Underdrive Pulleys

Dixie Design · #1 Sat, March 14th, 2009, 03:01 PM

Got them on! Was pretty impressed at the ease of the install once I got the correct kit for Summit. They STILL sent me the wrong belt, but I'm driving up to Duluth tomorrow, going to stop by with my collection of belts they've sent and give them an earfull.

Right off the bat I can't say I really "feel" the difference. My idle RPM's dropped about 125rpm's so I know it's working. Will be anxious to see how it effects fuel economy. I've given up on 0-60 and 1/4 mile times, tires are too expensive, lol.

dsilva584 · #2 Sat, March 14th, 2009, 08:31 PM

Quote:

Originally Posted by Dixie Design

Got them on! Was pretty impressed at the ease of the install once I got the correct kit for Summit. They STILL sent me the wrong belt, but I'm driving up to Duluth tomorrow, going to stop by with my collection of belts they've sent and give them an earfull.

Right off the bat I can't say I really "feel" the difference. My idle RPM's dropped about 125rpm's so I know it's working. Will be anxious to see how it effects fuel economy. I've given up on 0-60 and 1/4 mile times, tires are too expensive, lol.

the stock belt does work with this kit correct dixie??? also what belt did you order??

***88Racing*** · #3 Sat, March 14th, 2009, 11:41 PM

Quote:

Originally Posted by xthorxz400

the stock belt does work with this kit correct dixie??? also what belt did you order??

I know I am not Dixie but most ud pulley kits use shorter belts. Anywheres from 1/2 inch to 1 1/2 inch pending on the kit used. The troyer kit for the 5.4 requires a 1 inch shorter belt.

Lars

Dixie Design · #4 Mon, March 16th, 2009, 08:16 AM

Summit's kit works with a stock length belt. I'll get the Goodyear Gatorback part number tonight for you if you'd like, but it's the 100.5" belt I believe. Goodyear's site has a part cross reference tool, just matched it up with the Motorcraft part number.

***88Racing*** · #5 Mon, March 16th, 2009, 09:11 AM

Really, 4.6 still takes the stock size belt.

Just for curiousity what pulleys are swapped out?

The 5.4 swaps the crank and the waterpump, with new resized ones.

Lars

Dixie Design · #6 Mon, March 16th, 2009, 10:41 AM

Quote:

Originally Posted by 88Racing

Really, 4.6 still takes the stock size belt.

Just for curiousity what pulleys are swapped out?

The 5.4 swaps the crank and the waterpump, with new resized ones.

Lars

Summit's kit for the 4.6L 04 New body style and up replaces the same, crank & waterpump. The Crank was definitely bigger than stock. Their kit for the 04 Heritage and older was a 3 pulley set, with a new alternator pulley being the 3rd.

I was surprised it took the stock length belt, I bought the 99" belt first and it would NOT fit. Was half expecting the stock length to slip at WOT shifting like my old belt/pullies did, but it didn't.

way2qk4u2c · #7 Mon, March 16th, 2009, 11:05 AM

Does anyone know what part number is for the 04-08 5.4l UDP on the summit site?

***88Racing*** · #8 Mon, March 16th, 2009, 11:43 AM

Quote:

Originally Posted by Dixie Design

I was surprised it took the stock length belt, I bought the 99" belt first and it would NOT fit. Was half expecting the stock length to slip at WOT shifting like my old belt/pullies did, but it didn't.

Yes Neal that suprises me also. Just another ? Where is the belt tensioner indicating mark? I usually mark it if I am working on one that doesn't have them.

Lars

RZDANO · #9 Mon, March 16th, 2009, 12:59 PM

[QUOTE=Dixie Design;5734]Summit's kit for the 4.6L 04 New body style and up replaces the same, crank & waterpump. The Crank was definitely bigger than stock. Their kit for the 04 Heritage and older was a 3 pulley set, with a new alternator pulley being the 3rd.

Are You sure the crank pulley was larger???? That would be an overdrive.