Underdrive Pulleys bad according to HPP
Thread Starter
TECH Resident
Joined: Sep 2002
Posts: 803
Likes: 0
From: Charlotte, North Carolina
Underdrive Pulleys bad according to HPP Just read my newest HPP, one of the articles was the 15 LS1 upgrade pitfalls you should avoid. They claimed pulleys cause the engine to run hot,also cause the alternator to run slower causing charging problems and can cause problems with the computer pulling timing. What is your experience with pulleys both good and bad?
PS- Im looking to buy a modded 98 WS6 that has pulleys and Im curious
PS- Im looking to buy a modded 98 WS6 that has pulleys and Im curious
Re: Underdrive Pulleys bad according to HPP Running less coolant flow presents a limit to
heat extraction at high power output. You would
find out later whether it's a problem. Same for
the alternator, you make up for less RPM with
more field current at idle or high load (unless
you have two pulleys, crank and alt). Only, the
alt regulator has field current and thermal
limits of its own (my stock '02 is marginal and
drops out of reg on hot days, A/C on, idle).
It's a semi-cheap way to squeeze out ponies but
I prefer solid cooling and power supply; get the
upside from airflow (intake and exhaust) and don't
stiff the waiter, he might spit in your soup.
heat extraction at high power output. You would
find out later whether it's a problem. Same for
the alternator, you make up for less RPM with
more field current at idle or high load (unless
you have two pulleys, crank and alt). Only, the
alt regulator has field current and thermal
limits of its own (my stock '02 is marginal and
drops out of reg on hot days, A/C on, idle).
It's a semi-cheap way to squeeze out ponies but
I prefer solid cooling and power supply; get the
upside from airflow (intake and exhaust) and don't
stiff the waiter, he might spit in your soup.
TECH Junkie
Joined: Nov 2001
Posts: 3,604
Likes: 0
From: Los Angeles
Re: Underdrive Pulleys bad according to HPP I'd bet that thousands of people a day drive an LS1 car with an underdrive pulley on it and have no issues what so ever. I've had one on mine for the past 3 years in texas heat, WITH a stereo, and never once have I had an issue related to it.
Re: Underdrive Pulleys bad according to HPP According to their specs, Idle speed is still enough to give a complete charge (even with the end alt pulley, i think)
As far as cooling, yeah it could under some conditions. Theres a solution for that though, thermostat, fan settings.
As far as cooling, yeah it could under some conditions. Theres a solution for that though, thermostat, fan settings.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Re: Underdrive Pulleys bad according to HPP The only time the alternator may not be putting out enough to charge the battery would be at idle; the rest of the time the voltage regulator is cutting back the alternator output anyway. Since most people increase the idle speed when they install a cam, it won't be a problem for them. As popular as these pulleys are, we should be hearing about it if there are charging or cooling problems. I've also heard power steering pumps are being way over-driven in the stock setup; a pulley will probably help it last longer as well. Lowering the engines parasitic losses is like removing weight from your car; free horsepower.
Re: Underdrive Pulleys bad according to HPP I like my ASP pulley. I found that my car actually ran COOLER with the underdrive pulley (I live in AZ). By slowing everything down, the engine had less "work" to do (even with the AC on) so it ended up running lower temps.
The think I tell people to make sure they get is the overdrive for the alternator. This will bring it back up to factory speed and prevent charging problems.
The think I tell people to make sure they get is the overdrive for the alternator. This will bring it back up to factory speed and prevent charging problems.
Re: Underdrive Pulleys bad according to HPP I'm about to put an ASP underdrive on my '99 and have no worries. You should NOT need an overdrive on the alternator unless it is an A4 car.
I have run March pullies on my '94 for years. No problems, although I did have to get the alt. pulley as the '94 has an A4 and only idles at 600 (vs. 900 for my M6 cars).
I have run March pullies on my '94 for years. No problems, although I did have to get the alt. pulley as the '94 has an A4 and only idles at 600 (vs. 900 for my M6 cars).
Re: Underdrive Pulleys bad according to HPP I am having a heck of a time getting my factory crank pulley off. I have loosened the
crank bolt, tried a three prong puller and can get the factory pulley to budge. I am afraid
of tapping the pulley with a hammer and damaging something. Any tips would be greatly appreciated.
Thanks
John
crank bolt, tried a three prong puller and can get the factory pulley to budge. I am afraid
of tapping the pulley with a hammer and damaging something. Any tips would be greatly appreciated.
Thanks
John
Re: Underdrive Pulleys bad according to HPP Because A4's have a lower idle since they stay in gear even when you come to a stop. A4's also tend to shift sooner and keep rpms down in city traffic, whereas you can buzz your engine as high as you want with a M6. Alternator output is quite sensitive to rpm. Someone with an M6 that boggs the engine all time will have the same problem.
Re: Underdrive Pulleys bad according to HPP I'm not saying he WILL have problems with an auto, just more likely to. Depends on the type of driving also; alot of city driving that involves being stopped at traffic lights with the headlights and other electrical asessories on obviously will pull the battery down. Another bad thing is to start the car and just leaving it sitting idling for an extended period of time.
Re: Underdrive Pulleys bad according to HPP
I am having a heck of a time getting my factory crank pulley off. I have loosened the
crank bolt, tried a three prong puller and can get the factory pulley to budge. I am afraid
of tapping the pulley with a hammer and damaging something. Any tips would be greatly appreciated.
Thanks
John
crank bolt, tried a three prong puller and can get the factory pulley to budge. I am afraid
of tapping the pulley with a hammer and damaging something. Any tips would be greatly appreciated.
Thanks
John
Re: Underdrive Pulleys bad according to HPP
I am having a heck of a time getting my factory crank pulley off. I have loosened the
crank bolt, tried a three prong puller and can get the factory pulley to budge. I am afraid
of tapping the pulley with a hammer and damaging something. Any tips would be greatly appreciated.
Thanks
John
crank bolt, tried a three prong puller and can get the factory pulley to budge. I am afraid
of tapping the pulley with a hammer and damaging something. Any tips would be greatly appreciated.
Thanks
John
A tip given some time ago on this site suggested making an indentation on the center of the crank bolt. This can be accomplished with a small drill bit.
Also, I recall having to play around with the three adjustable fingers on my puller so that equal pressure was being applied to the pulley. Hope this helps!