Different boost readings (Is this normal??)

[JMB Justin]

About 700whp seems to be the max a Paxton kit can make on these trucks regardless of pulley size and blower speed. Seems like the ported heads and headers actually make it worse instead of better. Too similar big builds on this forum quickly found that 4-5 psi and 650ish whp was all the blower had to offer on their heads/cam/intake setups. Intercooler changes made no noticeable difference in power or boost number. Sounds like you are experiencing similar results unfortunately. I would make a manual tensioner for the belt and see how much boost you can make without belt dust showing up on the bracket. My guess is 650-700whp is where you will end up when you are done, no slouch but probably not what you were trying to achieve.
Justin

 

[Mighty1]

About 700whp seems to be the max a Paxton kit can make on these trucks regardless of pulley size and blower speed. Seems like the ported heads and headers actually make it worse instead of better. Too similar big builds on this forum quickly found that 4-5 psi and 650ish whp was all the blower had to offer on their heads/cam/intake setups. Intercooler changes made no noticeable difference in power or boost number. Sounds like you are experiencing similar results unfortunately. I would make a manual tensioner for the belt and see how much boost you can make without belt dust showing up on the bracket. My guess is 650-700whp is where you will end up when you are done, no slouch but probably not what you were trying to achieve.
Justin

I have a dedicated belt drive with manual tensioner now and was going to send out the blower pulley to carbinite racing to get coated to see if that would get rid of that little belt slip I seem to have. Where do you recommend I pull my boost reading from and should everything that is activated by boost be attached there as well?

I see that the Procharger F1C is rated at 1625 cfm which is 225 cfm more than the paxton. Would that make a difference for me or would I need to go bigger, like to the F1X which is 2000 cfm? I know the F2 is 2700cfm but that has to have a cog belt right? Would a procharger mount up in the same bracket as the paxton?

Thanks for any info :burnout:

 

[JMB Justin]

I have a dedicated belt drive with manual tensioner now and was going to send out the blower pulley to carbinite racing to get coated to see if that would get rid of that little belt slip I seem to have. Where do you recommend I pull my boost reading from and should everything that is activated by boost be attached there as well?

I see that the Procharger F1C is rated at 1625 cfm which is 225 cfm more than the paxton. Would that make a difference for me or would I need to go bigger, like to the F1X which is 2000 cfm? I know the F2 is 2700cfm but that has to have a cog belt right? Would a procharger mount up in the same bracket as the paxton?

Thanks for any info :burnout:

The brackets will all be different. The F1X/F1R are race blowers, they will be very peaky with less midrange and are much harder to drive than a F1A or F1C (which are much harder to drive than a Novi 2000). How many ribs is your belt on the dedicated (im guessing 8) and whats the belt wrap on the blower pulley look like? Boost source doesnt really matter if it cant make the power you want, Ive used both places and not seen a big difference. The BIG power adder stuff is a different story, they will make certain cylinders leaner than others with the stock intake manifold (i.e. more boost in certain places).
Justin

 

[JMB Justin]

Also dont read too much into CFM ratings, the F1C was rated at 1850 until very recently, they changed it when the F1X came out in order for the F1X to seem like a "fair" blower for that race class (X275). Its a marketing game just like any other, fact is a F1C has made 950whp on an srt10 (and 1200whp on other applications) with only 225cfm more than a novi 2000, which has never made more than ~700whp on the rams.
Justin

 

[Mighty1]

Also dont read too much into CFM ratings, the F1C was rated at 1850 until very recently, they changed it when the F1X came out in order for the F1X to seem like a "fair" blower for that race class (X275). Its a marketing game just like any other, fact is a F1C has made 950whp on an srt10 (and 1200whp on other applications) with only 225cfm more than a novi 2000, which has never made more than ~700whp on the rams.
Justin

Do you have to run a cog belt at the 950whp power level? How do they (cog belts) do on the street?

It's a 7 rib belt. I will post up a pic on the belt wrap when I get home.

 

[Mighty1]

Here is a pic of the belt wrap...

 

[JMB Justin]

Put an idler on the top of the belt as close to the supercharger as possible. IMO your going to be compromising something to make 900+ with a street supercharged centrifugal setup, either going to a cog which is less streetable, or dealing with belt slip on a serpentine drive. I feel confident I could build a near 900whp serpentine setup that's reliable but everything would have to be right, especially blower selection.
Justin

 

[Mighty1]

Put an idler on the top of the belt as close to the supercharger as possible. IMO your going to be compromising something to make 900+ with a street supercharged centrifugal setup, either going to a cog which is less streetable, or dealing with belt slip on a serpentine drive. I feel confident I could build a near 900whp serpentine setup that's reliable but everything would have to be right, especially blower selection.
Justin

Thanks for the tips and info!! I sent the blower pulley out to be coated so I will try that first. If still slipping I will modify the bracket and add another idler like you said. If still slipping then I might have to bite the bullet and ...

I will keep you guys posted on the results.

 

[Mighty1]

Well I finally had the time to put the coated pulley on and it raised my peak boost from 5lbs to 7.5lbs....and then started slipping again I am going to have something welded to the front bracket to add another idler closer to the pulley for more belt wrap and that is where I'll stop. If that doesn't stop the belt slipping then I give up on the Paxton. I will be calling JMB today to get some prices on other options.....

 

[505'sFastestViper.]

Well I finally had the time to put the coated pulley on and it raised my peak boost from 5lbs to 7.5lbs....and then started slipping again I am going to have something welded to the front bracket to add another idler closer to the pulley for more belt wrap and that is where I'll stop. If that doesn't stop the belt slipping then I give up on the Paxton. I will be calling JMB today to get some prices on other options.....

Good luck justin does good work and has more experience with fi builds then anyone on this forum!!

 

[Mighty1]

Since the coated 2.85 pulley was slipping I got a 3.25 (only 2 choices were 3.00 and 3.25). Just got back from the test drive and I have 6lbs of boost with no slipping of the belt. The tires are a different story. I am trying to decide if I should have the pulley turned down some to try to get a little more boost or just leave well enough alone. Maybe I need to find a HA meeting (horsepower anonymous).

 

[BAD SNAKE]

what did you get the pulley coated with? And how is your set up so far?

 

[Yellow venom]

I believe he has since sold the truck now.

 

[Mighty1]

what did you get the pulley coated with? And how is your set up so far?

I sent the pulley to Home

It does seem to help if you have belt slippage but it makes a lot of belt dust too. I ended up going from the stock 2.85in pulley (coated but still slipping) to a 3.25in but lost too much boost so I dropped back down to a 3in one. Ended up at 8lbs of boost and no dust to speak of. I then sent that pulley out to get coated (because I can't leave well enough alone) and did not get any additional boost but got a ton of belt dust. I had the coating removed and left it at that.

Just a FYI my crank pulley was 7.5 inch.