Prototype - Underdrive Pulley Kit (pics)

[turboe30]

I have completed the prototype for the m20 underdrive pulley. This is a slightly different concept than I originally intended, but it keeps the cost down and you get to keep your AC.

This kit required the modification of the harmonic damper. In short - we machined the pully off of the damper and balanced it. As this is for my motor, I also ground off all but 3 teeth as to use it with MSnS for ignition control. I did this instead of the 60-2 wheel reader because it was simple, proven, and reduced a little weight. I also didn't have to make any electronic mods to my standard MS box.

The pulley is 6061 aluminum. Everything is a 10-20% reduction in speed except the AC which stays the same as stock. Assuming testing goes well, there will likely be a harmonic balancer exchange program as well as the option to take the instructions to a machine shop and have the modification performed.

There is a slight gap between the pulley and the harmonic damper as to not interfier with the damper vibrations and function.

When comparing to the kits available for the m50, I am hoping for over 8hp gain. This will not be confirmed until it is before and after dynod on a NA m20.

Anyways... here are the pics...





What do you guys think?

[Jand3rson]

Color me impressed.

[Bimmerfanatik]

Where do I sign? :) I'm local, I'd be MORE than happy to test one out for you...got a nice NA eta completely bone stock...

[gstuning]

Remember to test on a completly stock car.

[Bimmerfanatik]

Remember to test on a completly stock car.

Exactly...and on an e as well as an i. I can vouch for being bone stock...

[turboe30]

It shouldn't make a difference if the motor is stock or not. The gains from this would not be affected by any modifications on the engine.

It would free up the same amount of HP no matter the engine, as long as we are talking about the same accessories here.

[Bimmerfanatik]

It shouldn't make a difference if the motor is stock or not. The gains from this would not be affected by any modifications on the engine.

It would free up the same amount of HP no matter the engine, as long as we are talking about the same accessories here.

Granted, but isn't it always better/nicer to start with a baseline figure? Dyno an unmodified, stock car, then put JUST the mod you're trying to measure?

I mean, I was planning on coming down to see you guys, and your shop anyways, and I'm gonna buy one of these...I just figured since I have NO mods at all, I'd be a good candidate to test the full potential gains of this mod.

[tonytony]

Color me impressed.

[Skafrog]

are you going to be making one that doesnt have provisions for A/C?
That would be great.

[turboe30]

I mean, I was planning on coming down to see you guys, and your shop anyways, and I'm gonna buy one of these...I just figured since I have NO mods at all, I'd be a good candidate to test the full potential gains of this mod.

I think you may have us mixed up with another company. We're in Canada.

Sorry, there is already someone who is going to test the pulley.

[tonytony]

Keep us updated :up:

[Jand3rson]

are you going to be making one that doesnt have provisions for A/C?
That would be great.

I'm interested in this as well, as I plan to remove my AC.

[turboe30]

The AC is the middle pulley, so there is no way to remove just that one.

However, if you wanted no PS or AC then yeah... we can do a kit for just the one pulley only and no support for the other two. Would save a lot of weight.

[tonytony]

I'm all for the AC and powersteering, granted it doens't get as hot here in oregon as it would somewhere more south. But power steering is a nice luxury :D