Wow, that is some answer!! Thank-you very much. Is there anywhere I can take the car to in Surrey that would do this for me??
Hi. Is there an idiots guide on how best to set up the suspension? I have not touched it since I bought the car but the back 'looks' a bit high. It drives ok but obviously if there is an easy method to set up correctly I would quite like to do it. Alternatively is there somewhere in Surrey I can take it to to get it set up properly? Thanks
Corner Weights and Flat Floor Set-Ups
One of the important items that should be checked when trying to optimise the handling characteristics of your Seven are the corner weights in order
to ensure that each tyre is carrying its proper share of the overall weight of the car. This can be done by one of the many Seven specialists who
advertise in Low Flying or with the right equipment and plenty of patience you can do it yourself.
What is corner weight ?
The corner weights of a car are the weights which you would see if you placed a set of scales under each wheel whilst the car was on a flat level
surface with the driver sitting in the car
In order to understand the subject of adjustment it will help if you have a grasp of the concept involved. Imagine for a moment that you drive your
car into the garage and someone has left two 1" thick planks of wood on the floor exactly corresponding to the positions of your front offside
and rear nearside wheels when at rest. When you get out of the car all four wheels are still touching the ground (surprise surprise !) although the
front offside and rear nearside are actually 1" higher from the floor than the other two. What has happened here is that the front nearside and
rear offside wheels have dropped by 1" to touch the floor and in so doing the weight that was exerted on their springs by the vehicle has been
reduced. Because the car still weighs as much as it did when we started, if the weight on two wheels has reduced then it follows that the weight on
the other two wheels has increased. You can liken the car to a four legged chair which in the above example has had two legs shortened by a clumsy
carpenter and now has most of the weight of the occupant resting on its two longest legs. It will pay to think a little about these two examples
before moving on.
On a Seven the corner weights and the ride height (which is the distance that the bottom of the car is above the surface of the road) are adjusted by
moving the platform on the shock absorber upon which the road springs sit. You should take note that when you are adjusting the ride height this way
you are automatically changing the corner weights as well and vice versa..
It should be said at this point that in order to easily adjust your corner weights you need to have adjustable spring platforms on your shock
absorbers. This adjustment is usually (but not exclusively) carried out by screwing the spring platforms up or down the threaded outside of the body
of the shock absorber. Some Sevens are fitted with non adjustable platforms and whilst it is possible to adjust these (by fitting purpose made shims
under the springs) it is not very practical.
In order to successfully carry out corner weight adjustment certain conditions must be met. Firstly, all weighing must be done on a flat level floor
(which is where the term "Flat Floor setup" comes from) This is because readings taken on a non level floor will wrongly understate the
weights taken at the high end of the car and overstate the weights at the other end (think of the car parked on a 45% hill, the weight over the rear
wheels will be a lot greater than if it was parked on the flat) Second all weights should be taken with the driver in the car and with an average load
of fuel. Third you should ensure that all suspension pivots are correctly adjusted and that they are not stiff or binding. (it is a good idea to
slacken off to finger tight any suspension rubber mounting points in order to ensure this). With this in mind also wind your shock absorber rebound
adjustment to fully soft if this is possible on your units. Fourth you should disconnect any anti roll bars as any pre load (caused by twists in
manufacture or wrongly adjusted drop links) will affect the corner weights. Next, make sure that your tyre pressures are correct (this will affect
ride height) and finally wire brush and lubricate the spring platform threads on the shock absorber bodies (it makes the job a lot easier).
You should first of all set the ride height of the car by adjusting the spring platforms. Different people have different points at which they check
their ride height measurements and any ride height discussion is valueless unless you define these positions. I used a point between the heads of the
bolts holding the engine mountings at the front of the car and a point just in front of where the rear mudguard fixes to the body (by the front A
frame bolt) but you can use whatever points you like as long as you record the positions ready for the next time you set the ride height
You will find that adjustment is a lot easier if you jack the car up to take the weight off the springs, oh, and please invest in or borrow some
proper c spanners, using a punch to move the spring platforms is slow and leaves very unsightly marks on the adjusting nuts (or the car body when you
slip !)
Adjust these heights to your own requirements (to be equal on both sides of the car) bearing in mind that you need to be able to drive over speed
ramps in the supermarket car park as well as around Brands Hatch! The rear height as advised by Caterham in their build manual should always be about
15mm higher than the front whatever the measurements. After every adjustment you should roll the car forward and backwards and bounce the suspension
in order to settle the car to its true position. Having set the ride height (with the driver in the car remember!) you can now start to adjust the
corner weights
First you need a method of weighing the car. If you are related by birth to Mr and Mrs Fatwallet buy a set of corner weight scales from someone like
Demon Tweeks. This will make the job very easy as you weigh all corners at the same time. More realistically you will buy or borrow a Pace or ADA type
corner weight gauge which although not as accurate as corner weight scales will suffice with careful use for most needs. It is also possible to use
cheap bathroom scales providing you do so in a way that ensures that their mechanisms do not bind due to sideways movement of the suspension.
My Pace Gauge was not supplied with any instructions but as with all equipment there is a right and a wrong way of using it. You should insert a thin
stiff card under the wheel to be weighed, place the gauge (which is basically a lever on a post with a weight read out dial) under the wheel rim and
carefully lever the car off the ground to a point where the card can be just slipped out from under the wheel (like a feeler gauge). Note the weight
reading, then roll the car forward and backwards and bounce the suspension in order to settle the car to its true position. Repeat this four or five
times on the same corner and average your readings in order to get a more accurate result. Repeat this procedure for all four corners.
Having got your starting corner weights recorded you now need to decide what weights you would like to see when the job is complete (your ideal
finishing weights). Here in order to make things a little easier to follow I will give a working example
Recorded starting corner weights:
Front left 150Kg [A] 165Kg [B] Front right
Rear left 185Kg [C] 197Kg [D] Rear right
From these figures you can establish that the total weight of the car and driver is 697Kg (A+B+C+D) you can also establish that 45.2% of the overall
weight is on the front wheels by the following arithmetic: Total weight on the front of the car of 315Kg (A+B), divided by the overall weight of the
car and driver of 697Kg. Likewise you can establish that 54.8% of the overall weight is on the rear wheels by the same method. Total weight on the
rear of the car of 382Kg (C+D) divided by the overall weight of the car. (As a check on your arithmetic the two percentages when added should give
100. If not stay behind after lessons !)
Now for the clever bit ! If the car was a single seater with all components (including the driver) placed on the centre line of the car then both
front wheels should be set to the same weight which is exactly half of the total weight sitting on the front wheels (in the example above 315Kg
divided by 2 which is 157.5Kg) However in a Seven the driver sits to one side and so the centre of gravity of the car is also offset to that side.
In order to cope with this, the total weight on the right hand pair of wheels should be split 45.2% to the front and 54.8% to the rear to establish
your ideal finishing weights. In my example the total weight on the right hand side of the car is 362Kg (B+D) and so your front right ideal finishing
weight will be 45.2% of that (163.6Kg) and the rear right ideal finishing weight will be 54.8% of it (198.4Kg) Carrying out the same arithmetic for
the left hand side of the car gives an ideal finishing weight for the front left of 151.4Kg and the rear left of 183.58Kg
Now compare your recorded starting weights [As] with your ideal finishing weights [Af]
Front left 150Kg [As]
151.4Kg [Af] 165Kg [Bs]
163.6Kg[Bf] Front right
Rear left 185Kg [Cs]
183.5Kg [Cf] 197Kg [Ds]
198.4Kg [Df] Rear right
You will notice (given my very clumsy rounding of decimal places) that all corners are 1.5Kg out with two corners being light and their diagonal
opposites being heavy.
Now if my corner weights were within 1.5Kg first time out I would definitely leave them alone, but as you are doing the job yourself you must be a bit
of a perfectionist so start with a heavy corner (in this example front right for instance) and wind the spring platform down to reduce the weight on
it by 1.5Kg. Move to the other wheel on the same axle (front left) and wind its platform up to increase the weight by 1.5Kg. Now work on the corner
diagonally opposite the last corner and wind the spring platform down to reduce the weight on it by 1.5Kg. Move to the other wheel on the same axle
and wind its platform up to increase the weight by 1.5Kg.
If you adjust all corners instead of trying to work on just one or two you will avoid dramatic ride height changes (remember that altering the spring
platforms also changes the ride height !). The secret with this work is not to adjust too much at once, a little on each corner is the way to go
When all adjustments have been completed check both your corner weights and ride height (just to be sure !) and refit your anti roll bars one at a
time. Check the corner weights again. If they have changed you either have a twist in the anti roll bar which must be straightened or if that is not
possible adjust the mountings so the pre load can be removed or in the case of bars with adjustable drop links one of the links is too long.
The result of all this work (given that all other parts of the car are functioning correctly !) is that you will be able to take both right hand and
left hand corners with the car behaving predictably.
Finally and most importantly corner weight work like this gives you a perfect armoury of technical excuses with which to baffle your friends when your
driving is not up to par !
now thats what you call an answer.
quote:
Originally posted by gordon h
now thats what you call an answer.
Wow, that is some answer!! Thank-you very much. Is there anywhere I can take the car to in Surrey that would do this for me??
Bloody hell !
i spent 60 sec's checkin my tyre pressure's off i went
do it yourself, scales about £3.00 a set @ tesco
appologies I think for size of pic.
Rescued attachment corner weight setup.JPG
I thought I'd read all that somewhere before 
quote:
Originally posted by Hellfire
I thought I'd read all that somewhere before
Someone sent it me in word format so I had no idea were it came from originaly
appologies and credit to original author
tony
quote:
Originally posted by mr henderson
quote:
Originally posted by gordon h
now thats what you call an answer.
To type all that in 22 minutes is good going. Perhaps MB uses one of those voice to text programs?
John
Hi. Just one more question..... I will follow the instructions to corner weight it but how low do you guys set the suspension. Do you run up at one height for road use and then lower it for the track?
Hi
Setting the geometry is what needs doing first. Then the corner weights as any adjustment to the geometry will require re setting of corner weights.
Then if keen enough what makes the biggest difference to the ride quality is having the dampers matched and setting in a working range. No point going
to all the effort of corner weighting and then having dampers that are 50-80 Lb out of balance.
I will not comment on bathroom scales
Cheers Matt
quote:
Originally posted by procomp
I will not comment on bathroom scales
) picture above. Hi
And just how many people who have done it with bathroom scales have then back to back checked it with a set of race scales. The answer is not many i
bet. Those that have where left wondering why they bothered. The thing with corner weighting is it is either right or wrong. And that means being very
accurate.
PS most companies only charge £30 for a quick corner weight setup.
Cheers Matt
It's not a question of whether any test procedure is accurate or not, it's a question of whether it is accurate enough.
The bathroom scale method, if done carefully and on a flat surface (which would be needed for any method) is indeed accurate enough.
How much any particular company might charge may also not be relevant to somebody who doesn't have a convenient method of getting the car there,
or where there may not be such a company within easy reach.
So, anybody who thinks they might benefit from the batchroom scales method, and who is able to ensure a flat surface, or at least 4 pedestals which
are level to each other, should go right ahead
John
Hi
Only goes to show you simply do not understand what is actualy needed with corner weighting. "accurate enough" Is not accurate. It needs to
be done absolutely right other wise it's wrong. That means getting to with in 0.5 KG. Not the nearest 5kg.
I can not be bothered to argue with you again. But it is simply either right or wrong.
PS anybody who is taking it even slightly seriously would find people with in an hours drive who could do the job both accurately and with knowledge
to see other benefits at the same time. As it's not just about shifting the numbers but many other factors should also be taken into account to
gain the full benefit.
Cheers Matt
[Edited on 11/5/09 by procomp]
quote:
Originally posted by procomp
Hi
Only goes to show you simply do not understand what is actualy needed with corner weighting. "accurate enough" Is not accurate. It needs to be done absolutely right other wise it's wrong. That means getting to with in 0.5 KG. Not the nearest 5kg.
quote:
Originally posted by procomp
I can not be bothered to argue with you again.
I've got to agree with Procomp here. Whilst bathroom scales will give a rough idea on the weight of the corner, I think you're far better
off just measuring the compressed length of the spring versus the uncompressed length to find out the weight on that corner (sprung, at least).
The variables in the spring rates will be far less than those encountered trying to spread the load of each corner over 2 scales, when each scale will
have its own tolerance and accuracy anyway.
You won't really be able to work out what your weight split from front to rear is, but you'll be able to get both sides pretty accurate to
each other by measuring.
The bathroom scale method just looks far too error prone to me.
Henderson you say that it's just a case of getting it close enough, but I'm not sure if you could get within 10kg of what cornerweight
scales could. If you did, it's more down to lottery than skill because there are so many variables involved.
Also with the "close enough" comments, what procomp is saying is that the difference between 0.5kg, and say 10kg of accuracy is multiplied
where it really matters.
Let's say your corner weights at the front are 10kg out because of inaccuracy, if you brake at 2g then you are actually going to see a lot more
than a 10kg difference between the two, and you'll be locking one up before the other.
I think corner weighting is one of those things that just needs to be done properly, and unfortunately it costs a lot of you want the satisfaction of
doing it yourself to a good standard.
quote:
Originally posted by mr henderson
As anyone who has dieted will tell you, they are surprisingly accurate, maybe not in an absolute sense, but comparatively, and that, of course, is what is needed here.
quote:
Originally posted by Frosty
I've got to agree with Procomp here. Whilst bathroom scales will give a rough idea on the weight of the corner, I think you're far better off just measuring the compressed length of the spring versus the uncompressed length to find out the weight on that corner (sprung, at least).
The variables in the spring rates will be far less than those encountered trying to spread the load of each corner over 2 scales, when each scale will have its own tolerance and accuracy anyway.
You won't really be able to work out what your weight split from front to rear is, but you'll be able to get both sides pretty accurate to each other by measuring.
The bathroom scale method just looks far too error prone to me.
Henderson you say that it's just a case of getting it close enough, but I'm not sure if you could get within 10kg of what cornerweight scales could. If you did, it's more down to lottery than skill because there are so many variables involved.
Also with the "close enough" comments, what procomp is saying is that the difference between 0.5kg, and say 10kg of accuracy is multiplied where it really matters.
Let's say your corner weights at the front are 10kg out because of inaccuracy, if you brake at 2g then you are actually going to see a lot more than a 10kg difference between the two, and you'll be locking one up before the other.
I think corner weighting is one of those things that just needs to be done properly, and unfortunately it costs a lot of you want the satisfaction of doing it yourself to a good standard.
Hi
So if your going to spend £80 on scales and then make some run up ramps. Why not just go half way and get a simple guage that would be a darn sight
more acurate than the TEHY MIGHT BE ACURATE aproach.
Cheers Matt
quote:
Originally posted by procomp
would be a darn sight more acurate than the TEHY MIGHT BE ACURATE aproach.
) but this is
the Locostbuilders forum and discussing ways of getting good results without simply paying others to do stuff for you is what this forum is all
about. Hi
You really are a Pratt. I was trying to help you get accurate results rather than guess work. At an affordable price.
End off
quote:
Originally posted by procomp
Hi
You really are a Pratt. I was trying to help you get accurate results rather than guess work. At an affordable price.
End off
Hi
Now you see you just do not get it it at all really. You see what i am trying to do is get those people who are genuinely interested in going to the
trouble of setting there cars up. To At least do it so they end up with results that worthy of the time money and effort spent. If you actualy had
any idea about how i operate you would know that i spend an awful lot of time helping people with handling issues with there cars and that taking
money of them it certainly not my priority. It is just a case that i personally think that if a job is worth doing it is worth doing right. And that
dose not mean chucking money that is not in a persons budjet at the problem. And if you actualy bothered to read what i had said in this thread which
was that there would be people who would have professional corner weight scales within an hours drive. Maybe we should start a data base of people who
do have this sort of equipment and are prepared to help forum members. as it is simply not just as you put it companies but also many motoring clubs
regional area groups ect and many small race / rally teams.
You on the other hand seem to have this logic that when ever i make a comment ( In your own words. Even if it is fact based ) it is your job to have
an argument. Which given the emails and u2u's i have had means you are quite frankly weeing a lot of people off by simply just arguing rather
than actualy having somthing constructive to say without any knowledge of the topic.
So here we are again another recked thread that could well have been useful info. Brilliant.
PS i did read your offer in your U2U.
Cheers Matt
quote:
Originally posted by procomp
Hi
Now you see you just do not get it it at all really.
quote:
Originally posted by mr henderson
I invite anyone with a reasonably decent set of scales in their bathroom to first of all place the scales on a hard, level surface, then try weighing themselves, then to have someone pass them something that weighs 500gms, and see if the scales registers it.
quote:
Originally posted by MikeRJ
quote:
Originally posted by mr henderson
I invite anyone with a reasonably decent set of scales in their bathroom to first of all place the scales on a hard, level surface, then try weighing themselves, then to have someone pass them something that weighs 500gms, and see if the scales registers it.
Again you have missed the point that whilst an individual scale might be good enough to resolve 0.5kg, you would have to repeat this on 8 separate scales, ensuring that each scale registered not only the same starting weight, but the same increase in weight. And again, I suggest the chances of getting such a well matched set of scales when you are paying peanuts for chinese built items is slim to none.
Hi
The reason i have continued this is because it shows that a set of professional setup scales giving an accuracy of 0.5KG over 4 scales is a darn
sight more accurate than a set of bathroom scales as some people on here seem to be able to grasp. Where as you clearly do not. As i have said unless
you are going to do the job properly with accurate results there is no point doing it.
And the other thread by Welderman clearly shows that people can get there cars setup / corner weighted for as little as FOC albeit at the cost of a
sushi dinner in return .
Ps when you do purchase your bathroom scales. How much are you going to charge to corner weight a car.
Cheers Matt
I think your final comment is a bit out of order
tony
I'm sure that bathroom scales are accurate enough in isolation, but I think that when you balance loads across 2 of them using wood or something
similar, you would see varied results.
Every set of bathroom scales I have ever used to weigh myself has varied by half a stone just based on where you stand. If you stand at the edge or in
the middle it will vary, and you have no way of controlling this when using wood to spread load over two.
As for the comments on procomp's "self promotion", this is very unfair to suggest. Not so long ago I helped a good friend on here set
up his MK Indy and put a post up for some help relating to bushes.
Procomp then took the time to write me a big long message about things to look out for on the car, and due to the inaccuracy of the entry-level
Protech shocks, even offered to balance them.
When asked how much this would cost, he did not want any money at all as long as we arranged collection and delivery. Once the shocks were returned,
he would not even accept a drink as payment which I think is incredibly generous.
It seems to me that as long as people are genuinely interested in setting up a car and understanding what makes things work, procomp is more than
happy to offer his input and advise.
He's doing exactly that in this thread, and being gunned down for it 
quote:
Originally posted by Frosty
I'm sure that bathroom scales are accurate enough in isolation, but I think that when you balance loads across 2 of them using wood or something similar, you would see varied results.
quote:
Originally posted by Frosty
As for the comments on procomp's "self promotion", this is very unfair to suggest. Not so long ago I helped a good friend on here set up his MK Indy and put a post up for some help relating to bushes.
Procomp then took the time to write me a big long message about things to look out for on the car, and due to the inaccuracy of the entry-level Protech shocks, even offered to balance them.
When asked how much this would cost, he did not want any money at all as long as we arranged collection and delivery. Once the shocks were returned, he would not even accept a drink as payment which I think is incredibly generous.
It seems to me that as long as people are genuinely interested in setting up a car and understanding what makes things work, procomp is more than happy to offer his input and advise.
He's doing exactly that in this thread, and being gunned down for it
Hi
So in your own words there you are saying that whilst weighing an engine / box around the 300 kg mark shall we say and maybe you where lucky you got
to 1%. You really just do not seem to be able to grasp the fact that that tolerance just is not accurate enough for corner weighting. You say i keep
repeating this thats because as i said earlier those that have done back to back testing have found simalar tolerances with bathroom scales and found
it to be to far out when tested. You keep repeating that this is an acceptable tolerance but i ask have you ever done any serious testing with cars
corner weighted to this tolerance and then had the car setup properly as back to back testing. Any one who has will tell you there is a marked
difference. And it's a difference that is well worth having if taking the setup of your car remotely seriously.
You keep banging on about £80 worth of bathroom scales yet when i pointed you in the direction of a lever type gauge that can be brought brand new for
as little as £120 you still threw it back in my face as a waste of time compared to your bathroom scales.
If you really want to do it locost style why not have a search for the article that shows how to corner weight with balance beams etc. even that is an
awful lot of work to go to compared to a £120 gauge and as the scale will cost you at least 3/4 of that price.
Again you are continually going on about comments i make regarding others products. As you have already said before they are FACT based comments and
are comments made that help people see problems that they are encountering or they can avoid. Maybe you think it is perfectly OK for a manufacturer to
sell a chassis kit That they claim is the best. Which dose not actualy legally pass the SVA / IVA test and they then tell you to illegally bodge it to
get through. Maybe you think it is OK for a manufacturer to sell a kit that has not even been engineered safely and is likely to cause serious harm
when it goes wrong possibly even death if the worst was to happen.
Lets take your friend here Madbutcher. Is it right that he has had to buy wishbones from an other source just to get his car to Handel as it should
have origanly. Just because the kit he built was so shockingly bad in manufacture in the first place. The point is when these manufacturers start to
turn out products that are of a decent quality i will gladly stand up and say that i think they are good quality and i will then recommend them. But
as it is when these problems are being discussed by others i see no reason to not comment on what is already a known problem whilst offering help to
people who are trying to overcome these problems.
Cheers Matt
quote:
Originally posted by procomp
Hi
(various stuff, read it above)
Cheers Matt
Ok, i'm going to dive in here a little.
Many years ago I bought 8 sets of scales from a well known supermarket that was selling them off cheap. The logic was one day I'd want to have a
go at corner weighing my car. [cough] years later I still do want to do this and will when its finished.
I realised quite quickly that bathroom scales aren't that accurate. I did a simple test. I set each one to zero and stood on it. Depending on how
accurately I was standing directly over the scales it gave a slight difference in value - the pointer is a little away from the scale so if i'm
a little to the left I see the value a little to the right. So I resolved to be careful and be really really right above the scale.
I noticed not every scale read the same. Being utterly convinced in the 30 seconds it took to move one scale from being in front of me to another I
hadn't lost weight I decided the scales where wrong (I didn't take any back - perhaps I should and the ones I got cost less than £10). Oh
and no comments about a bad workman and his tools .....
To help me test the scales I set them all to zero and stood on each one a number of times. They always read the same. So I deduced that the issue was
the calibration.
This got me thinking ..... maybe the scale accuracy through the range wouldn't be consistent. Eg at 80kg it would be 5% heavier than the
reference scale but at 40kg it might be 0% or 10%. (made up values before someone picks up on them).
I then got a series of weights to test the scales through the range to about 100kg. Being a sad git i made up a spreadsheet to track the differences.
Obviously a couple of computers later I no longer have the data but the thinking was - I'll have a reference scale and an extrapolated variation
between the reference and an actual scale. I'll mark each scale with a number.
I could then weigh the car, plug the numbers for each pair of scales into a spreadsheet and get a 'true' value. I could then adjust the car
until the 'true' values worked out.
(and do i have a perfectly level garage ....... depends how level the concrete set when the builders built it)
Would I be as accurate as procomp - naaaah.
Would it be an interesting waste of an afternoon ..... hell yeah.
Would I then take a trip and spend 30 quid to see how accurate I was .... knowing me probably.
Do I believe I could *improve* my car with my method ...... I'm not sure, I'd hope so but i suspect it depends how far its out. If its miles
out then yes, if its close then I think the risk is I'd be randomly playing.
Fight fight fight!
As someone with no experience of this it sounds to me like bathroom scales are a low cost option, but as the old saying goes "you get what you
pay for" no idea how old our one upstairs is but they weigh me at 17 stone and wii fit says 18 (so I'm going for the lower number!)
Then again if there's anywhere that can do it (for a whole day mind as you'll be doing adjustments?) for less than the price of the scales
then I reckon I'd go for the (more) accurate version.
Bathroom scales for at home while you work on it then professional scales to make 100% sure is the way I'm seeing it
This topic seems to have become focused on corner weighting and the merits of using weighing scales in setting the corner weights. I always hold to
the ideal that if you're trying to achieve something - make sure it's as near exact as possible. Having said that, anything used to
determine and reduce a problem has to be worth a shot and that’s exactly what you’ll be doing with weighing scales.
There is of course much more to a setup than just corner weighting and it really depends what you want to achieve and how much money you’re prepared
to spend, to try and achieve it. You start off with what you get from the manufacturer and you can either accept what you have, or try to improve it.
The level to which you change it and the accuracy you aim for is down to you. My way of thinking goes something like this;
You decide to take your kitcar to be set up but the place you take it to can only work with what you present them with. I’d imagine they would set it
up as best they can and then suggest making alterations or buying alternative parts so that it can be improved further. You then go away and decide
whether you want to make those changes but ultimately if you do, you’d need to go back to have it all done again and part with some more hard
earned.
My advice would be to read and learn and try to understand suspension setup and then experiment yourself to set it up as best you can, with the
equipment you have available or are willing to purchase. Don’t be afraid to change things but unless you’re experienced, make sure you change one
thing at a time before testing it otherwise you’ll never know if the change actually improved it or made it worse. In our case, this process has taken
years and it is still very much ‘work in progress’ but we’d like to think we’re going in the right direction even if we haven’t achieved our ultimate
goal. Eventually we’ll run out of ideas/knowledge/equipment or all three and then take it to Matt at Procomp to be done properly and accurately.
Phil
Hi
John your still working on 1% over two scales with around 300kg on them. IE one corner of the car. Thats 2-3kg per corner out randomly give or take
with a bit of luck.
So the general consensus seems to be that the bathroom scales will not give an accurate enough reading to actualy have the car corner weighted. Now
funnily enough one of my ex customers who used to race was an engineer at AVERY / SALTER scales and he came to the same opinion when he tried it
himself on his own kitcar.
And i agree with Phil or was it Steve. The more people can learn about how thier suspension works the easier it is to determine what adjustment they
need to be altering to gain better handling. It also gives you much more confidence in the car when driving at a higher limit as you can understand
why such handling characteristics are happening . ( on track of course ) But one thing is for sure once you have a light weight car such as the
majority of kitcars and you have the handling setup so as too inspire confidence rather than a car that is bobbing and weaving down the road. You will
enjoy it far more.
Cheers Matt
quote:
Originally posted by procomp
More stuff
Hi
Although i see you still haven't answered the question i asked.
Have you ever corner weighted a car and done any back to back testing ?
In fact have you ever actualy corner weighted a car yourself or are you just working from what you have read on the net.
Cheers Matt
I have no actual experience of corner weighting a car as yet, and don't want to stir up any vitriol here, but I am interested in knowing what
accuracy is really required? For a race car on the track you will obviously need the best balance you can get, but in that case you will have a known
driver sat in the car, with fixed clothing etc.
In a road car, if I have a passenger, the load split will change if the passenger is not sat on the COG! A 60 kg passenger (or driver) moving their
COG by 2% of the vehicle wheelbase gives a 0.5kg corner weight imbalance. In a sylva riot, the fuel tank is at the front of the passenger footwell.
This must significantly alter the corner weights when the tank is full compared to empty - a rough calc scaled from the assembly photos: 30 kg of
fuel, centred in the middle of the footwell at about 70% forwards of the wheelbase will add 17 kg to the near front/off rear daigonal and 13kg to the
other diagonal. This surely can't be disasterously bad?? Or can it???
Has anyone got experience of adjusting corner weights in a controlled way (e.g ONLY the corner weights change) by small increments and is willing to
post to say what amount is noticable for fast road use?
Thanks
hugh
Hi
As far as accuracy goes it is quite noticeable when it is say 20 kg or so out of balance. Once you have had your corner weights set close and then
finalised all your geometry it is then that you need to start honing in on the final accuracy of the corner weights. At this point with the geometry
set the corner weighting being out of balance will be more noticeable. This then really needs to set accurately. Ie to a 0.5kg tolerance.
In general when corner weighting a road car a decision has to be made as to whether you are having it set for use with A. driver only. Or B. driver
and passenger. 99% of people settle for the fact that they are going to be pressing a bit harder when they are on there own in the car. Ie driver
only. So the compromise is to set the car for driver only and then suffer the imbalance of a passenger.
Yep on both the Mojo and the Riot varying amounts of fuel can play a bit of havoc espesialy on those that have tried competing in competition. But the
short wheelbase and height of weight over the rear wheels is the down side. Hence the wheel base seems to be increasing weekly on both the Mojo and
Riots. A BEC Riot will Handel far better than the CEC version.
Cheers Matt
Blimey! Marathon or what
Just to play Devil's Advocate here, surely an easy answer is A DUEL!
Mr H does a setup of a given car using the Locost method and procomp then measures the same car using his method. Then it will be easy to see whether
or not there is an argument??
Sorry, but I couldn't resist 
OK, I'll get my coat
quote:
Originally posted by Daddylonglegs
Blimey! Marathon or what
Just to play Devil's Advocate here, surely an easy answer is A DUEL!
Mr H does a setup of a given car using the Locost method and procomp then measures the same car using his method. Then it will be easy to see whether or not there is an argument??
Sorry, but I couldn't resist
OK, I'll get my coat
Hi
We are assuming MR H actually knows how to corner weight a car as he will not answer my question above. which brings me to a conclusion that he only
started arguing on this thread even though he has no knowledge of the subject. Just because i made a comment that put my point of view across. Hence
the reason i have been keen for this rubbish to be draw out to show that.
PS dont forget that if wanting to get the corner weight benefit balancing the dampers is also important. As no point trying to corner weight if the
dampers are 50-80 Lb out of balance.
Cheers Matt
Hi
Oh forgot to say i had our driver in the workshop yesterday who ran the MOJO for a few seasons trying to race it. His tip was that you cant easily set
the corner weights with layout of the MOJO / RIOT. But it was best to run a full tank of fuel to get best results.
Cheers Matt
quote:
Originally posted by procomp
Hi
We are assuming MR H actually knows how to corner weight a car as he will not answer my question above. which brings me to a conclusion that he only started arguing on this thread even though he has no knowledge of the subject. Just because i made a comment that put my point of view across. Hence the reason i have been keen for this rubbish to be draw out to show that.
quote:
Originally posted by procomp
PS dont forget that if wanting to get the corner weight benefit balancing the dampers is also important. As no point trying to corner weight if the dampers are 50-80 Lb out of balance.
Cheers Matt
And to all those who support locost methods of setting up, as well as building, kit cars they might be interested in an article I wil be publishing
here in the next few days on how to accurately measure camber and wheel alignment on 4 wheels with an outlay of less than £100.
I can already guess what my nemesis will have to say about it, but as I said earlier, it won't be for his benefit.
Funny thing is he's probably quite a nice guy really, just gets a bit caught up in things that he feels he's entitled to know more about
than the rest of us
John
quote:
Originally posted by asl
Hi. Is there an idiots guide on how best to set up the suspension? I have not touched it since I bought the car but the back 'looks' a bit high. ..........