12 replies to this topic

[monster_mini]

Hi,

I have just started racing mini 7's out here in New Zealand and we are running Hoosier Slick racing tyres.

ever since we started, we've been given so much advice from people it's scary!

we went on the basis of listening to the boys who are racing at the front, who run 2 degrees negative camber all round, and the tyre pressures hot 30 psi, (starting with 24 psi cold fronts, and 26psi cold rears)

however, i contacted Hoosier in america, and they recommended;

Start your cold pressures at FRONT(17 – 19 psi) and REAR(14 – 16 psi). After a 20 minute track session, your HOT pressures should be FRONT(22 - 24 psi) and REAR(19 – 20 psi). Camber settings in the front should only be -1.0 degrees to -1.5 degrees.

From this information what would you all recommend?

do i try changing all my settings to this instantly and go and try it? or change certain things slowely? or ignore it all together and do whatever all the other racers are doing?

Finally, what is a good way of checking if the settings are working? apart from lap times, what else should be happening? i've heard about using a thermal sensing gun to check temperatures across the tyres? ie hotter on the inside due to camber ect.

Advice from anyone with knowledge or there own opinion would be good,

thanks

Nick

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[Spud_133]

The only thing which I can input which will be any use is change one thing at a time you won't now what's good and what's bad? All settings will change with expirence and driving style as if you get in my oval going sierra, you may not be able to get round there but I will. Also, maybe the weather conditions will affect things like tyre pressures, as we pump them up in the wet. Have you also tried affecting tracking as it can turn in better more or less with more of less tracking.

Ok that's more than one thing

[monster_mini]

haha yeah, we've got 30 minutes of toe out, 0 toe on the back, rear anti roll bar ect....we've still got lots to do!

just had another email from hoosier after i told them the pressures we've been running, and they say they are way too high (with exclamation marks) and we're running way too much camber and will be wearing the inside too much(which is true because the temperature was 70 degrees on the inside and 40 on the out side(with the thermal sensing gun) soo...i guess we should just go and try it got lots to do ie corner weighting ect....

i guess im just struggling to believe that everyone in the field are all wrong on pressures!? (but if they've all listened to the guy before them, they wouldn't know any different!

[davedalton22]

Here is a link that shows the pressures much higher cold - just to confuse things a bit.
http://www.minimania...9/msgthread.cfm

This will add to the confusion on camber:
http://www.minimania...7/msgthread.cfm

This info is for the Hoosier TD-S

[racingbob]

with your hoosiers if i can racal 26 f 24 b

1-5 deg camber, half deg on back,1/16 toe out 5 deg caster spax were 9 front 3back
and 1/16 toe in on rear

when living in AUS racing at lakeside in club cars and appendix J this is what i used
and won the championship in 1998

but it probably weighed bit more than yours
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[jaydee]

Never raced a seven, but I suppose you could do the same way as if it was a normal racing car with very high drag coefficent but still low downforce.
So set the dampers the harder you can, then start playing with your tyre pressure.
After a bit of testing you'll find a set up that will make you fly on the track.

[monster_mini]

cheers for all the help so far guys at my last race weekend i came in half way through qualifying to drop the pressures, and the car felt completely different(like 10 times more than i could of imagined! unfortunately i couldn't compare lap times as i had one lap on low pressure and then the rain came and stayed all weekend, but will be very interesting to play with it at the next few meets making lots of changes for the next race,

Hydrolastic front arms,
new stiffer and better designed rear anti roll bar
lower the car much more
and set the corner weighting to perfection (plus lighten a few bits hear and there

will keep you posted

by the way, does anyone know where you can buy double adjustable shock absorbers from?(so we can adjust bump and rebound)

thanks

Nick

[racingbob]

i had some expensive avo shocks on the front like twice the price of spax
they were good sure i bought them in AUS

[monster_mini]

well at the moment i've got avo fronts and spax rears, (however the fronts have been played with by shock absorber people and had the bump made alot harder)

the reason i ask though is in the bill sollis how to build and race a mini(or something along those lines) he talks about 2 or 3 different options of double adjustable dampers...and i can't find any!

[bmcecosse]

The idea of 2 degrees negative 'all round' - is surely a red herring! I have run even more than 2 neg at the front - but that was on an Autocross car ploughing over grass (more often than not, mud..) and it was terrific for that. But I also had a welded diff in there. On the rear - 2 degrees neg is always going to be way too much. Be guided by your tyre temperatures - if the track is clockwise - you may want a tad more negative on the left side of the car - and vice versa for an anti-clock track. I can't comment on your tyre pressures - but I used to run 40psi on virtually bald Avon Wide Safety tyres for sprints and that seemed to work well - but they were a relatively stiff side wall low profile cross ply tyre - so sliding was the name of the game ! I beat the lads in my class who were on Dunlop Racers....

[racingbob]

try the tyres as i say 26 f 24 b i spent fair bit of time on this at Lakeside brisbane
they were hoosiers on a 5 and 6" rim

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[Wil_h]

What is important to find out here is what type of tyres they are (i.e. construction).

As they are Hoosier then I'm guesing they are a cross ply. so the nest thing to ask is how stiff are they (i.e how many ply).

Again assuming that they are a reasonably stiff wall cross ply (4 to 6 ply) then I would definately take the Hoosier advice over your competitors. Cross plys need little camber compared to radials which really need it to get the tyre working. Again, the same with pressures, the siff walls of the crossply means less pressure is reuired.

On my hill climber I run 16psi on the front and 12psi at the rear when cold, they never really get hot though. I run 0.5 degrees all round, but this is more because it's the minimum i can get on my adjustment, I would try 0 deg if I could.

[monster_mini]

okay thanks i'll take in what everyone has said and try different things on the next test day

another thing i've heard about is how if you get the camber and tyre pressures correct, the temperature across the tyre (from inside to out) should be the same?

is this realistic and worth the same for a mini, or is it directed towards the more f1 car setup? (ie is it still best to aim for this)

cheers