Supercharger belt routing

[RichyRich]

Hey all.

I've recently invested in a AMR500, and have the mounting, inlet and carb ideas sorted. My current hurdle is the drive/belt routing.

I have seen people running two belts, and people running one belt, with some tensioners.

I am looking for advice on both set-ups. Swaying towards twin belts, and would like to know what pulleys and belts people used.

I tried searching but haven't found my answer.

Thanks in advance
Rich.

[miniman82]

Common multiribbed belts from production vehicles is where I get most of mine, maybe try the junkyard?

[rubenski]

I use all the parts off a scat serpentine belt kit and got a custom pulley made for the amr500.

Routing isnt easy. 2 belts would make that easier. And if the blower belr breaks and you have no spare, there's still the other one driving your cooling!

Take a look at my project here, got the last setup now with the least belt slipping and the most pulley coverage!

Show us some pixs of your setup?

[RichyRich]

Oh right ok. Sounds interesting way of doing it.

For a duel pulley off the crank, what's the best way of doing thid? Have been told about a guy in Aus who makes a cog type kit too.

All I have is a amr500 at the mo. Plan on mounting it with the carb ontop.

[rubenski]

Heard a few bad things bout the gilmer belt kit. Its at www.kemotorsports.com i think. Or something like that.
Talk alexios on this forum about that.

Carb on top is easy but beware of manifold freezing.
One of my biggest issues with my setup.

Try a carb that lays on its side. So you can keep everything inside your engine compartiment.

Shout if you want help with anything. Still fresh in my memory

[RichyRich]

Oh right, would you be willing to PM more info about what you've heard?

Just realised your blog is one i have been getting alot of my own info from.

I'm planning on running a 34/36 carb, and going to keep it all under the decklid. This set-up is what I've got picktured.



My main hurdle is the twin belt set-up. I have no idea what 2nd pulley to use? Also, what size charger pulley to use? Only wanting 7psi?

Cheers

[rubenski]

That picture is an amr300. Smaller version on probably a 1200 34hp engine.

You need to find out what your top rpms are. Then mesure the diameter of crank and blower pulley and that ratio will determine what boost you will get.

For example. Mine limited at 5400rpm. Crank 17cm and amr now 7.5 cm. Divide those last 2 and then you got the ratio. Rpm * ratio and you get blower speed.

Dont drive the blower over 16500 rpm. Mine with the custom pulley will now be maxed out at roughly 15500 to keep some safety marge.

As for pulleys, junkyard shopping or ebay... kinda on your own there. Just get the ratio right!

[RichyRich]

I'm only planning to rev to 5k max. mostly 4500. So if i get the same pulley sizes, then i'll be looking at 7psi, and not running the charger too hard?

Aaah, i didn't think it looked as big!

Ok thanks!

[andy198712]

What about the AC equipped beetles didn't they run two belts? And have a twin pulley? Or have a equaliser pulley and put it in the lathe to make a groove unless you run a ribbed belt...?

[Alexios]

Hi there!

This will be the third season I am running an amr500.

I prefer running two belts for the following reasons:
- if supercharger fails/runs hot, you can remove the supercharger belt and still have cooling/charging.
- the alternator bearings are not dimensioned to handle high loads. The original alternator belt is quite slack, a supercharger belt is not in order to avoid belt slip.
- a single belt requires putting quite a bit of strain on the idler pulley in order to guide the belt around so you get some decent wrap on the pulleys. This puts a lot of strain on the bearing which tends to self destruct after a while.

Here are some pictures of the setup I had last season.
http://s684.photobucket.com/user/RideDo ... w.jpg.html

I use the gilmer pulleys from the kemotosport. I have mounted the kemotorshop glimmer crank pulley to the outside of a steel (think is is empi) pulley.

http://s684.photobucket.com/user/RideDo ... b.jpg.html

check out my tread at the norwegian vw forum for more pictures
http://www.vwnorge.no/index.php/topic,51274.120.html

Any competent machine shop can machine a pulley so it sits outside another.

I still have my old setup that was using a v-belt. Here are some pictures of it.
http://s684.photobucket.com/user/RideDo ... 6.jpg.html
http://s684.photobucket.com/user/RideDo ... a.jpg.html
http://s684.photobucket.com/user/RideDo ... c.jpg.html
If you want it, I can sell it for cheap but keep in mind that the belt slips at around 7psi.....


What is your engine size? Does the supercharger you have now have a pulley on it?

Alex

[rubenski]

i now have 4 to 6 psi running the pulley that the amr 500 comes with when i bought it..

[RichyRich]

Thanks guys!

Never seen a air conditioned beetle/pulley before?

Those sound like good enough reasons to run twin belts, and think this is the route I will take.

My engine is a standard 1600, and it did come with a pulley, measured 86mm.

So to get the 2nd pulley on, youve just bolted them together? Was that buy drill and tapping a thread? And if I go v or ribbed belt, how can I stop it slipping?:.

Thanks

[rubenski]

I wouldnt take a v belt for the blower.
You no want no slip on it.
Take pulleys for a micro v belt.

How to attatch, i dont know. I work with 1 belt. Maybe ask alexios

[Alexios]

I will get you a picture of how the pulley is machined in order to fit the crank pulley.


Sent from my iPhone using Tapatalk

[RichyRich]

Excellent thank you.