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View Full Version : upper or lower pulley?


Big T
07-03-2004, 01:42 PM
I have the SCT tuner with a program for 6# of boost increase. Should I get the upper or lower pulley? Don at modular madness recommended the lower because it is an exact pound increase with less belt slippage. Their lower pulley package looks nice. I also heard the lower is more difficult to install.

NO 5 OH
07-13-2004, 03:11 AM
I have the SCT tuner with a program for 6# of boost increase. Should I get the upper or lower pulley? Don at modular madness recommended the lower because it is an exact pound increase with less belt slippage. Their lower pulley package looks nice. I also heard the lower is more difficult to install.

Man... how did I not see this one ;)

I just recently installed a Metco 6lb lower on my car and while I don't have an aftermarket guage in my car I can tell it's definitely making a lot of torque :) I'm currently running a 3.00" upper with the above mentioned lower... boost should be somewhere around 15-16 lbs max.

Don is right as it will make 6lbs over the stock lower with minimal if no belt slip. I ran a 2.75" pulley for several months but changed to the upper/lower combo to get rid of the slipping belt problem. I also have the Metco idler pullies and it still slipped with the 2.75.

It definitely is a more difficult install as there's two additional brackets that have to be installed, as well as the lower hub and pulley ring. You'll have to change the alternator pulley to "underdrive it" and this requires removing the alternator completely from the motor and using an impact to take the nut off.

Don is definitely a reputable man to talk to... he's the one that sold me the "go fast" goodies on my car and the one that tunes it as well :D

HTH,

Shannon

Big T
07-17-2004, 03:02 PM
Thanks for the reply. I just haven't heard of many people using the lower pulley. Anyway, I'm going to go with the lower pulley. I think the extra time to install will be worth it. If stock boost is b/w 8-10 lbs, then should my new boost with a 6 lb ring be b/w 14-16? Should I get the a/f ratio checked afterwards? Does anyone do the boost bypass mod?

NO 5 OH
07-17-2004, 08:38 PM
Thanks for the reply. I just haven't heard of many people using the lower pulley. Anyway, I'm going to go with the lower pulley. I think the extra time to install will be worth it. If stock boost is b/w 8-10 lbs, then should my new boost with a 6 lb ring be b/w 14-16? Should I get the a/f ratio checked afterwards? Does anyone do the boost bypass mod?

I never saw more than about 8lbs with the stock upper/lower combo... so I'd say 14 psi should be max with a six pound lower. I'm probably seeing about 16 or so with my combo... but I'm running an upper as well.

You should definitely get the air/fuel checked afterwards to be on the safe side. If Don gave you a tune compatible with an extra six lbs of boost, it should be close but I'd still have it checked for the "knowing" factor. I've done the RPM Outlet "free boost bypass" mod and I haven't really noticed any difference in the cars performance. I definitely wouldn't pay the 50 bucks JDM wants for the "bypass mod" when you can do it their exact way for less than five dollars spent ;)

Shannon