My bug with 2.4 type 4

[evilC]

Hi Grtz,

Thank you for the explanation about the speedo. I guess its the same as the kph speedo I have in my Mercedes. Isn't it supposed to read in kph (as well as MPH) in Begium?

I also have a hydraulic handbrake on the rear of the Beetle that powers the main Porsche 928S4 calipers. But I thought it was a requirement Europewide to have a mechanical hand brake as the emergency/parking brake? My hydraulic handbrake uses the normal handbrake lever to operate the cylinder in a similar fashion to yours but it also still has the cables attached to operate the 944 handbrake shoes. I expect that the mechanical part won't do much on mine as the hydraulic circuit will lock up before the mechanical part does when I get around to filling the system with fluid, so the mech system is a bit redundant. It at least complies with the regulations.

Clive

[RuleO9]

Normaly it's kph, but it doesn't matter.. because, the same reason as the handbrake..
You have 2 choises in Belgium..
1.. you go each year to the controle and LET YOUR CAR IN THE ORIGINELE WAY..
That means, no brakes no engine like we do...
Or 2..
You go 1 time to the controle and than is your car "oldtimer"
And than you only can drive to meetings..
And you can make a testdrive 1 time in the week..
It's a shame up here!!

And my bug is an oldtimer and i can do "any thing a want" because i don't have to go the controle every year..
But if the cops see my brakes and my engine..??
I don't know what will heppen, i think i hear it from the judge!!

[RuleO9]

New pics of today!
Chassis is ready!





Adaptors for the boxster calliper..

[evilC]

Is this primarily a competition car? I notice that your brake bias is heavily to the front (assuming a 19/19 master cylinder) the Kersher rear brakes don't help with the small single pot calipers and solid discs.

Clive

[RuleO9]

No it's just a street car.. It's also a bigger master cilinder

Do you mean that my front brakes are to big against the rear brakes?
Grtz Roel

[evilC]

The front brakes will be 4 piston and the rear is shown as a single piston. A bug requires near to a 50/50 brake bias. That is to say that the braking power should be about the same front and rear because of the heavy rear weight bias transfers forward under braking. On a front engined car with a weight bias of 55% front and 45% rear the brake bias will be around 75% front and 25% rear to take care of the weight transfer under braking.

The way to calculate your current bias is to compare the total front caliper piston area/front master cylinder piston area with the total rear caliper piston area/rear master piston area. Also, the brake disc diameters will moderate the final figures but I am assuming that the front and rear discs are about the same diameter?

You say that the master cylinder is larger - why? The smaller the master cylinder the more power you can apply to the brakes as the hydraulic advantage = total caliper piston area/master piston area. The downside of the smaller master piston is the longer pedal travel but generally this is minimal on a well set system. The bug 19/19 master cylinder is usually big enough for almost all applications and it will be only where massive caliper piston areas are used will you need a larger master cylinder to compensate.

Clive

[RuleO9]

The diameter is the same.. You're the first to say that the brake bias isn't correct with these calipers..
So i need? Bigger rear calipers or smaller had the front?

[Wally]

Originally Posted by evilC

The front brakes will be 4 piston and the rear is shown as a single piston. A bug requires near to a 50/50 brake bias. That is to say that the braking power should be about the same front and rear because of the heavy rear weight bias transfers forward under braking. On a front engined car with a weight bias of 55% front and 45% rear the brake bias will be around 75% front and 25% rear to take care of the weight transfer under braking.

The way to calculate your current bias is to compare the total front caliper piston area/front master cylinder piston area with the total rear caliper piston area/rear master piston area. Also, the brake disc diameters will moderate the final figures but I am assuming that the front and rear discs are about the same diameter?

You say that the master cylinder is larger - why? The smaller the master cylinder the more power you can apply to the brakes as the hydraulic advantage = total caliper piston area/master piston area. The downside of the smaller master piston is the longer pedal travel but generally this is minimal on a well set system. The bug 19/19 master cylinder is usually big enough for almost all applications and it will be only where massive caliper piston areas are used will you need a larger master cylinder to compensate.

Clive

All of the above is VERY true. Took me a while to actually get to know the real world data against the 'theory'. The theory is rather off, but the above is spot on.
Just take really good notice of what he said Roel ;-)