heating up 205 coil springs yes/no?
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  1. #1
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    Default heating up 205 coil springs yes/no?

    I am getting wavering opinions on this and would like to hear somebody elses views ..... there seems to be 2 schools of thought on lowering a 205.

    School 1.

    Eibach springs at 30 mm make a vast difference with only 30% upgrading and are relatively cheap.
    NB: Eibachs combined with some particular dampers will give a very harsh ride. The Eibach combined with the Black Bilsteins seem to be what every one goes for and are very happy.

    School 2. Use the original 205 springs, heat them then reduce the free length measurement of the spring by 30mm. I like the sound of this option myself however when mentioned to not one but 2 workshops [Targa Tassie people and the other services v8 supercars ] however they both commented and said" under no circumstance should one heat up springs" it is dangerous!! :}

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    Over to you guys :}
    jr20516v

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    Previous: Honda EP3 Supercharged , 205 x34 [ including MI16 TURBO, 8v TURBO, CTI, 16V+TB's, 8V+TB's,] Fiat X1-9 X3, Beta coupes x5, Lancia Gamma coupe, GTI-R, Corvette C4, Fiero x5, Alpine GTA turbo, r5 GTT Dimma, 2cv ripple nose, Lotus Elise, 205 Dimma TT, Cliosport 172.x2, Clio rs 200

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    1000+ Posts robmac's Avatar
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    Quote Originally Posted by jr20516v View Post
    I am getting wavering opinions on this and would like to hear somebody elses views ..... there seems to be 2 schools of thought on lowering a 205.

    School 1.

    Eibach springs at 30 mm make a vast difference with only 30% upgrading and are relatively cheap.
    NB: Eibachs combined with some particular dampers will give a very harsh ride. The Eibach combined with the Black Bilsteins seem to be what every one goes for and are very happy.

    School 2. Use the original 205 springs, heat them then reduce the free length measurement of the spring by 30mm. I like the sound of this option myself however when mentioned to not one but 2 workshops [Targa Tassie people and the other services v8 supercars ] however they both commented and said" under no circumstance should one heat up springs" it is dangerous!! :}

    Over to you guys :}
    I suspect when you heat the springs they will loose the tempering and require re-tempering which is a process for someone with an induction oven.

    It cost very little to get the work done professionally.

    Failing that new springs to custom spec cost me $80 each last year.

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    1000+ Posts PeterT's Avatar
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    Option 2, but get a spring maker to do it. I've had it done several times and the results for a road car are much better. Expect to pay $120-$180ish. For this money they heat up the spring to red hot, reduce free length, then re-harden and temper.

    '92 205 Mi16
    '90 Mi16x4

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    cheap way:
    cut off as much of the spring with an cutting disc as required. put some locking pliers on to clamp the cut end down next to coil below it. heat the top coil with a gas torch till it is red hot. that will allow the top coil to twist to a new static position. quench. then grind the top coil flat as per original.

    that is what i did. i dont see how this is dangerous, but no doubt any number of people will say what could happen. if you were really keen you could re-temper by heating again till just starts to change colour ie about 200c, then let it air cool.

    that will lower the car, but bear in mind that cutting off coils also increases the spring rating. there are quite a number of spring rate calculators on the Net, and it is most informative playing around with the values of number of turns, coil diameter and wire diameter to see what really makes a difference!

    slightly less cheap way:
    do as rob did, and have new ones made or buy off the shelf. his $80 per spring is right on what i paid. actually i paid the guy cash, and when i had a second set made to different spec, he charged $100 for a pair, so we are not talking much money. then you can get exactly the same spring rate as the original or as you prefer.

    i used a spring rate calculator to define those parameters, and the free length (which sets the ride height, but not the spring rate), and they worked out exactly as intended.

  5. #5
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    In theory heating a part of the spring like that will affect the metal that is heated. You will end up with a spring that has different rates along its length. As I understand it anyway.

    Unless you get it done like peterT said, I would say no to heating.
    Lets just say we have a few pugs about!

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    Quote Originally Posted by robmac View Post
    I suspect when you heat the springs they will loose the tempering and require re-tempering which is a process for someone with an induction oven.

    It cost very little to get the work done professionally.

    Failing that new springs to custom spec cost me $80 each last year.
    What type of places do that for you ? What do they come under in the Yellow pages.?
    We only have one up here from QLD and that is Kingsprings......funny enough they are more expensive than Eibach landed from UK. Go figure .
    jr20516v

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    Previous: Honda EP3 Supercharged , 205 x34 [ including MI16 TURBO, 8v TURBO, CTI, 16V+TB's, 8V+TB's,] Fiat X1-9 X3, Beta coupes x5, Lancia Gamma coupe, GTI-R, Corvette C4, Fiero x5, Alpine GTA turbo, r5 GTT Dimma, 2cv ripple nose, Lotus Elise, 205 Dimma TT, Cliosport 172.x2, Clio rs 200

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    Quote Originally Posted by PeterT View Post
    Option 2, but get a spring maker to do it. I've had it done several times and the results for a road car are much better. Expect to pay $120-$180ish. For this money they heat up the spring to red hot, reduce free length, then re-harden and temper.

    and there is definately no detriment to the spring? [red hot then cold again usually means a weaker metal does it not? ] Just wondering thats all :}
    jr20516v

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    Exige SC [modded], 205 Si. 205 GTi , Megane R26 LY , Megane 225 [modded ]


    Previous: Honda EP3 Supercharged , 205 x34 [ including MI16 TURBO, 8v TURBO, CTI, 16V+TB's, 8V+TB's,] Fiat X1-9 X3, Beta coupes x5, Lancia Gamma coupe, GTI-R, Corvette C4, Fiero x5, Alpine GTA turbo, r5 GTT Dimma, 2cv ripple nose, Lotus Elise, 205 Dimma TT, Cliosport 172.x2, Clio rs 200

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    1000+ Posts PeterT's Avatar
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    Heating to above the upper critical temperature (approx. 800) will result in transformation from the hard martensite structure to soft and malleable austensite. Cooiling in air will result in a tougher ferrite/pearlite structure which has a lower ultimate tensile stress, which removes the ability of the spring to retain it's elasticity. The spring (or part there of) may therefore loose it's ability to be a spring and undergo plastic deformation (stay bent). However, whilst at the UCT (austenite) the spring can be reset to a lower height, or bent easily into any other shape.

    Quenching from the upper critical temperature rapidly to room temperature in a suitable medium (oil, water or bryne) will transform the austenite structure back to the hard martensite structure and the spring will again be a spring. However, some hardness needs to be removed in order to regain some toughness, thus the spring needs to be tempered in the range of 240-260 deg. C.

    It is a totally reversible process. Hope this helps.

    I don't have an oven that is big enough or hot enough to uniformly heat a spring to 800+, or any means of holding the spring straight whilst it's being quenched to avoid distortion, thus am happy to pay the money.
    Last edited by PeterT; 13th May 2011 at 09:58 PM.

    '92 205 Mi16
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    Or you could buy a set of these spring clamps for about 15 bucks and save time , money and do it yourself.

    They are available at Autobarn etc. and will take 30mm of the ride height easily.
    Every day when I wake up I reach up in the darkness with my eyes shut and if I cannot feel anything that resembles a wooden lid I know it will be a good day. No lid today.

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    check this article out http://autospeed.com/cms/title_Reset...2/article.html

    i sent my si springs to industrial springs in adelaide the lowered them approx 30mm. they are pretty switched on and seemed to know what they are talking about, the guy there assured me that if done propley most springs can be successfully reset without any problems.

    cost me $14 to post them there and $100 for the pair to reset them that included freight back to vic.

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    Quote Originally Posted by PeterT View Post
    Option 2, but get a spring maker to do it. I've had it done several times and the results for a road car are much better. Expect to pay $120-$180ish. For this money they heat up the spring to red hot, reduce free length, then re-harden and temper.
    +1.

    IIRC I got the rear springs reset on a Fuego for under $100.

    You will have to calculate/guesstimate how much the altered height of the spring will affect the ride height.

    That will alter depending on the leverage ratio of the suspension and the preload the springs are under before they actually hold the car.

    As a rough rule of thumb, measure the height of the spring in the car at normal loaded position (A) - then measure the static height of the spring removed from the car (B).

    Then use the following:

    B divided by A multiplied by the lowered height required.

    As an example -

    If A=300mm and B=600mm and you want a 50mm drop = 600/300x50 = 100mm

    If A=300 and B=400 and you want a 50mm drop = 400/300x50 = 66.6mm

    It may not be a precise calculation, but I have used it on a few cars with vastly different suspensions and always got the result I was after to within a bees private parts.

    Please note: the amount lowered will be at the spring, not the wheel. Depending on the suspension type and crank ratio, 50mm at the spring might lower the car by anywhere from 50mm to 110mm...

    The easiest was I have found is to first measure the springs length at normal loaded height.

    Then remove the springs altogether and (with the car on stands and the sway bar link disconnected) use a jack to move the suspension up and down until you get the height you are after and then measure the distance from the top spring seat to the bottom spring seat.

    You can then use the formula above to calculate how much the spring will need to be lowered/reset by the spring works.

  12. #12
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    Mmmmmm.....Brand new Eibachs landed =$160

    Resetting old existing springs = $100 to $180


    It seems the former is the way to go IMHO.....Thanks for all your inputs...mighty helpful ! :]
    jr20516v

    Now:
    Exige SC [modded], 205 Si. 205 GTi , Megane R26 LY , Megane 225 [modded ]


    Previous: Honda EP3 Supercharged , 205 x34 [ including MI16 TURBO, 8v TURBO, CTI, 16V+TB's, 8V+TB's,] Fiat X1-9 X3, Beta coupes x5, Lancia Gamma coupe, GTI-R, Corvette C4, Fiero x5, Alpine GTA turbo, r5 GTT Dimma, 2cv ripple nose, Lotus Elise, 205 Dimma TT, Cliosport 172.x2, Clio rs 200

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    JR. After freshening up ( still more to do ) the 205 a few weeks ago with new Konis etc, Im about to lower the rear and the front with eibachs. Last time I had these on the Pug I was 16 and thought they were a bit rough but didnt mind. I was loving in the country with really terrible roads.
    Im hoping to be swapping them over in the next week or so and will keep you posted.

    I rode in Patpugs 205 which has the reset front springs and standard dampers and it rode well but felt like it was Seesawing a tad. I never drove it so cant comment on the way it 'drove from the serious seat'
    Cam
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    1000+ Posts PugMonkey's Avatar
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    Oh jeezz JR, I have Eibachs with standard shocks and mate, I don't have a filling left in my mouth!

    The only thing that has toned down the front of the car was the 283mm discs & calipers i put on. They softend the ride a little as the weight is reacting to the bounce.

    No complaints though as I love the handeling.

    Moo
    ....now watch a Peugeot turn into a corner!

  15. #15
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    as a general observation about springs, it seems to me that there is nothing special a brand name can add to a spring, as there is nothing more to a spring than its dimensions. so if you know the free length and the spring rate you want, you shouldnt pay a premium over what any spring manufacturer can do it for.

    is that fair comment, or is there something more to it?

    ta.

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    Quote Originally Posted by alexander View Post
    is that fair comment, or is there something more to it?
    You're forgetting paint colour and packaging.

    '92 205 Mi16
    '90 Mi16x4

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    Colourful brochure.

    Tim

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    Quote Originally Posted by alexander View Post
    as a general observation about springs, it seems to me that there is nothing special a brand name can add to a spring, as there is nothing more to a spring than its dimensions. so if you know the free length and the spring rate you want, you shouldnt pay a premium over what any spring manufacturer can do it for.

    is that fair comment, or is there something more to it?

    ta.
    errr....the brand name is actually cheaper than getting the original old [and possibly sagged ] refurbed/treated. I know what you are saying tho :}
    jr20516v

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    Exige SC [modded], 205 Si. 205 GTi , Megane R26 LY , Megane 225 [modded ]


    Previous: Honda EP3 Supercharged , 205 x34 [ including MI16 TURBO, 8v TURBO, CTI, 16V+TB's, 8V+TB's,] Fiat X1-9 X3, Beta coupes x5, Lancia Gamma coupe, GTI-R, Corvette C4, Fiero x5, Alpine GTA turbo, r5 GTT Dimma, 2cv ripple nose, Lotus Elise, 205 Dimma TT, Cliosport 172.x2, Clio rs 200

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    Quote Originally Posted by PugMonkey View Post
    Oh jeezz JR, I have Eibachs with standard shocks and mate, I don't have a filling left in my mouth!

    The only thing that has toned down the front of the car was the 283mm discs & calipers i put on. They softend the ride a little as the weight is reacting to the bounce.

    No complaints though as I love the handeling.

    Moo
    Hey Mark,
    You could have a number of things adding to your harshness :}
    Your original springs are now 20+ years old and like my stomach it tends to sag after these sort of years :}
    Adding to all this could be droplinks, bushes, top mount bearings etc etc. all adding together to make a non compliant ride.
    jr20516v

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    Exige SC [modded], 205 Si. 205 GTi , Megane R26 LY , Megane 225 [modded ]


    Previous: Honda EP3 Supercharged , 205 x34 [ including MI16 TURBO, 8v TURBO, CTI, 16V+TB's, 8V+TB's,] Fiat X1-9 X3, Beta coupes x5, Lancia Gamma coupe, GTI-R, Corvette C4, Fiero x5, Alpine GTA turbo, r5 GTT Dimma, 2cv ripple nose, Lotus Elise, 205 Dimma TT, Cliosport 172.x2, Clio rs 200

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    bushes, top mount bearings etc etc.

    They's all new too.

    Nah it all just to tight. I like it though.
    ....now watch a Peugeot turn into a corner!

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    I have had rear springs re-set here in Adelaide a few times. They were rears for 505, 604, 504 . I used Industrial Springmakers on Port Rd and they were very good. Installed length is hard to measure on these cars, but they accepted a micrometer meas. of intercoil distance, and then re-created the installed length on their press while I watched. Blue King Springs were being turned out by the dozen, painted blue and boxed up. Jon H
    Currently own '69 404, '72 504 (V6), '72 504 cpe 4cyl (unrest), '74? 504 ti x2, '76 504 auto, '76 504 ti on gas, '80 604SL '81 505(ti) ba10/5 '83 505 (ti) ba7/5 fam,
    '84 505 Sti ba7/5, '86 505 Sli ba7/4 fam (project), 405GRI auto. Too many....

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    Quote Originally Posted by PugMonkey View Post
    Oh jeezz JR, I have Eibachs with standard shocks and mate, I don't have a filling left in my mouth!
    Your ride is harsh because your springs and shocks are mismatched, and the shocks are not adequately controlling the behaviour of the spring.

    These Eibachs are not that stiff, and you can get a reasonably compliant ride with quite high spring rates (see some of Thanos'posts), unless you are getting up round 600lb per corner.

    Do the springs have a RATE (expressed as lbs/inch, usually)? Do the shocks have a bump RATE and rebound RATE (also expressed as lb/in). Or are they a pretty colour?

    Tim

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    Quote Originally Posted by PugMonkey View Post
    No complaints though as I love the handeling.
    Hmmm, my cars tend to Liszt...........

    Tim

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    I bought a pair of "Raceland" adjustable coilovers from ebay for just over $300 and I personally couldn't tell much of a difference to my mates $800 Koni's and $1300 K'sports.
    Just a thought...

    Lewis

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    Quote Originally Posted by tcusack View Post

    Do the springs have a RATE (expressed as lbs/inch, usually)? Do the shocks have a bump RATE and rebound RATE (also expressed as lb/in). Or are they a pretty colour?

    Tim
    You should know me by now Tim - Pretty colours dont interest me. I just bought them for lowering the front of the car to a more suitable level - as is JR's original reference for having springs re-rated.

    Yes I know you are right in me having mis matched items and to be honest, never thought of it in that manner but as for spending big money on shocks, well I'll have to see what I can afford in the future.

    Purley explaining my situation.
    ....now watch a Peugeot turn into a corner!

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