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#21 gav240z

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Posted 29 September 2008 - 09:37 PM

People, IF YOU DON'T KNOW WHAT YOU ARE TALKING ABOUT - DON'T POST! >:(
I DO NOT want to see in-accurate information posted on this site.


oh my thats gold!  :o


Should we get pre-approval before posting from now on....


I agree with moonstonebluZ you can't expect everything on a forum to be accurate. I understand the frustration, but its kinda comes with the forum territory doesn't it?

Perhaps a discussion for another thread / email, but we can always award accurate information with sticky posts / front page articles etc..

#22 Hunter

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Posted 29 September 2008 - 09:54 PM

GENERAL ANNOUNCEMENT:

ALL POSTS MUST BE PM'ed TO LURCH FOR APPROVAL FROM NOW ON.  ::)


Lurch people sharing their experiences or putting links to legitimate websites that contain information does not mean "they do not know what the are talking about".

This forum is for learning and sharing information.

By all means post IN YOUR EXPERT OPINION WHAT YOU THINK but don't put down other peoples input.

Just think back to when you were learning about cars and how you have the knowledge you have to day.

ANDREW (DON'T KNOW F-ALL) HUNTER  :P

#23 chev z

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Posted 29 September 2008 - 10:24 PM

Gentlemens ,great response so far,hopefully by the time we collate ,decipher and eradicate we will have some concrete and accurate race suspension requirements for the beginner to motor sport.Now to answer some queeries.Tyre temp. after 5 laps of Winton long track , recording 1min 50 sec.laps,inside temp. 47 degrees  ,outside  53 degrees.  The wear pattern was pretty even across tyres slightly less inside, outside had scollaping and eventually chunked off pieces 1cm down side wall  , only on left tyre.The tyres were completely stuffed after approx. 200kms of which 130 were track wear.My Z is running a 3.9 lsd diff. The springs are 160lbs front and 170lbs rear. The only time I could get any rear drift was steering around the long left hand sweeper with throttle, the set up then was fully hard front and half a turn less on rear konis,which seems to be  a...    about .I feel that the starting point should be 3 to 4.5 degrees neg. camber, lowest front sway bar setting.Does anyone know about toe out ?

#24 nat0_240_chevZ

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Posted 29 September 2008 - 11:01 PM

back off your tyre pressures,  say around the 24-28 psi
lay off on the shock & swaybar on the front (softer),
add more front castor with shims and see how it goes (steering will get heavier, but bites on initial turn in more, also helps the inside of the tyre to)
toe out will help the car load the front outer corner gradually, not snap & loose grip
cant go a stray with camber, within in reasonable limits, keep an eye on tyre temos & wear patterns.
Dont go widest tyre the rim can take as you only end up with profile 'roll' not cornering load on sidewalls.
from personal exp., id stay away from the khumo's for trackwork or anything with high lateral loads as their sidewalls give way far too easily and you end up doing as you say stripping tread from the first groove out to the walls, try yokis, i havent yet had, seen heard any neg reports of them, however $$$ may or may not be a problem for you.

Lurch, please feel free to add, shoot down in flames, and/or make any suggestions/comments. as remember we are talking about another racing bus driver :P here, (more up your alley than mine.)

chers nat0


#25 Lurch ™

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Posted 30 September 2008 - 06:53 AM

Fine.

My appoliges to everyone. I'll shut my face from now on.

#26 PZG302

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Posted 30 September 2008 - 07:58 AM

Chev Z, here's my two bobs worth......
My experience in suspension on the track is 5 years running a 240 Marque Sports 2b car in NSW in the late 90's, plus another 10 or so years running other cars in street sedans and Improved production, plus hill climbs and sprints whilst I have taken a ten year break from serious racing.

Nat0's pretty much summed what what you need to look at, but here goes.....

I would say first off, with the tyre temperatures, check your toe in/out and make sure that it is a sensible figure, around 1-2mm either way depending on preference, toe out will give you more stability in fast turns under brakes and toe in will make the car more "twitchy" and responsive to turn in. This will be easier to alter than camber if you are already at the maximum adjustment for camber.

The maximum negative camber I would personally run is -2.5 to -3 degrees with road tyres. The slicks I use are designed to run at up to -6 degrees, but my car runs at about -2.5 degrees and it works well with even wear across the slicks.

For track work I would also just go straight to the maximum caster you can get across both sides, being an old car odds on it's not completely true so all adjustments will be a compromise.

Around Winton the left tyre does most of the work as all heavy load corners, bar the sweeper are right handers, so the chunkinmg is to be expected.

With the tyres you are running I would run the pressures around 22-24psi to start and adjust in 2 pound steps up to find where you are most comfortable with. I run Toyo Proxes as wets and hill climb tyres and found it took a while to get my head around running such low pressures for a radial street type tyre, after being used to running Bridegstones at 38 psi and Yokis at the same pressure on my 3J 180BSSS. The slicks I use are set to 23-24psi. A change of 1 pound can make a big difference to the car.

The spring rates you have, im my opinion are way to low. I would go for something in the 300 to 350 lb/inch rates, my car uses 420 lb/inch with koni adjustable shocks. Also, do you use a rear sway bar, if so take it off, I find the Zeds work better if the bum can wallow around a little, can also make it easier to drive on the throttle.

My car is set up for what would normally be an overseering car as I run weleded diffs, ratio dependant on what I'm doing, 3.9 for high speed tracks, eg Philip Island, Bathurst (if I get there for an Easter meeting :)), a 4.1 diff for everywhere else and a 4.875 diff for hill climbs. The locked diff promote understeer all through the corner and you have to change the driving style to be quite brutal on the car at times to get it to turn, however I can drive it on the throttle and it is quite forgiving to drive. With 140hp I do 1.50 laps around Eastern Creek

#27 DevilZ

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Posted 30 September 2008 - 08:25 AM

Also comparing an road car to a track is just plain silly...
DevilZ, Have you used them yourself? Or are you just going off what you've seen???
The setup of a 4WD Evo is a completely different kettle fish to a Zed...

People, IF YOU DON'T KNOW WHAT YOU ARE TALKING ABOUT - DON'T POST! >:(
I DO NOT want to see in-accurate information posted on this site.


Hahahahah actually Lurch I dont think you know what a track car is. A road going EVO on street radials will smoke your 4 seater station wagon anyday of the week. Hahaha sorry but its just the facts. Yes I've used Kumho's and yes they are crap. They are a cheap crappy tyres and yes I've used other much better tyres like yokohama Advans and Bridgestone Potenza semi-slicks. Actually even used Hoosiers from the states too. I like the way your asking up on spring rates etc...etc... You dont even know what the weight of his chev engine replacement is along with its positioning. Sorry champ but all your doing is talking crap like your an expert when infact your just talking crap........and yes I know your thinking the question and yes without a doubt my Z will smoke yours  ::)

#28 620Z

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Posted 30 September 2008 - 09:31 AM

I also reckon your spring rates 160-170 are way to soft. You must be getting some body roll when cornering which will definately effect the handling. I personally think you would need to run 300Ibs min if you want your car to go around corners at max speed.

#29 stevo_gj

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Posted 30 September 2008 - 09:32 AM

Usually I would keep quiet but..

Hahahahah actually Lurch I dont think you know what a track car is. A road going EVO on street radials will smoke your 4 seater station wagon anyday of the week. Hahaha sorry but its just the facts. Yes I've used Kumho's and yes they are crap. They are a cheap crappy tyres and yes I've used other much better tyres like yokohama Advans and Bridgestone Potenza semi-slicks. Actually even used Hoosiers from the states too. I like the way your asking up on spring rates etc...etc... You dont even know what the weight of his chev engine replacement is along with its positioning. Sorry champ but all your doing is talking crap like your an expert when infact your just talking crap........and yes I know your thinking the question and yes without a doubt my Z will smoke yours  ::)


Mate i'm afraid a lot of what you said is pointless, how old are you? 'My Z will smoke yours'... really. Lurch ultimately is trying to help and even though he may rub a few the wrong way or you may disagree with a few facts there is no good reason for you to start trash talking him. Posts like yours are magnifying the problem and the last thing this forums needs is members arguing with each other.

Sorry for going on a rant. I hope that the more educated people can get this thread back on topic and lend Chev Z a hand!



#30 620Z

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Posted 30 September 2008 - 09:43 AM

Ahhh DevilZ I see you are new to the forum and only made 12 posts. Probably half on this particular subject. I think you should show a bit of respect and chill out a little before you go firing off. Most of us on hear have known each other for years. We don't need some smartalec coming along and winding people up for there own amusment.

#31 DevilZ

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Posted 30 September 2008 - 09:57 AM

Ahhh DevilZ I see you are new to the forum and only made 12 posts. Probably half on this particular subject. I think you should show a bit of respect and chill out a little before you go firing off. Most of us on hear have known each other for years. We don't need some smartalec coming along and winding people up for there own amusment.


Yep I am new and I wasn't the person that started firing off at ppl. That wasn't for my own amusement I think those comments were for everyones benifit. Who goes around saying what ppl posted based on personal experience is wrong and pritty much tries to stand over everyones input as being invlid. In reality you cant give advice on spring rates, camber and castor etc.... without knowing some key things like for starters, the cars weight, ride height, drive line, tyre sizes, weather the koni's have been revalved, weather the rack and steering knuckles were modified to take a V6 chev engine, was the cross member modified to do any suspension relocation during the engine swap.
all i'm saying is dont dish it out to ppl if you cant take it. I've seen 3 post in this thread where his tried to shoot down ppl and his just been talking crap.
That's my input to this thread and I hope someone does come along and help this guy with his handling issues. But just from experience if you got problems with tyre scrubbing you can either try different tyres first or spend a few thousand and change your whole suspension setup......

#32 Hunter

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Posted 30 September 2008 - 06:39 PM

I know I posted this link earlier, but could everyone please review the flow charts at the bottom page of this link and give some feedback, if the information is CORRECT FOR ZED RACE CAR SUSPENSION OR NOT?

http://www.thorneymo...ensionsetup.pdf

#33 Zeddophile

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Posted 30 September 2008 - 09:56 PM

I also reckon your spring rates 160-170 are way to soft. You must be getting some body roll when cornering which will definately effect the handling. I personally think you would need to run 300Ibs min if you want your car to go around corners at max speed.


This is something that drifted across my mind yesterday, as I remember the original poster made a post a while ago trying to sort out his bodyroll.  Did this issue ever get sorted to start with, or is this thread the extension (in a manner of speaking) of the previous one?

In reality you cant give advice on spring rates, camber and castor etc.... without knowing some key things like for starters, the cars weight, ride height, drive line, tyre sizes, weather the koni's have been revalved, weather the rack and steering knuckles were modified to take a V6 chev engine, was the cross member modified to do any suspension relocation during the engine swap.


Yes, it is true you can't give EXACT figures without knowing exact details, but what you can do is give a guideline of a ballpark figure for a starting point, and an idea of what areas to look at to start improving the issues being detected.  You can do all the maths you like to work out the 'perfect' suspension setup, but ultimately the person behind the wheel may not like it, and want something different anyway.

  I was talking to a mate who races nationally (and competitively) in Formula Ford the other day, and he was talking about this exact fact - there are a small handful of people in the field who use 10psi more than the 'accepted' figure in their tyres, and it works for them to the point that they can post times in the top part of the field.  Doesn't work for him though.  That's just one example he gave, but there are apparently other people who run suspension settings that have the rest of the field scratching their heads and asking 'How the ___ does that work?', and again they make it work.  At the end of the day though, they all started from a guideline figure of a REASONABLE handling car, and worked out from there what they needed to suit their strengths and weaknesses (including tyre management).

People, IF YOU DON'T KNOW WHAT YOU ARE TALKING ABOUT - DON'T POST! Angry
I DO NOT want to see in-accurate information posted on this site.


Erm... sorry to everyone on here, but I actually agree with Lurch on this one, I feel the same way about it, and have the same problem on the Alfa club site.

The easiest way to put this, is to use a Zed manual conversion for example.  People will swear black and blue that you HAVE to change the whole pedal box.  I know for a fact you can simply swap the pedals themselves over in a late car at least.  Now, if you are paying a mechanic to do the conversion for you, and he isn't too bright at working things like this out, he's going to look around for how to do it.  Whats he going to be told?  Pull the whole pedal box out, and so away he goes.  3 hours of labour and a lot of swearing later, he's done.  However, he could have done that part of the job in 30mins by swapping just the pedals, and guess who pays for the extra 2.5 hours of labour, at $90 an hour?  Thats right - YOU do.

Now thats only a couple of hundred, but imagine if you go and buy a reco gearbox from some other model car because someone tells you it will bolt straight in.  A thousand or so later, you discover that there is no possible way to fit it.  Or someone tells you that you need to buy extra special race tyres at $600 each and its guaranteed to fix your understeer, and you put them on to find these tyres are actually more sensitive to the pre-existing setup issue in your car.....

Gentlemens ,great response so far,hopefully by the time we collate ,decipher and eradicate we will have some concrete and accurate race suspension requirements for the beginner to motor sport.Now to answer some queeries.Tyre temp. after 5 laps of Winton long track , recording 1min 50 sec.laps,inside temp. 47 degrees  ,outside  53 degrees.  The wear pattern was pretty even across tyres slightly less inside, outside had scollaping and eventually chunked off pieces 1cm down side wall  , only on left tyre.The tyres were completely stuffed after approx. 200kms of which 130 were track wear.My Z is running a 3.9 lsd diff. The springs are 160lbs front and 170lbs rear. The only time I could get any rear drift was steering around the long left hand sweeper with throttle, the set up then was fully hard front and half a turn less on rear konis,which seems to be   a...     about .I feel that the starting point should be 3 to 4.5 degrees neg. camber, lowest front sway bar setting.Does anyone know about toe out ?


The tyre temps definitely suggest more negative camber would be helpful, although I'd personally shy away from going towards 4 degrees you suggest for two reasons:
1. I suspect that to get that much you would require some fairly extensive mods to your front struts, meaning a lot of money, and I think it should be possible to get a well handling car which will be awesome fun on the track without needing to spend that much - someone mentioned slotting the holes where the strut tower bolts to the body, which is definitely a cheap place to start, although I don't know how much camber that will actually give.
2. If you use it on the road as well for a semi daily driver, it will probably be a pain to drive, and if you have normal road tyres for this use, they will be destroyed pretty quick with that much camber. 

The left tyre wearing considerably more is interesting, whether that could be attributed simply to a combination of bad setup and the fact that about 2/3rds of Wintons corners are right handers, or whether its a pointer to something else I don't know.....

Finally, I know a group S alfetta which has been dual entered for 4 sprint days with Bridgestone RE55s on it, and those tyres are only just starting to lose their outer edges.  I don't care how cheap and crappy your tyres are, if you can kill a brand new set of semi slicks in one track day, something is very wrong.

#34 stevo_gj

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Posted 01 October 2008 - 02:12 AM

The easiest way to put this, is to use a Zed manual conversion for example.  People will swear black and blue that you HAVE to change the whole pedal box.  I know for a fact you can simply swap the pedals themselves over in a late car at least.  Now, if you are paying a mechanic to do the conversion for you, and he isn't too bright at working things like this out, he's going to look around for how to do it.  Whats he going to be told?  Pull the whole pedal box out, and so away he goes.  3 hours of labour and a lot of swearing later, he's done.  However, he could have done that part of the job in 30mins by swapping just the pedals, and guess who pays for the extra 2.5 hours of labour, at $90 an hour?  Thats right - YOU do.

Now thats only a couple of hundred, but imagine if you go and buy a reco gearbox from some other model car because someone tells you it will bolt straight in.  A thousand or so later, you discover that there is no possible way to fit it. 


Those examples sound hauntingly familiar...  ;D

#35 gav240z

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Posted 01 October 2008 - 03:12 AM

Erm... sorry to everyone on here, but I actually agree with Lurch on this one, I feel the same way about it, and have the same problem on the Alfa club site.


I agree that people should not post information as fact, if they have no experience in the area. However people offering suggestions or theories isn't a problem. I noticed a while ago that Lurch put together a great thread about gearbox compatibility and there were some "suggested boxes" that "might work" posted afterward. I noticed Lurch removed them which is fine. Since we don't want to confuse people with inaccurate information.

As I said though we can promote accurate info with the use of stickies / articles etc.. This way the information is more upfront and obvious.

Also I could enable forum "karma" which is a setting that allows people to add ratings to posters, this would mean that people who provide relevant accurate information have a status bar that shows up under their name. However I decided against this at first due to the politics of it.

I guess this is a discussion for another thread too :).

#36 Zeddophile

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Posted 01 October 2008 - 06:59 PM

Those examples sound hauntingly familiar...  ;D


Not intentional, just the quickest and easiest example to give!  And before anyone jumps up and down, tyres was a probably fair enough suggestion of something to perhaps try at the time it was suggested, before the information was given as to how quick they are actually wearing.

I agree that people should not post information as fact, if they have no experience in the area. However people offering suggestions or theories isn't a problem.


Agreed, but my view on this is that if it is a suggestion or theory, put a 'disclaimer' on it to effect that you don't know if it'll work, but maybe it might be worth a try.  Or otherwise, try and phrase it in such a way that it becomes almost a question, to provoke a discussion on the pros/cons of that approach from someone who may have more experience or knowledge on the area.

The outright statement of misinformation as fact, and its devout defence by the poster tends to drive some people who have knowledge in said area away from bothering to post what may actually be extremely useful information both now and in the future.  Why?  Because they just can't be bothered defending their information against people who decide to have a vendetta against them for daring to disagree with their post.

I know its one of the reasons I often don't post on a thread - I usually get to a point about halfway through writing what I'm going to post, then think to myself "What's the point, this will just create a page worth of people tellling each other that what I've written is wrong because its not what their mates mate told them."  Not a criticism of this forum specifically, its actually more of an issue on Land/Range Rover and Alfa forums - both of which cars I have worked extensively on for a living.

I guess this is a discussion for another thread too :).


Agreed.  Perhaps we can leave it at enough said, but I somehow doubt that - although I'm amazed by the lack of flames occurring throughout the day today....

#37 chev z

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Posted 01 October 2008 - 07:30 PM

Zeddophile, I don't use the Z as a road car due to the 'neither your arse nor your elbow theory'. In answer to body roll , I bought a 26mm  3 way adjustable front sway bar [ set at med. ] made and installed front adjustable strut bar, hoping this would help.I think it did, but must admit when cornering I'm concentrating onbraking,correct line and timing exit acceleration, than noticing bodyroll.Hell I only picked it up at DECA due to photos posted.I will write alist of what I've learnt. People can agree or disagree on the order/priority/ or do the lot information

#38 chev z

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Posted 02 October 2008 - 12:52 PM

Well  I have tallied the posts up and so far the good and relevant information concerning this topic come in at    21    , the old women bitching about non relevant stuff totals    15  . Perhaps the moderators should cull these and just let relevant ideas  , good or bad, be listed.Thankyou to those that stuck to the topic.  A...change tyre brand - go lower profile    B....adjust front sway bar to softest position    C....replace king springs with 300lbs alround    D....toe out 2mm    E....run neg. camber to 2.5 to 3 degrees    F....start tyre pressure at 24 psi , work up 2 psi at a time    G....remove rear sway bar      Give me your positive opinions ,or constructive criticism with reasons,  thanks again Steve

#39 nat0_240_chevZ

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Posted 02 October 2008 - 12:56 PM

shall do another time, heaps heaps busy @ work at present.
so when im about to nod off one night ill put in a blurb, your list is pretty good for starters,
would mix the order a lil, but all very good easy starting point.

cheers nat0

#40 DevilZ

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Posted 02 October 2008 - 04:52 PM

Now to answer some queeries.Tyre temp. after 5 laps of Winton long track , recording 1min 50 sec.laps,inside temp. 47 degrees  ,outside  53 degrees. 


Hi just had a bit of time today so I did a quick google search on the Kumho's for you. I'm not sure on what exact tyre from kumho your running? (i.e what series of semi slick)
The link below is taken from a tyre supplier of kumho's.
http://firesport.com...s--ad125558.htm
For this particular semi-slick of kumho they are saying the optimum running temperature is 205 Fahrenheit which is
about 96 celcius.
Maybe your tyres aren't hitting temp thus making you lose front end grip and pushing stright through corners?
Here's another link below straight from Kumho motorsport on how to adjust setups for the tyres etc....
http://www.fsport.co...t/tyretech.html








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