GMG Oversize Crank Pulley & Super Damper

B8 S4
#1

Instead of crowding the JHM thread I will post GMG pulley info here.

Another member just received his. Asked him to measure and weigh since I did not.

Weight: 7 lbs 4 Oz
Size: 18 cm

http://images.tapatalk-cdn.com/15/10/17/763f792c952a447cb2f55bd2cb91deb2.jpg

http://images.tapatalk-cdn.com/15/10/17/2e8b3909af1b036e41a9fbb6132ca2b1.jpg

http://images.tapatalk-cdn.com/15/10/17/2ddce9bc7f42fb1bca554cd5b7faa246.jpg

http://images.tapatalk-cdn.com/15/10/17/5e2e2db6f72036b0f71ea065e7329a03.jpg

http://images.tapatalk-cdn.com/15/10/17/c15c5b36d47ae90065bd3ad6c81ce1da.jpg

#2

I like how this includes a damper. Is there any way they can get a measurement of the actual pulley rib diameter instead of the exterior diameter (which can technically be any diameter larger and doesnt have any meaning). Also a more precise measurement as the photo seems to show more than 18cm. Is GMG going to release this public? Thanks for posting about it.

Mike

#3

Thanks for posting that Jeff… Who’s going to run it? I bet it’s almost spot on to the JHM one if you used calipers and measured at the top of the grooves… Weighs 2 lbs more but I like that it’s dampened…

Mike, I inquired with GMG and they told me it was a 6 month lead time? May have changed?

#4

Ron,

When did you contact them? I first spoke to them in June. At that time I was talking with Fabryce, who then left the company shortly after. I started talking with Scott Centra who told me 3 months. It ended up taking 2.5months. He made a limited run of just a few.

The measurement may look skewed but this is really just the camera angle. I defiantly don’t own a caliber that large to measure. LOL. But I am sure they are relatively the same size.

I too liked the fact that it was dampened.

#5

It was several months ago I’d have to go through my emails, probably Juneish… I dealt with Fabryce as well and he told me 6 months, actually asked if I wanted to put a deposit down… lol Yeah, I’m sure they’re the same size or close enough… I like that it’s dampened but I’m fine with the JHM offering… If I didn’t have one and both were available I’d probably spent the additional money for the GMG one but not going to switch…

#6

Does anyone know, if any software modification is necessary to make use of an oversize crank pulley?

I am now GIAC Stage II and thinking of trying this, but is it just results in bypass valve opening, then it does not make any sense.

#7

From what i have heard and from the logs i’ve seen giac sets the target high enough you’ll be fine apr will need a tune…

#8

Wow that’s interesting to know. The giac stage 2 is that loose on the tune that it will allow that much more boost.

The GAG. And JHM pulley both raise the boost the same amount I would guess

#9

Agree.

I will add that we haven’t (or at least I haven’t) seen logs that capture actual and specified pressure (boost) from a GIAC car with both pulleys installed. I’ve seen GIAC logs on a regular stage 2 car with just the S/C pulley, and the specified values were definitely high enough (2600 hPa) that the extra pulley alone shouldn’t be an issue in terms of pressure.

With that said, the logs I did see from a GIAC car with both pulleys did bypass boost for some reason, but the specified pressure wasn’t logged in the logs I saw (so could be other factors beyond the pressure values- just don’t know).

#10

Yeah, good point josh…

Jeff would be the best to answer this from the giac perspective so hopefully he chimes in…

APR changed more than the specified in order to get my car to not bypass with the exception of during amax shifts they intenionally bypass vs lowering timing which i think is better…

#11

careful, sounds like you’re supporting revo’s tuning method (bypass over timing reduction)!

I’d be surprised if in cold DA, a GIAC tuned car would not bypass at all. I mean that’s great if so, but having watched a GIAC car make a dozen passes with 2 pulleys, while trapping 3-5 MPH less than it ought to be, I’m not convinced something isn’t holding it back.

On the GIAC side, just as primetime is testing a file for APR, is anyone in communication with GIAC? How long before a Tsivas piloted B8.5 DSG with a blue and white striped flag rips down the left lane at ATCO with two pulleys on it?

#12

Working on it Saki. Pete got the go from his pops. Think he has or will be contacting JHM for their pulley. Test it in winter conditions and ridiculous DA and be ready for early spring when atco opens up. Made some other requests to the Glykos boys.

I will make a GoPro video with “There’s Peps Ahmeed” reenactment when we go again. :grinning: We wanted to do it for you last outing but got sidetracked.

#13

BTW, on my Stage II GIAC car I never saw boost values more than 14.5 on pump…
Do not know if this is what it should be…

#14

Vi, keep in in mind all the logs we’ve looked at for 2-pulley cars are in the “ridiculously low DA” category, where boost/load requests are probably very close to specified with even one pulley.

In normal DA, it’s likely to improve performance with the second pulley more, even with a off-the-shelf tune.

#15

Interesting discussion… Looks like quite a few folks are going the 2 pulley route…

http://www.audizine.com/forum/showthread.php/683997-Dual-Pulley-Setup

Josh, The one set of logs I have show lambda values for bank 1, let me know if I didn’t send them and I can email them over…

#16

That’s pretty cool. I was wondering if people would be worry warts or what.

Seems like Apr is right on board with it. One of the last posts in that thread is Sean telling someone who runs Apr stage 2 with JHM od pulley (and a not yet installed Apr sc pulley) to put the second pulley on.

#17

Would the GMG pulley work well with Revo 1+ or not unless they custom tune it?

#18

I didn’t see a log with lambda values in what you sent, but it’s possible it just got lost in the mass of logs I have. I should have created a better filing system when I started doing logs because once you have about 20, it’s hard to keep track of everything.

I’d like to see it, but with that said, I probably posted more than I should have already and I’m not going to post anything else at this point. I was a little reluctant to post anything beyond the basics on the tunes that I know are actively being worked on (APR and EPL).

#19

It would work fine if you were not already running the smaller S/C pulley. There is a local guy doing that here with the Revo 1+ tune.

Based on the logs I’ve see for the newer Revo tunes, you’d bypass most of the additional boost if you run both (dual) pulleys at the same time. I don’t know if it is something Revo is considering at this point, but it may be worth while to ask them.

#20

I’ll shoot you them on email…