Brake Lockup on S13

[racedriver]

Hi Guys,

Has anyone here had any experience with edjustable brake bias?
The reason I ask is that the front brakes of my S13 lock up far too easily. I know I could soften the front to give it more bite but would adjusting the brake bias to the rear be a better option. I know adding an in car adjustable thing is illegal but I'm thinking an external adjustable unit that can be hidden away when the cops/rta won't find it or know what it is.

Thanks
Racedriver

[dattoman1000]

fitting the valve to the rear won't effect the front, as all you can do is reduce the rear brakes.
fitting a valve to the front reduces the whole braking efficiency of the car.......not a good look.

What pads and discs are you using ? There may be a prob;em there.
Are they STD brakes or upgraded ?

[Matty]

Originally posted by dattoman1000
fitting the valve to the rear won't effect the front, as all you can do is reduce the rear brakes.
fitting a valve to the front reduces the whole braking efficiency of the car.......not a good look.



Yes, but all cars have an OEM proportioning valve already, that reduces the rear load by a certain amount. If you REMOVE this prop valve, and replace it with an adjustable unit, the adj prop valve can be set to MORE or LESS rear bias than before...

Hence, more rear bias = less front lockup.

Is it legal if you fit it under the bonnet in place of the OEM valve?

[dattoman1000]

Not all cars have a valve.
The valve in the side of the Nissan master is basically an alloy piston with 4 o-rings on it. It doesn't proportion. This is done by using different sized calipers and discs front/rear.
Removing this isn't an option on this cyl.
Maybe you need better pads on the rear to give it more bite.

[racedriver]

Yes. They are stock brakes but with Metal Kings all round which I find are great pad.

I didn't think fitting different pads would work well because when they heat up the efficency of the pads is going to change and the balance will go out. Am I wrong?

I was thinking a ritrictor type valve on the front brakes will send more pressure to the back and balance them out?

[GTSBoy]

I would suggest that you see (or get a decent brake shop to see) if your master cylinder is not on the way out on the rear circuit. If the rear circuit is bypassing in the MC then you will get excessive front bias.

These cars shouldn't lock up the fronts any more easily than any other car, and so you shouldn't be looking to stick a bandaid on when you might actually have a real hardware problem that needs repairing.

cheers

[dbasteve]

What about your tyres?

Crappy or worn tyres will make the wheels lock up too early.

[racedriver]

GTSBoy: You could be right, but I think the front lockup has more to do with the non stock spring and damper rates making the original brake bias incorrect. Hence wanting to adjust it. I would do this if it's not 120% safe and reliable.

Tyres are good and not worn out.