What should be worth more HP? Also, If I installed an electric water pump, would the addition of an underdrive pulley be worth anything? Anyone have any experience with electric pumps??

Bad Andy

 

LS1's doesn't have a belt driven water pump like LT1's so an electric w/p would be useless for performance. So it would have to be Underdrive pulleys.

 

I am afraid Bad Andy has that in reverse. The LT1 does not have a belt driven water pump, the LS1 does. The pulleys are a better deal, since you can find them for a lot less than the electric water pump.

Pulley's and water pump would be beneficial, but not on a dollar per horsepower basis. Even if the water pump is electric, you still have the AC Compressor, Alternator, and Powersteering pump running of the crank, which robs power.

I would recommend the pulley, and when you have a spare $400 laying around with nothing else to do, or to replace the stocker when it fails, go electric.

Scott

 

...LS1 water pumps are belt driven...have a closer look, as for which one to get, I'd get the ASP, as for the AC, it only robs power when it's on and with the power steering pump...when your racing in a straight line your not using the pulley to much

 

That's true, other accessories don't create as much power loss as the waterpump, but ask any LT1 owner about pullies, and he will tell you they make a small change, even with the cam driven waterpump.

Keep in mind that in most cases you aren't just underdriving, you are also using a lighter pulley, which has the same effect as a lightweight flywheel. If you decrease wieght on the rotating mass (crank, pistons, rods, flywheel, damper), then you increase throttle response, reduce stress on the crank snout, and possibly improve power production. Most LT1's see around 6-8 HP from a pulley. That should give you an idea of what a LS1 will do with an electric waterpump.

Scott

 

There is no actual LS1 electric water pump kit on the market. You have to buy a race pump and rig it up. I believe Joe Somebody had one that was almost $800 (!), but I'm not sure if it is still availible. Meziere (sp?) is supposed to have one out later this year for LS1s. ASP makes a great underdrive crank pulley and I have had no probs with mine so far.

 

Meziers new street pump will retail for 499.95. It will be a direct bolton replacement for the stock unit. It will have an idler pulley built in so you can l the factory serpentine belt. All the outlets will match oe as well. Again, that's quite a bit more than the ASP pulley, but it's out there for anyone interested. The pum pshould be shipping by June or July.

Scott

 

I'm gonna buy one when it comes out! It should be worth about 10-15 rwhp. I wonder what size belt I'll need with an ASP and electric pump...

 

It would be the same size as with the factory pump. The Electric Pump has a dummy pulley to act as an idler so you don't have to reroute the belt, so it won't affect belt size at all.

Mezier is coming out with a whole bunch of pumps like that for TPI, 4.6L, 5.0L, etc.

 

I dont like the pulleys, so its hard to pick one.

 

An ASP pulley is a good move. Stay away from ost other manufacturers. There has been a lot of trouble with some.

Jay Fisher has a electric water pump but it is pricey. Good for maybe 10 rwhp and a little less torque.