Is a rear swaybar required??

[benny]

Hey Guys,

 

My 72' 240 didn't come with one when i bought it, did it have one from factory and is it required??

 

Ben

[Riceburner]

They didn't come with them, not essential but I found it helped handling. I still run a standard size on the Ricey, too big/stiff and then you get oversteer.

[Zedman240®]

If you have a too large front and big rear sway bar, on my 240Z it suffered from snap oversteer; everything is fine then you find yourself facing oncoming traffic in a blink of an eye. I disconnected my rear bar, now there is only a hint of understeer. 

[NZeder]

I do question why people want to run a rear swaybar on the rear of a car with IRS - yes a small item if you don't want to run heavier springs. But no sway bar and heavier springs with the correct damper/rebound setting is a better solution for controlling an IRS setup IMHO. And this is backed up by the feed back from Zedman240z

If you have a too large front and big rear sway bar, on my 240Z it suffered from snap oversteer; everything is fine then you find yourself facing oncoming traffic in a blink of an eye. I disconnected my rear, now there is only a hint of understeer. 

Why people want to add a bar and make a kind of live axles is beyond me - why have a car with IRS at all then. Again a small bar is ok for road usage with low spring rates but if it is the track and real performance you are after - again control an independent rear end with shock compression/rebound and a heavier spring. My 2c worth.

[GV260]

Spot on NZeder! Let the IRS do what it was designed to do and enhance it by focusing on spring & shock combination depending on intended use (and $$!)

[gilltech]

Perhaps one for you then NZeder, my NZ-new early '74 260 2-seat didn't have a rear swaybar when I bought it in '84, although mounting brackets are installed on the body. I've always wondered - would it have had one that a PO removed, perhaps for the reasons outlined above? I can't see any wear or disturbance of the paint or underseal, however. Other / later 260s seemed to have them.....

[Riceburner]

Would seem I am the odd one out    My reasoning for fitting the rear bar was I have lowered the car which increases the rear camber and not having one with moderately soft rear spring rates could result in excessive rear camber under load..... ?

 

Not trying to hijack, I'd be interested to see what spring rates and bar diameter people run, all info is good info and it may help you too Benny 

 

I have... 

343lbs fronts, kyb adj shocks, 3.5deg neg camber

220lbs rears, koni adj shocks, 1.3deg neg camber

23mm front bar

18mm rear

225 semi's

[NZeder]

Perhaps one for you then NZeder, my NZ-new early '74 260 2-seat didn't have a rear swaybar when I bought it in '84, although mounting brackets are installed on the body. I've always wondered - would it have had one that a PO removed, perhaps for the reasons outlined above? I can't see any wear or disturbance of the paint or underseal, however. Other / later 260s seemed to have them.....

Yep mine too mine you might recall it? It's the "Ghosts of Bay Park" car aka ex Palmer car a 76 build (sold in 77 and imported into NZ in 78) it has the factory mounts for sway bar but it appeared to never have been fitted/optioned in at purchase time. I think it was market dependant (that is a guess) and I assume spring rates for the given market. ie the US cars were known to run softer springs and it appears many of the later cars from the US do appear to have been factory fitted with a small 16-18mm rear sway bar.

 

Would seem I am the odd one out    My reasoning for fitting the rear bar was I have lowered the car which increases the rear camber and not having one with moderately soft rear spring rates could result in excessive rear camber under load..... ?

 

Not trying to hijack, I'd be interested to see what spring rates and bar diameter people run, all info is good info and it may help you too Benny 

 

I have... 

343lbs fronts, kyb adj shocks, 3.5deg neg camber

220lbs rears, koni adj shocks, 1.3deg neg camber

23mm front bar

18mm rear

225 semi's

Well just to let you know even if you have 400lb spring in the rear of the S30 you will still have camber changes under load unless you redesign the whole rear end, which is why many these days, who don't care about keeping the original rear end, install S13/S14/R32 type rear subframes to over come these issues but then they add so much weight you do have wonder why bother - but that is just my opinion. 1.3 neg on the rear is not too bad before my mate race car moved to adjustable rear arms he had over 2.5 on the rear.

 

Also 220lb is not that soft really. I would say 150lb is soft - 220lb is middle of the road and 500lb would be the highest you would want to run and you want a cage with that high rate too or the body becomes the flex point - which it will be anyway even with stock springs. Just jack up a zed at one end ie front or rear does not matter - open the door and see how it opens differently to when the car is on all four wheels - that is the flex in the S30 chassis right there.

[Scando]

Front:

~200lb

Koni reds

~3.5 deg neg camber

standard sway bar (16-18mm?)

~3mm toe out

 

Rear:

~200lb

Koni reds

~1.5 deg neg camber

16mm sway bar

~6mm toe in (not by choice)

 

Would seem I am the odd one out    My reasoning for fitting the rear bar was I have lowered the car which increases the rear camber and not having one with moderately soft rear spring rates could result in excessive rear camber under load..... ?

 

Not trying to hijack, I'd be interested to see what spring rates and bar diameter people run, all info is good info and it may help you too Benny 

 

I have... 

343lbs fronts, kyb adj shocks, 3.5deg neg camber

220lbs rears, koni adj shocks, 1.3deg neg camber

23mm front bar

18mm rear

225 semi's

 

 

Gareth, you said in another thread the car understeers slightly.  Have you ever tried running a standard front bar?

[Riceburner]

It's very subtle understeer on entry, but once it's turned in it stays there and I can go full throttle before apex without getting any oversteer(which is prob lack of power! Ha).Ideally I would like it so I don't have to lift off to get it to turn in... Hopefully the extra camber will be the solution. I could also soften the shocks off. Haven't tried a smaller bar but may do if problem persists.

 

I'd be interested to see what suspension setup GV260 runs on his car, if Its not top secret ofcourse...

[Zedman240®]

Gareth, Gerhard runs a rear bar also but has a small diameter front bar. Spring rates though on his vary only by around 20 lbs from front to rear. You have a rather large differnece from front to rear but it seems to be working fine around the island.. You just have to run the car now with the extra camber and see what happens and change things if needed.

[luvemfast]

Why don't you jack your car up and remove the rear sway bar for a session on Sunday at the Island Gareth?

[Riceburner]

Gareth, Gerhard runs a rear bar also but has a small diameter front bar. Spring rates though on his vary only by around 20 lbs from front to rear. You have a rather large differnece from front to rear but it seems to be working fine around the island.. You just have to run the car now with the extra camber and see what happens and change things if needed.

 

I've followed Gerhard round siberia and hayshed, his looks a bit twitchy in the rear for my liking. I'll see how it goes on the weekend if it's too loose I'll remove a link rod from rear bar. Taking the whole bar out means removing the exhaust first for me, it's a tight fit.