suspension setup for brands hatch

[gareth]

i'm doing the trackday at brands hatch on the 5th of feb ( http://www.e30zone.net/modules.php?name ... c&t=154363 ) and thought it would be worthwhile getting the car set up for it beforehand

the car is a fat arse 1400kg M30 touring

I have leda coilovers on there with 500lb/in front springs and unknown rate rears (though it feels well balanced). adjustable toe/camber rear beam and adjustable camber/castor top mounts at the front. standard 325i touring ARB's, poly rear beam and diff mounts. i'd guess at the current ride height being about 60/50. oh, running BBS's with 205/50/15 marangoni zeta linea tyres (similar to proxes)

at present the rear toe is set to factory spec and the camber is set to fully positive on the eccentric bolts (still some negative camber, more than standard but really set up to maximise tyre life in daily use and compensate for the camber from lowering it)

the camber situation is the same on the front - a bit more negative than standard but not a lot, again mainly there as a result of lowering and dialed out a bit to get reasonable tyre life.
i've not altered the castor from standard yet.

sooooo, should i dial in some more negative camber? I guess it's more use on the front left as i know brands is hard on front left tyres! but what camber angles should i be aiming for?
what, if anything should i do with the castor?

all advice greatfully recieved!
I'm not going to be setting any lap records but it makes sense to get the best out of what i have and have a laugh while i'm at it

[RPM]

We run the PBMW cars standard at the rear (not allowed to alter except by ride height)

4/5 degrees negative on R888's

We also dial in more castor

Due to our regs we have to keep the damper rod fully visable in the turret so end up adding more neg camber than castor.

I dont have the geo sheet here but will dig out the correct figures tonight and PM them if you like?

Also this little update from MSV on Brands:

Brands Hatch has carried out a major resurfacing project, replacing over half the Indy circuit to improve the quality of the track surface for it's competitors, who can experience it on test days available throughout January and February.

The track has been resurfaced from mid-way down Cooper Straight, through McLaren, around Clearways and down the Brabham Straight to the centre of the pit complex using Prixmat surface material, well known for its high performance friction surface qualities.

Other circuit improvements include the addition of new kerbing at the exit of Druids, reinforcing the area behind the kerb on the exit of Graham Hill Bend and reducing the width of the tarmac run-off at the bottom of Paddock Hill Bend.

MotorSport Vision Chief Executive Jonathan Palmer said, ”aThis resurfacing project represents a major investment in Brands Hatch. Even in these tough economic times, MSV is committed to developing and improving our circuits. It will be interesting to see what effect the new surface has on lap times.”a

[Wocka]

should i dial in some more negative camber? I guess it's more use on the front left as i know brands is hard on front left tyres! but what camber angles should i be aiming for?
what, if anything should i do with the castor?

IMHO you should dial in as much neg camber and caster as you can on the front, leave the back as is and lower tyre pressures to 25 cold.

Like you say keep an eye on your front n/s tyre (particularly the outside edge).

Enjoy

[UweM3]

should i dial in some more negative camber? I guess it's more use on the front left as i know brands is hard on front left tyres! but what camber angles should i be aiming for?
what, if anything should i do with the castor?

IMHO you should dial in as much neg camber and caster as you can on the front, leave the back as is and lower tyre pressures to 25 cold.

Like you say keep an eye on your front n/s tyre (particularly the outside edge).

Enjoy

I say RAISE tyre pressure! Especially with these Zingzangoni tyres, they are going to overheat after three laps.
And why max neagtive CASTER?

Gareth put some neagtive camber on the fronts and swap tyres after lunch. In the end of the day it's just a trackday and you won't ruin your day by 0.5 deg wrong settings.
Take it easy and have fun.

[Wocka]

Yes you want positive caster (turret goes backwards).

You're the only person I've ever heard say increase tyre pressures to prevent overheating Uwe.

[n1tr0_9]

Get your self an infra red heat temperature probe. Go to brands with car as is. After every time you come in write down temps inside/centre/outside on each wheel, then next time you'll have an idea how you want to change the setup. Try to get a fairly even spread of temps over tyre width.

[kimbo]

You're the only person I've ever heard say increase tyre pressures to prevent overheating Uwe.

On a road type tyre, increase the pressures to stiffen the sidewall - this is where a lot of the heat build up is generated.
On a race based tyre with a stiff sidewall (such as a 888) then conventional wisdom is more likely to apply. Still depends on setup though.

Kim

[UweM3]

Yes you want positive caster (turret goes backwards).

You're the only person I've ever heard say increase tyre pressures to prevent overheating Uwe.

now it's positive caster? In your first post it was negative.
But that still doesn't answer my question, WHY do you want to change the castor?

I am not the only person running higher pressure on road tyres. Has been discussed many times. I am not saying I am Mr. Knowitall, I am just saying what I personally do with the pressure. Give it a try, you might be surprised.

[Wocka]

My understanding of it is, you add positive caster for more dynamic camber. i.e. more camber while the wheels are turned.

[UweM3]

My understanding of it is, you add positive caster for more dynamic camber. i.e. more camber while the wheels are turned.

so what a difference does it make in reality? for Joe bloggs.
Have you tried it and seen a difference in lap-times?
I know some cars need a bit of help, but the E30 is fairly good out of the box IMHO for the average Joe.
More important to have the wheels pointing equally in the first place, especially the E30's rear can be a pain. Bit more or less castor won't brake the bank on a track day.

[Wocka]

My understanding of it is, you add positive caster for more dynamic camber. i.e. more camber while the wheels are turned.

so what a difference does it make in reality? for Joe bloggs.
Have you tried it and seen a difference in lap-times?
I know some cars need a bit of help, but the E30 is fairly good out of the box IMHO for the average Joe.
More important to have the wheels pointing equally in the first place, especially the E30's rear can be a pain. Bit more or less castor won't brake the bank on a track day.

The OP has got adjustable camber and castor and asked for advice on how best to adjust them. If you have adjustable top mounts why would you not use them? He also has adjustable toe/camber on the rear so the usual toe out and massive camber is largely irellevent.

No I dont have documented evidence/laptimes, I'm just offering the OP my advice/experience limited as it may be.

[gareth]

steady on lads cheers for the comments, it gives me a starting point for what to play with anyway.

RPM, ta for the heads up on the track surface, i've been warned about this already, it's supposedly rather green still great!
if you could PM me that setup info, that would be brilliant

regarding the tyres, i hope it's dry as they're directional. swapping across sides should be better than front to rear i guess? they're only about £50 a pop so no massive risk but it would be nice to get them home in one piece! More negative camber and positive castor should help with this then i guess?

it's a very simple job to adjust on mine, just loosen the top mount nuts and pry the strut top about with a screwdriver so i can try a few settings throughout the day. the same goes for shocks, just reach under and twiddle away.

as for pressures, 25 psi sounds low to me, what sort of increase in pressure am i likely to see when they get hot? it is a fat old thing, no stripped 2 door here so it will be harder on its tyres than most E30's

[UweM3]

The OP has got adjustable camber and castor and asked for advice on how best to adjust them. If you have adjustable top mounts why would you not use them? He also has adjustable toe/camber on the rear so the usual toe out and massive camber is largely irellevent.

No I dont have documented evidence/laptimes, I'm just offering the OP my advice/experience limited as it may be.

not everything which is there needs to be used. Sometimes less is more. A trackday can be ruined by too much fiddling. sometimes more driving equals better fun because of the learning effect.

first you tell him to add negative, than positive. Now you tell us that you have limited experience. Not meant offensive, but how does this help the OP?

[Wocka]

I admit I was wrong about caster as I couldn't remember which way was which.

I gave my advice as that's what the OP asked for, quite frankly I wish I hadn't bothered.

[Fushion_Julz]

Tyre pressures will depend on what tyre you are running....

When I used to race my 2002 on Kumho road tyres, I'd aim for a hot pressure of 35psi and try to acheive that on all 4 corners...
That could mean starting cold with different pressures...
But that car weighed 750Kg with me and a full tank of fuel and put out 198bhp at the flywheel.

Now on my E30 M3 I've tried different things with my setup, but I run R888s and Toyo say no more than 40psi hot...This car weighs 1200kg without me in it, though, so the starting pressures are a bit lower...Also the car is a road going car and the springs are a bit softer than the '02 was running...

All this means a lower cold starting point...Having said that, I find somewhere around 30psi is a good start unless it is really hot or really cold...

[UweM3]

Tyre pressures will depend on what tyre you are running....

When I used to race my 2002 on Kumho road tyres, I'd aim for a hot pressure of 35psi and try to acheive that on all 4 corners...
That could mean starting cold with different pressures...
But that car weighed 750Kg with me and a full tank of fuel and put out 198bhp at the flywheel.

Now on my E30 M3 I've tried different things with my setup, but I run R888s and Toyo say no more than 40psi hot...This car weighs 1200kg without me in it, though, so the starting pressures are a bit lower...Also the car is a road going car and the springs are a bit softer than the '02 was running...

All this means a lower cold starting point...Having said that, I find somewhere around 30psi is a good start unless it is really hot or really cold...

40 hot is what I try to run. Sometimes 40 front and 42 rear, depends on the track/weather.
But I use Dunlop DZ02, they are much stiffer than R888

[gareth]

so if i start at 30pis and check pressures after a while, i'll get a reasonable idea of what to look for. being a heavy car, should i be looking for nearer 40psi than 35psi when hot?
how long will it take to get the pressures up before i come in and check them? 10 laps?

[Dezzy]

We fill Tyres with nitrogen mate for £2.50 a tyre. It doesn't expand with heat at all. Use in f1.
Do an Internet search for a company local who does this it's top gear.

I use it but it's only filled the same as compressed air so get them to fill them to about 45psi get them hot drop them too 40 and they won't move all day. That's cold or hot.

[gareth]

now there's a idea ta!

[Dezzy]

I have never diven a gassed up M30 touring but I reckon 40psi will ruin feel IMO.
I would bet with nito set at constant pressure you will want about 36 ish. Just a guess and don't want to get involved in the handbags above.

That's based only on my excperiance of nitro and marras though mate.
If you find it's too high you just let a bit out anyway so no danger.

[UweM3]

I have never diven a gassed up M30 touring but I reckon 40psi will ruin feel IMO.
I would bet with nito set at constant pressure you will want about 36 ish. Just a guess and don't want to get involved in the handbags above.

That's based only on my excperiance of nitro and marras though mate.
If you find it's too high you just let a bit out anyway so no danger.

Dude, nothing to do with handbags. But if somebody is asking for information one should only answer with backed up facts or knowledge gained. Imagine the OP taking things serious and follows some advise given on the internet and it turns out just to be somebodys guess or read soemwhere else.

This is not meant to put people down or show off. Just to remind that driving a car at full speed is serious business and if things go wrong it can hurt.

A forums is there to help each other, but I think it's essential to weigh up your answers.

[Dezzy]

Ha ha chill ffs. It's only a game show.

[gareth]

I say RAISE tyre pressure! Especially with these Zingzangoni tyres, they are going to overheat after three laps.

back onto tyres, what's up with my Maras?

Last year the championship, run entirely on Marangoni tyres, saw the cars on the track fitted with the standard Zeta Linea tyres

they look like this


i've had these on two sets of wheels now but have so far never taken these or proxes on a track. on the road they are very similar to proxes for grip, feel and progression but a little harder wearing. they are also very stable under breaking - i guess partly due to the stable tread pattern not squirming much.

I guess they will behave in a similar manner to proxes?

it's not like i'll be using something like this:

[gareth]

right, i took some measurements and pics earlier.

the camber is as follows:
front left 3.0°
front right 2.0°
rear left 1.3°
rear right 1.3°
visually it looks like this:

not sure why there's a 1° difference between front left and front right though. it may be partly do do with the car not being on level ground, though i did measure the angle of the car was sat at and correct for it. good enough for a ballpark figure before i go tinkering anyway

the ride height is... err... lowered! i don't know how much by:
pic - on 205/50/15's

500lb front springs, unknown rears.
front leda shocks set to 12/24
rear leda shocks set to 10/24
it feels well balanced like this though it may change after i remove the rear seats and spare wheel etc

the top mounts are pretty much centred at the moment:
nearside

offside

definately room to adjust out that stray 1° of camber and play from there with both camber and castor.

is it worth adding more rear camber from a handling or tyre wear viewpoint? i don't have much at all at the moment and it's a doddle to do.

[Dezzy]

I think it is at least 60mm all round mate if not a touch more. I think I would try a few laps and tinker from there. Nothing screams at you and I find with everything if it looks right it normally is.

[kimbo]

definately room to adjust out that stray 1° of camber and play from there with both camber and castor.

Theres a flat patch at Brands just outside the scrutineering bay in the outer paddock - get there a bit early and check your cambers before 1st session.

Kim

[Dezzy]

definately room to adjust out that stray 1° of camber and play from there with both camber and castor.

Theres a flat patch at Brands just outside the scrutineering bay in the outer paddock - get there a bit early and check your cambers before 1st session.

Kim

Bear in mind you better be fooking fast if people have seen you setting camber before you go out on track

[gareth]

definately room to adjust out that stray 1° of camber and play from there with both camber and castor.

Theres a flat patch at Brands just outside the scrutineering bay in the outer paddock - get there a bit early and check your cambers before 1st session.

Kim

Bear in mind you better be fooking fast if people have seen you setting camber before you go out on track

haha, i could then don racing overalls, driving cloves and helmet, all colour coded to the car... and look like the stig!


i've bene busy this evening and only came indoors at 10:30pm, with ice on all of my tools!

i now have a fully functioning oil cooler, new(ish) rad and a decent fan! So hopefully i won't have to have the heater on full blast and the windows down to keep the engine cool!

i have noticed the AFM flap is sticking though so i'll need to sort that before friday. i runs badly on petrol and i hadn't noticed as it spends 99% of it's time on LPG which doesn't use the AFM

[Dezzy]

Chuckle just don't bin it or you will be the talk of brands. "See him he was here at 6 setting his camber, didn't fooking help him much".

Enjoy it mate. I wish mine was finished.

[RPM]

I found all my geo sheets at the weekend, but left them at home DOH!

Will send them tonight

[Theo]

definately room to adjust out that stray 1° of camber and play from there with both camber and castor.

Theres a flat patch at Brands just outside the scrutineering bay in the outer paddock - get there a bit early and check your cambers before 1st session.

Kim

Personally, I'd use one of the pit garages which have perfectly flat floors.

[cragles]

You definetly want more front negative camber than that, this is our pbmwc race car, we have more than this now.

[gareth]

i have yet to adjust the front but this evening i turned the rear camber adjusting eccentric bolts 180° and now have about 2.7° positive camber. I'll have a crack at the front tomorrow

from an educatonal viewpoint and just for the crack, i've got a infra red thermometer on order from RS components. only £30 too and a handy thing to have

[UweM3]

i have yet to adjust the front but this evening i turned the rear camber adjusting eccentric bolts 180° and now have about 2.7° positive camber. I'll have a crack at the front tomorrow

from an educatonal viewpoint and just for the crack, i've got a infra red thermometer on order from RS components. only £30 too and a handy thing to have

what range has it got? Might not be enough for brake disks.
They are quite handy, i.e. holding on the exhaust manifold after a cold start to see if one cylinder isn't firing properly.

[E30ToRing]

It would be great to hear your feedback from the trackday. Will you be keeping a record of your settings, Gareth? I'm guessing timing equipment won't be allowed, though...

I like the nitrogen suggestion above.