I am looking at putting some ASP underdrive pulleys on my 94 Z-28 M6. i believe its 23% underdrive on the crank and 15% overdrive on the alt..

 

I have been using the balancer replacement under-drive pulley for the past year or so with no problems. I'm even running a small 10" sub with no problems even at idle.

 

The ASP parts are high quality. Their integrated pulley/damper is a better choice than the "sandwich" type add-on pullies that mount behind your stock damper. But, since the LT1 water pump is not driven off the serpentine belt, there's not a lot of HP to be gained with an U/D pulley.

 

I remember Ion from Madz28 tune told me that:" if you got a bolt on car or with a small cam you should go with the ASP 945100 underdrivge only".It will full charge at 800rpm ,so it will be fine with the stock 750rpm idle.

If you got a bigger cam go with the kit(alt and crank).It will fully charge at 900rpm.

 

This is where the M6 guys have a slight advantage. They can keep the idle a little higher so their still charging the battery. If you have a A4 with a stock converter it's not that easy. But, as was mentioned, the pulleys are a very small gain.

 

Okay, so first, I'm not picking on you--I really would like to know: Is this really a concern? I mean, one would have to be stuck in city rush hour traffic and running a LOT of stereo to drain the battery down. I would think that regular driving is above idle and would not affect the charging.

 

I've had ASP crank/alt pulleys since 1999 with absolutly no probs. When I installed them, I didn't notice much of a power increase, but I did notice that it seemed to feel much smoother when reving. I can also say that they are very high quality parts. They are on my new motor now and I expect that they will be on the next one as well

 

Don't take it the wrong way, I'm not sure if my alt. pulley was overdriven or not. But at idle the alt. was not charging with my A4. It wouldn't start charging untill after 1k. I hear the ASP's are the way to go, as far as not being piggy back as was the case with mine. Just remember, for the money your not going to gain very much HP. It might be wise to spend or add that money to some other way to increase your output.

 

you won't see much gain at all, i had one and took it off after installing some subs. its not worth the trouble or the money. just like injuner said the water pump is not belt driven to you wouldn't see much from it.

it would be best spent elsewhere

 

i just ordered these from summit...

i want to know what does the stock damper look like?

all i have is a pulley bolted to a crows foot looking piece...
am i missing something?

 

That stock pulley bolted to the crows foot (balancer hub) is the LT1 "balancer" , its actually neutral balance and more of a dampener.

 

Of all the vendors on the market dealing with underdrive pulleys, ASP would probably be your best bet in terms of quality and a part that will give you some actual gains.

 

ASP 23% pulley/balancer combo in for 10 years...Never dyno'd before or after, but motor seemed to rev a wee bit quicker,or it could be wishful thinking...Its a high quality/durable piece and has no idle charging issues...

--Alan

 

I'd agree with most of that. Only I have had mine for about 2 years. Only pulley I'd buy for our cars.

-Dustin-

 

i dont like the idea of deleting the damper.