S130 Suspension Tech

[boostless]

how many people have sectioned their struts? I'm asking because the more I'm reading into it the more I get confused. My main questions about it are what struts are you using and what coil over sleeves/springs are you using? What I'm looking at is having my car lowered a few inches, a little more than springs will allow, and I don't want to mess anything up to badly. The car is going to be a street driven car for the forseeable future.

[PurePontiacKid]

you can go about 3" lower on 280ZX struts without having to worry about bottoming out on the strut itself. the hard part would be finding decent shocks that fit in stock length housings.

 

Some guys use MR2 Tokico shocks, although I don't really know how much shorter those are than 280ZX inserts.

 

there's a really nice thread or two about this on ratsun.net, where alot of 510 guys use 280ZX struts, section them, then go real low with their dimes

 

for springs and whatnot, either get some cheapo coilover springs and sleeves for like $80 which should be in the area of like 400-500lb/in springs, or you could get Ground Control coilovers and have them be in the area of 250-300lb/in springs.

 

it all depends on the ride quality you're looking for.

Edited November 15, 2010 by PurePontiacKid

[m1ghtymaxXx]

Been forever since I logged in, but perhaps my summer S13 coilover swap could be useful here: http://forums.hybridz.org/index.php/topic/94002-how-to-install-s13-coilovers-on-280zx-and-poly-bushings/page__gopid__911707#entry911707

[PurePontiacKid]

So, there was a lot of talk about it, but has anyone besides me ever actually attempted large amounts of camber correction on the rear suspension? Just would like to see other people's viewpoints on the subject.

 

 

I've pulled ~5* camber out.

 

started with -6*, I'm currently at -1.5* (had the car aligned, it's solid) and I can easily got to zero camber or even slightly positive if my wheels could fit.

 

downside is that I have no bushings in my rear suspension whatsoever now lol (heim ends on control arms, aluminum bushings in subframe, and solid diff mount)

[BluDestiny]

Pics of you're heim control arms sir.

 

Also what about you're toe problem? Did the heim joints solve that too?

[PurePontiacKid]

heims actually over-corrected toe-issue, I've got a bunch of toe-out now, but it is able to be adjusted out. Only problem is my dumb wheels now, adjusting toe affects my fitment, and going to 0-toe puts the tire well against the fender, even with a pretty gnarly fender pull, so I just deal with the toe for now lol

 

I don't have any actual pics of the control arms by themselves before I put them in, but I will get some with everything under the car by this weekend hopefully.

 

I've also done some pretty extensive work to the front suspension, as well. And doing more very soon, just picked up a '83 power rack I'm going to de-power and do some other tricks with.

[BluDestiny]

Does that power rack have more motion than the manual?

[PurePontiacKid]

power rack has a SLIGHTLY quicker ratio (3.2 turns lock to lock vs 3.5) and also allows me to use regular S13/S14/Z33 inner/outer tie rods and rack spacers to gain further steering angle. (I've also go modded knuckles now)

 

I also found a rough pic of what I have done to my rear control arms with the heim ends:

 

Basically what I did was offset the heims to make for less camber. the welding rod is a rough estimate of where the centerline of the bushings used to be.

[BluDestiny]

Ok so you actually corrected the camber by welding the centerline of the joint different.

 

At first I thought you just raised the outside joint, but I see you offset both. Inside high and outside low right?

 

Did you leave it like that or grind down the half cut old bushing holders?

 

Edit: also are you still using your slotted subframe or did you just get another?

Edited August 14, 2012 by BluDestiny

[PurePontiacKid]

I cut all the rest of the redundant bushing sleeve **** out just for appearances sake.

 

I think I welded the heim onto the outer end high, and the innner one lower, but I can't remember. common sense dictates which direction to go with the heims lol

 

I am still using my slotted crossmember, with a further lowered mounting point, all the way negative currently. With a slotted-from-stock-position crossmember, I'd be at full negative camber, which is still reasonable at -1.5*.

[mikeatrpi]

Hey all... I'm going to bump this back up with a question about the subframe bushings.  I have some Z31 prothane poly bushings that I'm going to machine down to fit the 280zx subframe - like this guy did, but on a lathe instead of using an angle grinder:

 

http://www.zdriver.com/forums/280zx-brakes-wheels-suspension-chassis-81/polyurethane-subframe-bushings-maybe-19834/

 

Rough measurements, the OD of the poly is 3.016" and the ID of the subframe with the sleeves removed is 2.341".  Roughly.  I used a set of cheap calipers, I don't have a micrometer!  So I have to cut about .700 total.  This part seems straightforward.

 

Now on the ID of the metal sleeve that goes inside the bushing - I measure 0.861".  The OD of the subframe bolt, at the widest hump, is 0.794".  For comparison, the ID of the stock bushing was 0.836".  What should I do here?  JeffP (http://www.angelfire.com/extreme/280zxt/page17.html) got some 14mm bolts and sized the ID of his custom stainless steel bushings to fit.  If I buy 14mm bolts like Jeff did, should I replace the metal sleeves that came in the Prothane kit and machine my own to fit?  How tight of a tolerance is good?  Should I stick with the stock bolts and machine a replacement sleeve with tighter fit?  I assume the hump is there for a reason - to allow it to rock up and down a little bit?  Is that really desirable?  If I machine my own - Aluminum?  Mild Steel?  My machine is feeble - I probably can't cut stainless.  

 

And about the height - the part that matters seems to be approx 1.600", and that correlates closely - new bushings to subframe.  But the z31 subframe bushings have a thick upper and lower part - I have to take some measurements, but does anyone know if that should be cut - face cut - down?  

 

Thanks for any tips.  That's a lotta questions!

[260DET]

This posted before? Anyway if anyone wants to get serious with the rear suspension then have a look at what BMW did with the E30 which has semi trailing arm rear suspension. This is the way I would go   http://www.e30m3project.com/e30m3performance/tech_articles/susp-tech/rear_curves/

[Doc_S130]

Read this entire 9 page thread but can't find an answer to this specific question:

 

Will s30 280z coilovers (like bc makes) bolt up to the s130 rear and weld right into the front of the s130, as opposed to modifying s13 fronts? Thinking that may be an easy alternative.

 

Edit: never mind. I see the 280z is weld in for the rear too. Won't work.

Edited February 24, 2015 by Doc_S130

[Doc_S130]

And for what it's worth, Altima coilovers also look like a close fit, the front doesn't have the knuckle tabs and the rear is 2 bolt uppers.

 

http://loweringspringkits.com/shop/nissan-altima-sedan-2007-2012/bc-racing-br-type-coilover-2007-2012-nissan-altima-sedan-l32/

Edited February 24, 2015 by Doc_S130

[JMortensen]

Hey 280ZX guys, just found something really really cool on another site. This is an Aussie Bluebird race car from the 80s. They cut off part of the semi-trailing arm and then make a bracket that bolted to the back of the diff cover and used it to make a couple of control arms, basically turning the semi-trailing arm into an upper and lower arm with a trailing link. 

http://www.performancegarage.com.au/blog/group-c-bluebird-turbo-vid

 

Edited December 7, 2016 by JMortensen

[260DET]

Wow that is interesting Jon, how did you find that? Lols aside, for a road car working the stock setup is the way to go. That may sound simple but for a start there is virtually no aftermarket support so it's either capable DIY or whatever assistance is available to you. If you want current chassis dynamics then there are plenty of off the self solutions  involving modern cars, otherwise with the Z replacing all the suspension consumables is a good start, these things handled pretty well back in the day, modern tyres and suspension bushes take that further.

 

As for the Bluebird trailing arm twin lateral links suspension, I'm going to give it a go just for the challenge and because race car and because well thought through stuff sometimes works in the real world. BMW used that suspension type on a couple of models, E38? Something like that.

Edited December 30, 2016 by 260DET

[JMortensen]

Found it on another forum where they were looking at different suspension setups for an AWD V8 swapped XR4Ti. http://www.corner-carvers.com/forums/showthread.php?t=49547

 

Definitely a DIY thing, and also won't eliminate the toe change, although there was some back and forth as to exactly what the difference would be. 

[260DET]

Hmmmm, it could be a coincidence of course Jon but it looks like someone may have 'borrowed' from a pretty extensive suspension discussion on Ozdat including the Bluebird suspension, hence my query. No real problem but one of the reasons for putting different ideas out there is to get some constructive comment, at least one fellow in that forum you linked did acknowledge Ozdat which is good.

 

I'm not a suspension guru but I know what I like when driving, one rear suspension characteristic I like for a powerful rear driver is some dynamic toe in the corners. So I find it strange when people talk about dynamic toe as undesirable.

[260DET]

Link to the Ozdat thread http://ozdat.com/forum/viewtopic.php?f=30&t=10296

[JMortensen]

I'm not a suspension guru but I know what I like when driving, one rear suspension characteristic I like for a powerful rear driver is some dynamic toe in the corners. So I find it strange when people talk about dynamic toe as undesirable.

I'm not a suspension guru either, but I think I have a pretty decent handle on this subject: dynamic toe change is bumpsteer. Do you prefer bump steer in the front? I know John Coffey talked about running different spacers left and right on some tracks to get better dynamic toe out of one side for tracks that had a lot more right turns than lefts, etc, but for the most part the consensus amongst racers is that less bumpsteer is better, and if you want to change direction of the wheels, you do that by inputs on the steering wheel. There are some pretty sophisticated link setups out there that feature dynamic toe changes, but the idea for me is that I don't want the toe changing without any input from the driver. 

 

What's a bigger sin IMO is using huge squishy bushings that allow toe change. Either way, bumpsteer on either end essentially causes hysteresis: the toe changes due to compression or droop of the suspension, which forces a change in the traction at the contact patch (can't steer the tire around without changing its available traction), the changing toe has an effect on g forces which causes the body to bob back and forth, which changes the compression of the shock, which adds more toe change, wash, rinse, repeat. I had my Z in a pretty bad part of the bumpsteer curve in the front end for a while and I would go through a sweeper and experience this firsthand. The car would roll, steering angle would change to keep the car pointed in a straight line, then it would come back, steering changed again, then it would roll more, etc. One of the most noticeable improvements I found after minimizing bumpsteer in the front was that I wasn't constanty sawing at the wheel on sweepers to keep the car moving in a consistent arc. The more bumpy the turn, the worse the effect. A car with less bumpsteer on either end of the car should tend to be more stable, and I think you can show this tendency in semi-trailing arm setups by watching older 911s spin at track days. I used to go to Porsche HPDEs when I was working for a Porsche shop 20 years ago, and I saw that phenomenon in person more than a few times, exacerbated by the rear weight bias no doubt. 

 

Don't get me wrong, as you've said so many times, there are plenty of fast race cars with semi-trailing suspensions, and having dynamic toe change doesn't mean a car can't be fast, but reversing the logic that dynamic toe on a fast car proves that dynamic toe is good or desirable doesn't work IMO.