Sprintex Superchargers

[Rosco]

Does anyone know what the maximum capabilites are of the Sprintex chargers?

I've been told that the PE set up runs 6-7psi, but how much scope is there to increase this?

[littlegems4x4]

Could you not just change the pulley for a smaller one, or is this not the done thing

[Rosco]

Yeah I've assumed that this is the only way to increase boost, unless you increase the size of the pulley attached to the crank, but there must be a limitation on what the 'charger can manage.

Or is this not the case?

[turboshed]

You will have to find out the max rpm of the charger,and the volume of air shifted per rotation,then you can work out what psi it would be producing.
Rob(super12v) is you man on that as he has had several different set-ups on his sierra,I know we measured the supercharger rpm on one of his smaller pulleys a few years back and it was running a tad fast to say the least but had the best and loudest whine i have ever heard on a charger.

[Rosco]

Cheers Turboshed.

I did try contacting Sprintex a while back but to no avail, but I dont mind the odd bit of perseverance so emailed them again this morning.

To my massive surprise I received an instant response , which reads as

"In terms of basic specs, the S102 had a theoretical displacement of 1.09 litres/rev, built in pressure ratio of 1.85 and a maximum recommended input speed of 13500 rpm (constant)"

So now we just need to measure the pulleys currently fitted and using the recently update blower calculator on the Sprintex website http://http://www.sprintex.com.au.cu...Calculator.xls we can work out the new pulley sizes.

[Sprintex]

Standard setup should be around 6.5psi.

Staying within the 6,000RPM rev limit (?) the S102 can go up to 9.4psi, which on a 2.9 should give 286bhp with a drive ratio of 2.33:1. Any more than this and it'll overspeed.


Paul

[Rosco]

Paul, do you know what size the pulleys are on the 2.9 kit to get to that drive ratio?

I'm guessing that the 2.8/2.9 kit uses the same sizes, and PE just changed the ducting work to suit.

[Rob]

You really need to look at the efficiency maps of the supercharger (much like you would on a turbo) often you will find you'll be stepping outside side of what is "efficient".

Parasitic losses are higher on lysholm over a roots and despite the gains on the adiabatic temperature efficiency you'll almost certainly need to run a heat exchanger to remove the heat. This said, know the maximum speed of the blower and try not to got beyond this, the danger is if things get too hot seals get damaged and the rotors can expand and clip the casing, I've done both with my eaton and once the rotors touch it's fubar.

My take on this is, use a modular pulley setup when you can test a variety of ratio's and do some data logging (with a keen eye on the inlet temperatures), the cologne is more limiting than the blower is in my experience, drive it too fast and supercharger performance drops off quickly and you end up with a compromised setup.

[Sprintex]

Paul, do you know what size the pulleys are on the 2.9 kit to get to that drive ratio?

I'm guessing that the 2.8/2.9 kit uses the same sizes, and PE just changed the ducting work to suit.

Not offhand, but I'll try and get out there and measure them for you at some point


Paul

[Rosco]

Cheers Paul.

Rob, thanks for the info. Is there a ready supplier of pulleys or did you have them bespokely made?

Hopefully you guys will be at Ford Fair so I can have a good look at your setups.

Ross

[Rob]

Hi Ross, no I was lucky with the eaton, as there are millions already fitted OEM out there I sourced off the shelf items. With the eaton there either interference fit or woodruff pulleys, the Jag blower I have uses interference fit and I have a modular setup. However it only really the hub this is specific the drive shaft size, something could be made up by a local precision engineer and the exchangeable pulleys the use the same PCD.

The pulleys I have, I have 3 different sizes. I'll have to dig them out as I have 3 different sizes. iirc I run 2.26:1 with my eaton which equates to 10psi intercooled, which puts it right up by it maximum speed, and I do have the ablility to run at 2.4 and 2.6:1 running a modded snout which allows me to run the smaller pulleys and to be honest if I get time I may for a giggle run these, but I seriously doubt I'll see any hike in performance, the noise is wicked though!

Link to the people I purchased my pulleys from.

http://www.zzperformance.com/grand_p...cts.php?id=111

Unfortunately I won't be at Ford fair...

Rob