Ride and suspension questions

[HAWAIIZR-1]

As some may know, during my rebuild I replaced every suspension bushing with poly. The only other things were the rear bolts to lower the back about 1/4" and new front stock shocks (I have new rear shocks, but did not have time to replace).

So after I finally got the Z running and before shipping I put about 200 miles on it. It rode really bumpy and was bouncing all over the place in my opinion. I know I have not driven it for a long time, but it definitely felt like something is not right. I understand that polys will not give like rubber bushing, but did not think it would bounce around like it does and seems more like shocks or binding of suspension parts.

When jacking up under control arms, etc. it seems to move freely.

Any ideas of what to check once I meet up with the Z again?

If anyone has done a total replacement of bushings and can share their input about their experience it would be great? I think it was Rich that might have done a replacement like this with stock shocks.

I wish I could describe it better, but other than saying that even on the freeway it felt like it was bouncing at the slightest dips and bumps. I could not see it, but if you can imagine it following a car that is bouncing like the idiots that cut springs to lower their cars. My Z is stock height other than the very slight lowering of the rear, but still keeping the front lower. It was aligned after the replacement of all the parts.

Thanks!

Craig

[Pete]

I have done poly bushings thru-out my Z.
Feels less bouncy on bumps,a bit firm but not as bad as i thought.
It freshened up the old rubber.

I give it a thumbs up.
With coil overs the car just feels great, it should have been like this from the factory.

I use 400/250 springs.

Some people don't like coil overs,i would not do it any other way.
Pete

[HAWAIIZR-1]

I have done poly bushings thru-out my Z.
Feels less bouncy on bumps,a bit firm but not as bad as i thought.
It freshened up the old rubber.

I give it a thumbs up.
With coil overs the car just feels great, it should have been like this from the factory.

I use 400/250 springs.

Some people don't like coil overs,i would not do it any other way.
Pete

Pete,

Thanks for your input and I too like how it feels other than the bouncing that I would like to resolve. Not sure if the new shocks need to break in, but it feels like bounce is front and rear.

I like the thought of going coilovers and even David mentioned how much he loves them as well as Daryll. I guess that will be the next project with some brake upgrades whoa the new found power I have.

[Pete]

Have you done the Moroca valving on the shocks?

I have stock valved shocks,i have driven a Z with Moroca too firm for me.

I don't know what you mean front/rear bounce do you mean it feels like a go cart.

Pete

[HAWAIIZR-1]

Have you done the Moroca valving on the shocks?

I have stock valved shocks,i have driven a Z with Moroca too firm for me.

I don't know what you mean front/rear bounce do you mean it feels like a go cart.

Pete

Pete,

No valving done and just new stock shocks on the front. The rear as original I think with 53K miles.

Yes, it feels like you are bouncing and kind of like riding a go cart. I wondered if not enough play in the bushings for sway bar poly bushings and too tight for the size bars if the binding will cause this bouncing?

I measured the bar (don't remember right now the size) and bought the appropriate bushings to match (DRMs).

Thanks!

[Pete]

Pete,

No valving done and just new stock shocks on the front. The rear as original I think with 53K miles.

Yes, it feels like you are bouncing and kind of like riding a go cart. I wondered if not enough play in the bushings for sway bar poly bushings and too tight for the size bars if the binding will cause this bouncing?

I measured the bar (don't remember right now the size) and bought the appropriate bushings to match (DRMs).

Thanks!


Mine does he same i don't know if it's bushing or too tight.

Some don't like this.

Pete

[VetteMed]

Just a thought, forgive me if I'm stating the obvious, but if the nuts are torqued with no load on the suspension (wheels hanging), that can adversely affect the bushing function.

[Pete]

Just a thought, forgive me if I'm stating the obvious, but if the nuts are torqued with no load on the suspension (wheels hanging), that can adversely affect the bushing function.


Most all bushing have matel sleeve in the middle so you tighten up the sleeve when tightening the nuts.

I would suggest doing this on a drive up lift.
With my two post i use a screw type jack.
Pete

[lbszr]

I've only changed the control arms with polys on the front. Sway bar is still stock, but it does'nt have a bounce.

If your control arms moved kind of freely by hand before connecting the spring and steering knuckle, I wouldn't think that's the problem. I have heard of the polys too tight on the sway bar causing oversteer or understeer, not really a bounce though. You could take the front links off and give it a try to see if it's the bar.

Don't ask me how I know....but if someone were to jump up down on the engine of mine(and no I wasn't mad at it either and a bath towel protects the plenum good), it moves about 1 to 2 inches. It may not of moved that much when the polys were new though. It had a more solid feeling when the control arm bushings where new when going over bumps.

Can you feel a difference with the FX3 settings?
Could try putting old shocks back on. Maybe they messed the valveing up.

I don't know bout the rear. Have heard some complaints polys make too much friction in the rear because the dogbones bind when they
don't move in a straight line since camber changes as the wheel goes up and down. The Banski dog bones are suppose to take care of that.

Can you bounce the back of the car an inch or so? Hope some of this might help.

[HAWAIIZR-1]

Guys,

Thanks for all the thoughts and ideas that I will address when I meet up with it next month. I did try to bounce the rear and there is no give (not an inch anyway) so I'll do some checking and as mentioned if I can get it on a lift it would be good too. I will also try to meet up with one of the Z brothers there and do some comparisons. Everything was very tight with the polys for sure and I should have done more checking for binding upon assembly.

[secondchance]

Guys,

Thanks for all the thoughts and ideas that I will address when I meet up with it next month. I did try to bounce the rear and there is no give (not an inch anyway) so I'll do some checking and as mentioned if I can get it on a lift it would be good too. I will also try to meet up with one of the Z brothers there and do some comparisons. Everything was very tight with the polys for sure and I should have done more checking for binding upon assembly.

Hi, Craig,

Glad to hear all is well.
Jim and I have replaced rear bushings with poly versions. In my case those were four dog bone bushings (trailing arms), struts (the member w/ camber adjustment under the diff) and shock uppers.
Make the long story short, after the work backg off the Jim's lift ramp , as the rear whels hit the draive way we both heard a distint snap one time and figured out it was poly binding unloading as the rear went into compression hitting the driveway.
Then I realized combination of different material (rubber originally) resulted in different pivot location. Factory rubber bushings looked like they were bonded to inside of the barrel and, like one of the post, pivot seemed to be between the bolt and the metal sleeve inside the rubber bushing. For the poly, pivot actually occurs between poly outer and inside barrel of aluminum extrusions. I ended up removing dogbones and structs and re-applying thick layer of sillicone grease (I bought an extra jar of this stuff. What comes in the package just wasn't enough) and reinstalling.
I hope sharing my experience helps.

[HAWAIIZR-1]

Hi, Craig,

Glad to hear all is well.
Jim and I have replaced rear bushings with poly versions. In my case those were four dog bone bushings (trailing arms), struts (the member w/ camber adjustment under the diff) and shock uppers.
Make the long story short, after the work backg off the Jim's lift ramp , as the rear whels hit the draive way we both heard a distint snap one time and figured out it was poly binding unloading as the rear went into compression hitting the driveway.
Then I realized combination of different material (rubber originally) resulted in different pivot location. Factory rubber bushings looked like they were bonded to inside of the barrel and, like one of the post, pivot seemed to be between the bolt and the metal sleeve inside the rubber bushing. For the poly, pivot actually occurs between poly outer and inside barrel of aluminum extrusions. I ended up removing dogbones and structs and re-applying thick layer of sillicone grease (I bought an extra jar of this stuff. What comes in the package just wasn't enough) and reinstalling.
I hope sharing my experience helps.

Thanks Yun, I really appreciate the info and your thoughts. I'll check it out when the Z gets here next month and see what the heck is going on. One thing I am considering is the rear shocks are crap. I made the mistake of hanging them for years with the suspension in the air the whole time and had intentions of replacing so did not care. I was reading where people have had the same issue so I will try to replace those since I was going to anyway to see if that helps and at the same time check for binding while I'm at it. I thought I put enough of the grease, but did not confirm and those polys are very tight either way.

Thanks again and take care.

[GOLDCYLON]

Reading this on the rear shocks Craig (Hanging in the air) yeah it maybe time to replace those. I do not suggest the morocca valving unless you are planning on x-crossing the car. I also ditched the rear trailing arms (Dog bones) for the Banski Heim Traing arms. A hell of an improvement. When I went to coil overs we had to use a Guldstrand front sway bar relocator set up. If I remember the poly bushing were too "FAT" and had to be ground down a little for freedom of movement. Im wondering if your issue up front is binding causing a dampening or bouncing response?

[HAWAIIZR-1]

Reading this on the rear shocks Craig (Hanging in the air) yeah it maybe time to replace those. I do not suggest the morocca valving unless you are planning on x-crossing the car. I also ditched the rear trailing arms (Dog bones) for the Banski Heim Traing arms. A hell of an improvement. When I went to coil overs we had to use a Guldstrand front sway bar relocator set up. If I remember the poly bushing were too "FAT" and had to be ground down a little for freedom of movement. Im wondering if your issue up front is binding causing a dampening or bouncing response?

I have just stock replacement FX3 shocks and plan to keep it that way unless I end up going with coilovers someday. I like those Banski arms and might consider that too. I really do think the swaybar bushings could have something to do with it even though I purchased the correct size for the bars I have, it seemed tight and it makes sense that it could affect the bouncing being experienced. Thanks for your input and for sharing your experience. :cheers:

[GOLDCYLON]

I have just stock replacement FX3 shocks and plan to keep it that way unless I end up going with coilovers someday. I like those Banski arms and might consider that too. I really do think the swaybar bushings could have something to do with it even though I purchased the correct size for the bars I have, it seemed tight and it makes sense that it could affect the bouncing being experienced. Thanks for your input and for sharing your experience. :cheers:


No sweat yep I bought the right size as well but for some reason they needed to go on the Weight Control Program lol. The trailing arm mod is really some thing you have to consider if you go to coil overs as the rear dog bones would need to be shaved as well to allow for clearance. It gets a little tight in there with the hypercoil springs in the way. Carters rear adaptor plate may have solved this problem but I am not sure as he didnt finsh in time for my project. Mine (rears) were installed the old school way by notching forward in order to allow the top hats freedom to clear. BTW Craig glad to hear you are all right.

[HAWAIIZR-1]

No sweat yep I bought the right size as well but for some reason they needed to go on the Weight Control Program lol. The trailing arm mod is really some thing you have to consider if you go to coil overs as the rear dog bones would need to be shaved as well to allow for clearance. It gets a little tight in there with the hypercoil springs in the way. Carters rear adaptor plate may have solved this problem but I am not sure as he didnt finsh in time for my project. Mine (rears) were installed the old school way by notching forward in order to allow the top hats freedom to clear. BTW Craig glad to hear you are all right.

Thanks again for the input and thoughts; I have a few things to consider and will try to resolve it.

[rhipsher]

I did a complete poly rebushing with the Prothane kit of the entire car front to back. I absolutely loveit love it love it. It is a stiffer ride. But not a bouncy springy feeling ride at all. Its a more planted feel with much less body roll around corners. Im not even running the Bilstiens. Im running KYB's which is nothing special. Bilsteins and actuators are in a box.

[HAWAIIZR-1]

I did a complete poly rebushing with the Prothane kit of the entire car front to back. I absolutely loveit love it love it. It is a stiffer ride. But not a bouncy springy feeling ride at all. Its a more planted feel with much less body roll around corners. Im not even running the Bilstiens. Im running KYB's which is nothing special. Bilsteins and actuators are in a box.

Thanks. I really value your input and should have just asked you direct. I remember that you did this a few years ago. Sounds great and I should have went that route too with just KYBs or otherwise. I thought the polys should not have anything to do with the ride so much unless I have so binding that I will confirm. :cheers:

[tomtom72]

Craig, I put a poly sway bar kit, ends & frame mounts, in my car when I replaced the A-arms with NOS units. The result was more energy transmitted to the frame because the poly bushings do little to absorb any road harshness.

The first thing I noticed when I drove it is yes the response is crisp, but the bad roads where I live are coming thru the chassis more. It feels like it darts and it feels like it bounces the whole car more. When I get to smooth road it feels great & steering response is precise. However there is still a go kart bounce & harshness that I can feel. The issue is that the poly does nothing to absorb it is too rigid so it transmits...Dave McLellan talks about this in the suspension/chassis chapter in his book. That's why it's not OEM.

Any rigid ( or more rigid ) bushing system will transmit energy to the chassis with a negative effect on ride and it will require more work from the driver to pay attention. The rubber absorbs most of the junk that would make us have to concentrate more on what the car is responding to...the extra energy input. That bit I got from the guys at VB&P when I inquired about their heim jointed suspension parts. This is also consistent with what Dave says in his book.

just my two cents....
:cheers:
Tom

[HAWAIIZR-1]

Craig, I put a poly sway bar kit, ends & frame mounts, in my car when I replaced the A-arms with NOS units. The result was more energy transmitted to the frame because the poly bushings do little to absorb any road harshness.

The first thing I noticed when I drove it is yes the response is crisp, but the bad roads where I live are coming thru the chassis more. It feels like it darts and it feels like it bounces the whole car more. When I get to smooth road it feels great & steering response is precise. However there is still a go kart bounce & harshness that I can feel. The issue is that the poly does nothing to absorb it is too rigid so it transmits...Dave McLellan talks about this in the suspension/chassis chapter in his book. That's why it's not OEM.

Any rigid ( or more rigid ) bushing system will transmit energy to the chassis with a negative effect on ride and it will require more work from the driver to pay attention. The rubber absorbs most of the junk that would make us have to concentrate more on what the car is responding to...the extra energy input. That bit I got from the guys at VB&P when I inquired about their heim jointed suspension parts. This is also consistent with what Dave says in his book.

just my two cents....
:cheers:
Tom

Tom,

Thanks for taking the time to share your experience. Gosh, I hate to think what I am experiencing is normal when doing the poly bushings mod. I'll check it all out when it arrives and maybe on the better roads here in Japan it won't seem so bad. It does handle and feel much better for sure and no regrets about that part. I knew I would be giving up comfort and just hope parts don't start falling off the Z since it seems to rattle much more now too.

Take care,

Craig

[Locobob]

Guys,

Thanks for all the thoughts and ideas that I will address when I meet up with it next month. I did try to bounce the rear and there is no give (not an inch anyway) so I'll do some checking and as mentioned if I can get it on a lift it would be good too. I will also try to meet up with one of the Z brothers there and do some comparisons. Everything was very tight with the polys for sure and I should have done more checking for binding upon assembly.

Hmmm, did you put the rear sway bar on backwards? I did that once and had similar symptoms.

[HAWAIIZR-1]

Hmmm, did you put the rear sway bar on backwards? I did that once and had similar symptoms.

Thanks, I will check that out and did not even think or know that it was possible. Once I get the car in the next two weeks I'll check this out. :cheers:

[Locobob]

Thanks, I will check that out and did not even think or know that it was possible. Once I get the car in the next two weeks I'll check this out. :cheers:

Yep it's quite easy to do if you're not paying attention. The car will feel like it's all bound up and ride like crap with the bar upside-down.

[HAWAIIZR-1]

Yep it's quite easy to do if you're not paying attention. The car will feel like it's all bound up and ride like crap with the bar upside-down.

Okay, that will make me feel like a putz alright. If anyone has a photo of a correctly installed rear sway bar that will be good?

Thanks for sharing Robert!:handshak: