masha Posted May 16, 2002 Share Posted May 16, 2002 I've got the bilstein upside down shocks on my SL. The car has just been rebuilt and the front end is far too high. Can anyone advise: - where to get the bilstein adjuster spanner cheaply? - what is involved in a "flat-floor" setup, why is it so expensive? - where else can I book into to adjust and test the suspension, tracking etc accurately? thanks gang Matt Link to comment Share on other sites More sharing options...
scooby dooby doo Posted May 20, 2002 Share Posted May 20, 2002 Aflat floor setup is expensive cos it takes quite a lot of time. you put a set of scales under each wheel and measure the weights on each. then adjust the ride heights and weigh again. you keep going until you get both front wheels to have the same weight on them (so they can both provide the same grip when you brake so one doesn't lock before the other). You also want the rear of the car to be about 12 mm higher than the front. so there's lots of adjust, weight, adjust weigh, measure etc etc. to do all this needs a flat floor. ie literally a totally flat bit of concrete. they may also adjust the castor, camber, toe, tracking etc etc. castor and camber adjustment mean you need to unbolt bits of front suspension so it also takes a while. Dave Hooper - North London dmch2@lineone.net Link to comment Share on other sites More sharing options...
STEVE GILBERT Posted May 20, 2002 Share Posted May 20, 2002 Mmmm Dont sound quite right Hoopy, Its all to do with the weight on the diagonals, or rather getting even weight on the diagonals with the car riding level/ at your required ride height. The only way in an inbalanced car like a 7 to get even weight on opposite wheels is to actually move weight, and thats tricky. Do a search Matt its all in the archives Link to comment Share on other sites More sharing options...
StewartG Posted May 20, 2002 Share Posted May 20, 2002 The problem with a flat floor set up is, you get a set up someone else (albeit experienced) thinks you should have. Do it yourself it's easy and you don't even need scales or a flat floor. Just adjust the suspension until the car does what you want it to. It doesn't matter what the scales say if one wheel locks up first it needs adjusting. If it oversteers you can improve that with a lower ride height at the back etc. etc. The bilstein adjusters can be acquired from Caterham agents, try Ratrace they fit loads of adjustable platforms for people who don't want to adjust them and therefore don't need the spanners. Link to comment Share on other sites More sharing options...
scooby dooby doo Posted May 20, 2002 Share Posted May 20, 2002 you *can* get even weight on the two fronts (which is required for braking reasons) and have the rear higher than the front by the required amount. however, as you say, unless you move mass about the rears will have a very different amounts of weight on each of them as the diagonals will stay the same. this isn't a problem as you can fit an lsd and remember that the car will handle slightly differently going left or right. unequal braking is not a thing you want to compromse on though. Dave Hooper - North London dmch2@lineone.net Link to comment Share on other sites More sharing options...
Peter Carmichael Posted May 20, 2002 Share Posted May 20, 2002 Hoopy, braking gets done by the rear wheels as well. Even if you have even front weights statically, you won't when the weight shifts forwards. Think again and don't tether yourself with dogma. StewartG is on the money. Smooth. Edited by - Peter Carmichael on 20 May 2002 23:55:40 Link to comment Share on other sites More sharing options...
scooby dooby doo Posted May 20, 2002 Share Posted May 20, 2002 ok i take your point - engage brain before speaking.... But the fronts being closer to equal is more than the rears being closer to equal is it not? as the fronts do more braking? > ie say we have a car with perfect front-rear distribution and it dives under braking so that it has 2/3rds of the weight on the fronts and has a driver weighing 60 kg giving a total all up weight of 800 kg so my "method" suggests the ideal is: FL 190 FR 210 RL 180 RR 220 or have i already done half a dozen things wrong and grasped the wrong end of the wrong stick? biggrin.gif Dave Hooper - North London dmch2@lineone.net Link to comment Share on other sites More sharing options...
Blatman Posted May 20, 2002 Share Posted May 20, 2002 Look at the diagonals.........then think of what happens to a kitchen table if you shorten two diagonally opposed legs. This is what happens when you adjust the springs to get the corner weights right, you shorten/lengthen the spring heights.......see it wobble.........of course, with the kitchen table, you just shove a copy of Low Flying under one leg to save from slopping your gazpacho onto the marble floor........... Link to comment Share on other sites More sharing options...
rynicolson Posted May 21, 2002 Share Posted May 21, 2002 I think this is going to a knockout... Tricks Y57 CDS "Mutley" Link to comment Share on other sites More sharing options...
rynicolson Posted May 21, 2002 Share Posted May 21, 2002 Masha, I had a set up problem with my car, having driven a very sorted 1.4K on prisoner wheels that was glued to the road I found the SL a nightmare, which included some very odd front wheel wear (so odd I can't put it into words)... I looked into getting someone else to do it for me and there are various recommendations on previous posts, however in the end I went alone and now have a set up which is superb, it takes time, but in my case I simply drove the car, weighed, adjusted, drove... always worth keeping a record as you progress (on one occasion I went back to square one / mid settings cos I was LOST!), in respect to diagonals... these guys are confusing simple old me but I worked fronts, then rears, then fronts. Tricks Y57 CDS "Mutley" Link to comment Share on other sites More sharing options...
Peter Carmichael Posted May 21, 2002 Share Posted May 21, 2002 I'm not an expert. The front brake disks are clamped with the same hydraulic pressure; you get the same amount of braking force each side. Same goes for the rears. If the same force is applied backwards from each side of the car, the net force acts down the centreline of the car. Problem is that the CoG is offset to one side of the car, so this will cause the car to rotate in yaw. Somehow or other, the tyres have to react this yaw moment and that requires grip that isn't being used for braking. I suspect it is too simple to just look at front wheel weights, especially on cars where the front/rear brake balance is marginal - by compromising the rear wheel weights, you might introduce a far nastier rear lock up trait. A Seven is a comparably softly sprung car with rubber bushes and this makes flat floor type settings less important than on proper race cars. Running level is obviously a good idea. Link to comment Share on other sites More sharing options...
Robster Posted May 21, 2002 Share Posted May 21, 2002 Peter I agree with you, one observation: Having just fitted the adj ride height dampers and guessing at the settings using a ruler to judge ride height..the car pulls to one side under braking. This must be because one spring is more compressed than the other, so when you brake and weight is transferred to the front, one side compresses much more than another. Link to comment Share on other sites More sharing options...
Anthony Micallef Posted May 21, 2002 Share Posted May 21, 2002 What I want to know is, how can a complete novice of these sort of things tell the difference between a badly set up car and crap driving? Would it be case of let someone who is experienced have a drive of the car? The Happy 7 Ownerteeth.gifteeth.gifteeth.gif Link to comment Share on other sites More sharing options...
scooby dooby doo Posted May 21, 2002 Share Posted May 21, 2002 hmmm... hadn't thought of that either... i'd thought straight line braking would be a nice simple case as well! I *really* need to buy a book on race car setups. Its interesting from a straight physics POV and will give me more excuses for not being faster! any recommendations? or should i just subscribe to race car engineering? Dave Hooper - North London dmch2@lineone.net Edited by - hoopy on 22 May 2002 00:14:15 Link to comment Share on other sites More sharing options...
Anthony Micallef Posted May 23, 2002 Share Posted May 23, 2002 Back to the top to give someone a chance to answer my question. The Happy 7 Ownerteeth.gifteeth.gifteeth.gif Link to comment Share on other sites More sharing options...
No Nuts Posted May 24, 2002 Share Posted May 24, 2002 All very interesting and if you have many hours to spend in the garage I'm sure fascinating to do yourself. Unfortunately I don't and the £200 I spent on having the car flat floored last year is the best money I've spent on Eric so far. Handling is peachy!! Mind you, I'm a relative driving novice (from a speed point of view) and am just starting to learn what going fast is all about. The results so far this year (three thirds in class in local sprint c'ship and second in class 2 at Curborough) with relatively low power (115 bhp) seem to point to the handling of the car being reasonably well set up. I can't even begin to tell you how much better the car felt after the flat floor set up (ride hight, toe and camber were also checked / adjusted - castor is, as Hoopy says, expensive) and prior to that we had tried basic scales / adjusting to feel but just did not have the time to get it right. I see Caterham offer similar set up for some £175 in LF. In my book, this is good value. Maybe now I have a good starting point some fiddling may be helpful but I am loathe to ruin what, as far as I am concerned, is the best handling car in the world! If you haven't had your car flat floored - do it now! Guy says so! NN blush.gif Edited by - No Nuts on 24 May 2002 09:14:38 Link to comment Share on other sites More sharing options...
Peter Carmichael Posted May 24, 2002 Share Posted May 24, 2002 Anthony, Trying to answer your question: Does the car feel predictable. If you push a bit harder can you guess what is going to happen? If you push that bit harder and then back off gently, does the situation recover? Are the messages clear as it does it? Repeat again, trying harder These are all signs of a good handling car. The best education is to try a few others yourself. Letting others try yours depends on the experience of the "others" and many so called experts don't have much of a clue. It is much more fun (and more important) for you to have a target in mind for that elusive blend of response and feel that is labelled simply: "good handling". Even a good handling car can have bad days (worn tyres, dodgy pressures, too many pies for breakfast). Nutless One, I was not disparaging the discipline of the flat floor as such, but it is as well to understand its limits as a technique. Flat flooring sets the car up to run straight and true given a particular loading. This means that if you flat floor for a racing configuration with just a driver's weight accounted for and a low fuel load, then the set up is compromised for road use. While it is enticing to believe that even front wheel weights enhance braking, static measurements do not necessarily give you the right answer in the dynamic heat of the moment. I prefer to aim for even loading on the diagonals, set through a flat flooring process - it seems to be a better all round hope than even fronts. If you search the archives there are various links to my description of how to do a flat floor setup without the use of specialist tools or equipment. Link to comment Share on other sites More sharing options...
No Nuts Posted May 24, 2002 Share Posted May 24, 2002 Peter As an absolute suspension novice, I took the easy way out! I seriously admire your huge amount of technical knowledge but find many of your posts (I know you do your best to word them for numpties like me) go way over my head. Even so - I'll have a nose in the archives sometime as the whole setup thing is fascinating. I would love to spend loads of time experimenting but just do not have the balls to do this (nothing to do with my handle you understand!). I think the DIY route is excellent but just wanted to advise that I think a flat floor is money well spent if you are in the "not quite so confident" camp as I am. Anthony can make up his own mind as to what he wants to try!! I am tempted, as I said, to have a go at suspension changes myself but the car handles just so damn well right now I'm too chicken to change anything!!! Maybe one day... Anthony, if it helps, I do know that I hated the way the car handled before the flat floor. I was not convinced it would make a huge difference but it did. I have no idea what the weights were set to in terms of distribution but I do know the ride height was set according to my handling preferences that I discussed with the person who did the set up before hand. Hope this helps. NN blush.gif Link to comment Share on other sites More sharing options...
Charlie7 Posted May 25, 2002 Share Posted May 25, 2002 I live in Jersey and can't seem to find a person who'll do a flat floor set-up for a decent price - so I bought a book:- "Competition Car Preparation" by Simon McBeath (a Haynes book) There is a whole chapter on suspension set-up and its in plain English! (with pictures). It advises what tools you need, and how to get away with non-specialist equipment. Using their know how and the info supplied in my build instructions when I bought the car (Roadsport 1.6k with adjustable Bilsteins) I'm going to give it ago next weekend. I'll let you know how it goes... Book cost £16.75 on amazon.co.uk Charlie7 Jersey Link to comment Share on other sites More sharing options...
No Nuts Posted May 25, 2002 Share Posted May 25, 2002 Hey Richard Good to see you in here. How's Charlie? Regards Guy NN blush.gif Link to comment Share on other sites More sharing options...
Charlie7 Posted May 27, 2002 Share Posted May 27, 2002 Hi All's fine - just need to get the suspeniosn and wheels back on. How's the racing? Charlie7 Link to comment Share on other sites More sharing options...
No Nuts Posted May 27, 2002 Share Posted May 27, 2002 Sprinting this year. Three thirds in class and a class win (yesterday) in the local sprint championship. Second in class 2 at Curborough. I'm chuffed to bits so far this season! NN blush.gif Link to comment Share on other sites More sharing options...
Charlie7 Posted May 27, 2002 Share Posted May 27, 2002 Guy e-mail: richard.germain@btinternet.com Charlie Link to comment Share on other sites More sharing options...
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