FuriousGeorge

+1

Wally39

I've read just the opposite. Since your alternator, water pump, etc spin slower they last LONGER. Not as much wear on them.

cekim

Alternators electronics generally die long before the mechanicals...

That is, if you spin the alternator slower, it has to be in "charge" mode more often as each time it charges it takes longer to replace the energy consumed by the engine running - so its "duty cycle" is higher - potentially much higher...

So, it is a function of how "loaded" your electrical system is...

All I can say is that I have replaced an awful lot of Ford alternators - not once because the spinning parts no longer spun...

P.S In theory you could compensate with a higher current alternator... It produces more current per rotation - so you would be close to where you started.

That said, I have not heard of electrical issues with UDP often - more often cooling...

QuickShortBus

No, a tune doesn't have any bearing on the hp that you will see from UDP's. UDP's only reduce parasitic drag on the motor, it's not anything that the the computer controls.

FlaSVT

I can see some validity in saying UDPs are harder on an alternator but it doesn't totally add up. If all you ever did was let the car idle then I'd buy the slower spin = greater charge duty = quicker to burn out. Problem with this theory is most people don't just let their cars idle the whole time they are running. Once you start driving, the speed at which the alternator spins increases dramatically. I'd bet that the difference in spin rate with UDPs at 30 mph is not all that much slower that it would be with stock pulleys. I'd attribute the alternator failures to 1) being overloaded trying to push all those sub amps or 2) the alternators are just crappy alternators.

Oh yeah, hooray beer!

CrazyAl

On the one hand, since the accessories are spinning slower the mechanical wear on them is reduced. HOWEVER, the output of these devices also drops, but the load does not. Therein lies the problem.

Think about it. If there really were no drawbacks to UDPs, then why doesn't Ford spec out a lower pulley ratio from the factory? (In other words, "Stock" UDPs?) It's becasue the Ford engineers know how fast these accessories need to spin under normal driving conditions in order to properly function.

A slowed-down water pump won't wear out any faster. But, it won't cool the engine as well. Do you really want a high performance motor with a "low flow" water pump?

lukoi66

all good points and I certainly can't argue with "hooray beer."

Lemme ask this then....the Mezier Water pump....instead of UDPs can I get the MezWaterpump and free up about the same rwhp? If so (and I think it's so), what's the downside to that pump? It "appears" to be high enough flow, but is it?

cekim

Downside is cost and additional electrical load...

Nothing is free... (even electricity - despite what some thing - CA residents are getting lesson in that these last few years!)

That said it does reduce inertia to spin up the motor (during a puch of the pedel, the electricity comes from the battery more so than the alternator - under costant load, it is another story) and from most accounts and my experience, it does do a good job cooling...

I await real data on whether it actual provides an improvement in 1/4 mile time as your electrical system has to produce a lot of current to feed those plugs, the pump and injectors at high RPMs...

lukoi66

hmmm it's sounding more and more like I should bypass the UDP. But dammit I wanted that 10hp!! What else is there to do?? LOL.

Can't SC yet.....damn my paranoia about blowing the engine!!! (but I'm gonna stick with that paranoia for now, lol)

cekim

Well, the meziere isn't going to blow your engine and I have yet to hear someone who added it for power say "man that thing sucked" - they all say "butt dyno happy[sm=smiley20.gif]"...

So, take my cynicism on power with a grain of salt...

I know it cools - I just did not do it for power... nor do I trust my butt as a dyno... (did not do it on the '06)