LAST EDITED ON Feb-29-00 AT 02:05 AM (EST)

A few days ago I realized that I still had some Tbird 4.6/Mustang 4.6 underdrive pullies sitting in the garage doing nothing... Got 'em on tonight, and folks I really believe this mod is well worth the bucks. Improved midrange power quite a bit -- it seems, much better pickup on the freeway. Can't see a major difference at low speeds though.

Luke Walling

http://www.wallingdatasystems.com/93mark8.html
'93 Mark VIII
ASP "Tbird" underdrive pullies
True Dual Exhaust (Edelbrock Tru-Flo's)
17" OZ Nova 17" Wheels
More to come...

Do you remember what ratio the pulley system was? I have been thinking about doing that some time since it is such a minor price.

Mike Gilbert
http://nightsky.home.texas.net/markviii
'93 Mark VIII
black/black

I think we had this discussion on the old board. The only thing that concerns me with the underdrive is the alternator. Our cars can suck a tremendous amount of current, and from the plots I've seen of my company's alternators, as well as stock ones, they're not even close to putting out any juice at idle, and it looks like 1600-1800 engine rpm is where they begin to produce over 100 amps of current. If you drive a lot in traffic, with the motor idling for long periods of time, underdrive pulleys might not be such a good idea. If you drive a lot on the highway, then it may be the ticket for you.

Just my $0.02.

Calvin Louie
<callouie@mindspring.com>

Calvin Louie
1989 Porsche 928 S4 - Linen Metallic / Linen

I have the same concern. My lights will already "dim" slightly if I am stationed at a red light at night, and I turn up the sounds. Do you have subs in your car?

The other alternative is to get the 130 amp Cobra alternator. I've heard it puts out some good juice at idle.

Kale

Not sure on the ratio -- they are just ASP Pullies made for a 96 Tbird or Mustang (4.6ltr), one catch to it is you have to machine off the back of the supplied alternator pulley to get it to fit correctly, no problem.

As far as current drain.. I flicked the a/c on max, stereo on, and headlights on bright last night at about 2am and it took about 20 seconds or so for the headlights to dim down a bit.. Not noticably worse that it was before w/o the pulleys -- quite suprising to me, but that really isnt a true test I imagine. I am suprised at how well they do seem to work so far. I dont drive alot in traffic, in the mark8, regardless... So I may not be the best judge of what will happen if you do .

In response to Kale, I have no subs Just the factory JBL stereo setup.

Luke Walling

http://www.wallingdatasystems.com/93mark8.html
'93 Mark VIII
ASP "Tbird" underdrive pullies
True Dual Custom Exhaust w/H-Pipe
17" OZ Nova Wheels
More to come...

I'll have to do some research on that one... One of the things I have to replace first is my alternator. It is only putting out 13.0 volts now compared to the 13.8 that my battery says it requires for proper charging. I have no idea what sort of amps it is throwing out. As for the subs, I found it always good to invest in a nice capacitor. Keeps that battery and alternator from feeling a strain so often.

Mike Gilbert
http://nightsky.home.texas.net/markviii
'93 Mark VIII
black/black

If anybody is looking for a 'hotter' alternator, please check out Wrnagler Power Products. A 200 amp cold/180 amp hot alternator is available for our Marks. I put one in four years ago and the damn thing still pumps out a 100 amps at IDLE! No kidding, honest. Not a lick of problems with electrical current. I am toasting optima yellow tops, but I think it is from a different problem, relataing to a battery back-up on the alarm. BTW-If anybody has one of those, yank it ASAP. They go bag quickly and eventually start draining the battery, cycling it every time you start the car. I've seen it before and now it is my turn....time to pull it!

I have a red top that gives me problems occasionally... I have to put it on a charger to get it going again right... The battery backup that you are talking about, is that an aftermarket or OEM system?

Mike Gilbert
http://nightsky.home.texas.net/markviii
'93 Mark VIII
black/black

Let me clarify, the battery back up is for my aftermarket alarm. Those things are soooooo useless. I put it in for kicks and grins. I yanked it recently and will put my alarm and remote start of my second battery. I know, more weight slower car, but I still love loud and clean stereo systems. It is a toss up at the moment. Plus, it will give me an excuse to by the supercharger for it
BTW-I wouldn't recommend underdrive pullies with aftermarket stereos. As mentioned, before our cars are current draining pigs and less current/power and things WILL start blowing up. I have seen it happen many a times. Just my $.02.

Optima batteries do not do particularly well after being deep cycled. The red tops are pretty much toast after a few complete discharges (they were never designed for it anyway), and the yellow tops, while advertised to be deep cycle, loose a significant portion of their capacity after only 3-4 deep discharges. Additionally, I've had problems in the past with leaking around the top posts on a red and blue top Optima.

There are a number of better batteries with similar high energy densities, I personally use a battery based on the Hawker Energy Products battery, much smaller and more powerful than stock, and comparable to an Optima.

Calvin Louie
<callouie@mindspring.com>

Calvin Louie
1989 Porsche 928 S4 - Linen Metallic / Linen

Folks,

I'm guessing my '93 will need a new battery soon. If left for several days (4-5) it turns over pretty slow. The battery in the car (after a very brief look) appears to be shorter (less tall) than other car batteries due to its location. Any suggestions on good brands? Any problems finding a replacement?

Chuck in NC