Phyte Posted November 12, 2003 Share Posted November 12, 2003 Just curious. I don't race my Z, but would like to lower it an inch. I know the draw backs of cutting springs. I won't use heat. Do people do this to their Z's, or just buy the aftermarket springs. Phyte Quote Link to comment Share on other sites More sharing options...
Drax240z Posted November 12, 2003 Share Posted November 12, 2003 I've done it to 4 or 5 cars with no problems. Just remember you can't add anything back on if you mess up! Quote Link to comment Share on other sites More sharing options...
Guest 73TPIZ Posted November 12, 2003 Share Posted November 12, 2003 I cut off 1 round from all 4 of mine. Seems like it was 1.25" or so. After cutting, i just heated the first few inches to fold it back down like factory to sit it in the pocket. that area won't see any coil/rebound so i didn't see any harm in it. Worked fine for me. BTW: I had to get 4 stock springs from the junkyard as a previous owner had cut 5+" from all 4 springs. when you jacked the car up, you could spin the coils by hand. what an idiot. Good Luck w/ it Quote Link to comment Share on other sites More sharing options...
ZR8ED Posted November 13, 2003 Share Posted November 13, 2003 I lowered my car 3" by cutting the stock springs...infact I still run my same original stocko front springs..I had them cut 13 years ago I think... you do use heat after cutting them! I cut mine with a torch...I then heated up the last 1/2 coil red hot..I then flattened it slightly. This takes the pressure off the tip of the spring (why many cut springs break or fail) Now that it is flattend and STILL red hot, you keep the heat on it and slowly take the heat away... 1-2 min I figure...this helps realign the molecules in the spring...They all need to be laying the same direction.... I have pushed my car very hard through the years...no probs.... Quote Link to comment Share on other sites More sharing options...
zxtman Posted November 13, 2003 Share Posted November 13, 2003 Just keep in mind that cutting a coil spring (shortening it), increases it's spring rate. The more you cut, the more the spring rate increases. If you don't have the shocks to handle the increased rate, the car will "bounce" as a result of not being able to handle the rebound. And as far as: BTW: I had to get 4 stock springs from the junkyard as a previous owner had cut 5+" from all 4 springs. when you jacked the car up, you could spin the coils by hand. what an idiot. ...there's nothing wrong with the springs not being loaded when the car is when jacked-up and the suspension is under full droop unless at the time when the car is lowered to the groung the springs do not sit in the upper and lower perches correctly. If this occurs, you can tie wrap or safety wire the spring to the upper perch or with coilovers you can use a "helper spring". Quote Link to comment Share on other sites More sharing options...
spdsk8r Posted November 13, 2003 Share Posted November 13, 2003 I put MSA lowering springs in my ZX and the car looked like a 4x4, it sat about 2 inches higher than the stock springs. I solved it by cutting one coil off each spring. Now it sits about stock height with a little stiffer ride. Quote Link to comment Share on other sites More sharing options...
Phyte Posted November 13, 2003 Author Share Posted November 13, 2003 Ok then. To the butcher the springs shall go Sounds like cutting one loop off each will do the trick! Thanks Phyte Quote Link to comment Share on other sites More sharing options...
Guest Z-rific Posted November 13, 2003 Share Posted November 13, 2003 I think the best recommendation is to cut the springs a little, then do a test fit and drive and cut some more. I've heard people recommending 1/4 of a coil at a time, but I think 1/2 would be fine. It's a PITA to reomve the springs a few more times, but you will avoid cutting more than you wanted, forcing yourself to buy new springs. Quote Link to comment Share on other sites More sharing options...
z-REX Posted November 14, 2003 Share Posted November 14, 2003 ZR8ED... I love the stance of your car. do you remember how much of the spring you cut off? you said it was years ago, and half the time i can't remember what i had for breakfast, so after all that time i wouldn't be surprised if you'd forgotten. Quote Link to comment Share on other sites More sharing options...
Guest 73TPIZ Posted November 14, 2003 Share Posted November 14, 2003 zxtman, the springs loose at full droop seems wrong to me. I mean if you ever went over a hole or a hill at speed and the spring topped out, it could come out of the pocket and wedge sideways (and trust me, these were that loose). Before i cut springs that much, i'd look into dropping the bottom spring perch on the strut tube. I did body work for years on customers cars and have yet to see springs done that way. (and i've seen some pretty 'bootleg' stuff done by people) take care. Quote Link to comment Share on other sites More sharing options...
Guest Z-rific Posted November 14, 2003 Share Posted November 14, 2003 My front springs are a little loose when the car is fully jacked and I've never had a problem. Now, when I say "loose", I mean you can turn them by hand, but not real easily. The springs won't completely come off the perch. Several owners have springs that are loose with no load and no problems ever reported. Now, if the spring were just flapping around, well that's a different problem, but I really don't see that happening with the removal of 1 coil. Quote Link to comment Share on other sites More sharing options...
ZR8ED Posted November 15, 2003 Share Posted November 15, 2003 My front springs have several inches of up and down play when the car is fully jacked up... As someone mentioned.. use some safety wire to tie them down. That way they will stay lined up correctly when the car comes down.. As for unloading the car like that on the street....you will have much bigger problems if you get the car in the air like that...I have not even come close....car is very solid... I recall cutting 3-4 coils out of my front springs....and trust me..that is very low... my car has much larger tires than what I had on originally (225/60/14's)... that brought my frame rails under the floor about 2" off the ground. The car sits much higher now. I am running chevette springs in the back with 1.5 coils cut from them..much stiffer than stock..work awsome.. $50 brand new...hehehe I was going to put them in the front, but with my engine sitting so far back, I just do not need that much spring up front..that is why i have left them stock in the front...Though I am going to replace them in front...the bottom of my airdam is about 1.75" off the ground...toooo low even for me..... 8) Quote Link to comment Share on other sites More sharing options...
baddriver Posted March 24, 2004 Share Posted March 24, 2004 This thread almost answers all my questions, it just needs one more thing. If I am flattening out the ends as suggested above, should I use a heat sink to avoid over-heating the rest of the spring? If so, what should I use and where should It go? Thanks Jeff E. Quote Link to comment Share on other sites More sharing options...
utvolman99 Posted March 24, 2004 Share Posted March 24, 2004 This thread almost answers all my questions' date=' it just needs one more thing. If I am flattening out the ends as suggested above, should I use a heat sink to avoid over-heating the rest of the spring? If so, what should I use and where should It go? Thanks Jeff E.[/quote'] I am not sure what you could use but I don't think a heat sink would be a bad idea at all. I feel the most important thing though is to not let the spring cool down too quickly. Just removing the heat and allowing it to cool at room temp will allow for the formation of martensite in the metal. This is a very hard grain structure phase for metals. You want to gradually take the torch away from the spring (Probably over around 10 min). This will ensure the formation of more austinite which is a better grain structure for this application. Quote Link to comment Share on other sites More sharing options...
SHO-Z Posted March 24, 2004 Share Posted March 24, 2004 Slow cooling will allow pearlite to form. The transission form austenite to pearlite is around 1350 °F. To keep in the austenite grain stucture, Austempering The steel is brought above 1350 °F and then quenched to 800 °F. Then allowed to cool slowly to room temp. No martensite is formed. The is from a mechanical engineering materials book. Quote Link to comment Share on other sites More sharing options...
jgkurz Posted March 25, 2004 Share Posted March 25, 2004 Ok. You all have me worried about my springs now. I cut a coil and a half off with a cutting wheel which brought my car down about 3/4". The only difference is I cut my springs so the end or tail was in the same position as the original springs. They seat and stay nicely in the original location. I didn't heat the ends or anything like that. Am I driving a death trap? Quote Link to comment Share on other sites More sharing options...
Michael Posted April 9, 2004 Share Posted April 9, 2004 It is not necessary to “flatten†the springs after a coil is cut – the springs will still sit securely in their perches, because the stock spring perches have enough helix angle to accept the unflattened spring ends. At least, this has been my experience with a 280Z, with one coil cut from each spring. Quote Link to comment Share on other sites More sharing options...
(goldfish) Posted April 9, 2004 Share Posted April 9, 2004 cutting a spring does not increase its spring rate ( making it stiffer). it only makes it shorter and have less travel. Quote Link to comment Share on other sites More sharing options...
Drax240z Posted April 9, 2004 Share Posted April 9, 2004 Er goldfish, spring rate is inversely related to the number of active coils present in the spring. Less active coils = higher overall spring rates all else being equal. k=(Gd^4)/(8*D^3*N) Where: k = spring rate G = materials shear modulus d = wire diameter D = spring coil diameter (centerline) N - number of active coils As you can see if you change N from 6 to 3, you are going to end up with 2 times the beginning spring rate. Quote Link to comment Share on other sites More sharing options...
Synlubes Posted April 9, 2004 Share Posted April 9, 2004 I`ve used both a torch and a cut off wheel. I find that the cut off wheel cuts more quickly and doesn`t heat the coil up very much. I use to bend the coil down flat, but the last couple sets I just cut them and reinstalled. Works great. No problems. Quote Link to comment Share on other sites More sharing options...
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