DASC boost level ??

[xxxJohnBoyxxx]

Yep those pictures really help. You have the same one we run here in the US with the 6-rib belt. You need the 3.4" pulley. That will add about 1.5-2 psi of additional boost. You have a smaller crank pulley then we run which is why you a little light on boost. A smaller SC pulley will make up for that smaller crank pulley. No need to change to a different belt that will be fine.

Purchase a new pulley here: http://www.pulleyboys.com

I have a used one that is not pretty but straight. I would need to dig it up. I suggest you buy new from the site I posted above since your engine bay looks clean...

Best, John Smith

Ask any questions you have and I will try my best to help...

[markrnorton]

PM sent John

[markrnorton]

Gents

can i assume that s/c speed is linear/proportional to boost ?

ie if i increase s/c speed by 30% i will get a boost increase of 30% ??

or am i way off ??

help/advice please gents

[marko]

think so... cause you are increasing the volume of air entering the motor.
i.e. smaller pulley spins the blades/rotors faster & as a result you get to push more air in, no?

Originally Posted by markrnorton

Gents

can i assume that s/c speed is linear/proportional to boost ?

ie if i increase s/c speed by 30% i will get a boost increase of 30% ??

or am i way off ??

help/advice please gents

[pnosker]

Most people only get ~6.5-7 psi with the stock pulley. Add a check valve and you can get 7.5-8 psi.

[m3nut]

Mark did you fit the 3.4" Pulley? I am looking into this for mine too!
Will have a mesure of the crank and sc pulley, but would think it will be the same as yours.
OT, I need to get another pair of Idler Pulleys don't think I will find anywhere in the UK that sells them any ideas from you guy's in the US?

Thanks
Neil

[roadrash]

I don't know anything about them except that I've seen them recommended by other folks: http://www.pulleyboys.com/

[marko]

I recently realized that my 3 inch pulley is a bit too much for the hot summer months.. I'll be switching to the 3.2 now, & going back to 3 next fall.
15psi on a 9.7:1 is a bit dicey in the summer months.

[markrnorton]

what psi does the 3.2 " pulley yield ?

[pnosker]

15 psi for M44, 12 psi for Metric Mechanic motors

[markrnorton]

wow, ok i better buy the 3.4" then, i dont want that much boost

[marko]

3 inch pulley is good for 14-15 psi on my motor... then again, I insisted they keep the compression high on my build. yielded 9.7:1 - while they suggested I should have stayed on 8.5 - 9.0:1. I didn't listen... now I got to switch pulleys.

3.2 inch pulley yields 11-12 psi on my motor...

the day you drove it, it was 11-12psi...

say - did you ever get that thing to run again?? we should get together soon...

Originally Posted by pnosker

15 psi for M44, 12 psi for Metric Mechanic motors

[markrnorton]

Ordered a new 3.4" pulley from pulleyboys, should get it next week.

one quick question for the "in the know", which way does the nut on the front of the pulley come off ? is it a LH thread ? or normal RH clockwise tighten

i want to spin it off with the impact wrench so i'd like to get it right !

thanks

[pnosker]

Marko: Not running still... just took last final so will be home shortly and hopefully can fix it

mark: I think it's a standard thread, but you won't need an impact wrench. Just hold the pulley with a wrench and hit the nut with another.

[marko]

pat -dont feel too bad. I just changed my oil & pulled out 4 small pieces of metal of the magnetic drain plug. Looks like a piece of a bearing!

mark - when you unscrew the pulley, DONT bang on it to try & pull it off the snout! get yourself a 'pulley/gear puller'... otherwise you'll **** up the bearings inside your SC.