Suspension

[Zedrally]

Rolf ( Doehring );

the rear anti-roll bar was standard on all S30-S, PS30, PS30-SB and HS30 models right from 1969. Only the poor old S30 and of course the HLS30 didn't get them from the get-go. Seems they thought the "poverty" model S30 and the USA / North American market version owners would not be interested in going around corners!.................

This means that Mike's car ( as an Australian market HS30 ) already had a rear anti-roll bar. Sounds like he upgraded to an RS30 rear bar for extra beef.

Alan.

Small correction Alan. My 240 didn't [doesn't] have a rear sway bar. The mounting brackets are there though. My 260 has the bar.

There where some 240's that where destined for the UK market delivered here [wharf strike in UK meant they diverted the ship here instead, that's an unsubstantiated rumour, maybe you can confirm]. On of my firends has one, they stand out as they have the large front indicators, must check if it's got the rear sway. wonder if any Australian delivery 240's made it to the UK to replace the ones that we pinched! [maybe a new thread on this, I leave that up to you]

Thanks for the in depth explanation on springs, rates etc. I don't feel as I'm floundering now, not a expert but able to reasonably understand.

[Zedrally]

Just to bring all up to speed on the Latest.

Saturday brought forth many ideas and suggestions, some good & some not to good. An interesting point was made regarding 260 front struts.

Apparently they are a better strut than the ones used on the 240. News to me, I thought they where similar. A quick check into the factory manual indicates a hard and soft suspension option. I guess that it would be in the springs, however, are the struts the same all the way through the model series or did they upgrade/strengthen then over the model years? I start to wonder about the front end in the 280C series, being a heavy car, I can only guess the front struts would be "beefed up". Thats something to look into later.

Luckily as far as the RAlly Zed goes, the local koni distributor owns a rally zed thats had the covers draped over it for a while [these cars just seem to have been "ferretted" away for a rainy day here]. Enquires are progressing into his setup.

Cheers......

[2ManyZs]

I don't know what happened in other parts of the world, but here in the US the 260 and later 280's had a longer and larger diameter strut housing. You might want to measure the diameter and lenght before you purchase anything for a 260 hoping to use it in a 240 housing.

The strut housing is completely different here in the States after the 74 models. I know this from previous experiments, trying a 260 spring on a 240 doesn't work. The springs themselves are longer by about an inch. Not sure the exact measurements on the differences, since I no longer have the 280 sitting here. But I do know the housing is also a larger diameter as well.

[Rick]

Wow!

I have read so many replies to your suspension request that I thought I should add what I run on my car.

My car was originally purchased to run in the Australian historic series which has strict rules on what you can and cannot do to your suspension.

You can lower the car using stiffer springs and use non adjustable telescopic dampers. add sway bar to rear and not change camber angle by any remodelling of turret.

All cars to run 14x6 wheels max with 60 series tyres allowed.

Very limiting to say the least.

I opted for street sprints as I did not want to fit a welded roll cage and came up with the following suspension setup that allows me to drive the car on weekdays and race on weekends.

Shortened 230lb progressive springs with Koni adjustable inserts in modified struts. New rubbers in front suspension with urethane in rear. The front must be more flexible. 14mm swaybar at rear with 20mm in front. This allows the independant suspension to dive and bite for grip on acceleration out of corners.

This road setup provides awesome handling when combined with 16x 6.5" wheels and 205X50 sticky tyres.

Now does anyone know where I can find an R180 LSD

Oh! you also need to brake harder when slowing from 180 kmph so I fitted twin pot calipers from a hilux 4wd and high temp pads.

The corner speeds are already frightening and now I do not have enough power so guess what happens next?

Rick - Brisbane

[Zedrally]

Hi Rick,

Thanks for your insight into your setup. I'm not sure which Historic Series you're referring to, however, the Historic Rally Car [hrC] Eligility Regulations Cat 2 [1968-1975] Wheels section 5.6.4 states that wheel size may be varied by one size from manufacturers specifications. [see page 11-79 of the CAMS Manual. This was derived from the Historic RAlly Association eligibility regulations. Consecquently, a 15" rim is within guidelines for this type of competition.

Generally, we need to raise the car for this type of work. The rally tyres I have when fitted actually lower the car to what we now know is an un-acceptable height.

Sounds like you've got a great setup for sprints and motorkhana's, it's more or less what I ended up with, less rear sway and 16" rims.

As for the L180 Diff, best bet is looking for a wrecked Subaru.

[Rick]

Hi Mike,

The "Australian historic car racing category" I am talking about is track racing.

CAMS state that the wheels may be a maximum of 6" wide but must retain the original manufacturers wheel size which is 14" for the 240Z. They have recently changed tyre size to 60 series which would theoretically allow one to use a 205/60 x 14 tyre. However only 195/60 x 14 road race tyres like Yokohama ADVAN are available which reduce rolling dia to 589 mm. Good for sprint work but not for top speed.

What Subaru model had the R180 diff?

By the way one of the most informative guys I have met on 240 Z's and especially rally cars is Alan Stean of "The Z Workshop" in Brisbane.

He has rallied Z's for 20 years and is currently campaigning one in NZ and Aus.

His website is www.zcarworkshop.com.au and email address is zcar@iprimus.com.au

Rick

[Zedrally]

Not sure about model, the advantadge here is that Subaru marked their diff's.

So look for a sticker with 180 on it..

Now if Alan only lived in Victoria! This is the best part about these forums, the depth of knowledge that is out there, if one only new the question....