Expectations versus reality

[mgood]

ksechler,

I have 1976 280 and am the original owner and like you have only driven my car.

My car does not smell at all, you need the weather strips in the back hatch area and also good rubber seals around the tail light.

My car is not loud, I have a normal muffler on it, I have only the stock sound proofing..  The car does get hot inside because the exaust pipe runs along the trans tunnel under the driver.

I have 205 - 60 - 14 tires and they are simi hard to turn and very low speeds, at speed not a problem.

[87mj]

Regarding the steering, I read an article from road and track about the new 280z when it was first introduced.  I believe they mentioned the steering was heavy compared to the earlier models.  This was caused by the additional 500lbs or so on the new 280z.  In the article, they felt it was time for power steering. 

Regarding the ride, I have an old 240 and it is stiff and loud.  I have always wondered what the impact of running low profile tires has on ride quality. I assume it would make it worse.

Edited February 21, 2017 by 87mj
typos

[Jaymanbikes]

On ‎2‎/‎18‎/‎2017 at 10:32 PM, Zed Head said:

Howdy folks.  A materials person here.  Don't overlook that "PU" covers a huuuuuuugge range of physical properties, from goo to rock-hard.

These guys seem to have addressed the issue.  Don't know if they got it right or not, but they are aware.  https://whiteheadperformance.com/product/whiteline-differential-moustache-bar-bushing-kit-w91045-datsun-240z-260z-280z/  If I had the free cash I'd try a set just to see what they ended up with.

I reduced the diff warbling with my PU bushings significantly by extending the length of the inner sleeve for the mustache bar mount.  For whatever reason, many PU mustache bar bushings have a shorter inner metal sleeve than the PU bushing, which compresses the PU  against the washers, creating a solid path to the cabin for the diff noise.  I used washers to extend the sleeve.  Many of the aftermarket parts out there require a little bit of finishing work, in my opinion, to get them how you like them.

I rebuilt my entire suspension with one of the Poly kits, I also lowered the car a bit with lowering springs.  The ride result is pretty harsh, but I expected it.  The one thing that however seems extremely harsh is the noise apparently coming from the mustache bar and so I would like to address this.  This noise is especially evident on short sharp bumps, small holes etc..  I have a spare mustache bar and was going to install a NOS set  of Nissan isolators.  I have since decided to try the White Head isolators with lower durometer.   Probably could have just drilled the harder bushings a bit to soften them as I did with the TC rods up front.

Edited February 21, 2017 by Jaymanbikes

[siteunseen]

I used poly and rubber backs on the t/c rods after reading about them breaking from full poly.  Never thought of softening them with small holes.

That could be the solution for the poly steering rod coupler that is so hard and causes a twitchy steering wheel.  The OE rubber ones are NLA.

Good thinking!  Did you just drill 1/16, or close, holes around the outer part of the t/c bushings?

[Jaymanbikes]

4 minutes ago, siteunseen said:

I used poly and rubber backs on the t/c rods after reading about them breaking from full poly.  Never thought of softening them with small holes.

That could be the solution for the poly steering rod coupler that is so hard and causes a twitchy steering wheel.  The OE rubber ones are NLA.

Good thinking!  Did you just drill 1/16, or close, holes around the outer part of the t/c bushings?

Exactly

[Zed Head]

3 hours ago, Jaymanbikes said:

 one thing that however seems extremely harsh is the noise apparently coming from the mustache bar and so I would like to address this.  This noise is especially evident on short sharp bumps, small holes etc..  I have a spare mustache bar and was going to install a NOS set  of Nissan isolators.  I have since decided to try the White Head isolators with lower durometer.  

The mustache bar bushings are known for transmitting gear noise from the diff in to the body and cabin.  Usually noticed on the highway when cruising along.  Or they're noted for being loose and letting the diff move when shifting, causing a thump.  Not really known for bump noises.  You might be looking at the wrong area.

[Jaymanbikes]

8 minutes ago, Zed Head said:

The mustache bar bushings are known for transmitting gear noise from the diff in to the body and cabin.  Usually noticed on the highway when cruising along.  Or they're noted for being loose and letting the diff move when shifting, causing a thump.  Not really known for bump noises.  You might be looking at the wrong area.

Good to know, I definitely have some of that going on as well although I rarely get the car past 60mph for any distance or on a highway.   Might be I just have something lose that is causing the noise.  Plan on checking everything out when I swap the spare bar.

[Zed Head]

You haven't really described the "noise", beyond noise.  Just saying...

[Jaymanbikes]

2 minutes ago, Zed Head said:

You haven't really described the "noise", beyond noise.  Just saying...

Hard to describe in words.  Lets say its a clunk.....

[Dave WM]

does the clunk happen on down shift or up shift? typical clunk sound as drive train is loaded and un loaded is u joints in drive shaft.  I read that the diff of a z can rise up in  the front as well if mounts are bad (down shift I think), making a clunk sound. Seems best thing to do would be get it on a lift and look for worn parts in drive line and mounts.

[Jaymanbikes]

1 minute ago, Dave WM said:

does the clunk happen on down shift or up shift? typical clunk sound as drive train is loaded and un loaded is u joints in drive shaft.  I read that the diff of a z can rise up in  the front as well if mounts are bad (down shift I think), making a clunk sound. Seems best thing to do would be get it on a lift and look for worn parts in drive line and mounts.

No, drive line is nice and tight, diff and trans isolators are also new.   Clunking happens on sharp sudden bumps, more prevalent when the car has less weight (fuel or another person)