Brake balance

[kelvin]

I'm up to the stage of my build where I need to think about brake balance.
My plan was to disable the "proportioning valve", under the master cylinder, which should then give excess pressure to the rear, and put an adjustable valve in the cockpit for the rear brakes.
But probably best to see what everybody else has done before I waste too much time.

[Whitey]

Hi Kelvin,
being a FWD the dual circuit brakes pair the FR with the LR and the FL with the RR thru two prop valves, one for each rear cylinder.

Im sure there has been a thread on this here already.
search is your friend :)
http://www.excelrally.com.au/forum/showthread.php?t=232

[kelvin]

Thanks for that. It didn't make sense to me that the 2 lefts were paired and the 2 rights were paired. I thought my car must be wired wrong. What is the reasoning behind that. I would have thought both fronts together and both rears together. Must give very wierd bracking if one master cylinder fails.

[kelvin]

Sorry, just read the link you gave.

[MSA77]

thought i might butt in here and see if anyone knows what a proportioning valve costs,

[Glenn]

I've posted this elsewhere I just thought I'd add a bit regarding brake balance of the cars......they're bloody brilliant stock standard!

In my opinion, there's no need to change the brake balance from stock. The effort to put a hydraulic handbrake in the car is really not worth it AND you're likely to stuff it up (with regards to brake balance).

[kelvin]

I think Glen's post is what I was looking for. I think we all love to fiddle. Change this, alter that, but if there is no real improvement, why bother.
I think I'll drive it as is for a while, then see if I need to change anything.

[haggers]

I've posted this elsewhere I just thought I'd add a bit regarding brake balance of the cars......they're bloody brilliant stock standard!

In my opinion, there's no need to change the brake balance from stock. The effort to put a hydraulic handbrake in the car is really not worth it AND you're likely to stuff it up (with regards to brake balance).


I agree. We have the standard Race Brakes pads etc and a cable handbrake and it is fine. The car stops very well. I wouldn't bother dicking with the brakes.

Haggers

[Latho]

What are people using for the rear shoes? A few of us up here are using QFM's A1RM 780 degree race pad on the front and at $95 is a bloody bargin!!! But as far as I know everyone is just running std shoes so far...

[fro]

After spending so long trying to get the brakes in the Datsun to a point where I liked them, I was devastated when I sat in the Excel. It brakes much better than the Datsun out of the box.

Greg, I'm ran the "Race Brakes Sydney" package, which was cut down SBS pads for the front, and re-bonded splinky shoes in the rear. It stopped great... too well in fact. I'd find I'd go to give the brakes a touch to adjust the car, and end up wiping off a bunch of speed and having to wind it up again!

[ernysp76]

Fro,

Try reversing the boost hose takes 10 sec, that way you have no boost but lots of feel. The Sydney Race Brake package is great.

[RBS MATT]

Fro,

Try reversing the boost hose takes 10 sec, that way you have no boost but lots of feel. The Sydney Race Brake package is great.

Thanks for the support from everyone we try our best to please everyone.The package is a great set up for these and many other rally cars.

MSA77 thought i might butt in here and see if anyone knows what a proportioning valve costs,
The adjustable brake bias units start from $90.00

[fro]

The RBS Package is awesome. Got to drive the car with the DMS last weekend (but not this weekend, dammit), and the brakes are just fantastic.

I tried reversing the booster hose, but felt that the pedal was "too dead" without the booster assistance.

[HMCA]

The RBS Package is awesome. Got to drive the car with the DMS last weekend (but not this weekend, dammit), and the brakes are just fantastic.

I tried reversing the booster hose, but felt that the pedal was "too dead" without the booster assistance.

This is Paul's prefered method of brake pedel feel. I haven't really driven the car that way but Geoff drove it to Scrutineering at ROM and said that the brakes were crap, so after a bit of thought and a confirmation call to Mouldie we reversed the hose back to the normal way and all was happy. I have spoken to Paul about his thoughts on this and a few other things like sway bars etc and he does set the car up differently to most. Works for him I would say.

We run the complete Racebrakes package with both pads and shoes.

[Mooa42]

Does anyone know if there is any difference between the splitter under the booster on a SOHC '96 model and DOHC '98 model? I am still suffering from really spongy brakes. I have changed booster from DOHC and pedal setup, new M/cyl and wheel cyl, and rebuilt front calipers, (which I think may have been off the SOHC).

:(