JoaoCaldeira
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| posted on 4/9/07 at 11:13 PM |
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Front right locking up
Hi.
Under hard break, my right front wheel locks way before the left one.
My setup is R16 with standard solid discs front and standard sierra calipers with standard solid discs rear.
My car (on scale weights - which seemed pretty accurate (?)) without a driver (on the LEFT!!)
Front
. right: 95 kg
. left_ 129,5
Rear
. right: 129,5
. left: 132
Opinions?!
Thanks,
Joao
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daviep
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| posted on 4/9/07 at 11:55 PM |
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I take it both your front brakes come from the same port on the master cylinder?
To set your weights up correctly the driver needs to be in the car.
Obviously it is a good idea to try and balance the car as you build it, putting items such as the battery on the opposite side to the driver can help
towards static balance.
Once the static balance is as good as it can be then you can start adjusting individual corner ride heights to fine tune your corner weights.
Increasing the ride height on one corner will cause the weight to rise at that corner and also on the corner diagonally opposite, the other two
corners will lose weight, and vice versa.
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Paul TigerB6
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| posted on 5/9/07 at 07:33 AM |
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Personally I would start by checking the piston(s) is/are not sticking in the caliper and that the front left brake is properly bled as it doesnt seem
to be anywhere near as efficient. Probably something really simple like an air bubble in the fluid to that corner.
Hope this helps
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britishtrident
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| posted on 5/9/07 at 07:37 AM |
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CORNER WEIGHTS are a mile out
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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ReMan
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| posted on 5/9/07 at 07:40 AM |
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By the looks of your figures there is no weight on the right front wheel, once you are in (on the LEFT ) there will be even less.
I had the same problem and have dialed it out now by adjusting ride height front to back, reducing tyre pressure and (without scales) putting more
weight on that wheel. It seems fine now
As above they are both fed from same pipe/master cylinder?, also may be good idea to re-bleed the front brake just in case the one had a small airlock
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JAG
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| posted on 5/9/07 at 07:50 AM |
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I agree with these guys!
There's nothing wrong with your brakes but your corner weights are a mile out 
Sort them out and your 'right front locking' problem will go away.
Justin
Who is this super hero? Sarge? ...No.
Rosemary, the telephone operator? ...No.
Penry, the mild-mannered janitor? ...Could be!
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JoaoCaldeira
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| posted on 5/9/07 at 09:19 AM |
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Hi.
Thanks for all your replies.
Front calipers are feed from the same master cylinder port.
I'll start to bleed both sides.
You RHD guy are quite lucky in a BEC setup, as the engine is biased to the left, but in this side of the pond I prefer be on the left, which agrevates
my problem.
If we consider cross weight, the difference (without driver!!!) is just 32 kgs, but the right front side is clearly VERY light (95 kg).
To balance with the left side (129,5) I suppose I need to raise it quite a lot. After balancing the weight won't it be way too different (ride
height, left and right)?
Thanks,
Joao
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higgsti
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| posted on 5/9/07 at 10:22 AM |
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what engine is in your car is it dry sumped weres the battery and coolant expansion tank these are things that could possibly be moved around to alter
your weights which is your problem.you could even try some ballast on front right not what you want to hear but im sure the car wont corner well
either
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britishtrident
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| posted on 5/9/07 at 11:08 AM |
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Don't get side tracked the problem is nothing to do with air in the brakes ! all you have to do is jack the spring seats on the front right and
left rear slightly -- how many turns required depends on the spring rate.
Cornerweights should be set with the driver or equivalent ballast in the car. Two or three 25kg bags should do nicely.
quote:
Originally posted by JoaoCaldeira
Hi.
Thanks for all your replies.
Front calipers are feed from the same master cylinder port.
I'll start to bleed both sides.
You RHD guy are quite lucky in a BEC setup, as the engine is biased to the left, but in this side of the pond I prefer be on the left, which agrevates
my problem.
If we consider cross weight, the difference (without driver!!!) is just 32 kgs, but the right front side is clearly VERY light (95 kg).
To balance with the left side (129,5) I suppose I need to raise it quite a lot. After balancing the weight won't it be way too different (ride
height, left and right)?
Thanks,
Joao
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JoaoCaldeira
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| posted on 5/9/07 at 10:23 PM |
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Hi all.
Thanks for your replies.
This is a BEC, R1 inj. powered, not dry sumped (just baffled).
I have the battery in the centre of the car, inside the tunel (battery top at scuttle's surface)
The expansion coolant (less than half a litre, I guess) is on the right (against the body).
The car was originally setup by Marc @ MNR (ex-BTCC driver).
It has done less than 3.000 miles.
The left shock platform is higher than the right. By your comments this shouldn't be right, but Marc is quite experienced.
Any comments? Could this be for cross weight balance rather than side to side balance?
Joao
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britishtrident
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| posted on 6/9/07 at 06:52 AM |
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quote "The left shock platform is higher than the right."
Screw it down a bit.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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higgsti
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| posted on 6/9/07 at 05:27 PM |
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i would corner weight the car with your weight or equivalent in the drivers seat and see if theres anything you can move around the car to front right
to help balance out the weight on the left.if not try some ballast see if it improves things
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britishtrident
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| posted on 6/9/07 at 06:48 PM |
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quote:
Originally posted by higgsti
i would corner weight the car with your weight or equivalent in the drivers seat and see if theres anything you can move around the car to front right
to help balance out the weight on the left.if not try some ballast see if it improves things
All cars even F1 cars are asymmetric to varying degrees, not ideal but it has to be lived with and by the time the driver is seated on the left any
weight that can be moved around is pretty trivial.
In this case whats wrong is patently obvious the front-right---rear left diagonal is carrying not enough of its share of weight -- a minutes work on
a spreadsheet or caculator shows it is shy by 9kg or 17kg depend on which criteria chosen ie best handling or best braking.
To redistribute the weight on the front wheels from left to right by 17kg on a Seven type car by moving heavy items would require moving items or
item totalling about 40 kg.
Of course the corner weight figures are made useless by the fact they don't include the drivers weight.
[Edited on 6/9/07 by britishtrident]
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higgsti
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| posted on 6/9/07 at 09:40 PM |
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Of course the corner weight figures are made useless by the fact they don't include the drivers weight
and when you ad another 70 kgs to left hand side (drivers side in this case)what will this do to the balance of the car .there are often things that
can be moved around the car to alter weight .after all with drivers weight in seat hes got even more weight on the wrong side of the car to move
around.
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higgsti
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| posted on 6/9/07 at 09:44 PM |
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quote:
Originally posted by britishtrident
quote "The left shock platform is higher than the right."
Screw it down a bit.
the clue comes here he is already jacking the left shock platform up to send the weight over
and your answer "screw it down a bit" this sends the weight back to the left hand side
this is presuming left shock platform is the drivers side looking forward over bonnet
[Edited on 6/9/07 by higgsti]
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britishtrident
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| posted on 7/9/07 at 07:07 AM |
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quote:
Originally posted by higgsti
quote:
Originally posted by britishtrident
quote "The left shock platform is higher than the right."
Screw it down a bit.
the clue comes here he is already jacking the left shock platform up to send the weight over
and your answer "screw it down a bit" this sends the weight back to the left hand side
this is presuming left shock platform is the drivers side looking forward over bonnet
[Edited on 6/9/07 by higgsti]
No it won't --- screwing down the left front spring abutment will reduce the weight on the left front/right rear diagonal which is what is
required.
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higgsti
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| posted on 7/9/07 at 08:19 AM |
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btitish trident thats presuming you are looking at the front of the car
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marc n
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| posted on 7/9/07 at 08:30 AM |
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hi joao
corner weights are quite a bit out not unusual after a few miles once everything is settled, check dampers are on the same settings side to side
left down or right up keeping ride height as equal as poss
cheers
marc
please email rather than u2u
direct workshop email ( manned 8am till 6pm )
www.mnrltd.co.uk enquireys to :-
chrismnrltd@btinternet.com
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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JoaoCaldeira
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| posted on 7/9/07 at 08:52 AM |
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Hi all.
Thanks - again - for your replies.
As Marc pointed out, the cars was not reset after the initial run in, so after things shaked a bit it's most natural it's a bit off.
I usually drive with a passenger (even on track) with unknown weight, so I think it wil be better to corner weight without the driver. Opinions?
Better handling or better braking:
In terms of weight distribution, what does this means? (percentage wise)
Thanks again for all inputs,
Joao
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marc n
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| posted on 7/9/07 at 10:23 AM |
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always setup with driver, then add passenger afterwards and note results then at track you can add or adjust turnss dependant on passenger or no
passenger
cheers
marc
please email rather than u2u
direct workshop email ( manned 8am till 6pm )
www.mnrltd.co.uk enquireys to :-
chrismnrltd@btinternet.com
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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britishtrident
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| posted on 7/9/07 at 11:01 AM |
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quote:
Originally posted by higgsti
btitish trident thats presuming you are looking at the front of the car
No !
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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britishtrident
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| posted on 7/9/07 at 11:11 AM |
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As Marc said things settle especially springs, they undergo internal stress distribution due to low temperature creep.
The stress redistribution happens in 3 phases,
Phase (1) When first out into service the spring will quite quickly settle to a noticeable degree.
Phase (2) Normal service ---- spring continues to sag but at a much slower rate.
Phase(3) end of life ---- spring sags/looses tension rapidly
Good spring manufacturers out the springs through what is called a "Scragging" process to try and reduce the intial setting.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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JoaoCaldeira
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| posted on 16/9/07 at 09:18 AM |
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For a given point, which is the biggest difference between left and right in ride height that is acceptable?
Where are the best places to measure (either at the front and at the rear)?
Thanks,
Joao
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britishtrident
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| posted on 16/9/07 at 03:36 PM |
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Getting the corner weights & rideheight right usually means juggling the ride height setting on the diagonally opposite rear wheel.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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