asp underdrive
Drifting
Joined: Jul 2005
Posts: 1,969
Likes: 8
From: NJ
Rock,
There are 2 methods to do this. Basically you need to get the steering rack out of the way to take off and remove the pulley. One method is to remove the steering rack, or more accurately slide it to the passenger's side out of the way, the other is to support the engine and lower the k-member. I prefer lowering the k-member but either way works.
While you are in there you may want to think about pinning the crank to avoid the dreaded bolt back out.
If there is any interest in a complete list of steps I could try and pull them off the top of my head. I actually just did this last week to take off my ASP. Had to go back to stock for a blower.
There are 2 methods to do this. Basically you need to get the steering rack out of the way to take off and remove the pulley. One method is to remove the steering rack, or more accurately slide it to the passenger's side out of the way, the other is to support the engine and lower the k-member. I prefer lowering the k-member but either way works.
While you are in there you may want to think about pinning the crank to avoid the dreaded bolt back out.
If there is any interest in a complete list of steps I could try and pull them off the top of my head. I actually just did this last week to take off my ASP. Had to go back to stock for a blower.
Safety Car
Joined: Jan 2006
Posts: 4,598
Likes: 78
From: Miami FL
2020 C6 of the Year Finalist - Unmodified
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16,'17,'18-'19-'20-'21-'22
Charging issues?
Some tuners (OK, one tuner) are saying that there are charging problems with the UD pulley, so they want to sell me (1) an overdrive alternator pulley, or (2) a high-output alternator. 
(1) seems like it would defeat the purpose of the UD
(2) seems like a way to maximize their revenue.
Real world experiences ? ? ?
I have a battery tender that is usually on mine when it is parked in the garage.
(1) seems like it would defeat the purpose of the UD
(2) seems like a way to maximize their revenue.
Real world experiences ? ? ?
I have a battery tender that is usually on mine when it is parked in the garage.
Safety Car
Joined: Dec 2005
Posts: 4,157
Likes: 37
From: North Carolina
St. Jude Donor '07-'08-'09-'11-'12
I have seen no problems with my UD pulley. No messages, no dimming lights, no drain on the alt gauge, nothing. If you REALLY wanted to be ****, you could just increase the idle 15% to compensate for the 15% reduction in the pulley and you'd be back to square one.
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Thread Starter
Team Owner
Joined: Mar 2005
Posts: 20,933
Likes: 905
From: salem OR
Some tuners (OK, one tuner) are saying that there are charging problems with the UD pulley, so they want to sell me (1) an overdrive alternator pulley, or (2) a high-output alternator.
(1) seems like it would defeat the purpose of the UD
(2) seems like a way to maximize their revenue.
Real world experiences ? ? ?
I have a battery tender that is usually on mine when it is parked in the garage.
(1) seems like it would defeat the purpose of the UD
(2) seems like a way to maximize their revenue.
Real world experiences ? ? ?
I have a battery tender that is usually on mine when it is parked in the garage.
Melting Slicks
Joined: Feb 2004
Posts: 3,131
Likes: 148
From: Sugar Land TX
Were they not so labor intensive I would have one on my car already. They are good for almost a tenth in 1/4 et. Get a little better fuel mileage and your accessories turn slower so they will last longer. Good protection too for the alternator and AC compressor at high rpm. I don't believe our compressors turn off at WOT so the pulley would certainly be good protection for it.
I got almost .2 et improvment on my old 88 Mustang with a three pulley system.
I got almost .2 et improvment on my old 88 Mustang with a three pulley system.
Safety Car
Joined: Dec 2005
Posts: 4,157
Likes: 37
From: North Carolina
St. Jude Donor '07-'08-'09-'11-'12
This pic will give you an idea of what needs to come off to get to the pulley...this is my engine after the new pulley was in. The radiator, condensor, steering rack, shroud etc all had to come out.
Last edited by Craigster05; Aug 7, 2008 at 03:56 PM.
Thread Starter
Team Owner
Joined: Mar 2005
Posts: 20,933
Likes: 905
From: salem OR
Cant really tell for sure, as we put in the pulley when we did the L92/L76 conversion and a cam swap all at the same time. I picked up about 100RWHP overall. You can figure an UD to be about 5HP or so, but the labor is very intensive. Most feel unless you are doing a cam swap at the same time, it is not worth the bang per buck.
This pic will give you an idea of what needs to come off to get to the pulley...this is my engine after the new pulley was in. The radiator, condensor, steering rack, shroud etc all had to come out.
This pic will give you an idea of what needs to come off to get to the pulley...this is my engine after the new pulley was in. The radiator, condensor, steering rack, shroud etc all had to come out.
Thanks, The ASP website shows 25 percent reductionplus they are worth a solid 10 plus rwhp. I have had two of them. They are nice mod. Web site says dyno'd 13 on a ls-1 and 2-3 mpg and .2 in the 1/4. For 249.00 and the trouble
no one would do them for only 5hp.
Drifting
Joined: Aug 2004
Posts: 1,803
Likes: 17
From: Walnut Creek, CA
Pulleys WORK
You'll gain 5-10rwhp
They are a PITA to install, so unless you want to do it yourself (and have the know-how to do it), it's not worth the gain to pay a shop to install it.
/End thread.
You'll gain 5-10rwhp
They are a PITA to install, so unless you want to do it yourself (and have the know-how to do it), it's not worth the gain to pay a shop to install it.
/End thread.
Safety Car
Joined: Jan 2006
Posts: 4,598
Likes: 78
From: Miami FL
2020 C6 of the Year Finalist - Unmodified
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16,'17,'18-'19-'20-'21-'22
.