brake bias valve..

[joe_thompson]

anyone know where to get brake bias valves from fairly cheap? iv fitted some big 4 pots and im indeed of some as all my powers going to the back.


Thanks

 

[DOSvtec]

have you checked ebay!? theres wilwood ones for about £50 and there is a few more expensive ones as well

 

[joe_thompson]

yee had a look at them, just wasnt sure if there are any cheaper ones, i dont want it on display or anything .

is there honda ones i can use?

 

[Kozy]

Eh ho, all the power is going to the back with big four pots? Should be the other way round shouldn't it?

 

[joe_thompson]

Eh ho, all the power is going to the back with big four pots? Should be the other way round shouldn't it?

hmm thats what i would of though, im abit unsure of what to do, the pedals feels really firm but the brakeing power just insnt there,its hard to make them lock up. Iv bleed them a loads aswell.

Any ideas?

 

[Kozy]

So the pedal is hard, no brake force from the front and you're locking up the rears? What brake kit have you fitted?

 

[joe_thompson]

So the pedal is hard, no brake force from the front and you're locking up the rears? What brake kit have you fitted?

yep the pedals hard, there is brakeing at the front as i ran the car and tested the brakes whilst it was on stands. But there is defo not enough, id go as far as saying there is less that before.

Its a 1997 ej9 non abs, with a rear disk conversion and now iv fitted some brand new 4 pot brembo brakes that came of a the rear of a jaguard XKR R edition ( the fact that ther off the rear shouldnt make any differance should it?)

I am also using the stanard ej9 brake proportion valve, im unsure what ratio this is though

any idea's kozy?

 

[Kozy]

It's all on the piston sizes TBH, I'd imagine that the total piston area is far smaller than the stock 262 caliper, so they'll be nowhere near as powerful!

Can you find out the piston sizes?

 

[Kozy]

Found them, 30mm and 28mm, that's a 2.04sq.in caliper, the stock 262 caliper is 3.56sq.in! Those brakes are hopelessly underpowered mate, they are completely wrong for the car!

 

[joe_thompson]

Found them, 30mm and 28mm, that's a 2.04sq.in caliper, the stock 262 caliper is 3.56sq.in! Those brakes are hopelessly underpowered mate, they are completely wrong for the car!

Where did u find that info from? i was under the impression they were a bigger area in today as i measured them ages ago. hmmmmmmm

 

[Kozy]

Rockauto I think the site was called. You may have been adding all the pistons together, a lot of people do but the effective area is only one side, so in comparison to the stock caliper which exerts equal pressure on either side of the caliper, they are tiny!

These are the right ones I think.
http://www.rockauto.com/catalog/moreinfo.php?pk=2053444

 

[joe_thompson]

Rockauto I think the site was called. You may have been adding all the pistons together, a lot of people do but the effective area is only one side, so in comparison to the stock caliper which exerts equal pressure on either side of the caliper, they are tiny!

I atually feel sick! i carnt belive iv made such a **** up and it such a simple thing, and im not exactly new to all this. Dont suppose you have a link to the page you found the info from do you? i carnt seem to find it.

 

[Kozy]

Added above. Even if they aren't the exact ones, it's definitely the cause of the problem, despite being four pots, they are still rear brakes and so are actually pretty weak.

Easy mistake to make mate, brakes are not an easy thing to upgrade well! Sorry to hear you've probably spent out good money for these!

 

[joe_thompson]

Added above.

Easy mistake to make mate, brakes are not an easy thing to upgrade well! Sorry to hear you've probably spent out good money for these!

pay £112 for them over a year ago, well guess il just sell them, iv got some other front brakes (4 pots) off a nissian 300zx soo il just use them i guess.

Defiantly feel stupid though although this is the only real time i done a big brake up grade, learning curve for me i suppose.


Cheers cozy mate, im pretty sure i wouldnt of thought about that untill id tried a few more things

 

[Vtec6000]

If you still have the EJ9 servo and brake master cylinder then there lies your problem. Fit a servo and master cylinder off a EK9 and you'll be amazed how much better the brakes will be

 

[joe_thompson]

If you still have the EJ9 servo and brake master cylinder then there lies your problem. Fit a servo and master cylinder off a EK9 and you'll be amazed how much better the brakes will be

im running a 1inch master and servo

 

[stevenEK9]

If it's an EJ9 prop valve then it's deffinately the calipers at fault, the rear drum prop valve sends less fluid to the back and you would normally fit an oem 40/40 prop for a car with no ABS and rear discs

I have huge 4 pots on the front and my rear brakes are massively under worked as a result!!!

JJC rally / Demon tweeks do bias adjusters, but as mentioned i would investigate a bit further first.............

 

[Kozy]

If you still have the EJ9 servo and brake master cylinder then there lies your problem. Fit a servo and master cylinder off a EK9 and you'll be amazed how much better the brakes will be

I'm not sure, I think that would exacerbate the problem. Bigger MC = less line pressure, meaning he'll have to push the pedal even harder.

 

[stevenEK9]

there is more servo assist on an EK9 though, the servo is a fair bit deeper thus higher volume than the EJ9 unit

 

[Kozy]

You're correct, checking on Lings it uses the VTi 7+8" one vs the 8+9" on the EK9/DC2, I thought they all used the same one for some reason. That's interesting actually, I would have guessed it to have been the other way round if anything, grandads shopping car surely needs more assist than a rip-snorting road racer! Learn something new every day.

Unfortunately I still don't think it compensates for the badly mismatched calipers in this case.

WRT to servos: Do you know if you can change servos only? So run 15/16 MC on the EK9 servo or visa versa?