Zeds in the Wet

[Huw]

Howdy all

 

Just wondering if anyone else finds the zeds 'sudden' in the wet?

Mine has been particularly lethal in the wet since restoration, initially because the springs were not the right springs (higher than stock) and setting was impossible....however this has been fixed with new lowered king springs and proper alignment. Suspension is slightly adjustable due to eccentric bushes and front cross member adjuster.

 

Anyway, have put new bridgestones on the front (14") and moved the Yoko's to the back as a result of someone cutting my previous Michelins. Had re-adjusted by local bob Jane (eeeeek....should have waited for Trackside Tyres but had a country drive ahead).

 

Today while driving home, had some interesting tail action going on the zed today in the wet while coming out of a roundabout (large one between on highway between Frankston and Tooradin)....

 

Was travelling at a low speed and accelerated coming out, almost instant loss of adhesion.

 

Anyway......that's the background, today's was a combination of factors but having always had a fairly tail happy zed, was wondering if many other people found them this way, or if there are any suggestions for improving grip and handling in the wet (apart from changing the driver!).

 

I drive it daily but it is at the point where driving on really slippery days is concerning.

 

Huw

 

 

[Huw]

P.S. it a 1971 240.

Shocks are KYB numbers.

Brakes are 4W disks, stock on front and skyline rears.

 

[C.A.R.]

IRS cars get 'taily' when the rear Toe is set at Zero or Toe OUT.

Zeds are particularity sensitive to it.

Try getting the rear realigned with 1 to 2 Deg. of Toe IN & see see how it feels.

 

FWIW I had my old 2+2 set at 0 deg Toe on the rear, and well... ZZZ8 can tell you how it went on the trip to Thredbo in '09...

[Huw]

hmmmm....good to know although...just having a look at the setting sheet they gave me (Bob J) it was fantastic on original setting by Trackside (12 months ago)....but this is what Bob have set it on...I still seem to have toe in on back,

 

Front:

Total Toe: +.4 (was -.2 when went in) [+.3 LH +.0 RH]

Camber: -0.45s LH -0.10s (was -0.45s, -.05s)

Caster: +2.50 LH, +3.4 (was +2.45, +3.10)

 

Rear:

Total Toe: +2.4 ) [+2.6 LH, -0.2 RH] <--------Do you think RH is prob?

(was +2.6 with +2.4, +.2

 

Camber: -1.15, -1.15 (was -1.2, -1.15)

 

Suggestions/settings everyone else running would be appreciated.

 

Cheers

Huw

 

 

Caster:

 

 

 

[PZG302]

Take it back to trackside to set it up properly if you were happy with their work.

 

Personally I wouldn't take a skate board to get a wheel alignment done by a "Franchise" type shop, especially when they mainly work on shopping trolleys and make their dollars on turn over of cars through the shop. I've been stung too many times.

 

I now pay a little extra for the tyres but get great service and a wheel alignment that I know works, and great follow service if I have any dramas with the tyres, alignment, balance or punctures.

 

If I'm reading the figures right, you have toe out on the rear as well as the front. As Lurch said the rear can get a little taily with toe out, so if possible I would try to get some toe in on the rear through the available adjustment.

 

Also with the loss of adhesion , was it due to too much throttle, ie wheel spin, and you don't have to be hooning to provoke wheel spin. If you are getting too much wheel spin how old are your tyres? Over 4 or so years old they will be starting to get pretty hard with UV attacking the rubber and they will be hardening, also due to heat cycles through the rubber as well. Even though the tyres aren't worn you maybe up for some new boots....

[Huw]

Yoko's on the rear about 1-2 years old....fronts were bought 3 days ago (Bridgestone).

 

[dazzed]

the king springs maybe too high in the rate, do you have a sway bar on the rear , if you do take one of the links on one side out , for a road car softer springs and a small diameter rear bar, all the after market rear bars are 18mm diameter which i found to be too rigid , also if your car is a 71 model does it have the diff in the forward position that can cause all sorts of weird things in the rear

[Zeddophile]

I'd be taking it back to Craig at Trackside, he takes the time to get as good as possible to the adjustments provided, not to mention having the knowledge of when to alter the factory settings to get better tyre wear and handling, especially on later model cars.  Of course, the fact that he deals with a lot of datsuns and other older cars, both for road and track uses, is a great advantage!

 

In the meantime, you could try swapping the wheels front to back, if your new bridgestones are of decent quality?

 

I'm interested to know however, why you got the alignment readjusted by Bob Jane, since it sounds like you haven't changed anything in the suspension since the last alignment, and your previous alignment wasn't that long ago?  The only reason for it to have changed is if suspension parts have worn out, or you've bent an arm somewhere...

[Huw]

Gonna sound really dumb....figured would get aligned with tyres as had been 12 months or so.....no other reason. had been handling well.

 

Will check the Spring rates....again, got done through trackside on their advice for a road car and have been very happy with all rates.

 

no rear anti-roll. stock '71 with front only (for now).

had also heard after market ones too hard.

 

If i recall correctly (couple of years back now)....when we restored my zed we shifted it back a bit with the diff.

 

Huw

 

[dat2kman]

for what its worth, I run 10mm toe in on rear, and 3mm toe out on front,  approx 270lb springs, and  stiff bars at each end, with no rubber in the bar links, spring perches have been lowered, I run a 6" rim ( control tyre size) and at 2009 Phillip Island Historics Sunday 12 lapper, in the pissing rain, was running third outright behing Porkers of Morgan and Adler, with Hall"s white Zed on my tail, we were all aquaplaning and twitching down the front straight, and hitting water wall on track around Siberia, I looped it, Hall got in front of me, I then came up onto Sperry Spiridis in the DeTomaso at full noise spinning in front of me down main straight on next lap.

I had no brakes or steering, due to water on track, I just backed off throttle got some steerage, and passed him nearer to the pitlane wall than I wouldhave liked.

Ended up fourth behind Hall.

Tyres were 185/60x14 Kumho V700, quite low on tread.

I feel that by using such a "skinny" tyre is what enabled the car to do as well as it did, considering conditions and car setup.

Camber is around?? -2 deg on front maybe a bit more?, castor is approx +3deg, rear arms had to be cut and rewelded to get the rear toe equalised.

Zeds under hardish acceleration tend to move into +toe at rear, due to all the elasticity and movement in all the joints/connections.

 

I had a Westfield clubman with IRS once, on hard bump/compression at rear, the outside rear whell went into TOE OUT, great fun!

I checked out why it handled so evilly by doing a bumpsteer test on the rear ( with shocks but no springs fitted) and discovered over last 20% of movement in bump, it went from -1/2 to plus 3mm.

 

No Camels were harmed during this procedure.

 

I have seen real old photos of Zeds racing in Japan, ( On Japan Watanabe website) in the dry they run the homologated rim sizes, ie 8"fronts, and 10" rears, with rather tallish period style race rubber ( this is 1969/70 I'm talking) and in the wet, they whack on the stock 4.5 " wide stock steel rims with tyres puped up to like? 60 psi to cut through the water. They handled perfectly. Said drivere are wearing "pudding basin" style helmets too!

[Mr240z]

hmmmm....good to know although...just having a look at the setting sheet they gave me (Bob J) it was fantastic on original setting by Trackside (12 months ago)....but this is what Bob have set it on...I still seem to have toe in on back,

 

Front:

Total Toe: +.4 (was -.2 when went in) [+.3 LH +.0 RH]

Camber: -0.45s LH -0.10s (was -0.45s, -.05s)

Caster: +2.50 LH, +3.4 (was +2.45, +3.10)

 

Rear:

Total Toe: +2.4 ) [+2.6 LH, -0.2 RH] <--------Do you think RH is prob?

(was +2.6 with +2.4, +.2

 

Camber: -1.15, -1.15 (was -1.2, -1.15)

 

Suggestions/settings everyone else running would be appreciated.

 

Cheers

Huw

 

 

Caster:

 

 

 

 

Can anyone recommand the perfect settings for street car (mine)

I just had different place do my again and I think he completly stuffed it up..Not happy.

 

Need some help on settings so I can take with me.

[Mr240z]

I just found a sticky over at HybridZ.

Does these settings sound about right.

 

Street

 

For 225 to 245 width radial DOT tires try these alignment settings:

 

Front

 

Camber: 1.25 to 1.5 neg

Caster: 4 to 5 positive (even on both sides)

Toe: 1/16" out or 0

Ride height: 6" to 6 1/2" measured at the front of the rocker outboard of the pinch weld seam.

 

Rear

 

Camber: 1.25 to 1.5 neg

Toe: 1/16" to 1/8" in

Ride height: 6 1/2" to 7" measured at the front of the rocker outboard of the pinch weld seam.

http://forums.hybridz.org/showthread.php?t=126789

 

Lurch or one of the senior members give me some feedback.

 

p.s Has anyone had a Pedders 28 Point Safety Check.

I've invested alot of $$$ with koni's & almost new everthing steering, suspension and still can't get it right.

[PZG302]

I just found a sticky over at HybridZ.

Does these settings sound about right.

 

Street

 

For 225 to 245 width radial DOT tires try these alignment settings:

 

Front

 

Camber: 1.25 to 1.5 neg

Caster: 4 to 5 positive (even on both sides)

Toe: 1/16" out or 0

Ride height: 6" to 6 1/2" measured at the front of the rocker outboard of the pinch weld seam.

 

Rear

 

Camber: 1.25 to 1.5 neg

Toe: 1/16" to 1/8" in

Ride height: 6 1/2" to 7" measured at the front of the rocker outboard of the pinch weld seam.

http://forums.hybridz.org/showthread.php?t=126789

 

Lurch or one of the senior members give me some feedback.

 

p.s Has anyone had a Pedders 28 Point Safety Check.

I've invested alot of $$$ with koni's & almost new everthing steering, suspension and still can't get it right.

 

Can't see anything wrong with those settings.

 

Who have you got to do the alignments in the past?

 

Unfortunately I've been out of sydney for way too long to know whos who with regard to set up, thogh I would recommend Wholesale suspension out at Penrith, they have a good reputation and I know a couple of race cars they have worked on and they were very good at setting them up.

 

HAve a quick look on the Improved Production Car association web site and forum to see who those guys use and you should find someone local that will get your car set up right.

 

Unless you've spent a fortune on a fully adjustable set up you're pretty much stuck with what adjustment is avialble, however a good operator will get you a setup to suit your car.

[Zeddophile]

I just found a sticky over at HybridZ.

Does these settings sound about right.

 

Street

 

For 225 to 245 width radial DOT tires try these alignment settings:

 

Front

 

Camber: 1.25 to 1.5 neg

Caster: 4 to 5 positive (even on both sides)

Toe: 1/16" out or 0

Ride height: 6" to 6 1/2" measured at the front of the rocker outboard of the pinch weld seam.

 

Rear

 

Camber: 1.25 to 1.5 neg

Toe: 1/16" to 1/8" in

Ride height: 6 1/2" to 7" measured at the front of the rocker outboard of the pinch weld seam.

http://forums.hybridz.org/showthread.php?t=126789

 

Lurch or one of the senior members give me some feedback.

 

p.s Has anyone had a Pedders 28 Point Safety Check.

I've invested alot of $$$ with koni's & almost new everthing steering, suspension and still can't get it right.

 

Just by a general rule of thumb, those number seem a reasonable starting point, although I have no experience with Zed suspension as such.  The fact that they've specified a ride height is a good sign though, suggests that they've experimented a little, and found these settings to work best with the roll centres found at that height (obviously as you raise or lower the car, the point around which the car rolls changes height, and affects the handling)

 

As far as a Pedders check, I wouldn't bother - but then again, I don't trust any of the big chains in the auto industry (Ultratune, Kmart, Midas, Bob jane, etc).  Too much focus on shoving the car through to make their couple of bucks and get on the next one.

 

I remember when I was working on Land Rovers having a Range Rover come through the workshop which the owner was proud to announce had just had new shocks fitted all round by Pedders.  Needless to say, he was a bit surprised when we told him it might be a good idea to turn all the shocks around so that the little arrows with "top" printed next to them didn't face the ground anymore.....

 

What exactly do you mean by "I've invested alot of $$$ with koni's & almost new everthing steering, suspension and still can't get it right."  Whats not right, the handling, the alignment.....?

[.]

Hey guys, Sorry to revive the thread but I can't see an answer to the ideal settings question?

 

I just had my wheels aligned after a few events and the front was pretty good but the back is a bit wonky. 10.5mm on the left and 4.0mm on the right. Its the first time I've had the back done.

 

Is re welding my only option?

 

and Should I increase the right to 10.5mm or decrease the left to 4.0MM The wheel alignment guy thought it should be more like 4mm???

[sco_aus]

A quick fix that i know of a few people that use it, is to disconnect one of the sway bar links on the rear.  This softens up the suspension and helps with grip, though it will change the handling characteristics.

[260DET]

What setting are you talking about Greg?

[.]

I have since purchased a kit so I can adjust the rear alignment without welding. But I would still like to know what is the ideal settings for the rear (castor I think). My understanding is that 0mm is not ideal. If I had to guess I would think 4mm sounds reasonable???

 

 

[Riceburner]

Hey Galderdi,  What was the kit you purchased, where from and how much? 

[Thomo260]

It's funny how different (but same) cars handle and the lengths we go to to make them handle well. This thread got me thinking of my 260 2+2 that I drove on the Tassie run in Feb. It had Dunlop 3000A tyres, King lowered springs, standard front & rear swaybars, rebuilt wet legs with tranny fluid and I have no idea what the alignment settings were as I done it with a string line on the floor in the shed  . But it handled the wet twisty roads flatout brilliantly, even clutching half way through the corner to get it to slide but it just stuck.

[620Z]

Lurch nailed your problem in one. It's your rear wheel alignment IMO. Get that fixed and you will be OK.

[260DET]

I have since purchased a kit so I can adjust the rear alignment without welding. But I would still like to know what is the ideal settings for the rear (castor I think). My understanding is that 0mm is not ideal. If I had to guess I would think 4mm sounds reasonable???

 

For rear caster just get both sides even near zero I would think, can't recall it being discussed ever but while its important in front, because its relevant to steering movement, at the rear it would tend to make the car more straight ahead stable which could result in front turn in problems, understeer, etc. So avoid any significant rear caster unless there is a rear end stability problem that toe in will not fix.

 

Rear camber is a relevant adjustment of course  but thats usually measured in degrees.

 

 

[620Z]

Ahhh Galderdi a 4mm toe in would make your Zed handle like crap. You would be sliding all over the place like he is now.

Per 260DET comment when you get the adjustment ready to go on the rear close to zero toe is best. Fronts are a differnet kettle of fish depending on your application. But even then I see people always over doing it on their road cars which results in worn out tyres losing 50% or more of their life.

[.]

Thanks guys I will aim for 0mm Toe.

 

Hey Galderdi,  What was the kit you purchased, where from and how much? 

 

Here is the kit I have. I know it is listed as a camber kit. But I figure for the minor amout of adjustment I require I am hopeful I can dial out the front mount more than the back mount to correct the allignment problem. If I can get a small amount of camber in the process all the better.

 

http://www.thezstore.com/page/TZS/PROD/PSDC07/23-4171

[620Z]

Yep there the ones.