A new alternator is a worth while investment on ANY fox body. The stock systems are barely adequate for just the factory stuff, let alone adding stereo systems and underdrive pulleys.RUNINAGT said:Does that mean a new alternator??
Hope not. Have no more $$$$$$$$
Yes the 1 7/8 pulley is OK. As far as the belt size...... Are you running all the factory acc?RUNINAGT said:1 7/8 pulley? Ok do you know what size belt? Do ya have a Ford or Gates part #
Yes, at the very least.RUNINAGT said:04sleeper you mean put the stock pulley back on with a smaller belt?
Synned said:Um, I bought pulleys from 50resto.com and my crank pulley is actually smaller. Now the waterpump pulley is pretty big and the alternator is bigger, but the crank was smaller.
The crank is what everything runs off of. It is what spins the rest of the acessories. So if it is smaller then less belt will travel across it when it turns one full revolution.Synned said:Um, I bought pulleys from 50resto.com and my crank pulley is actually smaller. Now the waterpump pulley is pretty big and the alternator is bigger, but the crank was smaller.
RUNINAGT said:That's how there supposed to be. Last night I installed the factory alternator pulley back on to cure the low charging sytem issue. Suprisenly we were able to keep the same belt.
04sleeper said:Remember Math class.
If you measure the distance around a circle and divide it by the distance across the circle through the center, you will always come close to a particular value, depending upon the accuracy of your measurement. This value is approximately 3.14159265358979323846... We use the Greek letter (pronounced Pi) to represent this value. The number goes on forever. However, using computers, mathematicians have been able to calculate the value of to thousands of places. View attachment 493420
Pulley diameter VS circumference:
6 inch diameter pulley (stock) = 18.84955591 inches of belt travel.
4 inch diameter pulley (street underdrive) = 12.56637061 inches of belt travel.
3 inch diameter pulley (race underdrive) = 9.42477796 inches of belt travel.
So if you put a street pulley kit on your car the 4 inch crank pulley is slowing the alternator down already by approximately 33%. Then you add a bigger alternator pulley as well and it spins even slower. So you are really spinning the alternator down twice! Hence low charge.
Actually depending on how short your belt was the tensioner will take up an inch or so of belt.
I hope this helps.
04sleeper said:The crank is what everything runs off of. It is what spins the rest of the acessories. So if it is smaller then less belt will travel across it when it turns one full revolution.
The acessories are dependant on how fast the crank is spinning them so they are opposite. The bigger pulley you put on them the slower that ascessory spins. The smaller the acessory pulley the faster that acessory spins.
You have to think of the circumference of the pulley, not the diameter. Just a little change in diameter makes a big difference in circumference.
Remember Math class.
If you measure the distance around a circle and divide it by the distance across the circle through the center, you will always come close to a particular value, depending upon the accuracy of your measurement. This value is approximately 3.14159265358979323846... We use the Greek letter (pronounced Pi) to represent this value. The number goes on forever. However, using computers, mathematicians have been able to calculate the value of to thousands of places. View attachment 493415
Pulley diameter VS circumference:
6 inch diameter pulley (stock) = 18.84955591 inches of belt travel.
4 inch diameter pulley (street underdrive) = 12.56637061 inches of belt travel.
3 inch diameter pulley (race underdrive) = 9.42477796 inches of belt travel.
So if you put a street pulley kit on your car the 4 inch crank pulley is slowing the alternator down already by approximately 33%. Then you add a bigger alternator pulley as well and it spins even slower. So you are really spinning the alternator down twice! Hence low charge.
Actually depending on how short your belt was the tensioner will take up an inch or so of belt.
I hope this helps.
40th 2004Stang said:I've read the tech articles too that say the stock air box with the silencer removed and a K&N works just as well if not better. We did this experiment on the 04 GT. Went to the track, ran the car with the stock air box, K&N, silencer removed. The car went 14.30, 14.32, and 14.31 in stock form. Then we put the $40 CAI from ebay on it, with the blue filter that came with it. The car went 14.009, and 14.002 back to back. Did it pick up? I'd say it did, and well worth the $40.
40th 2004Stang said:I've read the tech articles too that say the stock air box with the silencer removed and a K&N works just as well if not better. We did this experiment on the 04 GT. Went to the track, ran the car with the stock air box, K&N, silencer removed. The car went 14.30, 14.32, and 14.31 in stock form. Then we put the $40 CAI from ebay on it, with the blue filter that came with it. The car went 14.009, and 14.002 back to back. Did it pick up? I'd say it did, and well worth the $40.
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?