Hello, I have a comptech SC with a VAFC. I am only making about 4-5lbs with the AC and larger heat exchanger. I was looking to get 4.2in pulley for the blower before I have a shop adjust the car with the VAFC to get an extra lb or so. I haven't been able to find a used pulley or a new one. It is easier to find the pulleys new on mustangs sites as they often have novi 1000 blowers but all I can find so far is the 4.25. http://www.horsepowerfreaks.com/performanc...charger_Pulleys


Does anyone have an idea where I can get the 4.2in pulley (stock AP2 size) for the novi 1000?

 

Are the comptech and vortech pulleys the same?

 

almost positive no. there are different pulleys for different novi blowers so i would assume pulleys from different manufactures wouldn't be compatible.

 

The Vortech does not use the same offset as the Comptech kit. We have the solution for you:

http://scienceofspeed.com/products/engine_...000_SC_pulleys/

The standard kit at sea level produces 6 psi. I assume you are not at sea level, or have something different about the kit (such as a front mount intercooler) to have this pressure drop. If not, that should be investigated further.

-- Chris

 

correct. But you don't have a 4.2in listed for sale. I actually just placed an order for a sport clutch a few hours ago from you guys. I would have bought the 4.2 but biggest you have is a 3.6. The next best option I have seen is the 4.25 (which is available almost anywhere including Paxton's site) which shouldn't be much different than the 4.2. I am still on stock injectors and if I go smaller than the 4.2 i might not be able to keep the air flows in line. I was just going to pick one up for a small power boost at a low cost (not having to do a better piggyback/stand alone or injectors)

 

I believe the 4.25 is the pulley size used on the stock Comptech ap2 kit, not 4.2. SOS uses a 4.2". I had good success running the 4" without engine management or meth injection. SOS seems to have discontinued production of their 4" &3.8" pulleys for some reason.

 

It says on the SOS site that the stock AP2 is a 4.2. That could be incorrect though or that 4.25 might actually be a 4.2 or there may be some reason it is listed as that.

Anyway, my FPR is backed out almost all the way and a 4.0in might be pushing it as that would probably be around a 2-3PSI boost increase. Right now I am just trying to find a 4.25 pulley that is reasonably priced.

 

I can measure my stock ap2 pulley if you want? - however some folk measure them from different points.

I have CT AP2 one on my AP1.

 

Thats ok it may be very difficult to determine the size from actually measuring the thing. At least when going for .05 of an in.

 

I assume you mean screwed down?

4" got me 8psi on the nose at 9k. I maxed out my fpr and used my vafc to lean out the fuel pre vtec. If you have a larger TB, or big single 70mm exhaust/header then you may not have enough fuel for the 4". With my breathing mods at the time I had just enough to run reliably.

Then I found meth injection and the rest is history....