Underdrive pulley

mx3autozam · Post by **mx3autozam** » February 15th, 2006, 7:14 pm

What does everyone think about a Underdrive pulley. I know you need to trim metal from the oil pump housing but my deal is there is no harmonic balancer on it like the OEM one has. And some people wills ay it w8ill give me more problems than Its worth. Any truth to this

The one I ahve is the Unorthodox Racing pulley made from aluminum

hppwdn · Post by **hppwdn** » February 15th, 2006, 8:10 pm

I had one on my Probe and on my MX3. Never had any problems because of it. I don't have a giant stereo or anything that pulls a lot of juice at idle though.

mx3autozam · Post by **mx3autozam** » February 15th, 2006, 8:46 pm

was just talking to a mx6 guy and he said they not bad on our cars provided we use the right belts and possibl;y a JDM 120amp alternator. I might even swap over alternators when i install it.

John

babyblueMX3 · Post by **babyblueMX3** » February 16th, 2006, 1:54 pm

hppwdn wrote:I had one on my Probe and on my MX3. Never had any problems because of it. I don't have a giant stereo or anything that pulls a lot of juice at idle though.

yup no problem here too, been running with one since 3 years

shawno · Post by **shawno** » February 16th, 2006, 5:53 pm

Hey i no the lightened flywheel how much hp does it add to the car.

Mnemonic · Post by **Mnemonic** » February 17th, 2006, 2:34 am

shawno wrote:Hey i no the lightened flywheel how much hp does it add to the car.

None the lighten flywheel doesnt add any hp, it allows for more bhp to be sent to the wheels from the motor. As we all know you loose somewhere around 20-30% of hp from transition from BHP to WHP. adding a lighten flywheel, underdrive pulley, stronger motor mounts (mazdaspeed, urethane filled, or solid) allows for that % to decrease. You can also remove parts to decrease that % even further, Such as AC and even an alternator (NOTE you would only remove your alternator if the car was 100% ment for drag, as your battery would die very quickly).

Now according to some if you were to go with the combo of a Lighten Underdrive pulley and Lighten Flywheel you would need to have your crank balanced to the new parts, because there is a chance you could be rubbing against your bearings because of the addition of the lighter parts. For someone runnning alot of Hp this theory makes since.

As for the having problems with a lighten underdrive pulley, I've ran one and never had a problem with it.

kiwi_MX3 · Post by **kiwi_MX3** » February 17th, 2006, 6:38 pm

Ok these are pic's of my new "under" drive pulley,
the water pump will be the same size 100mm in diameter
and the alternator about 60mm.

Im not dragging a power steering pump or a AC pump.

You do not need your crank balanced if you change the flywheel or
pulleys that is a myth as they are rotational parts.

The only time you need to do a check balance or balance the crank
is when you change to a heavier ROD and piston Combo.

Also the KLZE\ K8's are triple plane motors bascily two three clyinder
motors on a common crank....

My crank timming ring is the same size as standard though ive set mine
up not on a rising trigger which the standard ecu run's as im running
aftermarket.

excuse the large pic's works camera not mine.

JWMX3 · Post by **JWMX3** » February 17th, 2006, 7:00 pm

kiwi_MX3 wrote:.

The only time you need to do a check balance or balance the crank
is when you change to a heavier ROD and piston Combo.

.

or when you get your crankshaft knife edged

shiftingspeeds · Post by **shiftingspeeds** » March 4th, 2006, 10:24 am

Can anyone tell me the proper belt to change too. The under drive pulley I bought is smaller and requires a shorter belt

JWMX3 · Post by **JWMX3** » March 4th, 2006, 10:58 am

Waterpump/psp - Dayco 5040355

Alt - Dayco 5050315

Nd4SpdSe · Post by **Nd4SpdSe** » March 4th, 2006, 11:12 am

mx3autozam wrote:was just talking to a mx6 guy and he said they not bad on our cars provided we use the right belts and possibl;y a JDM 120amp alternator. I might even swap over alternators when i install it.

John

Actually it's 110amp and they are Millenia alternators, you should be able to get them from any parts place or even a junk yard. For what I remember however is that only the earlier years had them, later I think they moved down to the 90amps like the GS