Pelican Parts Forums - Locking the fronts only with my Big Red's

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- - Locking the fronts only with my Big Red's (http://forums.pelicanparts.com/porsche-911-technical-forum/793496-locking-fronts-only-my-big-reds.html)

Quote:

Originally Posted by Walt Fricke (Post 7880808)

The forum strikes again, or at least BV.

Wayne - that Tilton part looks like it is for a non-powered dual MC setup. Wouldn't the big pie plate vacuum boosters bump into each other if you tried to mount two MCs more or less side by side? Mounting a dual MC on an SC or 3.2 is pretty easy, what with the adapters out there. But power seems harder with the older vacuum systems.
. . .

The 72-610 was designed to mount in places where a "normal" dual master setup wouldn't work. But there is nothing that says you can't put it behind a brake booster. I had mentioned that it needed a bellcrank.
Here is what I was thinking of:
http://forums.pelicanparts.com/uploa...1391014061.jpg
Couldn't find a good "above view" so just used mine which doesn't have the booster. Through the joy of digital crayons I laid out the idea...
- Blue is where the booster would be.
- Green is the rough location of the Tilton 72-610.
- Red is the bellcrank assembly.

The exact angle of the bellcrank would have to be determined by where the rest of the parts fit. Optimally you would want the bellcrank arms to be at 90° to the pushrods when it is in the middle of its range. The bellcrank mount would need to be beefy. Pedal forces are very high. I'd figure you should design for about a ton of force so there would be a large safety margin and no chance of a fatigue failure.
(Look at the size of the aluminum body of the factory bellcrank that the power booster mounts to. Porsche built that WAY strong.)

Quote:

Originally Posted by westcoast911 (Post 7880088)

Hi Bill,

...

For the p/v removal, would you suggest a simple union, or something adjustable?

Cheers!

You won't want ant restriction to the back, so either a union or gut the p/v

p/v are pretty simple

here is a typical one, just discard the guts
http://forums.pelicanparts.com/uploa...1391020897.jpg

Quote:

Originally Posted by Bill Verburg (Post 7882018)

You won't want ant restriction to the back, so either a union or gut the p/v

p/v are pretty simple

here is a typical one, just discard the guts
http://forums.pelicanparts.com/uploa...1391020897.jpg

Thanks Bill, that makes it easy!!

Wayne - with all that fabricating needed, why not just mount the bias bar assembly directly after the vacuum booster? If you remove the air blower stuff, there should be room? The longer the rod, the less angle needed as the bias bar is adjusted through its range.

Aren't there electro-hydraulic systems which can be used instead of vacuum?

I have the GTP kit on my 84 Carrera, and as Bill points out there are many variants. I think I got mine through Pelican many years back.

I removed the p/v when I installed the kit (Bill's suggestion) along with installing the 930 M/C. I have not been to the track yet with the setup but have pushed it fairly hard on the street...what I noticed is the car simply squats with no lock up of the front or drama at all...you may be fine just removing the valve as it may have been an oversight on the install some time back...there is enough room or "slack" in the lines with removal completely, or you could gut it as Bill suggests.

In other words try that first as it is free...then move on from there.