Anyone have underdrive pullies?
Thread Starter
Drifting
Joined: Jan 2002
Posts: 1,484
Likes: 0
From: Northampton Ma
Anyone have underdrive pullies?
When I do my motor swap next winter, I was considering a March underdrive pulley system to save a few horsepower, but was not sure of the downsides. I'll be running electric fans, so the clutch fan won't matter, but will underdriving the water pump, power steering, and alternator cause more harm than it's worth? I don't want the car to run too hot, and I don't want to starve the battery since I have a stereo with 50Wx4 head unit and a 1,200W subwoofer amp :eek: . What do you guys think?
Safety Car
Joined: Aug 2001
Posts: 3,892
Likes: 13
From: Pettis Performance 565 with two stages of Nitrous Supply nitrous 1.082, 4.61 at 155, 7.17 at 192
Re: Anyone have underdrive pullies? (Ryan77)
I run the March set up on my big block. I do not have power steering or a radio (That I can hear :) ) I have no problems with overheating or keeping a charge in the battery.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,444
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Re: Anyone have underdrive pullies? (69 N.O.X. RATT)
You only underdrive pulleys on a higher rpm motor. If your motor exceeds 6500 rpm on a regular basis. You have to reduce the pulley size on the crank. Then get a higher flow water pump and higher amp alt.
Melting Slicks
Joined: Apr 2000
Posts: 2,145
Likes: 1
From: Ft. Walton Beach, Fl USA
Re: Anyone have underdrive pullies? (Ryan77)
I have them. No overheating problem but I do have a charging problem at idle with lights, wipers, etc. on. ET and MPH in the eighth improved after install but I can't determine how much if any can be attributed to the pulleys since I made a couple of changes at the same time. The looks alone are worth it. Especially if you do the occasional car show.
Safety Car
Joined: Jun 2002
Posts: 4,844
Likes: 0
From: Pearland TX
St. Jude Contributor
Re: Anyone have underdrive pullies? (nastee383)
The March Pulley systems are definitely nice looking, but I need some help convincing me that they are a real benefit to high RPM's on the drag strip where I worry more about flipping or tossing an alternator belt. Or is it best to have aftermarket brackets on the alternator & power steering pump in combination with March Pulleys to keep that from happening?
Le Mans Master
Joined: Aug 2000
Posts: 6,273
Likes: 14
From: Austin TX
Re: Anyone have underdrive pullies? (Ryan77)
Performance gains claimed are generally only at higher rpm. I think March or TPIS offers a set that maintains Alt speed with lower water pump speed. March billet pieces are simply beautiful.
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Thread Starter
Drifting
Joined: Jan 2002
Posts: 1,484
Likes: 0
From: Northampton Ma
Re: Anyone have underdrive pullies? (flynhi)
Performance gains claimed are generally only at higher rpm. I think March or TPIS offers a set that maintains Alt speed with lower water pump speed. March billet pieces are simply beautiful.