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Nov 21, 2007 19:38:53 GMT
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so to chop with angle grinder or not that is the question , is it nobler to suffer the vertigo ,or slam and be dammed and if not why not and think about the answers because questions will be asked so non of that old pony about it weakens the steel or alters the spring rate
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Lets clear up car terms: "Understeer" is when you hit the fence with the front of the car. "Oversteer" is when you hit the fence with the rear of the car. "Horsepower" is how fast you hit the fence. "Torque" is how far you take the fence with you.
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Nov 21, 2007 19:39:22 GMT
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Slam and be damned.
*n
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Top grammar tips! Bought = purchased. Brought = relocated Lose = misplace/opposite of win. Loose = your mum
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slammed 66
Posted a lot
www.gtturbo.org
Posts: 1,675
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Nov 21, 2007 19:50:16 GMT
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Agree with Penski
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86 Renault 5 GT Turbo 89 Renault extra 91 Skyline GTR 98 Mini 1275 mpi 99 Autech Rider www.gtturbo.org
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rysz
Club Retro Rides Member
Posts: 2,558
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Nov 21, 2007 19:52:54 GMT
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so to chop with angle grinder or not that is the question , is it nobler to suffer the vertigo ,or slam and be dammed and if not why not and think about the answers because questions will be asked so non of that old pony about it weakens the steel or alters the spring rate As a spring designer in a previous life - I can tell you that it scares me stupid when I see people do this. If you are using a spring with plenty of coils in and you are only lopping off a couple, then fine, but on a spring with wide spaced coils - this is very bad as the torsional stresses in the steel increase massively if you have less material to bear the load. The heat from grinding is not too much of an issue, but bear in mind that the alloyed super high carbon steel that is used in car springs is incredibly brittle. I have seen a coil of this stuff (8mm dia) crack on the former as it was being forced onto a mandrel to make a similar size spring and it shattered along its length, went flying over 100ft of busy factory floor and bury itself in the wall. Please bear in mind that when you use a cutting disk to chop springs if you REALLY have to do this PLEASE, PLEASE, PLEASE use a fresh new disk - not some tred old one that you have used on mild steel etc as this will introduce particles of very weak steel into the spring and this can lead to accelerated failure. If you can, get the springs glass bead or shot-peened as this will aid with fatigue life and relieve the stresses on the surface of the spring. Whatever you do, do NOT weld to spring steel and expect it not to crack as the heat brings all of the carbon to the surface and the weld will crack sharpish. Do it, just please do it intelligently! If you need any advice, then please just ask as I still have a lot of mates at the company who will be happy to check that the spring will not fail badly after choppage! Any hew my two penneth worth...
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Nov 21, 2007 19:55:52 GMT
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It dosent change the spring rate, i went through this last time it came up, the length of the spring is being change aswell as the number of coils, therefore the amount of angular movement is identical.
J
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Nov 21, 2007 19:57:23 GMT
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have a fig roll for that intelligent answer
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Lets clear up car terms: "Understeer" is when you hit the fence with the front of the car. "Oversteer" is when you hit the fence with the rear of the car. "Horsepower" is how fast you hit the fence. "Torque" is how far you take the fence with you.
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Nov 21, 2007 19:58:17 GMT
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See, even after typing all that ^^ he said do it!
As he said, DO IT, just do it properly. I will. (interesting about using a fresh cutting disc, not seen that before)
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The journey of 1000 miles starts with a single coffee.
I don't like coffee!
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Nov 21, 2007 20:00:22 GMT
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I chop (much to my current suffering LOL). Never had a spring break yet though. Obviously its not the BEST thing to do but it has been done for a long long time in the world of custom cars. although the springs were cut when made, I agree that the hieght/load ratio is gonna be unpredictable. My springs are now so short that the shocks are at the bottom so have no travel....so another problem has been thrown up to solve. I'm pretty uneducated on spring rates and the general physics behind it all....id love someone to explain it properley to me one day....but for now CHOP CHOP!!! (in fact I'm just gonna start a thread about the springs i need )
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Your car is not 'epic', this thread is not 'epic'....the OCEAN is epic, the UNIVERSE is epic.... please stop misusing this word!! It would appear Hotrods are the new VWs - aint fashion funny! '69 BUICK LESABRE 350
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Nov 21, 2007 20:02:59 GMT
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I'm not an expert but surely lowering springs are cheap enough to fit instead of cutting the existing springs?
Ive only lowered cars before by using an oxy aceteline torch to heat and bend the spring, and even then that was on a banger. Worked a treat though. Id never do it on a road car.
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1987 Maestro 1.6 HL perkins diesel conversion 1986 Audi 100 Avant 1800cc on LPG 1979 Allegro Series 2 special 4 door 1500cc with vynil roof. IN BITS. HERITAGE ISSUES.
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Nov 21, 2007 20:08:28 GMT
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I voted yes of course. I have a bad back which siezes up in cold/damp weather and running hard slams is not funny - except it is, which is why I do it ;D
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Peugeot 307sw - Suzuki SV650S - MX5.
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Nov 21, 2007 20:08:58 GMT
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As above.....plenty of 60mm drop kits kicking around at cheap as chips prices, tried ebay? A mate has recently bought a rst that turned out to have been lowered via a most proberbly stella fueled angle grinder attack and it handled like bamby on ice, tram lined and skitted everywhere. Fitted a nice easy going propper 40mm drop and all is honkydory
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Nov 21, 2007 20:10:33 GMT
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lol when I said as above...I ment above the person who just sneeked in with a reply between mine and lankytim
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Nov 21, 2007 20:16:04 GMT
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As above.....plenty of 60mm drop kits kicking around at cheap as chips prices, tried ebay? A mate has recently bought a rst that turned out to have been lowered via a most proberbly stella fueled angle grinder attack and it handled like bamby on ice, tram lined and skitted everywhere. Fitted a nice easy going propper 40mm drop and all is honkydory Have a search around on here, LOTS of threads (why aren't any stickied yet?), At this level, dropping 60mm or less, there is no harm in cutting your springs, as long as you do it properly. Its basically the same as buying lowering springs, but a lot cheaper! (there is a difference, but when you get down to it its pretty much the same) Past that point, you want to do some more special stuff. (don't ask!) Had summat else to say, forgotten now
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The journey of 1000 miles starts with a single coffee.
I don't like coffee!
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Nov 21, 2007 20:22:27 GMT
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The trouble with off the shelf springs is they are not really very low are they, I mean 60mm! That's like seeing a picture of Kylie then trying to convince your mates that you've slept with her.
My last ride went down 4 inches (200mm to young people) and still works fine with no signs of cracking or stress 3 years on (isn't that right tigran!).
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Peugeot 307sw - Suzuki SV650S - MX5.
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kee
Posted a lot
Posts: 4,991
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Nov 21, 2007 20:30:24 GMT
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4 inches is 101.6 mm actually ;D
1 inch = 25.4mm
mine has been dropped around 60mm on a proper kit.
lets put it this way. if you want the car to look better and your not fussed about handling improving much, chop away. else. new springs/kit
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Colonelk
Posted a lot
Posts: 3,742
Club RR Member Number: 83
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cutting springsColonelk
@colonelk
Club Retro Rides Member 83
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Nov 21, 2007 20:30:49 GMT
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. errr, 4 inches is 100mm (or 101.6 is you wanna get picky!) ;D DANG beaten to it!
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Last Edit: Nov 21, 2007 20:31:38 GMT by Colonelk
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rysz
Club Retro Rides Member
Posts: 2,558
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Nov 21, 2007 20:33:16 GMT
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It dosent change the spring rate, I went through this last time it came up, the length of the spring is being change as well as the number of coils, therefore the amount of angular movement is identical. J I am pretty sure I didn't mention spring rate, this is just a number, force over unit deflection - normally in N/mm It is the stresses involved that worries me, the steel used in car springs is much harder than standard spring steel, which in turn is much harder than mild. The reason why it often works so well is the level of redundancy that is placed in all safety critical aspects of automotive engineering. I have seen spring steel put a good crack in 10mm lexan when put under stress with a nick on the coil (Deliberately I hasten to add) I just don't want to hear about someone injuring themselves on a spring whilst chopping or through use...
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Nov 21, 2007 20:34:30 GMT
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As a spring designer in a previous life - You should have my name! ;D Really though, good answer. I have the dilema with my wee van at the moment, slight reverse rake chop, buy -60, or live with and muck about with weighting. I don't want to do any chopping on our daily if I can help it... basic physics surely says that load will be spread over less metal bar (spring) putting more stress on current coils left over and therefore making the ride harder (?). been a while since skool! not saying its altogether wrong but does change things, and as the man said, heat and history would affect the springs reliability, and some of us run some old spring with are probs dodgy eitherway! Personally I don't fancy cutting mine on the fiesta cos how it would mount in the cup, [/////|] thats my reason, not so bad if they start looking like this /////// but mine are like this ||/////|| or at least this |//////|
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it doesn't matter if it's a Morris Marina or a Toyota Celica - it's what you do with it that counts
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kee
Posted a lot
Posts: 4,991
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Nov 21, 2007 20:37:00 GMT
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rysz
Club Retro Rides Member
Posts: 2,558
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Nov 21, 2007 20:42:25 GMT
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As a spring designer in a previous life - Personally I don't fancyway cutting mine on the fiesta would mount in the cup, thats my reason, not so bad if they start looking like this /////// but mine are like this ||/////|| or at least this |//////| The || on teh ends of your spring are known as dead coils as they are not active, they are normally there to aid mounting and to increase the length of the unsprung spring. If your springs are like that, look at the ends, I very much doubt that they will be ground flat, so for instant stick hitting on your fezz, get rid of one or both of the dead coils and wire the spring to the cup - the stress will be fine as you are not removing active coil from the spring. I will now stop being a busy know all...
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