That is worth looking into. a leak would obviously not be helpful.
The flywheel isnt going to change anything so I wouldnt go down that path.
So maybe the slave cracked when I breaking it in. If so, replace here:
http://i64.tinypic.com/1zvyate.png
Here is the OEM clutch master:
http://i65.tinypic.com/qyclj7.png
The current wisdom is to modify it as such to move it closer to the firewall, so the hall switch bypass is not needed:
That should put it a lot further in.
I got confirmation it is indeed the slave cylinder that is leaking. So we are replacing the slave. Then we’ll pull apart the engine bay again, mod the clutch master so it inches forward, disconnect the hall switch grounding hack, and hopefully everything works normally again.
I don’t care if the slave cylinder becomes a consumable part. I’ll gladly replace it after every track weekend. I just want it to work while I’m out there.
why would you do all that modding if a slave will fix it?
Because it is dumb to leave the hall switch grounded and the finite state machine permanently confused. It injects wonky behavior. The reason the slave cylinder broke is because the clutch will only travel 70% of the way. Push it 75% and the slave sacrifices itself under massive force.
Fixing the master will allow full pedal travel as god intended.
Clutch slave cylinder was replaced yesterday. Pedal feel is back to normal. Today they are doing the clutch master cylinder mod. The hope is that moving the cylinder’s top dead center 1cm closer to the firewall will allow the clutch pedal pivot to do the last 1" of travel (without resistance), and properly disengage the clutch safety switch. The caveat is the clutch return point might also move down 1", as we aren’t changing the amount of fluid displaced in the system.
If this works, all of the time I have invested on car forums will have paid back in one miracle of homebrew re-engineering to push these entry level lux german sedan platforms to peak performance.
Of course the original reason we pulled the clutch apart was to use a stronger friction disc and a stronger pressure plate, so it can withstand the full 25 minutes of track abuse. We haven’t cleared that hurdle yet.
I am testing at Sonoma Raceway (full course, not drag strip) on Thursday, August 25. In fact if anyone here actually wanted to meet up, I could probably swing the Sonoma drag strip on Wednesday August 24 in the evening.
Good for you west. keep us all posted. I would be interested in hearing how this plays out. This clutch switch issue seems to be a big one.
Sounds like you are checking off all the boxes here and should have all the little issues sorted out with the clutch system and a nice sporty clutch
Hey, I’ve got a Black B8 6MT S4 myself and have about 7 days at Thunderhill under my belt – unfortunately on the last day someone’s GoPro fell off and then bounced off my hood at close to 100 mph on the front straight
Left a big indention and cracked the paint :’(
I’m wondering if I should just a get a CF hood like yours or maybe just buy your old one if you still have it?
I’m going to go to Sonoma for the first time September 10-11 and then again with the Golden Gate Audi Club in October
SonnyDeez you are in luck. Contact my friend Cynthia at Classic Auto Body in Berkeley (510) 526-0310 to schedule an appointment with that hood. You should let them install it since they stored it for free and by some miracle did not discard it.
You can give me whatever it is worth to you. I should note it’s Phantom Black Metallic, not flat black.
http://uploads.tapatalk-cdn.com/20160823/3d8deac0d10bdd506b6e55ccf573a2ac.jpg
Did the clutch master trim hack but the car still won’t start on its own without the hall bypass. So I’ll have to live with an EPC light - no chimes, no CEL.
The car seems to run and drive well. Occasionally first gear is a little bit notchy but then it goes away. The pedal seems to travel a normal amount again. The real test is Thursday.
The clutch did pretty well at the track today.
GOOD:
- 4/3/2 downshifts are perfect
- the clutch doesn’t stick on downshifts
- it engages much faster
- shifting is less “busy” in technical sections of the track
- granny shifting is over for me
BAD:
- 3 times the clutch wouldn’t grab 4th gear (and I have to try again)
- I had to notch some gears rather than just “throwing”
- the starter motor takes 2 tries to start the car
- sometimes first gear is sorta hard to get into on the street after
Overall this is an improvement. The car has some new quirks that I can live with. I’m faster.
Thats a good update.
The thing to consider on the BAD stuff. A few of those things sounds like its going to be syncro related and not clutch related.
That is a good point about the syncrhos. How do you even replace those?
Looking over what you posted again. It is a very good possibility that syncrhos are the issue. Do you notice any difference in how the transmission functions when cold vs warmed up.
The tough part about syncrhos is its not a job just any shop can do. There are only a few shops that can do it. JHM is the top shop and offers the top carbon replacement syncrhos. I dont know if JHM makes the carbon ones for your transmission yet but its worth an ask. Even if they dont they would be the ones most people send there transmissions to to get rebuild and inspected