AdamR28 Posted March 4, 2014 Report Share Posted March 4, 2014 Impressive fail on their part... Work out the rates in future, then all they have to do is pick the right number off the shelf 2 Quote Link to comment Share on other sites More sharing options...
Greetings Posted March 4, 2014 Report Share Posted March 4, 2014 Impressive fail on their part... Work out the rates in future, then all they have to do is pick the right number off the shelf If only I knew how Thankfully my friend needs racing springs and currently has springs which he used in rallysprint. So we just need to swap them over. Quote Link to comment Share on other sites More sharing options...
AdamR28 Posted March 4, 2014 Report Share Posted March 4, 2014 It's pretty simple maths - can dig out some links if you like? Quote Link to comment Share on other sites More sharing options...
MadManMike Posted March 4, 2014 Author Report Share Posted March 4, 2014 So, if I was to attempt to fit new wishbones and ball joints to my car with a fairly mechanically minded friend, how likely am I to fail? Is it very tricky to do? I plan to fix those few bits on and then drive to a place to get my tracking done straight after. Quote Link to comment Share on other sites More sharing options...
Jake. Posted March 4, 2014 Report Share Posted March 4, 2014 A guy in a pimped white mitsubishi evo who was going pretty quick in an empty lane on the dual carriageway slowed down next to me, mouthed "nice car dude!" I gave him a thumbs up, he did the same then accelerated off from 70 pretty impressively.How often does this happen to you guys? Just curious. 1 Quote Link to comment Share on other sites More sharing options...
AdamR28 Posted March 4, 2014 Report Share Posted March 4, 2014 Never. What car do you have? Hopefully he wasn't taking the mickey, haha. Quote Link to comment Share on other sites More sharing options...
Jolfa Posted March 4, 2014 Report Share Posted March 4, 2014 How often does this happen to you guys? Just curious. Occasionally. Last time I drove back from Nottingham, there was a guy in some shitty Kia or something couldn't get enough, pulled up along side and was all nods and thumbs, so I gave it some boot then let him catch up and he was massively over excited Used to get it a lot in my Mondeo too, always from boy racers in Saxos and the likes that I'd just wooped at the traffic light grand prix, mainly to ask what the f**k was under the bonnet (2.5 V6) 1 Quote Link to comment Share on other sites More sharing options...
Greetings Posted March 4, 2014 Report Share Posted March 4, 2014 It's pretty simple maths - can dig out some links if you like? Depends what you want to calculate surely? I'd assume some pretty advanced maths needs to be applied to actually calculate spring rates from scratch. One would definitely need to start off with a perfectly mapped bumpy surface resembling a special stage, work out the leverage of the suspension, centre of mass, load on each wheel, ARB stiffness and lots of other variables/constants and then match the spring rates to the desired suspension travel on that surface. Result is bound to be a multidimensional graph. Sounds like a job for F1 teams Quote Link to comment Share on other sites More sharing options...
AdamR28 Posted March 4, 2014 Report Share Posted March 4, 2014 Kinda... Leverage - yes, which is easy, just length of wishbones, shock mounting point and angle of shock. Centre of mass - not essential for spring rates, it's more linked to roll stiffness. Load on each wheel - don't need that, but could be calculated using a basic datalogger with vertican g reading, a zip tie around your shock (to check travel) and the spring rate being used. ARB stiffness should be calculated and considered separately to spring rates as they are doing different jobs. You do need the corner weights and unsprung mass for each corner though, but that again is easy. Plug all the numbers in and you come out with a wheel frequency, which will be somewhere around 1.5-2Hz for your application I reckon (edit: just checked a rallycross forum where a chap said... "In my Rallycross car (no jumps involved), I have tried 2.1Hz, 1.95Hz, 1.85Hz, and now 1.6Hz. Seems like I am going in the softer direction. Stock for my car is somewhere around 1.2Hz."), with ~10% higher rate at the front. My MX-5 is approx 1.8 rear and 2.0 front for reference, and a normal road car would be 1.0-1.2ish. This one helps explain but doesn't have the shock angle, which is important and does need factoring in: http://www.racingaspirations.com/apps/wheel-frequency-calculator I did all this on the kit car last winter and it's totally transformed the car. I also think it's good to have an understanding of these things in case you need to / want to make a change 'in the field'. Quote Link to comment Share on other sites More sharing options...
Skoze Posted March 4, 2014 Report Share Posted March 4, 2014 How often does this happen to you guys? Just curious. Pretty much every time I go anywhere in Das Capri. Usually the outside lane crew in Audis and Beemers, all slow down for a thumbs up and a burn. Had a few people pull up alongside to get photos and stuff before, quite good fun. There always ends up being someone next to me saying they can't hear it when I go through Dartford tunnel, too... (A) Landy just draws looks of "WTF ARE YOU MENTAL?!" 1 Quote Link to comment Share on other sites More sharing options...
Jolfa Posted March 4, 2014 Report Share Posted March 4, 2014 Oh yeah, I once came out of a petrol station to a bunch of kids taking pics of my car because it was awesome Quote Link to comment Share on other sites More sharing options...
Greetings Posted March 4, 2014 Report Share Posted March 4, 2014 (edited) Kinda... Leverage - yes, which is easy, just length of wishbones, shock mounting point and angle of shock. Centre of mass - not essential for spring rates, it's more linked to roll stiffness. Load on each wheel - don't need that, but could be calculated using a basic datalogger with vertican g reading, a zip tie around your shock (to check travel) and the spring rate being used. ARB stiffness should be calculated and considered separately to spring rates as they are doing different jobs. You do need the corner weights and unsprung mass for each corner though, but that again is easy. Plug all the numbers in and you come out with a wheel frequency, which will be somewhere around 1.5-2Hz for your application I reckon (edit: just checked a rallycross forum where a chap said... "In my Rallycross car (no jumps involved), I have tried 2.1Hz, 1.95Hz, 1.85Hz, and now 1.6Hz. Seems like I am going in the softer direction. Stock for my car is somewhere around 1.2Hz."), with ~10% higher rate at the front. My MX-5 is approx 1.8 rear and 2.0 front for reference, and a normal road car would be 1.0-1.2ish. This one helps explain but doesn't have the shock angle, which is important and does need factoring in: http://www.racingaspirations.com/apps/wheel-frequency-calculator I did all this on the kit car last winter and it's totally transformed the car. I also think it's good to have an understanding of these things in case you need to / want to make a change 'in the field'. Thanks a lot Adam I've played around with the calculator and must be doing something wrong. I'm assuming this calculator works on 1 wheel at a time. So I've started with the front left wheel. 401kg load on that wheel, the spring is a 180Kgf/mm judging by the 180-80 markings and unsprung weight I'm assuming is around 50kgs (20 for the wheel, 30 for the rest). I'm guessing the leverage should be around 90% so I've entered 1/0,9=1.11) and got 610cpm which doesn't sound right judging by the figures you mentioned? What am I doing wrong? edit: scrap that. Seems the calculator is either a bit faulty or kgf/mm is not the same as kgs/mm. I've converted 180kgf/mm to Lb/in which is 15.62 and entered that into the suspension calculator. That converts the value to 0.28 kgs/mm. Anyway, with that in mind, I'm getting 24cpm. Edited March 4, 2014 by Greetings Quote Link to comment Share on other sites More sharing options...
AdamR28 Posted March 4, 2014 Report Share Posted March 4, 2014 Hmm. 180kg/mm can't be right, that's over 10000lbs/in, haha. The stiffest spring I have on any car is 500lb/in. Are they AST springs? Edit: From a bit of Googling of how AST mark their springs, they might be 80N/mm... therefore 8kg/mm, which is ~450lbs, and therefore about 2.15hz wheel rate from your guesstimations. Quote Link to comment Share on other sites More sharing options...
AdamR28 Posted March 4, 2014 Report Share Posted March 4, 2014 So I guess it's only rebound, not a setting which works on both rebound and compression. Just seen this too.... normally there will be a tiny effect on the compression too (I have some damper plots if you wanna see an example) but yeah, mostly rebound damping. To set a start point for your damping, if you 'bounce' the car hard (eg. by jumping on the cage with all your weight) it should rebound to a tiny bit higher ride height than the 'at rest' position, then settle immediately. If it's slow to return or it bounces, you've got too much or too little damping. Quote Link to comment Share on other sites More sharing options...
Greetings Posted March 4, 2014 Report Share Posted March 4, 2014 (edited) Edit: Scrap that too Feel thick like a brick today. Like you say it's 80N/mm. Got lengths and rates mixed up haha So yeah, it seems the front is 142cpm / 2.38hz left and 174.25cpm / 2.9hz right. Yeah, I'm going to weigh it again, the differences between left and right are staggering. Would 2.38hz not be ok for a bumpy tarmac road? Edit 2: Adam, for future reference, would the suspension ratio on this carrier be 1:1? The coilover mounting points are at the bolts sticking out from near the hub. I would have thought that the suspension ratio should be measured from tyre centre to pivot and from coilover to pivot. Is this right? That calculator you sent seems to say that for a Macperson strut, this is 1:1 so they are not accounting for wheel offset etc. Edited March 4, 2014 by Greetings Quote Link to comment Share on other sites More sharing options...
Sam T Posted March 4, 2014 Report Share Posted March 4, 2014 A guy in a pimped white mitsubishi evo who was going pretty quick in an empty lane on the dual carriageway slowed down next to me, mouthed "nice car dude!" I gave him a thumbs up, he did the same then accelerated off from 70 pretty impressively. How often does this happen to you guys? Just curious. This happens to me quite a lot.. Probably because the 'dub' scene is so big at the moment Quote Link to comment Share on other sites More sharing options...
Pashley26 Posted March 4, 2014 Report Share Posted March 4, 2014 I used to get it in my A3 sometimes. Used to get the odd person comment at petrol stations saying it is an odd choice of car. A front mount tends to get you a lot of attention from people in the know. Quote Link to comment Share on other sites More sharing options...
N.Wood Posted March 4, 2014 Report Share Posted March 4, 2014 I give thumbs up to fellow silver 2001 - 2004 Skoda octavia estate drivers when I'm in the Skoda and also freelander 1's when in the freelander. Occasionally. When I'm in a '1 life live it' mood. 3 Quote Link to comment Share on other sites More sharing options...
dann2707 Posted March 4, 2014 Report Share Posted March 4, 2014 Once smoked a granny in a mobility scooter cos she was giving me da eye on the street. Bitch didn't even know what hit er. 1 Quote Link to comment Share on other sites More sharing options...
Greetings Posted March 4, 2014 Report Share Posted March 4, 2014 I do it to all Daihatsu Charade G102 owners I encounter. So far, in the past 1,5 years it's happened once and ended up in rather a lengthy conversation. Rare car, looks like a piece of crap but is actually brilliant and only owners know that. Quote Link to comment Share on other sites More sharing options...
Mark W Posted March 4, 2014 Report Share Posted March 4, 2014 Once smoked a granny in a mobility scooter cos she was giving me da eye on the street. Bitch didn't even know what hit er. I once ran past a little girl in a playpark so fast that she fell over when she tried to turn around and watch me. No joke. Pretty much every time I go anywhere in Das Capri. Usually the outside lane crew in Audis and Beemers, all slow down for a thumbs up and a burn. Had a few people pull up alongside to get photos and stuff before, quite good fun. There always ends up being someone next to me saying they can't hear it when I go through Dartford tunnel, too... (A) Landy just draws looks of "WTF ARE YOU MENTAL?!" A friend of mine in Southampton used to drive a Capri until it destroyed his license, and when we stopped to get petrol once some weird old dude came up to me as I waited by the car and started asking if we put sandbags over the rear axles or not. Got plenty of looks/chat courtesy of that car. 1 Quote Link to comment Share on other sites More sharing options...
Jake. Posted March 4, 2014 Report Share Posted March 4, 2014 Never. What car do you have? Hopefully he wasn't taking the mickey, haha.I have a mk1 caddy, it definitely didn't seem like he was taking the mickey but if he was oh well plus there's loads of shit cars out there everyone just seems to ignore them especially on dual carriageways when you're in slow lane doing 60 haha. Just seemed so odd.Good to see you lads have had the same stuff happen, not surprised Skoze haha your car is f**king fresh. I have had people come up to me at petrol stations for a chat about old vw's, and I've also been parked in the street once and had someone tap on my window asking for a chat about it haha. Just such a good feeling, makes me want to do the car up and make it all nice. Quote Link to comment Share on other sites More sharing options...
Tom Booth Posted March 4, 2014 Report Share Posted March 4, 2014 I just get some weird looks in the mini with the straight cut box. Got some strange looks when it made a mess of a corsa vxr too from some G's. They weren't impressed at all. Quote Link to comment Share on other sites More sharing options...
Mark W Posted March 4, 2014 Report Share Posted March 4, 2014 Actually on topic - rare for me - what sites do people particularly recommend for cheap cars? I'm fairly bored of my car producing a pretty cool old-school-Top-of-the-Pops smoke effect from under the bonnet whenever I stop, and it's got a few other niggles too. I'm thinking of just f**king it off and getting something else, but aside from AutoTrader and eBay I wasn't sure where to look. Thanks for any help! EDIT: Oh, and it also refused to turn left yesterday Quote Link to comment Share on other sites More sharing options...
N.Wood Posted March 4, 2014 Report Share Posted March 4, 2014 ? 1 Quote Link to comment Share on other sites More sharing options...
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