pdapaul's YellowSpeed Time Attack EKK24 on ITBS


pdapaul said:
Hi Jesse,
The servo delete took a LOT of getting used to, but once I had I liked it. I would suggest that if it is on a car that is driven daily it is a bad idea as you couldn't really react quick enough to people being dicks on the road. It gave a really progressive brake, and as the pedal is ROCK Z hard you can't easily lock it up.
Honest opinion, for the hassle of the install I wish I hadn't bothered. Fitment issues, set up issues and just general ball ache would mean I wouldn't suggest it as a viable option. If you were really interested you are more than welcome to have a drive of mine if you are ever trackside.
Click to expand...

Very brave of you! I might have to take the whole car home mind...
 
Just seen the last post, interesting..
If it turns out you did it wrong could you share your mistake? Means if I do fancy ago at this then I won't make that mistake lol
 
I've definitely done it wrong ha ha.. I'm going to get stuck into it again tonight do should have some more news later
 
Haha never mind. Good job you asked someone in the know really.
 
I'm 6' so I'll be abit cramped lol
 
jesse888 said:
Just seen the last post, interesting..
If it turns out you did it wrong could you share your mistake? Means if I do fancy ago at this then I won't make that mistake lol
Click to expand...

I managed to get some time to look at the brakes on Friday and it turns out that I have done it wrong so far. My error consists so far of 3 things:

I didn't know how a brake balance bar worked
I didn't really know how brakes worked in general
I fitted all of the parts incorrectly (sort of)

:)

Now that I have a good understanding of the above I have a fighting chance of getting the brakes even better.
 
Sounds like a minefield tbf.
I don't know how a bias bar actually works either.
Would prefer a tap myself if that's possible?
 
As per everything so far it's been an extremely sharp learning curve. The pedal box is going up be as good as I hope once I've made the adjustments, so I'm sure will help track speed. As per earlier comments effectively I was braking with a roughly 70/30 split(70% to the rear). So even when the rears were fully in the fronts were nowhere near their potential. Once it's sorted im hoping to be able to brake later, harder and more consistently. I was recording decent times when I went to Oulton, and that was my first time, with little track time and with the brakes not fully sorted. I would like to think that the brakes sorted will help me bring that time down, and will certainly help at the big braking tracks like Snetterton.
 
Last edited:
jesse888 said:
Sounds like a minefield tbf.
I don't know how a bias bar actually works either.
Would prefer a tap myself if that's possible?
Click to expand...
I don't think you can as the balance bar is part of the pedal box to bias the front & rear. Normally a tap(I have the Tilton lever) is used to adjust the rate at which the pressure is release, so mine is on the rear line.
 
Yeah acts like a lever that you can adjust sideways to alter pressure?
That's about as much as I know of them mind lol
 
i was about to try and explain the difference...but it's too hard, so here are some pictures :)





So the balance bar helps to match the front & rear master cylinders, whereas the lever effects the slope rate pressure of the line it's connected to. What I didn't fully understand was the implications of the different sizes master cylinders and how to control their relationship through setting the balance bar
 
When I first wrote my thoughts on the system, and said I had a solid pedal, this was due to not taking into effect the master cylinder size. The larger cylinder .750 on the rear actually creates a harder pedal and a shorter throw. So as I set the b/bar straight the rears were at maximum in a couple if mm , yet the fronts needed another 10-15mm to be fully on.

I was pressing the brake that hard that it did this to the rod connecting the pedal and the balance bar

 
Last edited:
So with an idea how to set it all up I got the m/c's set in the pedal box and then made a new rod to fit. You can tell how much I've adjusted the box by the length difference. I also didn't thread the entire rod this time to keep a bit more strength.



 
This is one of those things that you can easily get it in to your head that you've got it right when it's actually back to front or wrong

Did you have the rod lengths/throw set in a almost back to front way then tried to compensate it with the balance bar?
 
Smaller diameter master cylinder, softer pedal, longer throw, more force.

When you remove a servo, you use a smaller master cylinder to compensate.
 
I set the balance bar exactly square, so the m/c rods were the same length. So when I pressed the brake the rear m/c (smaller diameter, shorter throw) had finished its movement before the front had really even started. That's why the pedal felt so hard, and had no play in it. To make it even worse, I tried to dial out the rear using the in car bias, but all that did was reduce the flow to the rear, which upped the pressure. So the more I adjusted it to the rear, the higher the pressure went, the harder the pedal became and I therefore had even less front than before :)
 
You must log in or register to reply here.
Back
Top