Dyno result at .1bar (belt slip! !! !)

[3barboost]

Well I knew the belt was slipping but I ran it on the dyno anyway

results are 295wnm / 141 wkw and its an absolute blast to drive at .1bar - I cant wait for .7bar or more ! ! !! !

unopened jap motor of unknown everything

auto rotor 3150 supercharger - no intercooling

when the belt gripped a little a peak of 360wnm was seen - boost spiked to .25 bar !! ! ! ! ! !

so how on earth do I get the belt to grab and grip properly - there is so much slip that the charger doesnt even whine one little bit !

the standard tensioner isnt maxed out and the belt is nigh impossible to put on as its length is so close to being too small

do I need to fabricate a tensioner on the alternator or similiar and "crank" the belt really tight ? does anyone else have a slippage issue with the std toyota belt tensioner ?

 

[XR8tt]

Wider belt ? But that means replacing pulleys!! Fitting an idler pulley under blower to wrap belt around pulley much more ??
On the non tension side..
Hth...

 

[Zuffen]

I run an 8 rib belt on a dedicated blower drive and I've seen 15lb (a full bar) on my untuned engine and there isn't a sign of slipping.

The usual problem is insuficient wrap around the blower pulley.

Ford Lightnings suffer this when they get down to 2" pulleys on their Eatons.

One solution they use is to run two idlers immediately below the blower drive and very close to the drive and each other so the belt goes inside an idler then around the blower pulley then inside the next idler.

This can double the amount of wrap you can get. Try looking at some of the Lightning Sites in the States. www.lightningrodder.com or www.azloc.com

Another thing to look at is Gates brand belts have a special "gator back belt" that's supposed to resists slipping. Ensure all pulleys in the drive system are free of any oil or oil residual. If necessary clean the belt as well.

You can also buy a dressing for belts designed to stop/reduce slippage.

A photo of your current set up would be handy for us to comment on.

 

[3barboost]

Hi - thanks for the ideas

I will post a pic up over the weekend of the latest config

in short its the pulley blower at the highest point - going to an idler pulley below it - then over the std tensioner - over the alternator - to the crank - from the crank up to a small idler centred where the oil powered fan pump was - then up to the blower - there is no air con or power steering for me - all pulleys line up and the belt doesnt creep - it just doesnt grip enough - what I have seen is I can turn the belt through 90 deg - so I need more tension ! I will first see its feasible to push the alternator out a bit or else make up larger idlers

 

[gloverman]

Hello

Is your vehicle auto or manual?
Another idea is to add an additional external spring to the tensioner. Would require some brackets and tapping a thread into the tensioner bolt but works very well.

Cheers

 

[3barboost]

its got a manual 5speed bolted to the back of it - I am curious to know how the drivetrain impacts the belt - shift shock ?

 

[gloverman]

It would be interesting to compare the supercharger power delivery between auto and manual. The reason I asked was more due to the power you presently have. I don't want to get into who has more than who. I think at the moment you are yet to overcome the loss of power created by the supercharger. Very good touque but just wait until you really start pumping some boost. We did a M112 onto one of our customers cars (search MS112 to have a look) and got massive torque but only gained a bit more horsepower on 10psi. I would expect similar results from your one once some boost goes in there. Good luck - cheers