SVA Today - Brake Bias Setup
Discussion
Well today I took my car to the SVA but sadly failed on the brake bias adjusment.
Strangely I removed the locking mechanism and tweeked it on the fly (at one stage moving the bar all the way from one side to the other) but this made absolutely no difference.
When they run the original failed data through their computer but in reverse it would pass but this meant I had the cylinders the wrong way round. Spoke to the factory and I do have them correct.
There was minimal braking difference between front & back.
Any pointers to what can be wrong, other than swap the cylinders just for the SVA.
Cheers
Michael
Oooo, so close but yet so far on first attempt.
Strangely I removed the locking mechanism and tweeked it on the fly (at one stage moving the bar all the way from one side to the other) but this made absolutely no difference.
When they run the original failed data through their computer but in reverse it would pass but this meant I had the cylinders the wrong way round. Spoke to the factory and I do have them correct.
There was minimal braking difference between front & back.
Any pointers to what can be wrong, other than swap the cylinders just for the SVA.
Cheers
Michael
Oooo, so close but yet so far on first attempt.
Hey Mclark
Which way round do you have the masters? You should have the .625 to the front and the .75 to the rear. This is the way that you get more line pressure to the front.
By the way well done you've got to be well pleased
Cheers Pee
>> Edited by pee on Thursday 4th August 09:31
Which way round do you have the masters? You should have the .625 to the front and the .75 to the rear. This is the way that you get more line pressure to the front.
By the way well done you've got to be well pleased
Cheers Pee
>> Edited by pee on Thursday 4th August 09:31
Hi Pee,
I phoned the factory during the test and they confirmed the front should be .75 and the rears .625.
Yes, after the initial disappointment had worn off I was very pleased to come away with just this.
Now need to find a rolling road in Essex/Herts to get the car running/setup correctly.
Cheers
Michael
I phoned the factory during the test and they confirmed the front should be .75 and the rears .625.
Yes, after the initial disappointment had worn off I was very pleased to come away with just this.
Now need to find a rolling road in Essex/Herts to get the car running/setup correctly.
Cheers
Michael
Don't forget Green V8s that under breaking you get front end dive so therefor the weight is being sent to the front and as you say the disks are the same size front and back so that would be compensation for the weight split without offering it more line pressure.
Factory, I'm not arguing with you I am trying to obtain as much info so I can have the car as well set up as possible. Could you please tell me some more of the factors you are refering to.
Cheers Pee
Factory, I'm not arguing with you I am trying to obtain as much info so I can have the car as well set up as possible. Could you please tell me some more of the factors you are refering to.
Cheers Pee
I had my set up the factory way, but the balance bar was hard over I could only get 58/42 I could not get any front bias... Spoke to AP they have a setup that needs to be followed closely.. The balance bar should be setup so that it is level when under normal braking force, so when at rest with your foot of the pedal it is at an angle. The larger cylinder puts up more resistance so will travel less. The smaller cylinder puts up less resistance so travels further.
Got it so far......
So they say (untested by me but this is AP I spoke to)
The smaller cylinder due to traveling further etc will produce more pressure i.e. Front (even though I didn't have this on the GTR, but I'm no braking demon) I did not know about this until recently but the GTR I'm building has a Brake pressure sensing device so I will test both ways and report back when I've tried both setups......
Not trying to step on anyone’s toes here, just relaying information I have, as this is what forums are all about.....
All the best GTRClive
PS I had a SPA Brake pressure gauge on my GTR so that’s how I knew what I had…
www.wilwood.com/Products/005-PedalAssemblies/Pages/techtip/pedaltech.asp
This is how Wilwood Setup there Balance bars.. Interesting reading....
This is how Wilwood Setup there Balance bars.. Interesting reading....
Sorry guys, thought about this more and there is no way that this car should be running more breaking force to the rear. If you watch the 0-100-0 test you'll see the rears starting to lock and not the front.
mclark if you change them over you'll sort out all your problems. If you doubt me speak to anybody who deals with AP breaking systems and race cars.
Cheers Pee
mclark if you change them over you'll sort out all your problems. If you doubt me speak to anybody who deals with AP breaking systems and race cars.
Cheers Pee
gtrclive said:
The smaller cylinder due to traveling further etc will produce more pressure i.e. Front (even though I didn't have this on the GTR, but I'm no braking demon) I did not know about this until recently but the GTR I'm building has a Brake pressure sensing device so I will test both ways and report back when I've tried both setups......
Fortunatley hydraulics is not a wholly black art (although some people may have you bellieve it is). It acts as simply as a gearbox might with ratios.
In this case, its the ratio of the master piston area (not volume)to the caliper piston area. The smaller master cylinder, the *greater* the pressure exerted on the caliper piston.
Be cautious of your new pressure guages - absolute line pressure does not by itself indicate very much at all. However the ratio of pressures between front an rear lines will indicate relative breaking effort applied to the front and rear tyres... (assuming identical calipers, rotors and wheel sizes etc)
Look forward to your figures..
adam
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