Mark H
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 posted on 3/5/03 at 08:09 PM |
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SVA Warning - brake bias bars
Hi Guys,
If your car has a brake bias bar - It is a fail if the bar can be adjusted by hand. The sva inspector suggested a nut and split pin in the desired
position.
Please see pic. One more reason to fail gone!
Cheers,
Mark
PS You should see my "matchboxes-covered-in-foam" solution to the issue of sharp bonnet catches! If it passes, I'll show you a
piccy!
 
Rescued attachment cockpit - bias bar.jpg
Mark Harrison and
Q986 KCP back from the dead...
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Mark H
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| posted on 3/5/03 at 08:12 PM |
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sorry bout the size!!
The pictures a bit massive-sorry!
Also, have now got rid of the dodgy velcro covers, and put proper grip stuff on (you need something to grip as that is also an SVA fail!
Mark Harrison and
Q986 KCP back from the dead...
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ChrisW
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| posted on 3/5/03 at 08:27 PM |
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Is that a Luego pedal box Mark? Looks very similar to the one I have.
Chris
My gaff my rules
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Mark H
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| posted on 3/5/03 at 09:27 PM |
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Chris,
It's actually Stuart Taylor, does the job, and looks good. Hmm, apologies for being controversial, but who coped who then?!
Have a good time at Stoneleigh - take reams of photos!
Cheers,
MARK
Mark Harrison and
Q986 KCP back from the dead...
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Markp
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| posted on 4/5/03 at 04:29 PM |
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when it comes to the bias bar which way around does it go? there is a short side and a lond side.
Cheers mark
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ChrisW
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| posted on 4/5/03 at 05:57 PM |
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Have a look in my photo archive. The luego one looks very similar!
What master cylinders did you use btw?
Chris
My gaff my rules
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Findlay234
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| posted on 5/5/03 at 09:45 AM |
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would a nyloc nut do the job, cant really be altered by hand.......???????
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Mark H
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| posted on 5/5/03 at 06:12 PM |
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Nyloc nut
Debated this myself. I think that because my SVA man suggested a split pin through, it would be foolish not to put one on.
Of course, every sva man is different and there are no set rules! I would think that as long as it cannot be moved by hand, it will not be
highlighted by the man in the white coat.
Mark Harrison and
Q986 KCP back from the dead...
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merlin
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 posted on 27/5/03 at 09:13 PM |
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Bias valve
My SVA inspector insisted it was welded once set so that it can never be adjusted again! It passed!!
shit happens! (but why always to me!!)
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Mark H
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| posted on 28/5/03 at 09:05 AM |
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Doesn't that mean the bias bar cannot be adjusted for race type situations (surely the point of the bar)? Having said that i cant imagine ever
changing mine.
Mark Harrison and
Q986 KCP back from the dead...
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eddymcclements
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| posted on 12/8/03 at 10:40 AM |
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Mark - just looking at your pedal box photos, are your brake master cylinders retained by bolts which thread into rivnuts? Braking parts really need
to be fixed with high-tensile fasteners, and I'm not sure if a Rivnut is really up to the job in that application.
Cheers,
Eddy
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Rob Lane
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| posted on 12/8/03 at 03:50 PM |
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Have to agree with Eddy, the rivnuts are in danger of stripping with the amount of force applied to the pedal. In this case pushing the bolts away
from rivnut.
I think Dick Axtell came up with some figures for a 5:1 pedal leverage on a cylinder of something in order of 500lbs plus.
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blueshift
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| posted on 12/8/03 at 04:00 PM |
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Weld nut, pass sva, grind nut off is always an option.
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Stu16v
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| posted on 12/8/03 at 10:21 PM |
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And to add, the pedal bias will probably not work properly either, with the locking nut and washers bearing onto the 'fork' of the
pushrods, as opposed to the pivot in the middle of the forks, and will not allow the bar to pivot correctly.
Dont just build it.....make it!
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StuartA
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| posted on 13/8/03 at 12:02 PM |
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quote:
Originally posted by eddymcclements
are your brake master cylinders retained by bolts which thread into rivnuts?
Cheers,
Eddy
What looks like rivnuts on those pics are actually part of the pedal box. Must be OK, otherwise Luego and ST wouldn't make 'em that way
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Rob Lane
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| posted on 13/8/03 at 04:57 PM |
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I wouldn't trust my life to rivnuts in this application.
I have an ST pedal setup with brake bias bar and it did not come with any rivnuts but it did have the cylinder cutout and mounting holes.
I would be surprised if Ian at ST supplied them this way, he's a capable racer and would know the forces involved.
I used steel rivnuts on my seat bases and just getting in and out has caused two failures of the threads. Admitted they just stripped the threads
around the bolt but stayed in. But then again they weren't subject to any 'pulling' pressure as per the brake cylinder
application.
In the pic the pushrod from pedal is acting on cylinder piston and trying to push the whole thing forward under braking. The holding bolts are into
the rivnuts from engine bay side, therefore the pedal pressure is translated as a pushing force on bolt heads and the bolts could pull the threads on
rivnut. Exit any braking!
Just ten pennorth and not meant to offend anyones sensibilities. Mine are bad enough
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andyd
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| posted on 13/8/03 at 05:21 PM |
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quote:
Originally posted by Rob Lane
I have an ST pedal setup with brake bias bar and it did not come with any rivnuts but it did have the cylinder cutout and mounting holes.
But Rob do they look like Marks? We've got a Luego pedal box (same as ST's) and from that angle I'd bet that they look like
rivnuts.
quote:
Originally posted by Rob Lane
I would be surprised if Ian at ST supplied them this way, he's a capable racer and would know the forces involved.
Agreed, but that's what ours looks like too without modification by us.
Andy
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wicket
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| posted on 13/8/03 at 10:49 PM |
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No Rivnuts on my Luego pedal box !
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Rob Lane
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| posted on 14/8/03 at 07:46 AM |
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My pedal box is identical except no rivnuts and I've drilled the pedal pads.
They are rivnuts in the photo and you can see the deformation fixing. What is of more concern is that the bolts don't appear to even go through
the rivnut fully.
I've really used my brakes in anger many times and the forces on the pedal are very great.
I just don't wish anyone to get hurt for a simple fastening change.
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eddymcclements
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| posted on 14/8/03 at 03:12 PM |
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I have an ST-supplied pedal box with pre-drilled holes for Girling/Wilwood master cylinders. The holes didn't have rivnuts fitted and I've
used socket head capscrews to retain the master cylinders.
If you're happy with the set-up, keep it as it is. I'm not telling anyone how to build their own car. Just thought you might want to take
another look at it, taking into account the comments that have been made.
All the best,
Eddy
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Rob Lane
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| posted on 14/8/03 at 09:28 PM |
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Nicely put Eddy. My comments do seem to somehow come out strong, I don't mean it that way, just trying to be helpful.
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Peteff
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| posted on 15/8/03 at 12:07 AM |
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It looks o.k. to me. The rivnuts are the right side of the bulkhead. You aren't going to push it through that.
yours, Pete
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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Rob Lane
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| posted on 15/8/03 at 07:40 AM |
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Look at it again Pete.
It's not the rivnuts pulling out but the bolt pulling out of the rivnut if the threads fail. These things are not high tensile.
The pushrod is pushed at force into the cylinder which is trying to be pushed into engine bay. It's currently held by the two bolts on engine
bay side which are threaded part way into the rivnuts.
Sorry, I've gone on about this too much.
If anyones happy with the way they've built their car then that's fine, I've no intention, as Eddy said, to tell anyone how to build
theirs.
Rob
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theconrodkid
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| posted on 15/8/03 at 05:01 PM |
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Rob/Eddy this forum is for making coments like that,id rather be told my car was unsafe and have chance to fix/modify it than find out the hard way
into a brick wall
who cares who wins
pass the pork pies
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andyd
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| posted on 15/8/03 at 09:21 PM |
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quote:
Originally posted by theconrodkid
Rob/Eddy this forum is for making coments like that,id rather be told my car was unsafe and have chance to fix/modify it than find out the hard way
into a brick wall
Damn right! 
Thanks Eddy and Rob for pointing out something that wasn't obvious to me until now. I will certainly be cutting/drilling out the ones in my
pedal box and replacing them with locknuts! I think that ST and Luego (and anyone else that has this type of pedal box) should be made aware of the
potential risks in using such a fastener. I'll post to the Luego section to see what Grant has to say on the matter.
Andy
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