: Let's talk Pulleys, whose got one, what kind, how much power???



AlmostAV
03-10-09, 12:24 PM
Im looking to do an underdrive pulley. I know asp makes a descent pulley but some people have slippage. Trickflow just released one that I may look into. I know there are other brands out there so lets hear what you got. Id like some info regarding a few things

1. driveability maintained? this is my dd, so i want to maintain driveability
2. power gained?
3. was it worth it?
4. what brand pulley? and what type of belt?
5. ease of install?
6. any issues to date?

Thanks guys

trukk
03-10-09, 01:19 PM
I have an ATI 25% UD pulley. Installed the sametime as my cam, so I don;t have any idividual numbers for it. Since I've had it I'm on my 3rd Alternator. It may or may not be related. If The one I have now burns up in the next few months, the UD pulley will be comming off for sure. Untill then the Jury is out.

Comments inline:


Im looking to do an underdrive pulley. I know asp makes a descent pulley but some people have slippage. Trickflow just released one that I may look into. I know there are other brands out there so lets hear what you got. Id like some info regarding a few things

1. driveability maintained? this is my dd, so i want to maintain driveability.
No issues aside from the Alternator stuff listed above. No belt or other issues seen.
2. power gained? Installed same time as my cam, so not really sure. Perhpas 10ish HP?
3. was it worth it? Yes, unless my alternator goes out again. I tink this mod makes sense of you are swapping a cam. If not, not worth the effort.
4. what brand pulley? and what type of belt? The only pulley you should consider is ATI. The others just don't have the quality that I'd like to see. Remember the purpose of the harmonic balancer is to prevent shock and vobrations to the crabkshft. If it's not doing that you are in for real trouble down the line. Here is the belt I used with 25%:
http://img528.imageshack.us/img528/857/41154d1208200966accesorzy0.jpg
5. ease of install? Had shop install. You have to pull the front off the car, and the radiator. Don't forget to get a new balancer bolt, as the OEM GM one can only be used once. Get an ARP on (about $25), they are very high quality, and can be re-used as many times as you want. Liek I said earlier, this only really makes sense if you are doing the cam as well.
6. any issues to date? I'm still waiting on the laternator issue.

Thanks guys

As of right now, I'd wait ond see on the alternator issue. I know PeedRooster (or whatver his name is) had an issue with his, that really caused him some problems. I definately wouldn't use an ASP, if you are gonna do it, use ATI or go home.

-Chris

lollygagger8
03-10-09, 01:36 PM
Guess I won't be getting a pulley anytime soon.....especially after reading about Ewill saying he'll take the radiator out next time to make the alternator removal easier.

No thanks.

Thanks for the heads up Chris

trukk
03-10-09, 01:48 PM
Guess I won't be getting a pulley anytime soon.....especially after reading about Ewill saying he'll take the radiator out next time to make the alternator removal easier.

No thanks.

Thanks for the heads up Chris


No prob. If I have another alternator issue, I'll be sure to let everyone know.

-Chris

lollygagger8
03-10-09, 02:27 PM
Seems like......

Pulley = Alternator Eater

trukk
03-10-09, 03:17 PM
Seems like......

Pulley = Alternator Eater


My first alternator puked after getting spewed with power steering fluid at the track. The second one that went bad, did so all by itself. I don't think I have enough data points to make a conclusion just yet. If it goes bad again though.....

Might want to think about getting a smaller alternator pulley though, to match the 25% UD on the HB. No clue if anyone make them, or if the pulley could even be removed from the OEM alternator.

I have had no issues with cooling or the waterpump since I went to the new pulley.

-Chris

AlmostAV
03-10-09, 03:34 PM
do they make a 10 or 15%????

trukk
03-10-09, 03:48 PM
do they make a 10 or 15%????

Ya, ATI does make a 10%.

-Chris

ewill3rd
03-11-09, 08:23 AM
Chris I am not sure why this last one failed but I do know the connection was badly overheated on the back of that generator.
I had to turn it in for parts warranty or I'd show you.
I think I still have your original one around here somewhere, there was no core on it.
Yeah, here it is in this box... lol
I really need to throw stuff away.
;)

trukk
03-11-09, 11:47 AM
Chris I am not sure why this last one failed but I do know the connection was badly overheated on the back of that generator.
I had to turn it in for parts warranty or I'd show you.
I think I still have your original one around here somewhere, there was no core on it.
Yeah, here it is in this box... lol
I really need to throw stuff away.
;)


Bill,

Could you say that in english please? :D

Do you think my issue is heat related from my headers?

-Chris

ewill3rd
03-12-09, 08:17 AM
No it looked like an electrical issue. Again, not clear if there was some sort of internal connection issue here or what.
The main power connection had gotten too hot from current flow and melted itself from what I remember.
The control connection was fine.
The clearance to the headers is fine on that.

trukk
03-12-09, 09:19 AM
No it looked like an electrical issue. Again, not clear if there was some sort of internal connection issue here or what.
The main power connection had gotten too hot from current flow and melted itself from what I remember.
The control connection was fine.
The clearance to the headers is fine on that.


Hmm...OK.

Well I keep an eye on it. If it goes out again, it is almost certainly being caused by the UD pulley.

-Chris

thebigjimsho
03-15-09, 12:57 AM
I've never felt as though pulleys were worth it...

Scatillac
03-15-09, 02:06 PM
^^With the reduction pulleys, there may be some truth in that, especially for street use and they have no harmonic damping capabilities, but an ATI is a true harmonic damper as well as a reduction pulley (depending on how it's spec'd out), making it a good investment if you have an extensive (read:expensive) and high rpm modification list.

All endurance racing mediums employ the reduction technology to gain every edge possible, but their motors see 7500+ for hours at a time.

GM has done this through the years (especially in the 60s and 70s) on their really high rpm engines for two reasons: accessory life and reduction of parasitic loss of power. Most of these engines were easily capable of 7k crankshaft speeds.

As far as power gains from accessory drive speed reduction, GM did this on the Z06 LS7 (to further enable the breaking of the 500 hp barrier) by enlarging the power steering pulley and the alternator pulley, leaving the crank pulley and water pump pulley alone. This could also be true with all the Y-car engines after 2006 but I haven't looked to verify.

Vs also have a larger (and higher quality) alternator pulley than most LS-based variants.

With all this said, I do have an ATI setup on my car, but it's only a 10% reduction. Following the GM engineer's lead, I also have the LS7 p/s pump pulley. There are no issues with the cooling or electrical systems, and there is no discernible difference in the p/s feel.

If you're having alternator issues, monitoring the alternator output after a reduction pulley installation would tell the story. Output within factory spec would say that things should be o.k.

jpoole
06-10-09, 10:25 PM
^^With the reduction pulleys, there may be some truth in that, especially for street use and they have no harmonic damping capabilities, but an ATI is a true harmonic damper as well as a reduction pulley (depending on how it's spec'd out), making it a good investment if you have an extensive (read:expensive) and high rpm modification list.

All endurance racing mediums employ the reduction technology to gain every edge possible, but their motors see 7500+ for hours at a time.

GM has done this through the years (especially in the 60s and 70s) on their really high rpm engines for two reasons: accessory life and reduction of parasitic loss of power. Most of these engines were easily capable of 7k crankshaft speeds.

As far as power gains from accessory drive speed reduction, GM did this on the Z06 LS7 (to further enable the breaking of the 500 hp barrier) by enlarging the power steering pulley and the alternator pulley, leaving the crank pulley and water pump pulley alone. This could also be true with all the Y-car engines after 2006 but I haven't looked to verify.

Vs also have a larger (and higher quality) alternator pulley than most LS-based variants.

With all this said, I do have an ATI setup on my car, but it's only a 10% reduction. Following the GM engineer's lead, I also have the LS7 p/s pump pulley. There are no issues with the cooling or electrical systems, and there is no discernible difference in the p/s feel.

If you're having alternator issues, monitoring the alternator output after a reduction pulley installation would tell the story. Output within factory spec would say that things should be o.k.

Hi Scatillac, what belt did you use and do you have a PN on the LS7 pulley? Also, how hard was this to install?

Thanks, Jeff

trukk
06-12-09, 08:54 AM
I've never felt as though pulleys were worth it...

I only did it becuase I was doing a cam, and the OEM balancer was already off. Certainly not worth doing by itself.


No prob. If I have another alternator issue, I'll be sure to let everyone know.

-Chris

No problems so far. I'll let everyone know.

-Chris

SoJersey05V
07-06-09, 12:31 PM
if i can i want to open this back up... my car went in the dealer to check it out for this vibration i have... comes and goes away. high speed no problems, low rpm speeds vibrates like crazy... little to no vibration at idle...

dealer called me and told me that the harmonic balancer went bad... some sort of rubber pushing out of it... origional price was $1250... said for me they will do it for $720... that being said he said that the new balancer itsself was only $110 .... hmmm

now i'd like to know what you guys think i should do.. go with like a 10% under as Scatillac did? or does ati make a stock replacement if so is it worth the money? and also install.. how bad is it? is it something that can be done by the backyard man?

deedubb
07-06-09, 12:33 PM
AV, aren't you trying to sell your car? Why would you be upgrading parts if you're trying to unload?

thebigjimsho
07-06-09, 02:09 PM
AV, aren't you trying to sell your car? Why would you be upgrading parts if you're trying to unload?
Another one goes down to TBS, Thread Bump Syndrome....


Now if anyone can come up with an acronym making it TBJS, you win a prize. Not that I bumped this thread, though...

CTSV_510
07-06-09, 03:40 PM
Thread Bump Jackass Syndrome

thebigjimsho
07-06-09, 04:31 PM
Thread Bump Jackass Syndrome
Now, now. No prize for you.