[lt1097]

I thought Bullitts came with underdrive pulleys already installed. Will there be much of a difference using the Steeda pullies instead ?

 

[roushraven99]

yes

 

[Brad1790]

Well said, Arthur.

Get the Steeda pulley's and you'll see what we mean. It's well worth it. The crank pulley is the one that makes the most difference and the Bullitt has one from a stock GT.

 

[Bullitt4542]

Ford says we have "modified" alternator and water pump pulleys. They don't mention the fact that the crankshaft pulley is the same as the GT, as Brad pointed out.

 

[crs2879]

For you guys that have this, did you only change the crank pulley? Does it require a different size belt?

 

[Bullitt4542]

Most people just buy the whole set from Steeda and change all 3. That way you get to retain the original belt.

 

[Brad1790]

You do not need to change the alternator pulley. It is the same size.

 

[Mid Life Crisis #388]

I believe the stock Bullitt belt is 94.7 inches, the stock gt and cobra belt is 93.5 inches. So if you change the crankshaft pully you may want to go get the smaller belt.

 

[Mus408]

It do make a difference.......more so than my chip did! By using the Steeda crank and water pump pulley,the stock belt worked fine for me. Like they said the Bullitt Alt. pulley is the same.

<font size=-1>[ This Message was edited by: Mus408 on 2001-12-17 21:33 ]</font>

 

[tracktoy]

I only have the crank pulley and am having a hard time finding a belt that will work. i have taken the belt and pulley off three times and neither belt fit. I dont want to take it off but one more time so i am thinking a 92.x will do. can someone give me an exact belt size.

thanks

 

[TrueBlueBullitt]

Just take the stock belt to a parts store and tell them you want one that is 1.75 inches shorter. This is assuming you just changed the crank pulley. Ask for a poly-cog belt. They last longer.

John

 

[Badkharma]

Call me stupid, but can someone describe what the advantages are of replacing the 'underdrive pulleys'?? I don't know what they do or anything. Like many others on this forum, we all are learning a lot from you gearheads. :smile:

 

[Mus408]

The idea is that the slower you spin the water pump,power steering pump,and alt.,you decrease the amount of power needed to spin them. All these things take a certain amount of power to operate. 5 to 7 HP is what you should save.

 

[Badkharma]

Ok, I understand that (thanks!), but if you slow down those items, won't it produce less output (ie, alternator)?? It just seems to me that you're stealing power away from those items that require it. Basically what I'm asking is, do the underdrive pulleys reduce the REQUIRED output of those items, or is it reducing EXCESS power to those items??

 

[BullittMike]

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2001-12-21 22:57, Badkharma wrote:
Ok, I understand that (thanks!), but if you slow down those items, won't it produce less output (ie, alternator)?? It just seems to me that you're stealing power away from those items that require it. Basically what I'm asking is, do the underdrive pulleys reduce the REQUIRED output of those items, or is it reducing EXCESS power to those items??
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>

When you replace the underdrive pulley to a smaller one, you should replace the water pump pulley to a larger one. Think of your bicycle and it's gears. When you have a big gear in the front and a small one in back, its really hard to pedal, right? But when you increase the size of the rear gear, it gets really easy to pedal.

So, in this case, you replace the underdrive pulley with a smaller one and replace the pump pulley with a larger one. This way, the engine doesn't have to work as hard to turn the units at the same rotational speed (or close to it I guess).

Hope this helps.

 

[Badkharma]

Ahhh, gotcha. It all makes sense. I was sort of figuring that the sizes would have to be different. Thanks for the info guys, I learn something new every year!! :grin:

 

[llama_boy]

For further reading about interchanging the pullies try:

http://www.bullittclub.com/phpBB/viewtopic.php?topic=3232&forum=2

 

[Mid Life Crisis #388]

Using a smaller pulley on the crank will SLOW down your accessaries. Or using a larger pulley on the accessaries will do the same thing.
The kits changes both sides, larger pulley on the accessary and a smaller pulley on the crank. This way the are able to get more reduction and keep the factory belt. When Ford gave the Bullitt undersized pulleys, they only did the alternator and the waterpump. This was like half of the steeda kit. We got some reduction but adding the smaller crank will give you some more also.

side note. The tensioner is about shot at 50,000 miles and voltage at idle will be lower than it could be. If I were using an underdrive pulley system then I would want to change the tensioner around every 50K just because you are already on the edge with the reduced speed.

actually the reduced drive for the alt comes standard with the Cobra alt. they are at 2.82:1 ratio and the regular GT alt is at 3.16:1 ratio.
_________________
Mid Life Crisis #388



<font size=-1>[ This Message was edited by: Mid Life Crisis #388 on 2001-12-22 10:42 ]</font>

<font size=-1>[ This Message was edited by: Mid Life Crisis #388 on 2001-12-22 11:51 ]</font>

 

[Mus408]

I did a voltage check before and after pulley swap,with lights,A/C on at idle....no drop noted.