Underdrive pulleys BJ's

[twilightprotege]

anyone interested? if someone with a BG or BA is interested i'll need some measurements to check against mine. anyway, here's the GB thread on msprotege.com

http://www.msprotege.com/forum/showthread.php?t=78030

normal price is $138usd + shipping (prob $20usd)

[chipa]

How hard would these be to fit? I've gotta admit its one mod I've never done. And it's a part I haven't touched without the engine out of a car usually. Fun to do the work on E-W engine.

[platypus]

i'm interested to know if they would fit my car... but they ain't quite my budget atm...

[twilightprotege]

pretty easy to fit. for someone like me that's done it numerous times would take me about 1 hour tops to fit.

james, take pictures of your underdrive pulley and email them to me. the pulley we have (well atleast on the sp20) is actually the same as the V6 pulley on www.rr-racing.com, not the protege pulley. but they will still give us the same price as the GB

[BigMal]

Do some searching on the MX5 forums about UD Pulleys causing failure
to the components and also engine failures due to incorrect balance of
the lower pulley which is also the Harmonic Balancer as well. I looked
at some and then decided wasn't worth the risk.

[twilightprotege]

yes there have been problems, but a very small percentage of people have problems and naturally they are quite vocal about it.

you'll also find it's only the very high powered cars (ie mx5's that haev been turbo'd) that are having the problems. and it's also something to keep in mind that maybe it was something else that contributed to the problem not the underdrive pulley...

i have a ud pulley on my civic and had no problems at all.

[Riceboy]

yep put me down kneegrow :P

[BigMal]

Thats cool man as long as you know both sides of the story thats all I wanted to
achieve.

[Cosmo Dude]

Under drive pulleys are most commonly useful on engines that are very modified and will be pulling extreme RPM. This stops the other devices on the belt from revving too high and becoming damaged.
I believe that the harmonic balancer has been designed to be the weight it is for a reason and you should do your own research before saying 'that looks cool, I'll have one'.
I believe that twilight has looked into this for himself and now it's your turn.


An immediate down side is that the A/C, alternator and power steering most likely will need you to rev the engine past idle to work as they currently do.

[twilightprotege]

yep that's right. the alternator etc wont function well at idle. i'm ok with that as most of my driving isnt stop start

[BigMal]

Are you really going to spend that much time at 7000rpm+ for there to be a concern
over the longevity of your alternator or power steering or for the extra said 5kw for
the UD pulleys to make a difference.

[twilightprotege]

well it doesnt matter now - sorry guys, the pulley they are selling wont work on our cars. i had a look at mine and discussed the options with rr-racing and it's a no go. typical mazda making different items for different countries