Was a Paxton supercharger conversion, now a Rotrex C38-91

[stevieturbo]

searching just seem to suggest its ATF in them ?

Superchargersonline do a rebuild kit for a few hundred dollars

[kev_the_mole]

Nice toothed belt and pulley install Phil. Did you have any problems?

Cheers,

Ian

[ian.stewart]

Somewhere in the back of my memory, I was told not to run a centrifugal supercharher with a toothed belt, cant remember why for sure, but I think it was better to allow the charger to slip the belt on decelleration because of the torque multiplication within the charger, run a toothed belt and the gears wear.
Think it was Jay with the yellow Porsche who told me

[JP.]

Paxton uses ATF type-F (Ford spec transmsion fluid, not Dexron/Mercon)
(source : http://www.mustangdepot.com/onlinecatal ... n-info.htm )
Running a toothed belt means you'll need a backfire valve.
On a serpentine beld incase of a backfire it just slips on the belt.

Without one of these safety features a backfire will destroy the supercharger.

Running the serpentine belt means you'r able to run it on your existing serpentine system. Just need a longer serpentine belt and align the supercharger. No need for bottom pulleys, only need the correct top pulley.

In case you lost his email, Nigel Ukblowers@aol.com

Here's a teaser
http://www.youtube.com/watch?v=5s_Un43S2EI but you'll need to log-on to see it.

[stevieturbo]

you can run a toothed belt. But why would you want the hassle ??

A simple 6 rib serpentine belt will be more than up to the job of handling that blower

[Coops]

is that the charger screaming when he comes up the road???

[Coops]

right,
so,
i need to gear it to run at 35000, which will give 6psi yeah?
i need an intercooler, (looking on ebay but theres fookin loads )
need a recirc or bov ?
run serp drive, seperate belt or along with o/e belt setup?

not got a bottom pulley yet Mike as depends on how it needs to be driven,
if i can use the o/e setup i can measure my serp crank pulley then,
if not need to either find a pulley or get one made etc,

anything else i need to know?

will 6 psi be ok on my engine? or do i need to run a bit lower etc due to whats been done???

thanks for all your help guys, at this rate its going to be on sooner than i thought,

Stevie, i was thinking about taking it apart and replacing the seals bearings and drive balls and shaft before using, to make sure its near on new when we fit it.
got any links to the parts mate?????

[JP.]

right,
so,
i need an intercooler,

Why ???? its not a turbocharger which got heated by the exhaust gasses. You're going for about 6psi so ther's not much heat build up by the charger. It will create lag also.

right,
so,
run serp drive, seperate belt or along with o/e belt setup?

Run along o/e setup. I can remember Nigel was doing a setup for the RV8, He used our Capri once to measure things up.

right,
so,
not got a bottom pulley yet Mike as depends on how it needs to be driven,
if i can use the o/e setup i can measure my serp crank pulley then,
if not need to either find a pulley or get one made etc,

Running o/e setup no need for bottom pulley

will 6 psi be ok on my engine? or do i need to run a bit lower etc due to whats been done???

Depends on your CR ratio. Running 9psi myself on a 9:1cr. Did run 5psi on a 9.5:1cr without any issues either. Still running it on 95 fuel.
Alloy block's react in a differend manner (expansion & heat dissipation)than cast iron blocks so they can handle more cr & boost.
Your Vems could also retard your igntion timing to prevent detonation.

Nigel could calculate which top pulley you'll need and he can also make one (CNC machined).

[SuperV8]

Just going through a similar upgrade myself.

I think you may strugle to fit the blower with the GEMS crank pulley. There isn't much offset so it would need to be mounted high and or wide to get clearence at the back of the blower. Depends how much space you have. I'm using the intermidiate pulley with the GEMS timing cover, need to make various spacers for water pump, custom bracket for alternator but my Rush kit car has very little spare space with the v8!

What's your power target?
I'm looking for 400bhp. I've worked out (using Garrett's formular!) I'd need about 632cfm at 12.5psi. (Rover V8 4.6) You should definatley be using an intercooler at that pressure. Most of what i've read suggests above 5-6psi an intercooler is an advantage. There are calcs to work out sizes but they all point to the biggest that will fit! Whenever a gass is compressed it rises in temp. Boyles law. The more efficient your supercharger or turbo the less that rise will be for a certain pressure. Using an intercooler will mean you can run more boost before runnnig into detonation!

I wouldn't recomend sizing the pulleys for your max boost straight away. Start of lower then gradually increast the boost watching for detonation.

Good luck,
Tom.

[daxtojeiro]

right,
so,
i need to gear it to run at 35000, which will give 6psi yeah?
i need an intercooler, (looking on ebay but theres fookin loads )
need a recirc or bov ?
run serp drive, seperate belt or along with o/e belt setup?

not got a bottom pulley yet Mike as depends on how it needs to be driven,
if i can use the o/e setup i can measure my serp crank pulley then,
if not need to either find a pulley or get one made etc,

anything else i need to know?

will 6 psi be ok on my engine? or do i need to run a bit lower etc due to whats been done???

thanks for all your help guys, at this rate its going to be on sooner than i thought,

Stevie, i was thinking about taking it apart and replacing the seals bearings and drive balls and shaft before using, to make sure its near on new when we fit it.
got any links to the parts mate?????

I ran 8psi on mine at 9.75cr and it was fine.
I used a toothed belt, etc, as I had a source of them for free
Always fit a BOV regardless of what belt you use.
No, you dont need an intercooler, you will lose pressure through it and they are efficient anyhow, I forget what increase in temps I got, but it wasnt too much.
Youll find that the boost comes in at high revs, have a read of my page as I think I put what pressures I got at different speeds.
Yep, the oil was indeed Ford ATF, I remember now, it was a long while ago
Phil

[topcatcustom]

Do turbo intakes really get heated by the exhaust?? I thought it was more to do with the fact that turbo impellers spin up to about 150,000rpm and create a LOT of heat...

[Coops]

well i popped out this evening, came back about an hour later and the wife said,
you have had a parcel delivered,
told her not expecting anything till mid week.
open the box and inside was:









so yup i defo now have the paxton charger

[stevieturbo]

right,
so,
i need an intercooler,

Why ???? its not a turbocharger which got heated by the exhaust gasses. You're going for about 6psi so ther's not much heat build up by the charger. It will create lag also.

Dont talk gibberish.

All compressed air gets hotter, have you no notion about how they work ? It it will not increase lag one bit.

right,
so,
run serp drive, seperate belt or along with o/e belt setup?

Run along o/e setup. I can remember Nigel was doing a setup for the RV8, He used our Capri once to measure things up.

right,
so,
not got a bottom pulley yet Mike as depends on how it needs to be driven,
if i can use the o/e setup i can measure my serp crank pulley then,
if not need to either find a pulley or get one made etc,

Running o/e setup no need for bottom pulley

will 6 psi be ok on my engine? or do i need to run a bit lower etc due to whats been done???

Depends on your CR ratio. Running 9psi myself on a 9:1cr. Did run 5psi on a 9.5:1cr without any issues either. Still running it on 95 fuel.
Alloy block's react in a differend manner (expansion & heat dissipation)than cast iron blocks so they can handle more cr & boost.
Your Vems could also retard your igntion timing to prevent detonation.

Nigel could calculate which top pulley you'll need and he can also make one (CNC machined).

6psi will be fine Tony, as likely would higher if the blower can create it. You'll be re-tuning anyway, so wont really matter. Whilst it may be a different engine, Im hitting near 20psi on 9.5:1 CR

[stevieturbo]

Do turbo intakes really get heated by the exhaust?? I thought it was more to do with the fact that turbo impellers spin up to about 150,000rpm and create a LOT of heat...

No they dont, and no they dont.

Turbochargers, and most superchargers compress the air. That is why it gets hot.
Would matter if you compress it in a bicycle pump, or a blower spinning at 100,000rpm, same end result. Hot air.

[SuperV8]

Yes as I said boyle's law.
http://en.wikipedia.org/wiki/Ideal_gas_law

Gas pressure, volume and temp are all related. Change one and the others change.

i.e. increase in pressure increases temp. fact.

Yes turbos can glow red but so can exhaust headers. Also the air will be travelling too fast in the turbo so it hasn't got time to abrorb heat from the manifold.

Tom.