My Afternoon Adventure: Cutting Springs (w/ Pics)
10-24-2009, 03:52 PM
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My Afternoon Adventure: Cutting Springs (w/ Pics) Stock springs, stock struts and shocks on my 2000 SS, all with 101k miles on them. I just got the car and have wheels and tires coming in Monday (staggered 19s), so I couldn't be riding around like a monster truck. I already have upgraded shocks on the way (Bilsteins) and am trying to decide on lowering springs (leaning heavily towards DMS, but Hotchkis look nice too), but I needed a fix in the meantime.
Before Cutting:
Didn't take measurements, really wish I would have. My guess would be that I was sitting between 27.5-28" in the front and 28-28.5" in the rear. 4x4 FTL.
After Cutting:
Front - Just under 26.5" on both sides (cut 1.25 coils off bottom), Rear - Just under 26.75" on both sides (cut 1.5 coils off top and kept the isolator on).
Ride Quality Changes:
The car rides rougher over very bad road imperfections, but no worse than any other lowered F-Body I've been in that didn't have Konis under it. There are slightly more noticable "good vibrations" as I call them at highway speeds, meaning you just feel the road a little bit more, just like any other lowering spring. It's a little sportier ride, but it's also very soft just like stock over minor road imperfections. I hit a few dips and some rough spots in the road and never got into the bumpstops. Overall I'd say the ride was very minimally affected. I'd consider the stock ride a 7 out of 10, and the ride after cutting a 6 out of 10. I'm comparing those ride numbers to cars like my GTO and my truck, and my fiancee's Civic.
Handling:
The car is obviously lower and the spring rates obviously went up a little also. It definitely handled a little better on initial turn in, and has a more "on rails" feel, but during much harder cornering and heavy braking it's nothing like a properly springed and dampened car (there is still roll during hard cornering and nose dive under heavy braking). If stock handling is 5 out of 10, the cut spring ride is 7 out of 10. I think better shocks would bring it up to an 8, about even with what a car on lowering springs and fresh stock shock handles like.
Overall:
I'm actually really impressed that there was only a minimal amount of ride quality loss, and that there was a noticable gain in the handling department. The only downside to this is that I used an electric die grinder with a 5" cutoff wheel to trim the springs, and I did the front springs while they were still on the stock struts, and on both sides I couldn't get the springs compressed as much as I would have liked. There were a few times when the die grinder got into the lip of the spring perch as well as the coil above where I was cutting, so on both sides I've got about a 1/8" deep notch in each spring perch lip in one spot, and a little shiny spot on each coil above where I cut. That would make me pretty uncomfortable if I were planning on running this setup for the long haul. It's weak points begging for stress fractures after a lot of miles (although it may take more miles than the car will ever run to be a problem, it's not something I want to gamble on). A spring perch failure at speed could be deadly, hence why this is only a bandaid lowering job that will only have minimal miles put on it before I swap to a better setup.
Once I decide on DMS or Hotchkis springs I'll still be switching over, but for now this is a great way to lower the car IMO. I'm really leaning towards DMS with the isolator removed, because with Hotchkis I think I'll sit about where I'm sitting now, and I'd really like to be just a touch lower (closer to 26" front and 26.25-26.5" rear ride height).
Overall though I think this is a great way to lower the car a little as long as you know what you're getting in to (the ride will degrade a little, the handling will improve a little, and you will undoubtedly get into the bumpstops more). IMO this is a far better option that throwing something like the Eibach Pro Kit on stock shocks (I made that mistake once way back when).
Before Cutting:
Didn't take measurements, really wish I would have. My guess would be that I was sitting between 27.5-28" in the front and 28-28.5" in the rear. 4x4 FTL.
After Cutting:
Front - Just under 26.5" on both sides (cut 1.25 coils off bottom), Rear - Just under 26.75" on both sides (cut 1.5 coils off top and kept the isolator on).
Ride Quality Changes:
The car rides rougher over very bad road imperfections, but no worse than any other lowered F-Body I've been in that didn't have Konis under it. There are slightly more noticable "good vibrations" as I call them at highway speeds, meaning you just feel the road a little bit more, just like any other lowering spring. It's a little sportier ride, but it's also very soft just like stock over minor road imperfections. I hit a few dips and some rough spots in the road and never got into the bumpstops. Overall I'd say the ride was very minimally affected. I'd consider the stock ride a 7 out of 10, and the ride after cutting a 6 out of 10. I'm comparing those ride numbers to cars like my GTO and my truck, and my fiancee's Civic.
Handling:
The car is obviously lower and the spring rates obviously went up a little also. It definitely handled a little better on initial turn in, and has a more "on rails" feel, but during much harder cornering and heavy braking it's nothing like a properly springed and dampened car (there is still roll during hard cornering and nose dive under heavy braking). If stock handling is 5 out of 10, the cut spring ride is 7 out of 10. I think better shocks would bring it up to an 8, about even with what a car on lowering springs and fresh stock shock handles like.
Overall:
I'm actually really impressed that there was only a minimal amount of ride quality loss, and that there was a noticable gain in the handling department. The only downside to this is that I used an electric die grinder with a 5" cutoff wheel to trim the springs, and I did the front springs while they were still on the stock struts, and on both sides I couldn't get the springs compressed as much as I would have liked. There were a few times when the die grinder got into the lip of the spring perch as well as the coil above where I was cutting, so on both sides I've got about a 1/8" deep notch in each spring perch lip in one spot, and a little shiny spot on each coil above where I cut. That would make me pretty uncomfortable if I were planning on running this setup for the long haul. It's weak points begging for stress fractures after a lot of miles (although it may take more miles than the car will ever run to be a problem, it's not something I want to gamble on). A spring perch failure at speed could be deadly, hence why this is only a bandaid lowering job that will only have minimal miles put on it before I swap to a better setup.
Once I decide on DMS or Hotchkis springs I'll still be switching over, but for now this is a great way to lower the car IMO. I'm really leaning towards DMS with the isolator removed, because with Hotchkis I think I'll sit about where I'm sitting now, and I'd really like to be just a touch lower (closer to 26" front and 26.25-26.5" rear ride height).
Overall though I think this is a great way to lower the car a little as long as you know what you're getting in to (the ride will degrade a little, the handling will improve a little, and you will undoubtedly get into the bumpstops more). IMO this is a far better option that throwing something like the Eibach Pro Kit on stock shocks (I made that mistake once way back when).
Last edited by josh99ta; 11-24-2009 at 10:19 PM.
10-24-2009, 08:37 PM
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Nice write up man and overview! I hate how everyone says cutting the springs is soo evil, I have eibach lt1 springs on the front and knocked off 3/4 of a coil of my rear springs and I love it. My 60's havent changed much long as Im on d/r's plus having a 10 bolt still but 1.7s are no problem!
10-25-2009, 10:01 AM
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Nice review-I had Hotchkins TVS on my 79 Z and loved it. On my 2000 TA Its a calaboration of BMR-SLP-STRANO-KONI, and I made same mistake with sportlines on stock shocks. That lasted about 2 hrs before I changed it back. Its a good thing the SS has better sway bars to help with the new suspension geometry.
10-26-2009, 07:14 AM
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"The car is obviously lower and the spring rates obviously went up a little also."
The center of gravity is lower because the car is lower, and the spring rates went up because you remove the number of active coils (although only slightly). More spring rate + lower center of gravity = better handling, although in this case on the stock shocks it's only marginally better. When I get the Bilstein HDs in I expect the handling and ride to improve to better than they were stock. The HDs are valved for stock spring rates, so they should feel a lot better than these 101k mile DeCarbons. That leaves me with the only drawback being limited suspension travel, and by modifying the upper strut/spring mount and the bumpstops all around I should gain all of that back.
The center of gravity is lower because the car is lower, and the spring rates went up because you remove the number of active coils (although only slightly). More spring rate + lower center of gravity = better handling, although in this case on the stock shocks it's only marginally better. When I get the Bilstein HDs in I expect the handling and ride to improve to better than they were stock. The HDs are valved for stock spring rates, so they should feel a lot better than these 101k mile DeCarbons. That leaves me with the only drawback being limited suspension travel, and by modifying the upper strut/spring mount and the bumpstops all around I should gain all of that back.
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10-26-2009, 07:18 AM
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Also I want to note that the reason I did the cut springs and am going to modify the mounts and bumpstops is because this is a daily driver for me, and I'm not trying to make it into a G-machine. I want a ride that is as comfortable as stock, with a little more control, and a slight bump in handling. I plan to do sway bars, upgraded bushings all around, and basically everything else to bring the handling up a step, but I've had numerous suspensions under my previous F-Bodies and none of them rode the way I'd want a daily driver to ride. The only one I liked was the stock springs on Konis, but since I kept them pretty soft as the extra dampening wasn't needed for the stock springs, effectively the Bilstein HD shocks should work out well for these cut stock springs. That leaves me with gaining back the suspension travel that I lost, and I should have a perfect setup. I do not expect the DMS/GMS springs to improve anything but handling, the question is if they'll degrade the ride. We'll find out.
10-26-2009, 06:49 PM
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Josh that harness you are feeling in all likelihood is suspension getting into the jounce bumpers. Your stock spring rate only increased 10 to 15 lbs/in when you cut the springs, but you lowered the car about 1.25 inches in the front and 1.5 in the rear. So in essence, you gave up suspension travel but your asking the stock springs to absorb just as much energy is less distance. The jounce bumpers have a significantly higher spring rate than any mainline aftermarket spring so if your OK with the harness you have now, you'll be even happier with strano springs.
BTW, there's an easy way to check if you are getting into the jounce bumpers. In the front, push the bumper to the bottom of the shock and put a little grease on the top of it and look for the grease transfer to the top of the shock. On the back it's even easier, just put some grease on the axle and look for it to be transferred to the jounce bumper.
BTW, there's an easy way to check if you are getting into the jounce bumpers. In the front, push the bumper to the bottom of the shock and put a little grease on the top of it and look for the grease transfer to the top of the shock. On the back it's even easier, just put some grease on the axle and look for it to be transferred to the jounce bumper.
10-26-2009, 08:18 PM
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Batmobile, not exactly. By removing the number of effective coils, your spring rate increases, although minimally. It will translate into a slightly stiffer or more "sporty" ride, and the car will also handle slightly better too from slightly stiffer spring rates and a lower center of gravity.
I've had Konis before. This car rides nearly as well as is, and I fully expect it to ride equal to the Konis (on soft settings) once I get the Bilsteins in and modify the upper strut/spring mount and bumpstops all around to get full suspension travel back. Because this is a daily I don't think I could have asked for a better setup, especially for the price.
In the rear I am getting into the jounce spacers on heavy road imperfections. In the front I'm not. I will mention that TN roads are some of the best I've ever driven on. The kill us in taxes to keep the roads in the shape they're in.
Today I went a certain way to work that bottomed out nearly every suspension setup I've ever had on a F-Body (except the Koni setup I had on my Trans Am). This cut spring setup didn't bottom out. I was flat out impressed to be honest with you. I'm really looking forward to modifying the bumpstops and mount to get full suspension travel back and getting the Bilsteins on for some better dampening. I think it'll be exactly what I'm looking for.
Josh that harness you are feeling in all likelihood is suspension getting into the jounce bumpers. Your stock spring rate only increased 10 to 15 lbs/in when you cut the springs, but you lowered the car about 1.25 inches in the front and 1.5 in the rear. So in essence, you gave up suspension travel but your asking the stock springs to absorb just as much energy is less distance. The jounce bumpers have a significantly higher spring rate than any mainline aftermarket spring so if your OK with the harness you have now, you'll be even happier with strano springs.
BTW, there's an easy way to check if you are getting into the jounce bumpers. In the front, push the bumper to the bottom of the shock and put a little grease on the top of it and look for the grease transfer to the top of the shock. On the back it's even easier, just put some grease on the axle and look for it to be transferred to the jounce bumper.
BTW, there's an easy way to check if you are getting into the jounce bumpers. In the front, push the bumper to the bottom of the shock and put a little grease on the top of it and look for the grease transfer to the top of the shock. On the back it's even easier, just put some grease on the axle and look for it to be transferred to the jounce bumper.
In the rear I am getting into the jounce spacers on heavy road imperfections. In the front I'm not. I will mention that TN roads are some of the best I've ever driven on. The kill us in taxes to keep the roads in the shape they're in.
Today I went a certain way to work that bottomed out nearly every suspension setup I've ever had on a F-Body (except the Koni setup I had on my Trans Am). This cut spring setup didn't bottom out. I was flat out impressed to be honest with you. I'm really looking forward to modifying the bumpstops and mount to get full suspension travel back and getting the Bilsteins on for some better dampening. I think it'll be exactly what I'm looking for.
11-23-2009, 09:17 PM
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My M6 car was quite 4by, esp. the front after I replaced the standard steel hood with a fiberglass VFN. So I cut one coil from the front and 1/2 in the rear with the heater hose mod. Nice drop and with fresh Bilsteins it rode and handled really nicely, too. No downsides.
But Josh, why didn't you just wait till you got your Bilsteins to cut the springs off the car??
But Josh, why didn't you just wait till you got your Bilsteins to cut the springs off the car??
11-23-2009, 09:37 PM
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Because I was sourcing some upper shock mounts to modify before I swapped the Bilsteins in, and I wanted the car lower ASAP, so I figured I'd let my stock shocks get beat up for a bit before I did the UMM and swapped the Bilsteins in for a better ride and more suspension travel. I'm picking up my upper mounts tomorrow so I hope to have the UMM done shortly thereafter and the Bilsteins in within the next week or two, then alignment, then enjoying a nicer ride with more travel.
11-25-2009, 08:03 AM
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I'm going to take my DMS springs off soon. I got them directly from DMS about 5 years ago, don't know if they are the same as the Granatelli's now or not. Been on the car about 4 years but has rarely left the garage. Let me know if you're interested.