Suspension / ChassisQuestions about your suspension? Need chassis advice?
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I've decided to cut my front springs for a slight drop. I'm looking for 1" drop total. I've searched and it varies but it seems 1/2 coil is common for a 1" drop. I have stock 1982 Camaro Z-28 springs which are for A/C and stuff so unsure of the part number but I know they are stiff. I just don't have any heavy stuff anymore and the front end is higher than the back. Any idea what the average drop?
For the love of god people stop with the BS, you won't have anymore camber problems with cut springs than you will with off the shelf lowering springs. The camber problems come as the result of lowering, doesn't matter what kind of springs you use to do it.
From my experience 1/2 coil is worth any where from 3/4" to 1 1/2" of drop depending on the spring rate. With your lower rate springs you'll be closer to 3/4"-1"
spend the money and get new springs. you're gonna have all sorts of camber issues with cut stockers
So you've never trimmed any springs to get the desired ride height? It's pretty common place. And no I'm not advocating heating them whatsoever, but cutting is a acceptable method.
1/2 coil on the fronts of my camaro lead to about 1.25" drop, i'd go in 1/4 coil increments honestly.
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thats good info. i need to cut mine too. i've alot of wieght off the front and now the front end is jacked up. i'm just too lazy too get out here and do it.
So you've never trimmed any springs to get the desired ride height? It's pretty common place. And no I'm not advocating heating them whatsoever, but cutting is a acceptable method.
no i have not. i was just speakin of what i thought i knew. i know a few wyotech grads and they all seem to have the opinion that cutting stock springs will give you camber issues.
Camber issues come as a result of lowering....doesn't matter what type of spring you use. Camber is function of the suspension geometry and lowering will give you more negative camber, which can be corrected with an alignment.
The only true way to lower your car without any issues is with spindles and what not. You will not come across any problems by cutting your springs, that will not appear from lets say a set of Eibachs (unless of course you cut too much and you are on the bump stops)
There is nothing unacceptable about cutting springs, just make sure you use an acceptable method of doing your deed.
One question regarding cutting springs. If you would get a set of V6 springs, and cut 1/2 coil off, what would the spring rate be compared to the RS springs (I'm pretty sure I have the F41 option, since I have 34/21 bars, not sure if the springs were different on the F41 option cars though lol)
One question regarding cutting springs. If you would get a set of V6 springs, and cut 1/2 coil off, what would the spring rate be compared to the RS springs (I'm pretty sure I have the F41 option, since I have 34/21 bars, not sure if the springs were different on the F41 option cars though lol)
If you have a V8 and used V6 springs, then you cut them, you would bottom out everywhere you go. The spring rate is much softer. If you have a V6, then there shouldn't be any issues.
you guys normally torch the spring to cut or cut off wheel? I have seen both and heard a long time ago that the cut off wheel with some maching coolant is better to avoid the heat build up. bad part is the torching was in a magazine article from chp or super chevy or one of them from primedia.
I just use a 4.5" cut off disc on a grinder, the spring does not get hot at all if you go at a reasonable cutting speed. I would never use a torch on springs!!!
PS The V6 springs are super, super soft, do not bother messing with them, they are totally worthless unless you like a squishy ride.
skip the torch, I use grinding discs on an air grinder. I cut for about 30 seconds then go to the next spring, then go back and forth, they never get hot that way. Took about 15 minutes total to cut through them both going at a slow pace.
However you should use a torch after it's been cut, correct ? In order to be able to flatten the top of the spring ?
No. You would risk ruining the spring. If you have that rubber bushing that sits on the top of the spring you will be golden.
Besides, the top part where the spring sits should have a bump that helps sit the spring in place so again, this is nothing that should be worried about.
Thanks for pointing that out, because I've seen some instructions that say to heat them up, turn them upside down, and flatten the top *L*. OK, thanks.
how about if you installed lowering springs and the front end is still up alittle higher than the rear...springs have been in the car a year and havent settled any more...B+G sport springs from spohn. they told me to cut an inch off to drop the car 3/4''
If they are in the car right now, then take a measurement of how high one full coil length is in height with the spring compressed.The coil is aprox 42% on leverage point of the A-arm at spring centerpoint. What this means is for ever .42inch you cut, you will get 1 full inch of overall drop. Basically cut off ABOUT 1/2inch of compressed height coil to get close to 1 inch drop- BUT NOTE MY NEXT PARAGRAPH.
This is not an exact science formula, but very very close. The cut coil does become slightly stiffer so actually cutting .42 inch MAY only drop it .95 inch instead of a full 1.0 inch- you get my drift.
Cutting off a 1/2 of compressed hieght may be more like 3/4-7/8" free height- this is why you need to measure one full coil loop at compressed height. Then when you remove the coil and it has expanded, you will have an idea of how low each full coil taken off will make the car drop.
Now here's the kicker- Some springs may have a compressed free coil length of 1", others may have a free coil compressed length of 2"- depends on the spring diameter, the spring wire thickness, and the overall # of coils tthat make up the rate. A 5" diameter 10" tall 800lb spring may lower 1" with a half coil cut, and a 5.5" dia 14" tall 800lb spring may lower 1 1/2" on the SAME CAR- Depemds on the spring and the car- thats why my about suggested formula is the best way to calculate your perticular setup.
I just ordered a set of Lakewood 70-30 front strut's. I've been looking at quite a few spring set's but I kinda just wanna cut my stockers. I have the stock WS6 springs. How much would I wanna cut to drop about an inch? The car sat very high to begin with.
no i have not. i was just speakin of what i thought i knew. i know a few wyotech grads and they all seem to have the opinion that cutting stock springs will give you camber issues.
These are EXACTLY the people that should NEVER be allowed near a car that anyone cares about. How the heck is cutting a spring shorter going to do anything different to suspension geometry then installing a shorter spring??? Yes, lowering car can mess with the camber, but it that happens whether you put some eibachs in or cut stockers.
Drop spindles… probably shouldn’t even waste my time since they’re not available for most cars, but they can cause geometry issues also. Usually the problem is that the bearing spindle gets moved up, which moves the rim closer to the lower ball joint causing fitment problems or worse, a situation where the suspension will bottom if you have a flat tire, which is downright dangerous.
Now cutting springs… when you cut springs you increase their spring rate (think of the spring as a long piece of steel rod wound into a coil, if a sorter piece of the same rod is harder to flex/bend then a longer piece). This is an important thing to note since the front and rear spring rates have to stay in a certine ratio. If the front spring rate goes up faster than the rear it will cause the car to understeer (the front feels like it’s sliding out and the car doesn’t turn as tight as you have the wheels turned), and if the back gets stiff too fast than the car will oversteer (the back end will kickout). Neither is optimum, but oversteer is VERY dangerous (understeer you let go of the throttle and everything settles down, oversteer, well once you get there, no matter what you do you make it worse and the car will try to spin around, something that can’t be controlled on the street).
How much? Well, if you play with the factory spring rates you’ll find that you basically want to cut about 2x as much off the front than the rear to keep things reasonably balanced. Unfortunately, with a set of high performance (iroc, WS6, Z28…) springs, leaving everything else the same, cutting 1 coil off the front springs will lower things roughly 2.5-3”, depending on the year of the car (the earlier cars sat higher and cutting had more of an effect, the end result in height is about the same), where cutting ½ a coil off the rear is barely enough to notice (probably ½”-1” on most cars). There is an easy solution to this that I recommend, the rear springs have thick stock isolators, and swapping the rear isolators into the front pockets gets it back up to a reasonable height, and then using the thin front isolators (I think that they’re too hard to keep lined up in the pockets so I just use a length of heater hose pushed over the last coil of the spring) in the rear lowers the rear down roughly another inch or so.
What you end up with is a car that is lowered about 2.5”, about the same or slightly more than with sportlines, but with the higher spring rates of the pro kit.
With softer, non performance package springs you’re looking at more like ½ a coil in the front, and the same or slightly less in the rear, and you can even things out by heating the coil a ½ turn up and bending it in like the stock coil, that will usually get you to a good ride height and balanced spring rates.
What to cut with? Torch is fine IF, you know what you’re doing. You should be able to sever the coil in less then 10 seconds if you do and you won’t get the rest of the spring hot enough to cause a problem. If you’re a monkey with a torch and can’t get through it in 2 minutes, then don’t do it. Otherwise, a cutting wheel in a 4.5” grinder should cut them in about 30seconds or less, a little 3” wheel in a die grinder is a good way to spend a few minutes doing this, and dremel or hack saw… you’re in for the long haul, I’m guessing you’ll manage to turn it into a ½ hour job that way. Just make sure that when you’re done you dress/grind the cut edge of the spring so it doesn’t damage the spring pocket.
Unfortunately, with a set of high performance (iroc, WS6, Z28…) springs, leaving everything else the same, cutting 1 coil off the front springs will lower things roughly 2.5-3”, depending on the year of the car (the earlier cars sat higher and cutting had more of an effect, the end result in height is about the same), where cutting ½ a coil off the rear is barely enough to notice (probably ½”-1” on most cars). There is an easy solution to this that I recommend, the rear springs have thick stock isolators, and swapping the rear isolators into the front pockets gets it back up to a reasonable height, and then using the thin front isolators (I think that they’re too hard to keep lined up in the pockets so I just use a length of heater hose pushed over the last coil of the spring) in the rear lowers the rear down roughly another inch or so.
Mine is an '88 Formula with WS6. Best I can determine, I think the front springs in this thing are the same as the 1LE springs. Needs to come down about 2" all around.
A magazine article I just read said to cut in 1/4 increments, then drive a couple days to let them settle in. Then repeat the process as needed. Probably good advice.
From what you say, I could take the rear isolators out and replace them with hose on the top turn. Then cut about 1/2 coil from the front springs. This would give me about 1" drop both front and back? That would be a good starting point.
__________________ '88 Formula 400 "SR-71 Black 'Bird"
A couple of thoughts:
- GM springs are wound in increments of 1/3rds, in other words, they all have some number and 1/3 or some number and 2/3 windings, it really shouldn’t make that big a difference, but for the springs to seat like stockers I’d suggest cutting them in increments of 1/3’s
- To me spring rate is at least as important as ride height. Remember as you cut the springs their rate will go up, and the rate of the fronts will go up faster than the rear. A front wheel rate that’s proportionaltely too high is much safer than vice versa, so your approach would be safe, but a balanced setup is always faster, so I’d consider cutting the rear springs slightly, use rer springs from a stiffer suspension package or stiffer sway bars… (I will suggest that when I’ve ended up happy with 3rd gen suspensions, I’ve always encd up with rubber rear bar bushings and poly front, so reversing that or poly front and back might be just enough to balance things.
so your saying the drop spindles aren't a good idea I have some but haven't had a chance to install them yet. they are AJE 1.8" drop spindles. the later ones that have all the problems worked out. and also Caster/camber plates that are adjustable. The guy said he got them from Summit and was told they are BBK I couldn't find they anywhere and they look like the J&M from Hawks'. Does this sound like it will be OK? also also how much should I chop the rear springs to even it out? Thanks for the input too Crossfire you always have had great info.
so your saying the drop spindles aren't a good idea I have some but haven't had a chance to install them yet. they are AJE 1.8" drop spindles. the later ones that have all the problems worked out.
I couldn’t tell you for sure without seeing them… there are some that have great geometry (some of the truck ones) and some that are awful (nova/early f-body…)
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and also Caster/camber plates that are adjustable. The guy said he got them from Summit and was told they are BBK I couldn't find they anywhere and they look like the J&M from Hawks'. Does this sound like it will be OK?
To be blunt, these cars do not need camber/caster plates like something like a mustang. From the factory, ours adjust further than most mustang aftermarket plates, and there is less then a ¼” adjustment in most cars between the end of the adjustment range and the physical limitations of he strut tower.
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also also how much should I chop the rear springs to even it out? Thanks for the input too Crossfire you always have had great info.
I must have missed something, what are you evening out?
FWIW, I’ve never cut more than half a coil off the rear springs on an f-body, they have only a few, small windings so spring rate goes up REALLY fast when you cut them. Starting with a set from a performance suspension package, with half a coil cut you’re already over 200lb/hr, and these cars don’t like spring rates anywhere near as stiff in the back as they do in the front. The rest of the height adjustment can be done by adjusting the thickness of the spring isolator.
to even out the rear with the 1.8" drop spindles. wouldn't I still need to chop some off even with the thinner front isolaters on the back? I will post up a pic of the drop spindles so you guys can check them out. I ended up gettting a good deal on this stuff that is why I got the camber plates otherwise I didn't think they were really necessary either.
__________________ 88Iroc lt1 355, mahle pistons, compstar 6"rods , stock crank internally balanced, 4 bolt studded block, Advanced induction dominator heads Ai 22x/23x cam, holley 58mm tb, 1.6 comp cams rrs,home built equal length lt headers,custom built cat back,t56, street twin, hurst shifter, ls1 brakes front and rear. ronal r15s, homebuilt 8.8 rear fms 4:10 gears. Dyno numbers and new track times to come.
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83CrossfireTA--
Thanks for your input. Thought I would report on my results so far, as I just FINALLY got to the springs.
To start out, I have to point out that my Formula had about the worst "4X4" stance that I had ever seen. The car's handling and stance were well balanced. But I'm talking a good 4 inches of gap between the rear tires and the fender skirt edges.
In order of execution:
Removed the rear spring pads and replaced with hose. This lowered the rear about 3/4 of an inch, as the pads were about 3/4" thick. The LCAs are a little down in the rear, indicating it can take a little more drop without the need for adapter plates.
Cut 2/3 coil from each of the front springs, using a cutting wheel. No heat. (BTW, these are tagged "BZW.")
Installed the front springs with the thicker rear pads. Like the rear, I got a slight drop in the front, but not near what was needed.
Took the front apart again, and put the original thin front pads back on the front springs. Just like you indicated, I got about 2 to 2-1/2 inches of drop. It's looking good up front now.
I've decided to be happy with the front now. I've been working without a compressor, leaving the ball joints connected and raising/lower the inner end of the control arms. When I installed the shortened front springs with the thin pads, it became extremely difficult to get the lower control arms installed. The shortened springs wanted to push the control arms toward the center of the car. It took a lot... I mean a LOT... of force to pull the control arms outward and get the bolts in.
Besides, the control arm pivot bolts are now almost perfectly level with the pivot points of the ball joints. Can't ask for better than that! I'm done with the front.
Of course, this work has included all new bushings in control arms, panhard, sway bars, torque arm end, and transmission mounts. Also new boots on the ball joints and tie rod ends. I chose to use 100% polyurethane throughout. It's not that hard to replace the rear bushings with rubber if I feel they're too stiff later.
I also boxed the LCA's. Then I cut the panhard rod and put an adjustment bolt in it, then boxed it. You don't generally think about there being any flex in the front lower control arms. But the experience of putting the new bushings into them exposed a lot of flex in them. A new pair of tubular front control arms may be in the car's future someday.
So now I turn my attention back to the rear springs. (I had forgotten to look for tags on these springs. I'll check this time.) I will cut 1/3 coil from them and see how it sits. I bet it will be what I want. I hope the rear will come down about the same as the front has. I want the car to sit level or slightly tail up. Mainly, since the front control arms are now perfectly level, I would like to have the LCA's also perfectly level.
It appears that in lowering my 'Bird, I'm working to get it down to "normal" stock level, where others go lower. But I'm not willing to give up the solid handling of the stock non-variable WS6 springs. So getting down to "normal" will be enough. I also hope that this will properly line up the rear axle pinion angle. Had a slight vibration at high speed before, apparently caused by the pinion angle pointing up from the high ride height.
If it looks like I want, the final test will be a twisty road near home, approached cautiously at first to see how it handles. Previous to this work, I can't say that I'm sure how it really handled. It seemed neutral tending to understeer, but the rear sway bar links were completely rusted out and broken off! So in reality it had no rear sway bar at all!
If its understeering now adding a rear bar will push it neutral or to oversteer. Hopefully not that far, since understeer is slow but safe, oversteer is fast but dangerous. If you're going to make a mistake do it on the side of understeer.
WRT problems getting the springs back in in the front, jack the back of the car and you can generate more force jacking the control arm into the pocket, and i usually use a flat prybar to move the pivot points out and line up the pivot bolt holes...
Final report on mine, so others can see how much I cut for how much drop.
1/3 coil off the rears, removed the thick pad and replaced with hose. 2/3 coil off the fronts, using the original thin pads. It's still not sitting on the floor. But I have the front tires on and sitting on ramps. Rear axle is sitting on jack stands. I set the stands to hold the centers of the axles at the same level as the centers of the front spindles. Weight on the suspension is the same as if it were on the floor.
Bounced the springs both ends and measured. It appears that the car is lowered about 2 inches overall. The stance is about 1 inch higher in the back. That's perfect in my book. Of course, it will settle in some with driving.
To give our readers an idea of how bad mine had the "4X4 stance," even dropping it 2 inches, there is still a 3-inch gap between the rear tires and the fender edges! But the LCA's are now perfectly level, as are the front control arms. That's with original-size 245/50-16 tires.
I won't go lower. "BZW" springs front, "NNL" rear. Confirms my suspicions that WS6 spring rates were the same as 1LE spring rates, though WS6 is certainly not the same as the full 1LE package. Anyway, cutting more may make it too stiff. Aftermarket springs tend to be variable rate, and I won't go that route. I like to do hard cornering, and I like the predictability you get with single-rate springs. I'm happy with it now.
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Originally Posted by 83 Crossfire TA
If its understeering now adding a rear bar will push it neutral or to oversteer. Hopefully not that far, since understeer is slow but safe, oversteer is fast but dangerous. If you're going to make a mistake do it on the side of understeer.
Actually, as I think about it, as time passed I noticed that it had more understeer than it originally had. I haven't driven her in over a year. I hit a deer with it. Only going about 40 mph, and the deer was scooped up the hood and over the top. It landed behind the 'Bird, got up, and ran away wiser. Dented the hood and ripped off the left headlamp.
So I've had it parked while I repaired the hood and found replacement headlight parts. Found four replacement headlamp sets, with motors. Four replacement tail lights. Good to have for the future, just in case. Also scored a replacement aero rear wing. Rare because it's fiberglass but has the original "dish" in the top, not flat. One thing led to another, and I got started on suspension, which led to rear end rebuild. Then exhaust and the new Rhoads lifters. So memory of how it drove before is getting fuzzy. But it'll be back on the road within a month. Then I turn to paint.
Main point here: EVERY car is different. Cut with caution and care. Take your time. Mine did not come out the same as 83CrossfireTA's results! I had to keep the spring pads in their original locations. (Read on.) But I'm very happy and indebted to him for his input.
I ended up taking the springs out one more time, as I finally decided it was still a bit too "4x4." I applied a torch at the 2/3-coil point on the front springs, 1/3-coil point on the rear springs, and flattened the tops of the springs to fit the original spring pads. My thinking here was to get the true full result of how much I had cut. Seems to have worked. I reinstalled the springs with the original pads in their original locations.
Final result is about 2-1/2" lower all around. Slightly "tail up" stance. My son-in-law thinks it still has too much gap in the wheel wells, but I now have ONLY 4" GROUND CLEARANCE. That's low enough! I don't know how some guys can drive down the street with some of the "zero gap" stances that I see on here. They must avoid speed bumps and dips!
I cannot roll my jack under the front K-member, even with the jack's pad removed. Neither will it cleanly clear my 3" exhaust pipe to get to the right side sub-frame. I have built a set of "pre-ramps" to get the front end up on ramps or get a jack under it!
Small price to pay for the results I got.
Keep in mind that the spring work was done in combination with other suspension mods, rear control arm links were broken, and original bushings were shot:
New Energy Suspensions PolyGraphite bushings all around, including the rear axle torque arm and transmission mount.
Boxed the panhard and made it adjustable
Boxed the Lower Control Arms
The results: All I can say is WOW!
Preliminary handling tests have been unbelievable. "Like on a rail" does not begin to describe the difference.
Ride is a little stiffer than original. More than I expected, but not as much as I feared. Actually, the ride says to you, "Let's do it! Throw me into a curve!" Highway cruising (99% of my driving) is not uncomfortable at all. Very confident feeling.
Plans are to add subframe connectors, strut tower braces, and a "wonder bar." I will fabricate all these myself. Might as well. I haven't been able to find strut tower braces for a TBI car anywhere.
I'll try to remember to take a picture and post it. It's in the garage in all its bad-paint glory and its nose off, getting ready for new paint in the spring. But I can at least show you all the final stance.