) but that won't help you at all if you don't have the power to pull a taller gear ratio. Stock you should have the power to pull a few more mph but if it's running poorly you may not gain anything.

The nice thing about an aftermarket variator is it's nice wide potential gearing range. It allows you to be geared nice and low off of the line and still tall up top. If you shave the stock spacer (or the aftermarket one) you are going to end up geared taller but not just on the top end. You'll be geared taller across the board which makes for lazier starts too. If you just want more top end you can do this with a stock variator and if you just want better starts you can use the stock variator with the stock spacer but lighter weights BUT if you want a higher top speed and zippier starts you'll need an aftermarket variator with it's wider gearing range.

[chanito]

I shaved my stock variator spacer and also filed the nose on the outer face, and my top speed was up significantly, but pick up suffered some how, so i put some lighter weights and acceleration inproved, but i lost a couple of mph, is still faster than stock, but i will go back to the stock weights with the big bore and see if i get my top speed and my accel back, so DD is spot on, however shaving the spacer is way cheaper than a new variator

[jumpjunky]

I shaved the spacer today to 35mm and it greatly improved my top-end. I can now hit 41mph on the flats and 43 with a slight downhill.

So, was it the spacer or variator? My theory is the spacer - because the variator alone was shifting all the way until it bottoms out. I agree with DD's assessment that not enough weight will not shift out completely - but the limiting factor here was the spacer, not the roller weight.

As far as what weight to run - without a dyno sheet to show where my peak HP rpm is and what RPM I'm turning - it's TOUGH to tune weights (rollers). Seat-of-your-pants tuning for acceleration is very deceiving. To maximize acceleration, you want the engine RPM to be at its peak HP rpm while the variator is going through its shifting. Then on top-end, the engine can build a FEW more RPM.

After you get your CVT fully shifting, one can do the magic-marker trick. Basically, mark your sheaves with a sharpie. Go wide open and then check to see if the marker is worn off. If it is, you are shifting all the way and may be slightly under geared. If you're leaving sharpie marks on the sheaves, you're probably overgeared. Both of these scenarios consider the CVT can fully shift (with the spacer shaved and possibly different variator).

I may invest in some lighter weights now as the ones I'm running seem to lug the engine pretty good and I accelerate a little slower than stock. (RPM is down from stock during acceleration).
Proper CVT tuning controls RPM with weight.

Gosh - this is bad. I have 200+ HP snowmobiles that I LOVE to tune and always have the one to beat by my friends. Now, I'm applying this to my 3h

[jumpjunky]

OK - another thought here. Now that I've shortened my spacer, I've moved the fixed sheave inward and thrown off the belt alignment. Since I took 2mm off the spacer, I need to add a 2mm washer on the crankshaft, behind the variator. This will move the whole assembly out 2mm, bringing my belt alignment back to proper.

Anyone else do this?

I know with my snowmobile CVT's, alignment is critical to belt life, speed, heat buildup, and efficiency.

[Dandy Dan]

I think Chanito did this...it seems like a good idea but it's not something you have to do...a lot of people don't and haven't had problems including myself. You might get a bit more wear or drag though so you may as well do it. It's a 5hp engine not 200hp so you probably won't have the same problems with heat and stuff.

jumpjunky said:

My theory is the spacer - because the variator alone was shifting all the way until it bottoms out. I agree with DD's assessment that not enough weight will not shift out completely - but the limiting factor here was the spacer, not the roller weight.

This seems a little wierd to me because A LOT of other people own the Daytona variator and have been able to get into the 40's without shaving the spacer. I can't imagine the manufacturing tolerances would be so loose you'd get that kind of variety.

[jumpjunky]

My stock spacer was slightly shorter than the one that came with the Daytona (like .3mm). Installing the stock spacer game me 1mph over the Daytona one.

Now my next test is to put it back together stock, but with the shortened spacer and shim stack I'm going to put together for behind the variator.

I'll let you know the outcome.

[Dandy Dan]

Sounds good...I'm interested in the results....maybe the Daytona variator doesn't gear you as tall as the other variators? I've used the Kitaco and the Polini (which is my favourite). With the Polini, my 2006 redlines at 8850rpm at 46.5mph instead of 42mph with the stock variator (prior to 06 the redline was 8000rpm).

[jumpjunky]

OK, tested with stock variator/weights and modified spacer - MAYBE 1mph faster than stock. Put back together with Daytona variator, modded spacer, and added washer behind variator - saw 45mph (via GPS, not the speedo) on a slight downhill.

My next step will be to grind out the channels in the stock variator so the rollers can shift further - I think this will make the stock variator as good as the Daytona.

I'll post the results.

[Dandy Dan]

jumpjunky said:

My next step will be to grind out the channels in the stock variator so the rollers can shift further - I think this will make the stock variator as good as the Daytona.

That should work but keep an eye on the slope of the ramps. Why do you want to improve your stock variator if you've already got the Daytona though?

[jumpjunky]

Just to know - plus I have a 2nd Metro. If I don't need to spend a hundered bucks to get the same performance from the second, it would be nice ;D

[Dandy Dan]

Makes sense...good luck!