Underdrive waterpump pulley that fits with stock-sized main pulley?
 

Just as the title says, I'm looking for a 2nd gen underdrive waterpump pulley that will fit with a stock sized main pulley (in this case the Racing Beat). I can't use the Mazdacomp underdrive waterpump pulley as it's too big to fit with the stock sized main, and I can't use the Mazdacomp small main pulley as I need powersteering and the ps pulley won't bolt to it (that was a mouthful).

Any ideas?

underdrive main pulley
 

I am workeing on a mod for this problem on my fpcar will let you know on mon how it workes

You'll have to figure out a way to use the smaller eshaft pulley because there is only about 5mm of space between the stock units.

I would try to adapt something to the RB pulley that will run the PS etc.

I know I had mentioned an electric PS pump in another thread you were in. They are getting a lot more common on street cars, IIRC the last gen. MR2's had them. Have you thought about going that route and then running the available underdrive pulleys?

I definitely have thought about it; I read an entire thread either here or in the 2nd gen section about using a Citroen Saxo pump but they are somewhat difficult to come by here in the US.

Will investigate the MR2 pump, wasn't aware that it was electric!

Here is what you're looking for, 2nd gen MR2.

Wow that is pretty tiny looking. I'm guessing you could probably vary the PS output by regulating the voltage to it as well.

Thanks alot for this, I'll definitely be investigating it!

underdrive pulley
 

well due to machine shop @#@#@# mod was not a complet success so back to the drawing board

IIRC the newer BMWs are all running electric water pumps.
I dont knwo a part number though, but will see if I can get a part number if I remember Thursday at the shop.

mazda 3's and 5's run an electric ps pump.

bmw has an electric water pump? thats scary....

It looks like the Mazda 3 is using an electric rack (like the rx8) rather than a hydraulic rack with an electric pump. Can anyone confirm?

mazda 3 uses a seme electric/ hydrolic pump rx8 is campletly electrical

Is it a seperate pump with hoses or is it part of the rack? Most are part of the rack when they are electric powered.

rx8 its part of a rack but its controled buy its on module. mazda 3 has a pump driven by a belt w/ hoses to the rack

underdrive waterpump pulley
 

ended up with a racingbeat main pulley. powersteering bolts right on and a mazdatricks underdrive water pump pulley that i had machined down 1/8" to give a1/4" ssmaller d.i.a. than new. will let you know how it workes next week

Yes please do! Would love to see pics

underdrivepulley
 

pulleys worked fine granted it was not to hot this weekend . I am runing at lone pine this weekend its normalley hot and a 21/2mile track should let me know if it will keep the temps low. send me email i will give you my ph# as i live in whittier

At high RPM's the underdrive pulleys will help keep things cool. With the stock set up the water pump cavitates at about 6700-7000 rpm IIRC. The coolant basically stops moving above that RPM unless you slow down the pump.