Hi all -
I have a Boxster S 6-speed (G86-20) and I'm running a Tilton pedal assy. I currently have a 7/8" bore clutch master cyl (Tilton model 76) pushing the stock Boxster slave cyl.
The clutch is really abrupt. Great on track, not so great on the street.

So, which size bore are you using? And are you running the stock pedal assy or after maket?

I understand, though haven't confirmed, the stock master is 19mm. What I can't assume is the pedal stroke / activation geometry is equivalent between stock and the Tiltons. I suppose I can grab a stock pedal set and work it out, but I thought I'd check to see what others have done.

I talked with Tilton and I'm thinking I'll try the 3/4" or maybe even their 7/10".

Thanks in advance for any help.

Pretty sure the stock Audi/Boxster is 19" dia. I think 3/4" would work just nicely.

You want to make sure you get FULL dissengagement of the clutch. The Boxster/audi trans's dont shift well if there is a hint of drag.. Ask me how I know.

I did the math, then used a 3/4 Wilwood clutch master cylinder with my G86-21. IIRC, the slave cylinders are interchangeable between the G86-20 and the G-86-21.

Good luck!

Clay

@Andyrew @ClayPerrine

Thanks gents! I've ordered the 3/4" and will report back on how it works.

Hi,

I am using a 3/4 Wilwood MC.

Seems to work well.

David

These are for the 987 / 997 should get you close.

Cayman S/997 (std) 997.355.910.00
23.8 mm bore
Cayman S/997S (PCCB) 997.355.910.10
25.4 mm bore (+7%)

997 GT3 997.355.910.30/80
27 mm bore (+13%)

That being said I am not sure what slave you have so it could be any one of these or something off the 986 line.

Just like brakes when the slave cylinder is changed to a larger size, effort goes up, pressure goes down. With out changing any other variables.

It may be that the friction material on your clutch disc is very high u (coefficient of friction), and resulting in the abruptness. Might want to look there, should the change in hydraulic ratios not give you the result you're looking for.
Andys