Interesting.
Interesting.
All I wanted was a Pepsi, just one PepsiFar from suicidalStill I get them tendenciesBringing back them memories
That I really miss when I reminisce
Possibly even worrying?
Iain, presumably you've got a 0.625" front master cylinder? Just wondering what the spec of your front braking system is, and cos I'm a lazy B and can't be arsed schrolling back through your thread I wondered if you could let us anoraks know the grizzly details in an easy to read summary?
For instance I know your running 4 pot front calipers but wonder what the piston size is? Also what size discs...?
Hopefully I and others can benefit from your learning process (I was almost tempted to say mistakes but that would be plain rude)
0.625 front, now 0.75 rear. They're Wilwood 4 pot Dynalites, with 280mm discs, rears are Corsa C single pot sliding caliper. However I've done this very crudely and not measured the piston sizes, quantities etc and purely based it on 'what others have success with'.
I've noticed the front cylinder moves quite far in comparison to the rear, I'm not sure if the sign of a good set up is similar travel on both. Who knows.
Looking at the picture of your Calipers, the pistons don't look to be overly large, so that might explain why they feel a little on the heavy side?0.625 front, now 0.75 rear. They're Wilwood 4 pot Dynalites, with 280mm discs, rears are Corsa C single pot sliding caliper. However I've done this very crudely and not measured the piston sizes, quantities etc and purely based it on 'what others have success with'.
Hopefully the switch to a larger rear M/C will even up the bias bar a little?
That's pretty standard for a pedal box setup, especially when running a tarmac setup, presumably you've got the pedal box bias bar set up with the Bias Bar cocked such that the front brake clevis to M/C is longer than the one for the rear brakes?I've noticed the front cylinder moves quite far in comparison to the rear, I'm not sure if the sign of a good set up is similar travel on both. Who knows.
Thus allowing the front brake cylinder to have the extra stroke that it needs to move the pistons in the calipers without risking the balance bar lever binding?
At the end of the day I suppose we are all looking for a brake pedal that provides plenty of feel (I believe the technical term is modulation?) and give us confidence in them. The problem with servo brakes is that though they provide good power, they always lack any real feel. I always remember moving a friends 911SC and only after I'd parked and got out did I realised just how good a non servo brake setup could be, driving it albeit slowly, they just worked...
I have this joy to come!
The 0.75 didn't work, it was still locking the rears on maximum front bias. There was loads of travel on the 0.625 cylinder, so either there's STILL an airlock in the cylinder somewhere, or something isn't 'matched'.
I've fitted the old rear (0.7) to the front now, and the pedal is way firmer and pedal travel is much more what I'd expect, so I'm going to go out and see if the front locks before the rears on this setup. Hockly said they ran .7 front/.75 rear so I don't think it's unusual.
Imagine your 911 mate got all the calcs and worked out the proper sizes scientifically, or had it professionally configured? That's too complicated and involved for me!
Last edited by Iain; 19-03-16 at 06:36 PM.
hockly told me to run a 0.7 on front and 0.75 on the rear. I guess that's pretty common on a nova with 4 pods on front and disk brakes on the rear?
Maybe, having took mine out to attempt to set it up yesterday, I had an inline adjuster wound all the way down (maximum restriction) and the bias quite far forward to stop the rears locking, and was struggling to lock the fronts with the 0.7 cylinder.
I think I must have had trapped air in the 0.625, it's the only explanation, so that's going back on with a thorough bench bleeding prior to installing.
Blimey that sounds terrible, you definitely shouldn't need an in-line adjuster on the rear brakes, after all that's the whole point of fitting a bias box.Maybe, having took mine out to attempt to set it up yesterday, I had an inline adjuster wound all the way down (maximum restriction) and the bias quite far forward to stop the rears locking, and was struggling to lock the fronts with the 0.7 cylinder.
Hopefully the 0.0625 should give a better result?
Are you sure the bias bar isn't fouling its housing (tube) when you are leaning on the pedal? I'm a bit suspicious that the reason why the rear brakes are locking up, despite using an in-line adjuster wound all the way down, is because the side of the bias bar the rear M/C is on is fouling the back of the housing?
If your doing this all single handed, maybe you can persuade a mate/the missus to lean on the pedal while you watch what happens to the bias bar as the brake pedal is pressed.
Got my fingers crossed you can get to the bottom of the problem soon. Good luck.
Yes sir, definitely not fouling, there's plenty of slack for it to get an angle on. Here's Harvey applying the brakes while I watch my expensive disappointment in action. Can see the front moving excessively.
Well I've swapped back to the 0.625 by properly bench bleeding by hand, transferring a FULL cylinder to the car and getting fluid everywhere, and then manually and pressure bleeding through, still felt sloppy. I've then swapped to some 256 ATE calipers and it feels awful on both of them. Very soft and squishy.
Have you droiven another Vauxhall with one of these?
Mine always 'feels' rubbish until used in anger and tehn it really comes into play - with heat in the pads and the right mind-set mine is great... if I get in after a few weeks in a normal car they feel absolutely toilet!
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