turbo clutching

[devilrmk]

Getting hot primary.

Fairly happy with my clutching except for hot primary that is currently blowing belts running on the water. Never blew a belt on the snow.

Running correct Rpms.

Guess my question is, where can I go to get my primary to hook up better. Will heavier wieghts help without dropping my R's?

honestly I have not tried anything because I am broke and parts cost money, but at this point parts are cheaper than belts.

 

[Wheel House Motorsports]

this is just me blowing smoke out my ***, so take it for what its worth.

your secondary is putting to much load on your primary, so to maintain your rpm, your running certain weights. these weights dont generate enough side load on your belt, thus slippage/heat. you need more weight, which will drop your peak rpm, peak rpm can also be adjusted by helix angle, so going down in helix angle should load the motor slightly less, allowing the r's to come back up for the heavier weights...

this is just theory, but it makes sense to me, basically, the 2 ways I know of to tune a clutch for peak rpm is, weights first, and helix angle.. you can combine them in any which way to get the proper rpm, but with the wrong balance of to much of one, and very little of the other, althought you get the right peak rpm, you dont get a good balanced amount of squeze on the belt in each clutch, for example, your situation, the secondary is getting GREAT squeze, but the primary cant hold on with the tiny weights.

others with real world clutching info might be able to chime in and confirm.

 

[devilrmk]

Ok, that makes sense. I can play with that too as I have some other helixes I can grind.

 

[winter brew]

What sled and clutching? ANY chance you are getting water on the belt?

 

[devilrmk]

Sled is 02 polaris 800

Clutching is 70 gram weights 160/260 spring

Secondary is a polaris button clutch

Custom ground 30/34 helix. I don't recall the secondary spring but its setup in the 3rd hole and its pretty tight.


I blew one belt on the water doing a radar run that ended up sinking the sled. Then I blew another belt after getting it all dryed out just running it on the stand, it was a brand new belt.
Then at the ione watercross I made one good pull across the river and back and the new belt is pretty much wasted.


It was getting pretty hot during the snow season and I never really had any good long pulls so it probably would have blown belts if I would have ran it hard.

I have had both clutches apart and everything is ok.

 

[NapaMatt]

Sure the Clutches are aligned right???

sounds like your spacing could be off??


my .o2

 

[devilrmk]

clutches are aligned.

I checked that at the watercross, it was off a bit but we corrected it and it still wasted a belt

The primary is getting hot, like really hot. Probably 200 degrees or more

 

[winter brew]

Motor mounts good?
That seems like a pretty shallow helix for the button clutch....do you have something more traditional just to try?

 

[gus bohne]

Yup, driven is much to tight.
go to a straight 44 0r something similar and unwind that spring..You have NO drag or traction on water so the driven is murdering the belt..

we all go thru this on boost from time to time,
Thats why I put up the torsion vs straight pressure thread.

On boost you need much less driven tension ( much much )less..
heix angle is not as fussy to belt delamination as spring but your cam is reverse and shallow,, all of that is a little to much for water..

Gus.

fwiw
on the flats we run a good old beige torsion in the NEW xr turbos and xp turbos too,, ice cold belts, wicked accell and mph is WAY up vs the pressure spring and no blown belts..NONE. Even mikie knapp is using one in his fpp turbo trailsled,,,,, try it... moght work for ya,,

 

[devilrmk]

WB, yes I got 4 or 5 other helix's I can play with. Still got the setup I ran with twins. Motor mounts are good. I had the motor out after I sunk it in june, they were good then and the only other time it has ran is on the stand and at ione. I have the motor held down pretty good. It has the factory torque stop, a slp one on the mag side and the slp torque arm in front of the clutch side all setup tight.

I had the secondary spring all wound tight trying to let it wind up to spool the turbo. Worked pretty good for that.

Honestly I never messed with the clutching once I put that helix in. I liked the way it responded and it didn't blow any belts. It did get them pretty hot though.

Just got back here on SW, haven't seen that thread but I am going to go find it.

 

[winter brew]

Just some thoughs....I'm no expert with the turbo clutching. If you go with more helix and lose your snap/more lag, maybe bump up your primary spring to a 180-200 start or drop primary weight with the steeper helix???
Look at the D&D Cat primary springs, they have some higher engagement with low finish that are popular with turbo apps.