Underdrive pulley's worth it on a KLZE?

V6 Technical/Performance Discussions
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Juans_93_MX3
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Underdrive pulley's worth it on a KLZE?

Post by Juans_93_MX3 »

I have searched and gathered some info, read that it is better not to change the altenator pulley because all that would do is make the altenator work harder

Other than that, changing everything else (Water Pump pulley, Crank pulley, A/C pulley, power steering pump pulley) shouldnt cause a problem to the engine or belt... right? Because I havent found any other info saying that it would.

My question is, is it worth the money to buy underdrive pulleys just to free up some HP?
What if the engine is going to be SuperCharged? Would it still matter?
How about if I just replace the crank pulley?
Last edited by Juans_93_MX3 on February 19th, 2006, 4:23 pm, edited 3 times in total.
2008 Mazda 3
1993 MX3 GS
KLZE, Fidanza flywheel, KL31 CAMs, South Bend Stage I Clutch, Pacesetter STS, SS AutoChromes, Magnaflow muffler, 2.25' Exhaust, CAI, Blaster Coil HEI, KLDE Valvetrain, 5 Speed Swap
Teqnyck
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Post by Teqnyck »

I don't know how much power you will free up, but I do know that for every pound you take off of the engines rotating assembly, it's like taking 30 lbs off of the wheel.
KLZE/KL31 ecu/Pacesetter headers/track pipe cat delete/2.5 inch custom exhaust out to fart pipe/warm air intake for now :(/Fidanza 9lbs flywheel/Stage 2 kevlar road racing clutch which still slips/stock wheels/BFG KDW-2 tires. Looks bone stock ;)

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Rick Johnson
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Post by Rick Johnson »

I had one, the power was noticeable. My alternator has been weak for years so it was even worse being underdriven and I noticed my engine was running hotter at stops, so I yanked it.
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hppwdn
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Re: Underdrive pulley's worth it on a KLZE?

Post by hppwdn »

Juans_93_MX3 wrote:I have searched and gathered some info, read that it is better not to change the altenator pulley because all that would do is make the altenator work harder

Other than that, changing everything else (Water Pump pulley, Crank pulley, A/C pulley, power steering pump pulley) shouldnt cause a problem to the engine or belt... right? Because I havent found any other info saying that it would.

My question is, is it worth the money to buy underdrive pulleys just to free up some HP?
What if the engine is going to be SuperCharged? Would it still matter?
How about if I just replace the crank pulley?

Where are you finding pulley sets for a ZE? To my knowledge all that's available are underdrive crank pulleys.
92 MX3 Turbo ($100 junkyard KLG4) 11.904 @ 124.3mph, 14psi, DOT approved Hoosier drags, pump gas.
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As of July 2011 the MX3 has been retired and sold.
Juans_93_MX3
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Re: Underdrive pulley's worth it on a KLZE?

Post by Juans_93_MX3 »

hppwdn wrote:
Juans_93_MX3 wrote:I have searched and gathered some info, read that it is better not to change the altenator pulley because all that would do is make the altenator work harder

Other than that, changing everything else (Water Pump pulley, Crank pulley, A/C pulley, power steering pump pulley) shouldnt cause a problem to the engine or belt... right? Because I havent found any other info saying that it would.

My question is, is it worth the money to buy underdrive pulleys just to free up some HP?
What if the engine is going to be SuperCharged? Would it still matter?
How about if I just replace the crank pulley?

Where are you finding pulley sets for a ZE? To my knowledge all that's available are underdrive crank pulleys.
Actually I havent.
Nether did the searches I did
Ok, so I see that a U/D pulley for the engine's crank wont do anything bad. A UD pulley on the waterpump might make the car hotter at stops?
2008 Mazda 3
1993 MX3 GS
KLZE, Fidanza flywheel, KL31 CAMs, South Bend Stage I Clutch, Pacesetter STS, SS AutoChromes, Magnaflow muffler, 2.25' Exhaust, CAI, Blaster Coil HEI, KLDE Valvetrain, 5 Speed Swap
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JWMX3
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Post by JWMX3 »

I opted not to get one after reading a billion posts on probetalk, over there its about 50/50 those that say get one and those that say dont....... what it came down to was for the 1 out of 250 guys that have something bad happen to their engine its not worth it, you can make the 3 ft/lbs of torque elsewhere....and if you want weight off the rotating assembly, get a fidanza

i suggest you read the 1 million udp threads on PT and then make up your mind :)
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shiftingspeeds
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Post by shiftingspeeds »

I have the 1.8 and bought the underdrive pulley, but was unaware of the decrease in the belt size. Can anyone who might have completed this mod tell me what belt to use.
RaverChankoMX3
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Post by RaverChankoMX3 »

I have both: UR pulley and Fidanza on my straight neck ZE. I've daily driven the car for nearly 5 months now without a problem...unless you count balding your front tires a "problem" :lol:

Anyway, that's my opinion from someone who's running this setup. High recommended. Especailly, for AXing if you can squeeze in the mods.

The UR pulley:
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The flywheel:
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the CmIII:
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Final product:
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Where's waldo B1tc!h!! ...no, seriously.
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