Replacement bushings for Z32 rear uprights?

[underground57]

I've got a set of Z32 uprights waiting to go on, but as I was cleaning them up, I noticed that the stock bushings have had better days. Anyone know if someone makes urethane replacement bushings for them?

[SPIRONIUM]

splparts.com has metal spherical bushing inserts for em, these are the way to go, and may also be the only option you have anyway for the Z32 uprights.

Urethane bushings generally do not have enough torsional movement for use in the suspension of a car, unless you plan on greasing the bushings often, then try to avoid urethane all together.

[underground57]

Thanks. I checked their site first, but I guess I didn't look hard enough. Those solid spherical bushings will do. I wasn't looking specifically for urethane, but rather anything stiffer than oem rubber.

[gordonliu]

i hate to dig this thread up but i had a question about the different bushings

spl sells solid spherical bearing bushings and nismo high durometer bushings

for a lets say 30% street 70% track car, are solid spherical bushings going to kill me? (in terms of wear and ride discomfort)

[SPIRONIUM]

if you have all spherical bushings on your car, the ride feels the same as raising tire pressure all around by 5psi according to this chassis tuning book by henry something or other. Try that and see how you like it

[gumby74]

I am curios, where did this information on urethane bushings come from?

[SPIRONIUM]

the same book i mentioned above /\ search on other 240 forums and google for info as well

[Nismo_Freak]

if you have all spherical bushings on your car, the ride feels the same as raising tire pressure all around by 5psi according to this chassis tuning book by henry something or other. Try that and see how you like it

That's a poor assumption.

Spherical joints reduce wheel rate by removing rubber / urethane bushing bind from the effective motion. In that regard they improve ride quality.

The only noticeable effect from spherical joints is the lateral movement the car gets over bumps, ruts, and other irregularities. This is greatly dampened by stock subframe bushings, but if you have aluminum bushings you will pick up some rear walk.

The bushings you are referring to will make no noticeable change to ride quality with the exception of the lower shock mount bushing. You will involve the shock's high speed valving at a faster rate with less bushing deflection. If you have a high gas pressure in the shock then it can get bumpy. Otherwise it's an unsprung vs. wheel rate vs. dampening question.

[SPIRONIUM]

read the book Chassis Engineering, by Herb Adams.

This dude began his autmotive engineering career in 1957 and is still active today in NC. He has served as an engineering consultant for Goodyear, Pontiac, Oldsmobile, Koni, and other non automotive companys. He has also built numerous race cars for himself and with his company VSE who specializes in the handling aspect of race cars.

Needless to say, my claim was his assumption, i'm no engineer!

edit: PAGE 24: "I have found that nylon and spherical bushings will usually increase the impact harshness to the same degree as adding 5psi to your car's tire pressure."

[Nismo_Freak]

read the book Chassis Engineering, by Herb Adams.

This dude began his autmotive engineering career in 1957 and is still active today in NC. He has served as an engineering consultant for Goodyear, Pontiac, Oldsmobile, Koni, and other non automotive companys. He has also built numerous race cars for himself and with his company VSE who specializes in the handling aspect of race cars.

Needless to say, my claim was his assumption, i'm no engineer!

edit: PAGE 24: "I have found that nylon and spherical bushings will usually increase the impact harshness to the same degree as adding 5psi to your car's tire pressure."

I'm sure he's a great guy, but I can tell you that a completely solid rear suspension is not like driving with 5 PSI more air pressure in the 240SX.

[SPIRONIUM]

The point is not that he is a great guy, the point is that he is smarter than me and you combined when it comes to automotive engineering and suspension tuning. Even if you had an engineering degree.. i personally don't.

But i will say that his claim is obviously generalized, and probably an average.

[Nismo_Freak]

The point is not that he is a great guy, the point is that he is smarter than me and you combined when it comes to automotive engineering and suspension tuning. Even if you had an engineering degree.. i personally don't.

But i will say that his claim is obviously generalized, and probably an average.

Milliken & Milliken argue against his logic, and so does my applicable experience.