Unorthodox Water Pump Pulley

[Hijacker]

I thought they were making an underdrive pulley. It's not listed on the website though.

http://www.unorthodoxracing.co....html

[ca18det_boy]

Hey bart where did you hear that? I've only been able to find cheapy ones. Unless AEM makes one.....I don't know

[Def]

URI doesn't make *ANY* underdrive accessory pulleys AFAIK. The crank pulley is an underdrive unit, and the accessory pulleys are just engine bling and on some they might lightened them up a bit(if the original is steel).

Besides, I doubt you could really underdrive the stock waterpump more than 5-7% given how close it is to the stock crank pulley.

[Hijacker]

i could have sworn that Dave Coleman had written that UR was making an underdrive for the S13 SR....

I don't think I'd want to underdrive the crank pulley. Lightening would be good, but Having all of my accessories spin at different speeds than stock doesn't sound appealing to me.

[compression]

Unorthodox doesnt make an oversized pulley for the water pump because there is no room. THe stock pulley is only about .25" form the crank pulley. SO unorthodox chose, rather than enlarging the accessory pulleys, to make the crank pulley smaller. Same effect.

I would not swap out my crank pulley though, It has built-in engine balancing and vibration damping characteristics that a solid billet pulley would not have.

If you are worried about your accessories not turning fast enough because of a 20-30% change in pulley size, worry no more. It doesnt change their function.

[Def]

Yep, the problem is in removing the harmonic damper incorporated into the stock crank pulley, not the slight underdrive of the accessories.

[180crafter]

Um guys... I have already checked this out very thouroughly.

Check this thread. Very informative and read it through to the end.

http://forums.freshalloy.com/u...14989

[Def]

Yep, that's my post in there second to last.

With all that said - I did run an Unorthodox crankpulley(solid) on my E36 M3 for a little while, and the engines in those go for a cool $4-5k. I researched everything then accepted the risk. Of course, a set of cams for 8-10rwhp cost over $1k no including install(took factory tools or you crack the cams torquing them they're so long) - so the 8-10rwhp gained from the crank pulley was worth the minor risk.

I just wouldn't run one on an SR that's relatively easy to get power from. I mean come on - are you *really* going to even notice the 4-5rwhp you get from the pulley when you can just add 1 psi of boost and add about double that? There are better places to spend the money, especially given that the stock pulley isn't all that heavy(it weighed about 8lbs on my M3 and was about the 3/4 the diameter of an SR flywheel - i.e. it had HUGE amounts of inertia).