Guest Posted August 15, 2014 Share Posted August 15, 2014 you will never get a supple ride on our roads with 350lb springs on the front!! Link to comment Share on other sites More sharing options...
tomperkins Posted August 15, 2014 Author Share Posted August 15, 2014 Quoting tiddy1: I would strongly suggest setting the car up with about 1 deg toe in, it does make a huge difference to the stability and tram lining. its very easy to do yourself, no need for complex measurement set ups, just undo the steering arm lock nut and twist the steering arm a few turns then re-lock. if you note how many turns you do you can always put it back if you do not like it Simon That's a good shout, I'll give that a try this weekend and let you know how I get on. Link to comment Share on other sites More sharing options...
tomperkins Posted August 15, 2014 Author Share Posted August 15, 2014 Quoting Culminator: you will never get a supple ride on our roads with 350lb springs on the front!! What would you suggest, somewhere around 225/130 or 250/130? Link to comment Share on other sites More sharing options...
Area Representative Richard Price Posted August 15, 2014 Area Representative Share Posted August 15, 2014 Quoting tomperkins: Quoting Culminator: you will never get a supple ride on our roads with 350lb springs on the front!! What would you suggest, somewhere around 225/130 or 250/130? Tom, Standard springs are 150lbs/in at the front, and progressive (110 to 130 to 200) rear (but the 200 part is only used in extreme bump). If your AVO's work as originally intended (which may be questionable), then putting significantly softer springs on your existing dampers many give you a set up with too much damping. If I were you, I would place a "wanted" for a set of standard springs and dampers (preferably with a set of adjustable platforms fitted). In my opinion, 1 degree of toe in is a little too much, and could lead to greater tyre wear with no benefit. Anywhere between 0.25 and 0.5degrees of toe in will be adequate. Link to comment Share on other sites More sharing options...
Simon Owen Posted August 15, 2014 Share Posted August 15, 2014 Hi Tom There are a few options here and (IMHO of course 😬) there is room to 'upgrade' the standard set up without wrecking the ability of the car to travel down a bumpy road. This clearly depends what you want from the car though and what 'upgrade' means in your eyes. My aim was to tighten things up a bit but without making the car unusable on the road, it wasn't about going quicker .... more just altering the feel of the car. I'm running 100-275lb front & 70-200lb rear with one way adjustable damping. Link to comment Share on other sites More sharing options...
tomperkins Posted August 15, 2014 Author Share Posted August 15, 2014 Quoting Simon Owen: Hi Tom There are a few options here and (IMHO of course 😬) there is room to 'upgrade' the standard set up without wrecking the ability of the car to travel down a bumpy road. This clearly depends what you want from the car though and what 'upgrade' means in your eyes. My aim was to tighten things up a bit but without making the car unusable on the road, it wasn't about going quicker .... more just altering the feel of the car. I'm running 100-275lb front & 70-200lb rear with one way adjustable damping. Thanks Simon, when you quote two figures for your springs is that because they are progressive springs with one part softer and one part harder? Anyone got any tips on a good place to get some better springs for my AVO dampers? Link to comment Share on other sites More sharing options...
Harry No Sheds Flatters Posted August 15, 2014 Share Posted August 15, 2014 I suggest you speak with Simon at Meteor Motorsport and read the article in this months LF Link to comment Share on other sites More sharing options...
Simon Owen Posted August 15, 2014 Share Posted August 15, 2014 Tom, yes that is correct. There appears to be much debate on the progressive spring vs linear spring debate and from what I have read linear seems to be the preferred option for dedicated track work being more predictable at the limit, but for those of us looking for that ideal compromise and who are probably not pushing quite that hard it seemed to make sense .. insofar as I could understand the technical explanation that is 😳 Worth noting that 888's have quite stiff sidewalls i believe which will no doubt be a contributing factor, I can't comment from experience but 350lb springs on the front must be sooooo stiff Link to comment Share on other sites More sharing options...
myothercarsa2cv Posted August 15, 2014 Share Posted August 15, 2014 Before you spend loads of money though, make the free changes. Make them one at a time, too. See what does what. Link to comment Share on other sites More sharing options...
tomperkins Posted August 15, 2014 Author Share Posted August 15, 2014 Quoting myothercarsa2cv: Before you spend loads of money though, make the free changes. Make them one at a time, too. See what does what. That's good advice, thanks. I've just reduced the rake from 20mm to 15mm, as this is how the car was setup on the old setup sheets I have and what a number of people have recommended. Totally going against your advice (in fairness I've only just read it) I've also reduced the toe out by rotating each track rod end by 2 full rotations. I've read that 1 full rotation gives around 0.25 degrees, so on that basis I've probably reduced the car to 0.5 degrees toe out. Be interested to know people's thoughts on how much they think I may have dialled out (I'll obviously get it checked soon). Driving the car after those changes did give a noticeable improvement which is awesome. Front felt even less effected by cambers and bumps. If I'm still 0.5 toe out it will be interesting to feel 0.5 or 1 toe in! Next step is to lower the rear trailing arms. As a side note, the rear springs have no writing on them so I've now idea how to tell what rating they are. Link to comment Share on other sites More sharing options...
Area Representative Richard Price Posted August 15, 2014 Area Representative Share Posted August 15, 2014 Quoting tomperkins: I've read that 1 full rotation gives around 0.25 degree That is turns of the upright top ball joint that, where one turn is roughly equal to 0.25degree of CAMBER. Quoting tomperkins: As a side note, the rear springs have no writing on them so I've now idea how to tell what rating they are. You can work out spring rates by measurement of the coils. Try this calculator here Put your own values in the cells marked ** The "number of active coils" is the number of coils that are not actually in contact with either spring seat. Link to comment Share on other sites More sharing options...
Simon.Rogers1 Posted August 15, 2014 Share Posted August 15, 2014 Phone calls to me a free of charge Link to comment Share on other sites More sharing options...
tomperkins Posted August 15, 2014 Author Share Posted August 15, 2014 Quoting Simon.Rogers: Phone calls to me a free of charge Thanks Simon, may well do that. Link to comment Share on other sites More sharing options...
Simon.Rogers1 Posted August 15, 2014 Share Posted August 15, 2014 tom. Over the weekend is fine if it suits you. You may find me on the landline or the mobile. Link to comment Share on other sites More sharing options...
diggerman Posted August 16, 2014 Share Posted August 16, 2014 Toe out definitely causes the car to follow lines and undulations and can make it difficult to drive in the twisty lane situation. I've resolved this problem by adjusting to parallel or slight toe in. As far as bumpy ride is concerned, It was interesting to speak to the experts at Caterham Technology when we visited there earlier this year. They spend weeks finding the best spring rates and dampers for road going sevens only for us owners to spend good money mucking up their good work. In my opinion and for a normal blatting seven, you will find it hard to beat standard springs, dampers and roll bar rubbers. This set up rides really bad roads really well. This may seem like anti-upgradeitis BUT it works. Peter Link to comment Share on other sites More sharing options...
Simon Owen Posted August 17, 2014 Share Posted August 17, 2014 Peter, Really interesting thread 😬 Completely agree with the above .... but it is possible to change the way the car drives to suit individual preferences, by spending good money without "mucking up their good work". Note I did not use the word 'upgrade' 😬 😬 I am really pleased the way my aftermarket springs & dampers have sharpened up the feel & composure of the car, yet still maintaining the ability to travel down a poor road without shaking your teeth out ... to Simon Rogers who was very helpful in explaining the set up I was after ... Link to comment Share on other sites More sharing options...
Julian H Posted August 17, 2014 Share Posted August 17, 2014 Tom Did you try lower pressures than 18? Subtle changes in tyre pressures really impact on the way the suspension reacts to the road. J Edited by - Julian H on 17 Aug 2014 21:25:43 Edited by - Julian H on 17 Aug 2014 21:26:46 Link to comment Share on other sites More sharing options...
tomperkins Posted August 17, 2014 Author Share Posted August 17, 2014 Quoting Julian H: Tom Did you try lower pressures than 18? Subtle changes in tyre pressures really impact on the way the suspension reacts to the road. J No but I may well try that, good idea Link to comment Share on other sites More sharing options...
tomperkins Posted August 19, 2014 Author Share Posted August 19, 2014 So I've just finished lowering the rear trailing arms and taken the car for a test drive. To be honest couldn't notice much difference, maybe a slight improvement over sharp bumps. The biggest improvement has come from softening the suspension, raising the steering rack and reducing toe out. This has given a massive improvement in confidence and stability of the front end and steering wheel so thanks to everyone for their advice on that. The car does feel too stiffly spring as people have said, maybe it's worth considering some different springs or maybe some standard Bilstein/Caterham springs and dampers? Link to comment Share on other sites More sharing options...
James.S Posted August 20, 2014 Share Posted August 20, 2014 Try borrowing a set of CR500,s 888 are way to stiff and heavy. IMO they ruin the cars handling. If you want a set of Caterham spec Bilstiens, i have a lightly used complete set off a road R400. BM me. Cheers J Link to comment Share on other sites More sharing options...
tomperkins Posted August 20, 2014 Author Share Posted August 20, 2014 Quoting James.S: Try borrowing a set of CR500,s 888 are way to stiff and heavy. IMO they ruin the cars handling. If you want a set of Caterham spec Bilstiens, i have a lightly used complete set off a road R400. BM me. Cheers J Thanks James, I have actually got a a second set of wheels with CR500's on. Haven't noticed too much difference but may test again for comparison. Link to comment Share on other sites More sharing options...
Paul Deslandes Posted August 20, 2014 Share Posted August 20, 2014 According to your original post you had the car flat floored before you raised the steering rack, presumably to minimise bump steer. Did you measure and correct the toe after moving the rack as this almost certainly have altered it? By how much and in which direction is difficult to know. Link to comment Share on other sites More sharing options...
Simon.Rogers1 Posted August 20, 2014 Share Posted August 20, 2014 Its been said above previously by a number of people. The damping and springs will be way to hard in your current set up. How do I know that Link to comment Share on other sites More sharing options...
elie boone Posted August 21, 2014 Share Posted August 21, 2014 Suspension is more about feel than science, even professional racing driven can't agree what the best setting is, one will say it's as sweet as a nut and the other would call it a pig. 350 LBs springs with section 70 tyres will be softer than 250LBs springs with section 50 tyres. Normally a DD chassis would run toe out 0,25 degree +/- 15 but you could run it at 0 degree Link to comment Share on other sites More sharing options...
James.S Posted August 21, 2014 Share Posted August 21, 2014 Quoting elie boone: Suspension is more about feel than science, even professional racing driven can't agree what the best setting is, one will say it's as sweet as a nut and the other would call it a pig. 350 LBs springs with section 70 tyres will be softer than 250LBs springs with section 50 tyres. Normally a DD chassis would run toe out 0,25 degree +/- 15 but you could run it at 0 degree Racers go off the data - not the feel. Link to comment Share on other sites More sharing options...
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