propellerhead

Same here. I'm not sold on the "under pulley" thing. I won't argue there are gains, but there are too many issues at idle speeds. A slower water pump reduces cooling efficiency. A slower power steering makes it harder to steer. A slower alternator means less charging. Then you have two sides to the piggy-back or not issue. Some say do not remove the stock harmonic balancer. Aftermarket ones aren't made for daily drivers. Some say replace them. Dunno. Both sides claim seeing motors blow up due to harmonic vibrations. Do I want to deal with all these issues for 6-8 hp? No.

romancer

slow down power steering....i don't know about that.....[:@]

jdaniel

Ok, here it is folks. UD pulleys slow down your accessories by only 25%,thus your water pump and Alt. will spin a tad bit slower in turn allowing the engine to rev faster. I live in Texas and my car has seen temps of 110 degrees and never once has my car come close to over heating. I also use my lights in the day along with the radio and A/C and a cell charger and sometimes a laptop charger and not once have I experienced a voltage problem. Im convinced that Steeda UD pulleys are more than completly SAFE!

Any more questions?

jdaniel

WAY TOO MUCH CONTEMPLATION HERE!!! Never have I read such stupidity EVER! You will not blow an engine due to crank vibration because I drove to Killeen From South Padre Island (800 miles) in a '94 Cobra with a bad balancer seal making the whole car shake. It didnt blow and the car didnt even have UD pulleys! Like I said... ive had mine for over a year and never had a problem. Its stories like this that scare people out of modding their cars because ignorant people open their mouths and speak without experience!

DIVER8374

Thanks jd for clearing all this up, I was on the fence about pullys, but now and going to add them to the list of modd's that i must get!!!

jdaniel

No problem at all.

Chopper

Harmonic vibrations"torsional or twisting"are not the same animal as dynamic "side to side"vibrations.The only thing the bad balancer in your case would do on such a short trip would be to wear the front bearing a little more.Torsional vibrations work over a period of time to start stress fractures that lead to cracks that will cause failure at some point.This doesn't happen very often in cars because the engines are operated at low power levels most of the time.Aircraft engines,on the other hand are operated at high power levels ALL the time,and are built so much stronger than the engines in our cars it's pitiful.Some engine-propeller combinations are discouraged because of a problem of torsional vibrations causing the crank to break and the propeller to stop turning.This is a well known fact.Even more engine-propeller combinations are restricted from operating in certain RPM ranges because of the same torsional vibrations.This type of vibration can't be felt by the pilot.Dynamic vibrations are felt by the pilot and can be as severe as you can stand before they are dangerous.The reason why the aircraft example was given is because these failures have been tested and documented by the FAA and the NTSB.When was the last time Ford took a crankshaft out of a customers blown engine and tested it to see what caused it to ACTUALLY fail.

jdaniel

I have no clue when the last time they pulled one out to test it. LOL Im sure the crank would hold up under a lot heavier conditions though. Hell, it will hold what.... 1000fwhp? My question is why do they match such strong cranks to such weak connecting rods and so on?

propellerhead

There's vibration and there's harmonic vibration. http://www.atiperformanceproducts.co...mper_dinan.htm

Stupidity? You decide. It might apply to you. It might not.

I chose not to take my chances for the small gain the pulleys would give.

romancer: Isn't the power steering pump driven off the main pulley? If so, then a smaller main pulley will slow down the power steering pump too, unless you change the power steering pulley to compensate.

romancer

hell, i don't know. I am so used to using power steering i don't know if i would like it being slower...don't think that i am experienced of a driver enough to remember to pull my wheel just a bit to get back into place.