cheddaboy

I made 18psi with a backdoor intercooler, 3.6" and 6.75 pulleys on a 1500 blower at 8k rpm. I think you should be able to make atleast 16-17 with the aftercooler on a 1200 blower

amdaman

Isn't 6.75 a bit too big for the crank pulley? I heard it was an issue getting the belt off amongst other things hence 6.5".

So guys, I have an AP1 - I'm looking for the 16-18psi area (intercooled) with my N1200 what pulley would I need with my 6.5" crank pulley?

Also can I just confirm that the SOS crank pulley is the same as the Comptech one?

Thanks all for the help so far!

JUSTINTHECOASTIE

What size supercharger pulley do you have?

amdaman

I haven't yet - i'll be getting a 3.2" or 3.4" depending on what the outcome is here!

Still trying to figure out if the crank pulley offset for SOS and CT are the same as neither of them seem to know..

The fact that SOS sell a CT upgrade bracket might be a give away though... hmmm

s2k manic

i would go with the 6.5 i am looking into 8 rib without having to shim the blower forward much as the cold air intake pipe is already all in the passenger fans business and i have moved the radiator forward 10mm at the top. the 6.75 has to be removed to change the stock belt

amdaman

I've asked ASP to make me the 6.5" pulley based on the SOS diagram they already have. They don't have the Comptech pulley diagram but I'm hoping the bolt pattern is the same and it's not too far off the offset with the CT to SOS adapter plate.

Any idea what belt size I will need with a 6.5" crank and 3.4" blower pulley? Is there a formula?

Cheers

s2k manic

there the same i was running a novi1000 comptech kit with the 6.75 that came from arax who runs sos and now i have the sos adapter plate with a novi1200 with the 1000 and aftercooler i had 12psi max boost with 3.8 blower pulley on the 1200 i have a 4'' and 14psi with an efficient air to air

amdaman

thanks man!! Phew.

Sounds like I'm going to see some high boost on a 3.4" with air to air and a 6.5" then!!

What belt are you using? If you're using a 7" + 4" isn't that similar to a 6.5" + 3.4" ? I'm thinking the 4060400?

JUSTINTHECOASTIE

Novi1200 with 3.4pulley and ASP crank pulley will put you around 19.8 psi with a blower speed of 56592rpm. Understand, max blower speed is 52000rpm

amdaman

Wow that's quite a lot.. I expect 2-3PSI loss but maybe I should go with the 3.6" to be safe?? Also do you know what belt I would need for that combo? I do rarely take it up past 8000rpm though.

Also I doubt my little Bosch BOV will deal with that pressure, will a 25mm turbosmart valve be ok? I do have an HKS flange but really don't want to go down that route after what I've read on here?