How much boost are you seeing with your 8" pulley

**sinner** · 07-06-2003, 03:18 PM

I know it keeps being asked but nobody posts how much boost they're seeing except me and I know there's quite a few that are running one now.
I'm seeing 8lbs of boost at 6000 RPM. I have heads/intake and bolt on's.
I was told I would be seeing more then that so I want to know what other people are seeing.
Thanks

**sinner** · 07-07-2003, 09:40 PM

So whats the deal, has no one installed there's yet or does no one have a boost guage?

My buddy (three40seven) has called Paxton and talked to everyone that works there, except one guy who he's still trying to get a hold of, and no one at Paxton knows for sure how much boost your supposed to see, so I think I'm one of the first to put a 8" on.

**lx-convertible** · 07-08-2003, 07:55 AM

on the separate drive your talking about right? same drive w/8 inches=15psi!!! Me loves me old Novi kit!

**mygt8a4re** · 07-08-2003, 04:08 PM

i keep hearing 15psi as well, but i disagree. i dont think you go from approx 6 psi to 15 with a little over an inch in crank diameter! 6.88" to 8" to be exact.....im currently at 7 psi at 6k & i have heads & intake & morpheus powerpipe(& all usual bolt ons). when i squeeze a few more rpm i hit about 7.5psi.......im guessing a gain of 3psi, 4psi tops can be had.......i think to get 15 you would need to get a smaller blower pulley along with the 8" crank.........just my .02c....im ordering my 8" this week so ill respond with my results if noone else does........
-justin

**5150 LX** · 07-08-2003, 06:47 PM

Here's my take on it, those with the older style 1k will see close to 15 psi. Those with the revised 1k will see around 8-10. Would one of you guys with the revised 1k chime in as to the diameter of your blower pulley as well as the diameter of the crank pulley supplied with a new kit.

**5150 LX** · 07-08-2003, 06:52 PM

Ok, on my old style kit. Blower pulley 3.0", stock mustang crank pulley 6.0", F-150 crank pulley 6.5", FWIW, an extra .5" on the crank pulley gave me an extra 2#'s boost on my combo.

**mheinjr** · 07-08-2003, 06:55 PM

Well I have the new style, but I don't have the diameter of the pulley's sorry. I think with a 8" Pulley you will see 8 psi, with a powerpipe added you would see 10. This is with the new style this is just from what I heard I don't know for sure.

**sinner** · 07-08-2003, 07:07 PM

Alright, it's good to have some opinions. The blower pulley on the new one's look to be just under 4", it's hard to tell with a tape measurer cause of the big cap covering the bolt.

I guess I will just have to wait until Justin gets his on before I know for sure.

**sinner** · 07-08-2003, 07:21 PM

Oh, does anyone know the max RPM the blower can turn and does anyone know what the RPM would be at on a new style blower with the 8" crank, just wondering if I can put a smaller pulley on the blower in the future.

**frank woodall** · 07-08-2003, 07:36 PM

I saw 1.75-2.00 lbs of boost increase by going from a stock crank pulley to a F-150 pulley which is only 1/2 inch larger.......as soon as my 7.75 crank pulley comes in from ASP i will let you know what that does.

**mygt8a4re** · 07-08-2003, 08:20 PM

the revised crank pulley is 6.88" & the blower is 3.33" if i remember correctly.............the max rpm for the revised novi1k is 50k-rpms, i believe the 8" crank puts it approx 43k.....room for a smaller blower pulley........but were talking hot a$$ air at those r's! time for intercooler or water injection =)
-justin

**sinner** · 07-08-2003, 08:57 PM

You sure the blower pulley is only 3.33", I just tried measuring again and it looks to be atleast 3.5".
Justin, do you know the max efficient RPM?

**mygt8a4re** · 07-08-2003, 09:18 PM

yes your correct, it is 3.5" not 3.33"...........

efficient rpm is 50k but "efficient" in all aspects depends on if your cooling your charge or not. it can be spun at 50k all day long but the heat generated will hurt performance. were talking 5 minute heat soak.....50k @ 15 psi with a way to drop manifold temps would be very impressive! many older 1k guys have even spun at 51-52k consistenty............

-justin