Underdrive pulleys
 

So i've been toying with the idea of getting a set of undedrive pullies, i've read almost only good things about them.... ....but I also heard that the car can overheat if you run pulleys that are smaller than a certain size. So have you guys had any bad experiences with a specific brand, so far I was thinking of going with the BBK 3 piece pulley kit.
rockon:

You must be reading my mind thumb: I'm looking to do the same and also looking at BBK. Their only $140.00 on eBay and I've read some good reports on the Mustang Form with a 8 to 10 HP gain. I would like to hear what others (with more experence think) rockon:

I bought the Mac set.
And personally I noticed a differance.

But if you were smart you would buy the BBK's
I had to machine the Mac Water pump pulley approx. 3/8" Off.......
Maybe I just got a bad one!

sweet, bbk it is.

They will give a gain, probably 5hp or so.
Only problem I ever had with them is charging. With lights, stereo and blower on, you will be discharging the battery and taxing the alt. as well. If you don't drive in cold at night-you should be fine.
If you have a poor battery it will be quite noticeable. Best fix for it is a nice Optima battery since they hold a charge much better.

or a more powerful alternator!

^Idle output is usually the same regardless of max output, they need to spin to make power..............

So i guess i just wont stop for red lights! In all seriousness though, my 87 is pretty basic, no power anything, no ac, if i run an aftermarket stereo ill make sure to run a capacitor to take some of the strain off the battery. I have a new battery in there as we speak.

i have a set of underdrives on my 90. noticeable difference. but mine did start to get hot this summer like 195 where as before it never got over 180. I just fixed the problem 2 weeks ago by putting in a 4 core rad. and an electric fan.

electric fan is in the plans right now, maybe i will consider a new radiator

I noticed a significant difference with my 04 after I installed the bbk.

i have march pullies and i difenitly did notice a diffrence i have had no problems at all... i just noticed my power steering does get a lil weeker but id say for the better

I have them on my 94 and when I am at idal the lights will dim a little but that is about it

If you have a 87-93, you could go over to gtamc.com and PM Roland he has a set FS for only like $45.00 Shipped.
Hope this helps ;)

I ran underdrives on the '87 (and now on the Capri) and you can have them charge at idle.

A 3G alternator makes substantially more power, at a lower RPM, then our stock 65A alternators do.

SO,

Step 1 is to purchase a much more efficient 3G alternator in preparation of doing the 3G alternator upgrade.

Step 2 is to remove the stock tiny pulley from your 2G alternator and the larger pulley from the 3G and put the smaller, stock 2G pulley on your 3G.

Step 3 is to install your underdrives but intentionally omit the alternator pulley due to step 2.

You will now be underdriving everything (including the alternator, only now by a smaller margin) and the car will charge at idle.

I ran a Taurus SHO fan, small stereo, and with all power accessories running, lights on, the whole deal, the car would still charge at idle.

And, FWIW, I never had a heat problem either, even when the engine was modified with the underdrives.