UR underdrive pulley on AFI phase-I motor issues

STi-Nismo Dood · 05-23-2004, 02:56 PM

Hello,

I bought an Unorthodox under-drive pulley 2 years ago and still have not installed it. My AFI system consists of APEX electronic piggy backs to control my turbo. I have heard that underdrive pulleys may not have the correct harmonic balancers and I am worried I will damage my engine because I installed this (also lesser power to accessories). Has anyone actually known people who have installed an underdrive pulley on their AFI and created problems? I may consider selling the underdrive and get a lightweight perrin if this is really the case for my phase-I DOHC motor. Thanks.

-Vic

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Wedge · 05-23-2004, 03:27 PM

Don't bother with an underdrive pulley, and instead get yourself a lightweight flywheel.

STi-Nismo Dood · 05-23-2004, 03:34 PM

Whats the deal with the UR underdrive pulley for us phase-I motors? Also, my APEX piggybacks seem to be drawing a lot of power already with the OE crank pulley. This OE crank pulley is 10 years old and I notice it getting wobbly on occasions so I really need to fix this...

I already have the exedy lw flywheel, its just that I don't want my UR pulley to be laying around for another year, might as well use/trade/sell it.

Wedge · 05-23-2004, 03:41 PM

I've heard it's a bad idea to use a lightweight flywheel in combination with an underdrive pulley, something about throwing the crank out of balance.
So I decided to keep just the flywheel.

Kostamojen · 05-23-2004, 04:20 PM

All the talk about underdrive pulleys plus lightweight flywheels is pure heresay. There are several people with Subarus on these boards using that combination for years.

Wedge · 05-23-2004, 07:49 PM

Well then, there you go!
If you got it, go for it, I won't be getting one again tho.

White 2.5rs · 05-23-2004, 07:55 PM

there was also an article <from an experienced tuner, iirc> that said he had a LW FW and a normal pully or vice versa nad blew the engine because of the difference in rotational mass/vibration

leondal · 05-23-2004, 09:31 PM

I have run the UR underdrive pulley for two years and 30,000 miles with no problems whatsoever...

05-23-2004, 02:56 PM	#1
STi-Nismo Dood Scooby Specialist Member#: 4149 Join Date: Feb 2001 Chapter/Region: SCIC Location: Frisco/Diego/LosAngeles Vehicle: MY93 ImprezaRA Sedan GC8.6 Aspen White	UR underdrive pulley on AFI phase-I motor issues Hello, I bought an Unorthodox under-drive pulley 2 years ago and still have not installed it. My AFI system consists of APEX electronic piggy backs to control my turbo. I have heard that underdrive pulleys may not have the correct harmonic balancers and I am worried I will damage my engine because I installed this (also lesser power to accessories). Has anyone actually known people who have installed an underdrive pulley on their AFI and created problems? I may consider selling the underdrive and get a lightweight perrin if this is really the case for my phase-I DOHC motor. Thanks. -Vic * Registered users of the site do not see these ads.

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05-23-2004, 03:27 PM	#2
Wedge Scooby Specialist Member#: 2279 Join Date: Sep 2000 Chapter/Region: South East Location: The MIA Vehicle: 2000 Slingshot/99RS Pastelito Racing / SFSOC	Don't bother with an underdrive pulley, and instead get yourself a lightweight flywheel.

05-23-2004, 03:34 PM	#3
STi-Nismo Dood Scooby Specialist Member#: 4149 Join Date: Feb 2001 Chapter/Region: SCIC Location: Frisco/Diego/LosAngeles Vehicle: MY93 ImprezaRA Sedan GC8.6 Aspen White	Whats the deal with the UR underdrive pulley for us phase-I motors? Also, my APEX piggybacks seem to be drawing a lot of power already with the OE crank pulley. This OE crank pulley is 10 years old and I notice it getting wobbly on occasions so I really need to fix this... I already have the exedy lw flywheel, its just that I don't want my UR pulley to be laying around for another year, might as well use/trade/sell it.

05-23-2004, 03:41 PM	#4
Wedge Scooby Specialist Member#: 2279 Join Date: Sep 2000 Chapter/Region: South East Location: The MIA Vehicle: 2000 Slingshot/99RS Pastelito Racing / SFSOC	I've heard it's a bad idea to use a lightweight flywheel in combination with an underdrive pulley, something about throwing the crank out of balance. So I decided to keep just the flywheel.

05-23-2004, 04:20 PM	#5
Kostamojen Scooby Guru Member#: 2272 Join Date: Sep 2000 Chapter/Region: BAIC Location: haha XD Vehicle: 95 L AWD LIFTED!!! 1970 Subaru FF-1 Coupe	All the talk about underdrive pulleys plus lightweight flywheels is pure heresay. There are several people with Subarus on these boards using that combination for years.

05-23-2004, 07:49 PM	#6
Wedge Scooby Specialist Member#: 2279 Join Date: Sep 2000 Chapter/Region: South East Location: The MIA Vehicle: 2000 Slingshot/99RS Pastelito Racing / SFSOC	Well then, there you go! If you got it, go for it, I won't be getting one again tho.

05-23-2004, 07:55 PM	#7
White 2.5rs Scooby Guru Member#: 39936 Join Date: Jul 2003 Vehicle: 99RS TWE&SCAT EJ257 Hydra+HMist+PPG+35R=DEATH	there was also an article <from an experienced tuner, iirc> that said he had a LW FW and a normal pully or vice versa nad blew the engine because of the difference in rotational mass/vibration

05-23-2004, 09:31 PM	#8
leondal Scooby Newbie Member#: 43114 Join Date: Sep 2003 Location: Pownal, VT Vehicle: 1998 Legacy GT Turbo Green	I have run the UR underdrive pulley for two years and 30,000 miles with no problems whatsoever...