Which crank pulley is the big crank pulley, and how much boost with a 68mm?

[s2kvondeutschland]

I hooked up my boost gauge today in my mk1 G60, and I got 15-16 psi. I measured my charger pulley, it's a 68mm.

My question is: What are the diameters of the large and small crank pulleys? I'm trying to get a handle on how much boost I should be making.

The way I understand it, if I have the large crank pulley, I need to start looking at some apex strips, and if I have the smaller crank pulley, I'm all good to go.

Thanks for the help guys.

[petethepug]

There's three pages on this link. Don't reference the Lysholm pulleys. After clicking on each pulley pic (link) it will take you to the page that shows the approximate boost capabilities. Send your G Ladder out for a service before you start to boost or ... well you know

fixed the blue link ... sorry

[s2kvondeutschland]

... what link? I'm feeling really dumb right now.

Edit: makes sense now that the link is fixed, haha.

It would seem that my numbers are correct for my pulley then. I plan on cracking it open here soon for a rebuild, it has about 40,000tkms since its last.

[G60 Carat]

It was said that Passat Automatics had bigger crank pulleys (I've also read that all G60 automatics had bigger crank pulley's)

Personally I'm not sure if there ever was a bigger crank pulley. My engine originally came from a Passat Syncro Auto, and it has a normal sized pulley on it.

Gauge pressure is hard to test off of for a few reasons, but if you made 15-16psi @ 6000rpm with a 68mm your not leaving too much on the table. Aftermarket cams and/or head porting will lower boost on a G60, boost will also decrease as your elevation goes up, and same story with ambient temps. The higher they go the less boost you will see.

Also gauge inaccuracy is sometimes a factor. If you're hitting that number for PSI there isn't too much wrong with your charger that's for sure. With that number you would be looking for minor boost leaks, like at the collector box. etc.

With a 68mm on mine I see about 16psi @ 6000rpm, 17psi if it's really cool out, can be as low as 14psi if it's 30c + outside. I'm at about 2500ft for elevation.

[efritsch]

My engine originally came from a Passat Syncro Auto, and it has a normal sized pulley on it.

My understanding was that the Passat Syncro's never came in an Auto-Tragic. They were manual transmission only.

[s2kvondeutschland]

Thanks for all your input guys!

[JBETZ]

I hooked up my boost gauge today in my mk1 G60, and I got 15-16 psi. I measured my charger pulley, it's a 68mm.

My question is: What are the diameters of the large and small crank pulleys? I'm trying to get a handle on how much boost I should be making.

The way I understand it, if I have the large crank pulley, I need to start looking at some apex strips, and if I have the smaller crank pulley, I'm all good to go.

Thanks for the help guys.

I've never seen this mystery larger crank pulley...

[s2kvondeutschland]

I've never seen this mystery larger crank pulley...

That's why I'm curious. It's all over the internet about '91+ having a larger crank pulley that is good for another 2-3 psi. I measured mine but can't remember the damn number. I'll get on my hands and knees and hit it up again tomorrow morning. We'll see if it compares to what you guys have; I'm sure there is a possibility for some variation.

It's not like I'm not going to rebuild the charger... I've got the stuff anyway, and it's due by miles even though it's got no oil leaks and it still makes good boost. I just wanted to see how far off my numbers were; I guess not very far, if at all.

[G60 Carat]

My understanding was that the Passat Syncro's never came in an Auto-Tragic. They were manual transmission only.

Hmm Maybe it was a Manual, but it was definitely from a Syncro. Somebody else took the drive train.

[petethepug]

Yes, that's correct. Crank pulley was smaller on late 91 G60. It did spin things just a fraction faster. This used to be significant. Now with so many aftermarket G Ladder pulleys available,it's moot. No need to overspeed the p/s, alt & a/c anymore.

[DigiMatrix]

????? Crank pulley needs to be larger to spin the G-ladder faster I think. Smaller makes it spin slower.

[REPOMAN]

Years ago i did this larger Crank pully numbers for my Lysholm setup.
OEM G60 crank pully size is 5 3/4" I used a TDI OEM crank pully which is 6". this gives a larger
pully ratio and spins the charger to a higher RPM giving more boost.

5 3/4" = 146mm
6" = 152
152mm/68mm= 2.2:1
146mm/68mm = 2.1:1
When i was S/C setup I used 6" and a 50mm pully on lysholm for 3.0:1

[G60 Carat]

I think the stock G60 crank pulley is 133.6mm

But anyways running a 6" TDI crank pulley with a 68mm, would be the same as running with a 60mm charger pulley. Which is like 20psi at 6000rpm, charger life is definitely in question at that speed.

[petethepug]

????? Crank pulley needs to be larger to spin the G-ladder faster I think. Smaller makes it spin slower.

What he says Thnx

[mattrip]

To try and confirm the larger pulley size on the G60 Automatic I will get a measurement of my crank pulley this week. It's in a box in the shed pending engine rebuild...

92' G60 Corrado originally an automatic. I did the 5 speed swap 10 years ago retaining the original pulley. I was told back then the autos came with a larger pulley than the manual cars.