Well I have decided to have some custom light weight pulleys manufactured since I do not want to under drive and no one makes them. They include the crank, alternator and water pump pulleys as well as all new nuts and bolts made out of titanium for added weight reduction. Even the main support that holds the crank pulley will be made out of titanium. I already have the nuts and bolts and have them installed on my car for testing; the pulleys should be here in about two weeks. I have detailed pictures of the stock pulleys and all the fasteners including the titanium bits and will post tomorrow.

I did all the design and drawings myself in AutoCad 2000 and then had everything checked by a good friend of mine who is a PE and everything was reviewed by the manufacturer I have machining them...

Once I have the complete set I will grab a demo stock 6sp RX8 of the lot and dyno before and after... The goal is 8-10hp with no under driving, and they will be very good looking pieces...

Here is an AutoCad screen shot of the alternator pulley:

 

That drawing is pretty cool. I once did a drawing of a rotary-geared pump with AutoCAD2000. Good luck with pulley set .

 

Here is another CAD drawing of the alternator pulley before I added the belt grooves...

 

This is SO PRO, cortc.... cannot wait to see the final result.

Gee I am excited

 

Very cool Cort... have you considered selling these?

 

I would be interested in a lightweight non-underdriven pulley set... if one were for sale.

 

Will post more details in the morning...

 

One thing to note, in case you haven't already, is that the four bolts which mount the pulley to the crank hub are not equidistant from the center line. One bolt is on a slightly smaller radius from center to prevent the improper re-installation of the crank trigger, which sits behind the crank pulley.

Charles

 

Charles: Yes, noticed that; I have a complete set of stock pulleys from Mazda including the crank hub... The timing trigger is mounted first than the two stock pulleys, as the AC pulley is a separate piece... The new pulley set will reuse the crank trigger ring and I made sure that the alignment and bolt pattern is absolutely precise...

 

Omicron: I am currently focusing on the design and prototype set for my car, I have not decided if I will be making them available as a product... For the moment it is just a cool project of mine; if I do decide to produce it I will contact you and setup something to make sure no forum rules are broken...

 

Sounds good, Cort. I think there is at least some market for these, and if you do all the design work, it only makes sense for you to reap the benefits. :D

 

Once again, I anxiously await the results of your next mod cortc.

 

Make sure you get the torque figures when you dyno too... I'd very much like to see them.

 

These are all of the stock pulleys with a few titanium bits...

 

Oh jeez i hate cad key but you seem very good at it. Good luck

 

This is a picture of the stock alternator pulley with its nuts and washer... The nut at the bottom is the new titanium piece; less then half the weight of the original... The other nut is being machined, the stock washer will be reused as it is a pressure and lock washer...

 

This is a picture of the stock water pump pulley...

 

This is one of the original bolts next to one new titanium piece... There are three and the three titanium ones weigh a little less than on of the stock ones... All these bolts have forged heads and have a smaller head for even more weight reduction...

 

Here is a picture of the stock crank pulley pulled apart... This is a very heavy piece...

 

A close up of the stock crank hub, the new one will be titanium; very cool and very light...

 

Picture of the crank pulley stock bolt and the new titanium pieces; again these are forged with smaller heads 8mm vs. 10mm for the stock ones (10mm is overkill and just adds weight, most probably an attempt to keep fastener sizes to a minimum)... All four titanium pieces weigh in just a bit over one stock bolt... I have the weights at work but if I remember correctly the bolts and nuts alone shed almost 1/2 of a pound...

 

I will post some weights tomorrow along with some more details... As soon as I get the actual pulleys will post pictures of those and then some of them installed on the car. I am going to do several dyno runs, one stock, one with pulleys only, one with pulleys and bolts and one with pulleys, bolts and crank hub...

Alex: Yes, I will post HP as well as torque figures...

 

thats sweet.. looks like the project is coming along...

I bet yours will be completed before Unorth even ships...

Keep up the good work!!!!

 

magixpuma: Thanks, I spent three years during college and in my first job for an engineering firm doing 2D and 3D CAD & CAM; I have alot of practice...

 

Yeah well top this 2 months in my 9nth grade engineering class and i made a small little tube with a turnip shaped spike on the top of it. then we made it in a wood cnc lathe.

Oh yeah lol. You are good and if this actually works out for you maybee you can make a career out of it Maybee.....
nah i would like some pulleys later maybee so keep those programs saved