Ride and suspension questions

[secondchance]

Originally Posted by 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.

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]

Originally Posted by secondchance

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]

Originally Posted by 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?

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.

[GOLDCYLON]

Originally Posted by HAWAIIZR-1

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.

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]

Originally Posted by GOLDCYLON

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]

Originally Posted by 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.

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.

[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....

Tom

[HAWAIIZR-1]

Originally Posted by 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....

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