Crank pulley mounted supercharger

[Mat Grant]

Hi,

Has anyone on here ever mounted a centrifugal supercharger off a separate belt driven from an additional pulley in front of the existing crank pulley? ie using a separate shorter belt and not the existing aux belt.

On the car I've got there is tons of room in that area in front of the engine, but the bonnet is too low for the normal fish bracket approach.

I thought about fabricating a mounting bracket for the charger to go with the pulley located where the existing hydraulic fan pulley is, but the problem is the charger pulley would be driven off the plain side of the aux belt so slippage may be an issue.

Any suggestions or comments welcome!

Cheers, Mat.

 

[cribbj]

I think Zuffen set his up that way; perhaps he'll chime in about it.

 

[Zuffen]

I ran an 8 rib belt on a separate pulley.

The pulley was a simple "bowl" shape that fitted inside the harmonic balancer.

It was retained by the harmonic balancer bolt and had two bolts threaded through it that engaged the spokes of the harmonic balancer to reduce drive stress.

Worked well.

I'll have a look for a photo of it.

The pulley was around 40mm larger than the harmonic balancer.

One advantage of this setup is it removed the stress from the shock absorbing layer of the balancer.

 

[Mat Grant]

Hi, thanks for the replies, i'd be really interested in seeing a photo of that, and knowing where you got the pulley from. And knowing how you figured out a belt tensioner for the charger belt.

Btw does anyone know if a double sided 6 rib belt can be obtained in the same size as the standard 1UZ belt?

Cheers, Mat.

 

[Zuffen]

Matt,

I've just looked through thousands of photos and I don't have a single photo of the pulley.

Sorry I couldn't help.

Strangely enough I found an article I wrote years ago (and had forgotten about) that another Lextremer was looking for so it wasn't all in vain.

On the tensioner front.

A 10mm alloy plate was bolted to the front of the engine in 3 places using alloy spacers that varied in length, but the longest was about 50-60mm. The plate was on the alternator side of the engine and was a pain as you couldn't work on the power steering or alternator without first removing the plate.

Off this plate was an idler wheel, simply bolted through the plate and a tensioner.

The tensioner was off a Holder V6 and had the sprocket replaced with an 8 rib belt.

Again no photos.

If I were to go down that route again I'd use the alternator and power steering mounting points and use a similar plate and concoct my own tensioner.

 

[Sudsy]

One of the UZ engines I have came out of a truck or ambulance or something like that. Had a massive aluminium engine plate on the front with some sort of pump and also a twin serpentine belt pulley. All looked factory. Might be able to find something like that

 

[Mat Grant]

Hi guys,

Thanks for the replies looks like it will be feasible. My car is a lotus, has a very low bonnet, already a small bulge fro the 1uz, so the fish bracket won't work at all, and a blower on the plenum will be too tall as well.

I'm still considering attempting to put the charger pulley where the fan pulley was, will need a bit of thought and maybe a double sided belt if it slips, but that would be the neatest way, and from rough mockups will easily fit. Would need a fairly complicated bracket which looks like the fan bracket at the bottom and the charger plate mount at the top, with flanges or bolts/spacers to locate the charger. This sort of fabrication is beyond what i can do but there is a good place near me that can do stuff like this.

What i want to do is knock up a wood template to get the idea and see if it is feasible.

If that isn't going to work, Zuffen your idea of fitting a plate mounted on the PAS/alternator side of the engine is a good one, longer bolts and studs and some spacers.

If I get any progress I'll post it up here. If I end up generating a CAD with a bracket design (that works) I'll make it available free to people on here.

Cheers, Mat.

 

[Rock-a-Lex]

This is my SRT setup.

 

[Mat Grant]

Nice!!!

Mat

 

[iaksa]

I know this is all thread, but I'm in process of fitting MP2300 (TVS 2.3L) with 8 rib Crank pulley mounted supercharger, does anybody has CAD of crank pulley and CAD plate for belt tensioner, something similar to below ?

 

[Mat Grant]

Hi,

I stopped looking for the double pulley, as I've gone for a Rotrex C38 which can run off a 6 rib belt (although they recommend 8 rib belt) and found an OEM double sided aux belt, using the location vacated by the idler pulley which used to be the hydraulic fan pulley. It has more than 180 deg wrap, and I will be using a large pulley as the boost will be low.

I've not fitted it yet, but made a mock up, and as it will work I have no requirement for the double crank pulley.

I hope you can find something though, there are some really inventive people on this forum, although it is not as busy as it used to be.

Mat.

 

[iaksa]

Thanks, hopefully someone has CAD file to same time and $$$ ...
I have now M90 (on Richwood manifold, E420C, supra injectors, T56 gearbox with Rush dual clutch, supra LSD, coming bilstein coilovers) and can go with 6 rib for now - just make another manifold top, 4" intake to accept 102 mm throttle, but will like to go with 8 rib, methanol injector, and when all done put Kelford cams.