Rich do you have any trouble with Voltage? Like in when the efan is running with the defroster on and having the Underdrive pulleys?

I dont have the pulley but my truck will struggle at idle already I would hate to see this get worse after installing the Underdrive pulley.

 

No.. no problems at all.

Check out the two pics at the bottom of THIS PAGE for my voltage measurements.

This morning running I was playing with the scanner and it was reading 14.1V on the hwy.

The **only** problem I do have is in the summer and running the AC. If it's 90s and I sit in traffic for more than 2-3 minutes my AC will start to get warm. But.. I've also sat dead still for 40 minutes with the AC cranked (e-fan running) w/o a problem. It wasn't as cold as I'd like. But it worked fine.

Rich

 

Cool graphs. Exactly what I wanted to see. Thanks!

So I should get similar results, efan maybe a bit different. If I read a lower voltage with nothing on I could just assume its the alternator wearing out, I would think.

 

Oh.. something just dawned on me. My flex-a-lite starts the fan at 60% and will hold it there until/unless the controller sees added cooling is needed.

So... I don't know for sure... I'd guess it's pulling around 12-15amps in those graphs.

Tell ya what. At lunch I'll turn everything on max and let you know what the volts read. (after a 2-3 mile drive)

Rich

 

Ok cool, these results are at idle? Idle is all I am really concerned about. At idle my voltage gauge drops a lot when my efan is on it will not hold steady.

 

Yep. I have *in gear idle* set at 700rpms and *park/neutral* set at 800rpms.

I'll turn every thing on max and report both speeds.

Rich

 

Awesome. thanks

 

Idle results:

In park = 800rpms
In Drive = 700rpms
Nothing running = evrything possible turned off
Everything running = AC on max, wipers, both windows, e-fan @ 100%, radio, lights, fogs, brakes, turn signal.


Park-nothing running = 14.1V
Park-Everything running = 12.5V

Drive-nothing running = 13.9V
Drive-everything running = 11.8V


On that last one (11.8V) you could tell everything was running slower. The fan speed went down, the wipers were slower, ect... Raised the idle to 800 and it all comes alive and the volts go to 12.5

Rich

 

very nice Rich. Thanks.

That answers all my questions, only problem is I found that scangauge II group buy and bought one of those instead of the pulley. LOL

So many things to buy, not enough money to buy them with always seems to be the case.

I appreciate you checking on this. Looks like the effect on the alternator is not enough to hurt anything.

 

IMO no problem at all. *If* a guy spent a fair amount of time idling **and** could'nt raise the idle speed? Then maybe. But with a x-cal all you gotta do is raise the idle 100 to 150 rpms and there is no issue at all.

Rich

 

I am so good at finding these old threads..lol...
Has anyone with the OHV tried the underdrive pulleys? If so..which ones did you try..or all? And how do you know what size belt to get? Thanks

 

Anybody?

 

they workwell if you can install them yourself, just not worth the 2 hour labor charges.

 

Rich, off topic kinda but why is an underdrive crank pulley for a 4.0 is $250ish and one for a 3.0 is like $80?! Seems like alot of dough for what it is.

 

the 4.0 crank pulley comes from the factory with the harmonic balancer built into the pulley. This adds greatly to the cost. The 3.0 is a piggyback pulley from the factory, the pulley bolts to the harmonic balancer.

 

I see, that would explain the cost. Thanks.

 

hahaha....i love bumping threads. lol...


so...quick question....I run my a/c quite a bit in the summer. not on full blast, but on the bottom speed notch. would i have squeeling issues if idling and running a/c? just a bump up in idle rpm's using the xcal 2? oh...i'm a manual trans too.

 

I've used a 85" belt which is about the largest you can with just the crank underdrive and had no problems at all. I'd recommend a 84.5" belt.. and is now what I use.

As far as rpms I'm set at 704 in drive and 804 in Neutral.

Rich

 

Thanks Rich. Appreciate it. should be installing mine later today.

 

so if i've read all of this right i just need the 4.0L underdrive crank pulley and a 84.5" belt for the performance gains? how much decrease in the power will i see if i put the overdrive alternator pulley? Also what gains are ya'll seeing now?

 

I read it all too and I just want to be clear that underdriving the crank and over driving the alt should bring me closer to factory speed on the alt? I upgraded to a 130amp alt and I just want to make sure I won't be losing any gains from the upgrade by swapping the pulleys

 

I just read through the whole thread and I have the underdrive crank and fabbed up one for the water pump as well. I'm running the smallest alt pulley that I could find from Ford. I also have the 130 amp alt and electric fan. The voltage drops when everything is running but I've never had a starting problem. The a/c still blows cold and I average 19-21 mpg combined mileage.

 

How bad is this thing to put on? Are we talking like half a day with the correct tools? Just wondering cause I'm going to go get me an underdrive pulley asap.

 

With the right tools anywhere from an hour to 3 depending on your mechanical inclination. I'm pulling mine off because I just installed the blower. If my buddy doesn't buy it locally, it will be up for sale.

 

Talking about the correct tools, there is some kind of tool that "has" to be used to get the old crank pulley off. Is that really necessary? But yeah if your buddy don't want it, I will definitely be interested in it, let me know. Thanks!