Coilover ride quality?

[We Gone]

Question for you coil Over guys regarding spring rates? Been doing searches for a few days and found no good answer.

Been considering going to them so I can lower one to one and a half inches (lose the 4x4 look). I have lowered C4's in the past with the long bolt rear and cut rubbers front, while it looked great I did not like the effect on the ride and would not do this to my ZR-1. I see most use 425/275. Does lowering change this rate? if so would I need to go with a lower spring rate?
I do not want to lose the ride I have now would like a rate that will maintain the stock ride or no stiffer than a 96 Z51 (have a 96 LT4/Z51 and its not to bad at all) when ride control is set to performance. car will only be used for lots of road trips. tell me your thoughts on how the ride changed if any and what rates you went with. And yes I'm getting to old to bounce my kidneys all day ..LOL

Thanks Steve

[secondchance]

I'm thinking of coil-over conversion and also interested in feedbacks.

[XfireZ51]

My 84 Xfire was an original Z51. I like a taut German ride to my cars. So my ZR has 425/300 w Moracca valving for the Bilsteins. Also drive mostly in SPORT unless my wife is in the car. I switch down to Touring with a less than perfect road. It corners very flat w little to no body roll. I haven't tested the limits. The 12" Nittos in back really plant the rear.

[rkreigh]

in general I feel the stock springs deliver a much better ride than coil overs. I went with the 425 front and 275 rear and yes lowing the car down does stiffen that up a bit

I also have 19" runcraps which makes the ride MUCH worse. when I switch over to the 17" amolds with sumis on there the ride is actually pretty decent but still "firmer and more jarring" than stock.

handing improvement is good, car tracks tighter around bumpy corners but is still to skitish in comparison to my c5 with coil overs which rides like a cadillac in comparison.

I'd like to hear more about the van steel qa1 combo as the shocks might be setup better and I like the rear mount very much as it stiffens the mounting point and changes the shock angle.

yun,

we can do a ride anytime you like. I'll likely have the LSV out at Katie's on Sat. but the best thing is to ride in the car with the amolds mounted. I have an old set of hoosiers that haven't seen enough drag strip time and need to be "used up" I'll likely mount those up soon as I need to clean the wheels for carlisle coming up!

like to hear feedback from other coil over ZR-1 guys, frankly I'm a bit disappointed in my setup and it needs some fine tuning!

part of tha is that the C5 rides SO much better with the pfadt coil overs. much of this of course is the stiffer chassis and improvements, but I want to come closer to the great handling and relatively cushy ride the c5 z06 has.

step one for me is LOSE the runcraps.

the F1 (f@#$%ing 1) EMT (expesive malfunctioning tire)

[JimZRyd]

part of tha is that the C5 rides SO much better with the pfadt coil overs. much of this of course is the stiffer chassis and improvements, but I want to come closer to the great handling and relatively cushy ride the c5 z06 has.

step one for me is LOSE the runcraps.

the F1 (f@#$%ing 1) EMT (expesive malfunctioning tire)

I agree! I want to get my 94Z close to what I had in my C5. On that car I had the Pfadt C/O's with thicker sways and a thicker tunnel plate, after I switched out the runcraps for a good set of rubber the car rode like a dream! Smooth but planted. I'm really interested in the QA1 setup as well.

[Bob G]

I hated my coil overs made the car feel like a bucking bronco .I also tried lowering it with bolts & cutting robbers on front spring did not like that either It seams that lowering the car puts the control arms & or the shocks in a bad position that makes them not operate as intended
Bob G

[We Gone]

First thanks for the input so far.

Bob G, This is exactly what I want to avoid.
I hated my coil overs made the car feel like a bucking bronco .

rkreigh, I have read your posts on issues with coil-overs. We have met a few times over the years at SGC. Its looking like I may need to find another alternative to lowering. I can live with the front ride level so if I just do longer bolts to the rear to drop 1 inch, how will this effect the suspension geometry?

Reply from DRM

quote:
Thanks for the email,
For more of a softer ride we would have to drop the spring rates about 50 pounds all around. The problem with lowering the car down and using soft springs the shocks or car may bottom out frequently and cause a extremely harsh ride during that condition. At 3/4 to a 1 inch you will be ok running the softer springs. Lower then that extreme care will be needed not to hit pot holes and etc.

--
Randy Rippie
Doug Rippie Motorsports
412 Pacific Ave
Waverly, MN 55390
763-658-6109

[rkreigh]

I'm also going to try raising the ride height up a bit.

my c5 is "slammed" and it's so low the front spoiler scrapes all the time.

the zr-1 is not so low that I'm bottoming out, but if he helps with the shock travel and making the car less "boaty" over bumps, it would be worth it.

I also tried the DRM camber brackets, to be honest they made the problem worse.

bottom line, I think the c4 suspension is actually "pretty good" out of the box and coil overs are more for balls out racing and not so great on the street.

many will disagree of course, but the c5 was much more responsive and worked better with coil overs.

I've even considered switching back, but it's a big hassle putting the stock stuff back in and I'm going to play with tuning what I have a bit more before I throw in the towel.

[ZZZZZR1]

Tough call

I had my coil overs professionally installed and
when it was done I wasn't that impressed. I thought
the ride was harsh....

Took me a few months to get used to it and now
very happy with it. I did keep the FX3 shocks but
I don't have Moroccan valving. Thinking about
adding that but roads here suck!!


Just got back from almost 1k miles going to Canada
and back... LOVE THE COIL OVERS!! Many twistys
thru PA and with good tires, PERMAGRIN!

Yun. Your welcome to drive mine

:cheers:

David

[secondchance]

Ron, David,

Thanks for your offers - I'll take you up on it! Interested in variation if any.

[RHanselman]

I have two Z's with Coil Overs and a unmodified car as well. The Stock Ruby I drive all the time and she's a pleasure to drive around town. My Coil Over Ruby is another story. While a great car on the track she leave a little to be desired around town. She has a performance FX-3 computer and chip with the Morocco upgrade. She'll rattle your teeth on performance mode for sure... She also has a roll bar and x brace that stiffens the ride even more... Outstanding on the track but that's what it was built for. The wife will ride along but she doesn't much care for it.

My Turbo Car on the other hand is somewhere in between. I don't know what the spring rates are but I think Corey Henderson got it right. I'll have to ask if he remembers what he sold me. I actually installed them with Corey's help. Wasn't that bad at all. I believe Demps has some brackets that make the install even easier.

If I was starting out again and wasn't planning on tracking my car at a Spring Mountain or Miller Motorsport type track I'd just do a few minor upgrades. New Poly, new sway bar and maybe the Morocco FX-3 upgrade. I'd defiantly keep the stock springs...

One thing I've never heard of before riding in Roberts car is a mix of both. I believe he has coil overs on the front and the stock spring in the back. The car seemed to ride just fine...

Cheers,

[mike100]

...

One thing I've never heard of before riding in Roberts car is a mix of both. I believe he has coil overs on the front and the stock spring in the back. The car seemed to ride just fine...



I've been considering such a modification.

My FX3 shocks were revalved, but only a little bit more aggressive than stock. I already have a VB&P aftermarket rear spring so all that really needs to be done is to get a little more spring rate on the front to offset the weight of the LT5 block.
Another reason would be to regain a little bit of ride height (if at all possible to get full height on coilvers) since my front spring had the rubber bushings shaved and has those lowering wedges instead. I absolutely hate that because taking out the bushing material actually un-tensions the spring effectively lowering the spring rate.

[batchman]

I've been considering such a modification.

My FX3 shocks were revalved, but only a little bit more aggressive than stock. I already have a VB&P aftermarket rear spring so all that really needs to be done is to get a little more spring rate on the front to offset the weight of the LT5 block.
Another reason would be to regain a little bit of ride height (if at all possible to get full height on coilvers) since my front spring had the rubber bushings shaved and has those lowering wedges instead. I absolutely hate that because taking out the bushing material actually un-tensions the spring effectively lowering the spring rate.

Here's another possibility - it's what's on our car and it is not a bad street/handling compromise.

VB&P Sport front spring, I think ours is 770 lbs, with Bilstiens to match.
Hypercoil Rear Z51 spring, which I think is 375lbs, again Bilsteins to match. It's not enough for balls-out autocross but it did not kill the ride.

With the bolt kit in back and c5 style adjusters in front (available if you order the front spring that way) you're all adjustable.

I can't go coil-over due to class rules, but wouldn't in the rear anyway - I know everybody does it but I just can't get past putting all the force on a single-shear mount.

Cheers,
- Jeff

[rkreigh]

yes, the angle of the shocks, close clearances to the half shafts and single bolt "shear point" mount on the rear shock is a bit scarey

seems to be holding up well and I pound the car (and me) with runcrap EMT supercrud tires and 19 rims

not seeing any cracks yet.

might go back to a stock buggy spring eventually, but for now I'm content to just get better tires. car rides quite a bit better on the amolds, although the look of the ccw 505s is killer

first thing I'm going to try is rebuilding the shocks and raising the ride height up a bit. it's a bit too low in front and on really high speed dips I'm rubbing the tire on the inner fender

285/30/19s up front and in the weeds stance looks great, but not the best for the mean streets of DC

seems that as I put more miles on the car the shocks are freeing up too and the ride is a bit better. other odd thing is that with the top off and the R&D brace on it, I think the car rides better too. maybe just a bit more flex without being "floppy"

like to hear any tips you guys have to get the best of both worlds (handling and ride) which are typically a bit at odds

one thing for sure, the GM engineers are smarter than I am....:(

[Fully Vetted]

... I just can't get past putting all the force on a single-shear mount.

Bingo. That's why I haven't done it. That and I don't want to lose the ride quality. And since I don't track my car I think CO's are not the right choice for me.

We could always go the Brett Henderson route and just fill up the wheel well with the largest tire known to man that will fit :-D

[XfireZ51]

Originally Posted by batchman http://zr1.net/forum/images/buttons/viewpost.gif (http://zr1.net/forum/showthread.php?p=179511#post179511)
... I just can't get past putting all the force on a single-shear mount.


Has anyone run into this issue? This is the first concern I have heard of it.

[Daniel_Mc]

Originally Posted by batchman http://zr1.net/forum/images/buttons/viewpost.gif (http://zr1.net/forum/showthread.php?p=179511#post179511)
... I just can't get past putting all the force on a single-shear mount.


Has anyone run into this issue? This is the first concern I have heard of it.


I hear people talk about this all the time and have NEVER heard or seen an actual failure in this way. Now I have heard of the shafts on the rear shocks breaking where the shaft mounts to the frame on the Callaway coilover kits.

FWIW I have been running DRM coilovers for YEARS on our 89. This car is tracked in HPDE's and TT's 90% of the time and have zero issues.

-Daniel

[batchman]

Originally Posted by batchman http://zr1.net/forum/images/buttons/viewpost.gif (http://zr1.net/forum/showthread.php?p=179511#post179511)
... I just can't get past putting all the force on a single-shear mount.


Has anyone run into this issue? This is the first concern I have heard of it.

I have not seen an issue but haven't seen much real test of something done this way. As a guy who spends his free time with folks that beat the snot out of things it looks like a failure point to me. The mount is pretty stout so it may take a long time/big event but still, the middle or end of a lever is not a first choice to put all the load of a corner of a car. And that lever is seated in aluminum. It was designed for, and apparently sufficient for, damping forces - as the load path, not to my eye.

Your mileage may vary,
- Jeff

[batchman]

FWIW I have been running DRM coilovers for YEARS on our 89. This car is tracked in HPDE's and TT's 90% of the time and have zero issues.

Glad to hear. Continued good fortune to you,
- Jeff

[rkreigh]

I agree with you jeff, it's an area of concern and it just wasn't designed for this kind of pounding. I'm wondering about using the van steel mount with bilstein shocks. they sell it separately and it looks like it could help (but still just one bolt on the knuckle ear) so it's not a solution.

the shock towers in front are also a problem area. I talked at length with Dave M about this and he mentioned that even though it wasn't designed for coil overs, the stampings are beefy and although they might eventually stress crack, he hasn't seen the problem

honestly I'm more worried about the back. aluminum would be more likely to fail from the duty cycles

kinda like alum rods in a street motor, they let go in spectacular fashion!

so far, no worries. if anyone has the van steel setup and can measure the "gap" for the bottom shock mount please let me know.

looks like it's too narrow for the bilsteins, but it could likely be machined to open it up and make it work. machine work gets expensive in a hurry though!

[Daniel_Mc]

Just did a quick Google search here is an issue with the QA1's that I haven't heard of:

http://forums.corvetteforum.com/c6-corvette-general-discussion/2876399-qa1-coilovers.html

Also I was speaking to Randy at DRM years ago before I had gone coilovers and we were discussing any failures. He mentioned a C4 that had a high speed off at Sears point (I think if not then maybe the Silver State Classic) this happened in the late 90's, I believe, the vette had the DRM coilover set up on it and I believe he said the vette traveled something like 17 feet before coming back down on its suspension. The mounting points were fine the car on the other had did not look so good.

Here's some old pictues of the 89 despite the abuse over the years it is holding up great. The shocks have been rebuilt (from standard valving to Moracca).

http://carphotos.cardomain.com/ride_images/3/1903/721/29755360036_large.jpg

http://carphotos.cardomain.com/ride_images/3/1903/721/29755360069_large.jpg

http://carphotos.cardomain.com/ride_images/3/1903/721/29755360137_large.jpg

http://carphotos.cardomain.com/ride_images/3/1903/721/29755360088_large.jpg

[GOLDCYLON]

Question for you coil Over guys regarding spring rates? Been doing searches for a few days and found no good answer.

Been considering going to them so I can lower one to one and a half inches (lose the 4x4 look). I have lowered C4's in the past with the long bolt rear and cut rubbers front, while it looked great I did not like the effect on the ride and would not do this to my ZR-1. I see most use 425/275. Does lowering change this rate? if so would I need to go with a lower spring rate?
I do not want to lose the ride I have now would like a rate that will maintain the stock ride or no stiffer than a 96 Z51 (have a 96 LT4/Z51 and its not to bad at all) when ride control is set to performance. car will only be used for lots of road trips. tell me your thoughts on how the ride changed if any and what rates you went with. And yes I'm getting to old to bounce my kidneys all day ..LOL

Thanks Steve


Been there done that.

http://www.zr1.net/forum/showthread.php?t=11907&highlight=Coilovers+wait

That is the best spring rate. Best way to lower the car or adjust height in general. Best way to adjust ride height of your car San front and rear springs. Suggest poly to include Banski heim joints with covers for the rear trailing arms/ (dog bones) GC

This is my daily driver and one of my best mods to date