NW Iowa WS6

iTrader: (9)

I am really looking into an ASP pulley kit from t-byrne and it slows down accessories. Does that mean my power windows etc. will be way slower etc.?

Blue2002SS

iTrader: (13)

nope, It will not affect your power windows. It will just slow down your power stearing pump, alt., A/C, ect.

I love my underdrive pulley, I would say get one!

NW Iowa WS6

iTrader: (9)

Awesome.

ADAM SS exy

any actual gains?

VETTEX2

not enough for the money

98SS Blackattack

Thats how i feel at this point. They should be 150 with the belts

2001CamaroGuy

iTrader: (6)

I disagree......

I noticed a definite increase in the performance over the stock crank pulley



In addition to the HP gain, the factory crank pulley is a PITA to put on and take off. So much so that I WILL NOT help someone do a head/cam swap if they DON"T have an aftermarket pulley.


I did the ASP underdrive crank and the overdrive alt pulley....that way I gained some HP yet kept the charging system working at facotry specs

Blue2002SS

iTrader: (13)

I have to disagree also, I think its worth the money. you can feel the diffrence mostly in first gear.

jaberwaki

i disagree also but i would find someone selling a used one...
5-10 hp gains not un common at all... pretty much the norm...

samz28

less reciprocating mass, similar to lightening a flywheel, you are not GAINING any hp, just FREEING the driveline up a little. Makes the rev's come up a bit faster, puts less wear on the (anything tied to it). Can possibly unbalance the motor since it was factory balanced to XX mass.

The motor without the flywheel/pully accessories would probably make the same hp with or without the pulley you know what i mean?

jaberwaki

samz28
the rotating mass and speed of accessories in relation to the crank pulley is the same as your drivetrain is called parasitic loss...
lets say a turn key motor with all accessories in place on a motor dyno makes 400 hp with no drivetrain...
add the drivetrain and slap it on a chassie dyno and you will lose 15-20% hp over your drivetrain because your motor has to work to turn these parts...
now take off all the accessories and you might get 5% of that back...
is your motor any stronger ... well no ... but it will dyno higher and go faster because it is not working as hard as it was ...
underdrive pulleys are lighter and smaller creating less work for your motor over all your accessories....
thats why it dynos higher with this mod...

2001CamaroGuy

iTrader: (6)

GAINING/FREEING, it all comes down to "I have more HP at the rearwheels"

While lightening things will not "MAKE" HP (does not cause more air/fuel to be burneds, for semplicity people say "I gained 5 HP from ____ ." Don't be so picky on peoples words.

Changing flywheels and balancers will make ZERO difference to the balance of LS1s (unless they were not balanced correctly) as they are INTERNALLY balanced. The Flywheel and balancer are neutral.

Zo6Killer

I don't have the ASP, but I think I will. On my '67 327, I added March Pulleys (Crank, Alt. & PS) and picked up IMMEDIATELY 2 tenths with no other changes. The nicest thing, though, was that the motor revved much faster. I could get to 7K in 1st like I never had before. I'd say go for it. Just my .02

Benjamin Russick

iTrader: (1)

Got mine with the belts used for cheap. You just gotta jump on any that come up in the classifieds... Great mod and easy install, but I had my heads/cam before I could dyno with just the pulley, so no accurate rwhp #s for just the pulley.