The VW G60 supercharger and drive system

[MNTUNER 0]

I'm considering using a VW G60 SC on a twincharging project I'm doing for a a mag.

 

It's a different make of car with a intercooled turbocharger 1997cc four cylinder. Eventually the 1997 cc will get punched out to over 2500cc. Thats another article.

 

It already has extensive mods like a huge high efficency front mount IC, intake pipe, intake man, giant throttle body, cams, head porting/polishing, and huge 2 bb garret TC. Actually tons of other tid bits, AEM EMS you get the point. Basically it hauls ass already but low end and street manners blow.

 

I've been looking at the setup of twincharged cars like the lancia s4 and other exoctic odd balls and am pretty sure how to plumb, valve and actuate things so the two act harmoneously. The G-ladders output would route to the turbo inlet on a Y pipe and have a bypass valve inline. The other end of the Y will have a one way valve and an air filer on it. So when the TC spools and outflows the SC the one way valve opens giving it the air it needs and preventing a vaccum forming between the SC and TC.

 

Blowing thru the TC prevents turbo compressor surge and allows for the turbo to gradually and smoothy take over compression duties. It also makes it easier to get air from both to a single intercooler.

 

The the TC oulet goes to the front mount. After that the upper intercooler pipe with a tial BOV on it. Then thru a rather large GM hot wire MAS sensor wired to the EMS. Finaly it goes to the throttle body.

 

I've done rebuilds and machine work on more complicated devices than the g-ladder sc. So I can handle the usual things like the wider internal SC timing belt. Apex strips, bearings. porting... etc... Ive looked at aftermarket superchargers and they are just too expensive and flow way more CFM (like 1000) than I'll need for the low rpm forced induction. So the g-ladder looks like a perfect part to source for this extreme tinkering.

 

I want to use smaller pulleys to spin the g-ladder for low RPM power. So it maxes out at around 3600? crank rpm. The exact gearing will be based on what makes the supercharging curve fill in the low end void from the turbocharger.

 

 

I GUESS I REALLY JUST NEED TO KNOW THIS...

 

How many RPM you can safely spin the G-ladders input shaft?

 

If you give me both pulley sizes and engine rpm I can figure it out.

 

As long as I know what RPM to keep that shaft at I can match pulley sizing to put the max SC RPM where it produces the smoothest response based on crank RPM.

 

I will be using a clutch on an intermediate shaft and mounting the SC on the opposite end of my engine compartment as the timing end of the engine. Which incedentally puts it in exactly the same place as in a VW engine bay. Passenger side of the bay. My trans is on the pass side where as a VW is on the drivers side. There just is'nt any room left on the timing end of my motor. So a drive shaft and a second belt will be required.

 

The intermediate shaft will have a governer actuated clutch on it set to disengage when the SC would be spinning too fast and re engage when the pulley system has slowed again to a RPM that will not harm the SC.

 

 

Thanks in advance for any help when I've completed the project and article I'll post a link to it!!

[MNTUNER 0]

I guess it would also be nice to know the efficiency curve. What is the most efficient PSI. It's the same with the turbos I work with all the time. You look at a compressor map and draw demand lines to see if it is right for what you want to do.

 

My turbo makes 10 psi at 3k rpm then really takes off around 4k. For max turbo psi it's set at 26 psi when I'm running race fuel. From idle to 3k+ its gutless. From 4k to the 8k revlimiter holy sh%t.

 

I guess if I could get it to push 14 psi at 3k and 16 psi just before the clutch lets go it would be a good starting point.