Smaller pulley vs 10% overdrive?

[Big50]

My tuner will hopefully be in my area again soon and I am thinking of upping the boost. I was looking at the 2.75 pulley or a 10% overdrive pulley. I would like to know if there is a benefit to either one? I know the overdrive pulley will help with belt slip over going to a smaller pulley but don't know of any other benefits.

I am leaning towards the smaller pulley because it's only $75 and the underdrive pulley's i've seen are around $400. Why such a high price tag?

-Thanks in advance

 

[Mustang30212]

The o/d pulley is also the balancer...hence the cost difference.

RH

 

[tmcolegr]

Each option has advantages & disadvantages


The smaller S/C pulley will:

• increase the RPM/boost of the S/C
• decrease S/C belt wrap and be prone to slipping without other supporting mods

The larger overdrive crankshaft pulley will:

• Increase belt wrap on the crankshaft pulley and increase boost
• Increase RPM of all other accessories which increases parasitic HP loss

 

[Big50]

The o/d pulley is also the balancer...hence the cost difference.

RH

thanks, that makes sense.

Each option has advantages & disadvantages


The smaller S/C pulley will:

• increase the RPM/boost of the S/C
• decrease S/C belt wrap and be prone to slipping without other supporting mods

The larger overdrive crankshaft pulley will:

• Increase belt wrap on the crankshaft pulley and increase boost
• Increase RPM of all other accessories which increases parasitic HP loss

I haven't had any best slip so far with the help of the Mosaleen belt tensioner. I think I'll just go with the pulley than in interest of saving money.

 

[Vapour Trails]

The OD balancer will provide much better belt wrap, so I'd lean that way.

 

[Dread53]

Depending on which balancer you choose, verify the size. I have the 10% Innovators West and only saw half the boost increase I was expecting. I ran into Jim Sr. at the Sturgis Mustang Rally and he said they are 'a bit smaller' than the advertised 10%.

I had been running a 3.8 pulley (Saleen) and wanted 10 psi, which mathematically worked out with a 10% lower. To get to 10 I had to buy a 3.6 pulley. You check the math.

I'd suggest the pulley.

 

[circusboy]

I did both 2.75" blower pulley and 15% OD IW crank. I managed 17 PSI with a 1/4" of the impeller blades missing.

 

[SteveP]

i went from a 2.85 pulley with stock crank and had 15lbs. i went with the 10% and a 3" pulley and went to 17lbs. crank is a must!

 

[tmcolegr]

I did both 2.75" blower pulley and 15% OD IW crank. I managed 17 PSI with a 1/4" of the impeller blades missing.

i went from a 2.85 pulley with stock crank and had 15lbs. i went with the 10% and a 3" pulley and went to 17lbs. crank is a must!

You both realize he has a Saleen S/C???