STEXIER

Thank you Carl,

I hope we will have a best result with an intercooler to
planned with next evolution!

edz968s

Just got hold of a double sided belt from VW, not cheap though.
Am awaiting on the grooved pulley, so should start to see good figures.

pudjnr69

The 7-rib VW Phaeton belt should fit the standard crank pulley and SC pulley set-up. To get this to fit the larger crank pulley set-up, we will drop the top idler to a 70mm diamteter grooved idler to decrease the overall belt length required. This will also have the added benefit of reducing the bending moment applied to the canterlevered support bar from the belt.
If there is a problem with the overall length of the 1560mm belt being too short - there are many top idler pulley options to reduce the overall wrap/length on the idler.
This is not yet a proven solution, nor do we know what sort of boost levels we will get. hopefully a couple of weeks will tell.

edz968s

I think using a smaller idler, will bring the belt run down from the alternator to run closer to the head drive pulley, dropping 20mm the belt will be close.

pudjnr69

Supercharger is back from Raptor today with mods done. Belt went in an overnight bag to Melbourne yesterday (but will most likely get there tomorrow), one rib will be sheared off and then sent back. Hopefully everything back together and ready to tune end of next week.

edz968s

I`m also getting a step closer. Got the grooved drive pulley machined and grooved idler puley.
Cut the 7th rib off the belt myself, quite straightforward with a long straight edge and clamps.
See what this goes like with standard crank drive and 55mm pulley.
May start getting fuel issues, but I have the uprated injectors from the origional S2 kit, so maybe now I will get to use them

pudjnr69

Edz, the fuel issue will depend on whether or not you are using the rising rate regulator. I am running an aftermarket ECU and custom tune, but when running the initial crank pulley and stock SC pulley - the larger S2 injectors leaned out at high rpm and we had to go another size higher.

Lemming

You might want to consider a high pressure fuel pump, the Welbro 392 is a great option and costs less than half of the high pressure bosch (044 IIRC) that most turbo guys run. Specs are almost identical.

Jimmy586

Karl, that would be a big plus for us. We look forward to seeing some results.

Eric_Oz_S2

Carl - earlier post, but of interest to me as I am currently refining my AFRs for my supercharger install on my S2.

I have advice from other tuners that a desired AFR for a high comp supercharged engine is 10.5-11 at peak torque to minimise chance of detonation and provide sufficient cooling to valves/cylinder head and also keep exhaust temps down for the cat converter.

Do you think that for a tracked car the AFRs would be better on the rich side? Yes it will slightly reduce power but to the benefit of an additional safety margin.

My current tune is AFR 11.5 at 4500 tapering do 11 at 5000 rpm to rev limit.

Maximum boost on my set up is about 6-6.5psi and intercooled.

Carl Fausett

Yes - generally speaking we tune to 10.5:1 to 10.8:1 for safety in high boost or high compression motors.
That surrenders about 15 HP from the "ideal" HP producing level with gasoline of 12.5:1 AFR.

The problem with setting the engine to 12.5:1 is that very few intake manifolds feed all the cylinders the same, there are small dfifferences in injectors, then the combustion chamber shape and piston crown take effect in the equation - modifying the flame front as it passes, the length and location of the spark plug, etc.

So we opt (as your tuners are telling you) to be on the safe side between 10.5:1 and 11:1.

Below 10:1 you will see diesel-like black smoke out the tailpipe and there is no reason to be there.

Jfrahm

A quick rummage around the inter-nets suggests this part number for the 7 rib belt:
7PKD1560

This site has it, as do other European parts shops but offhand I do not know if any ship to the USA.

http://www.thehappymotorist.co.uk/fa...2.php?vid=2525

I found a place that does ship but does not list the part on their website. Inquiring...

pudjnr69

Jfrahm - the part you are quoting is a non-OE part for the VW application. Given the application is a European VW Phaeton (and most of the sites selling the non-OE part are in Russia), plus I wanted it quickly - I bought a VW OE one.

THere was a Goodyear non-OE part and another belt manufacturer who made one (but the other one was 1558 long - so 2mm shorter).

I talked to the Goodyear distributor in Australia and he could not get one Worldwide.

Jfrahm

Ahh, thanks. I see a Dayco 7DPK1558 might be an option, does not seem to be available in the USA though.

pudjnr69

Mechanic has just told me that the 1560mm belt is in, but had to change the top pulley to a 70mm diameter to get it to fit. Now for the tuning.