beams SW20 @ trackday.

[Romanv]

Just a short video of me being a dick on track day.

Yes yes, I know that going sideways isnt the fastest way to corner.... But it's damn good fun.

Definitely learnt heaps about controlling my car at higher speeds, it was a great day out.

Definitely learnt heaps throughout the day, about the right lines to take, braking distances, etc.

Both videos below are the same, just hosted on Youtube/google.

The car ran GREAT, the only problem I had was snapping my shifter cable, with half an hour before we had to leave. I was glad it didnt happen earlier! I got some great track time in.

http://video.google.com/videoplay?docid ... 6723559925

http://www.youtube.com/watch?v=tc-omIy-jyI

And a few pics

And a few pics

[Romanv]

Got a little bit more from when it dried out a bit.

For some reason it almost seems to sound rowdier when it's dry. hehe

http://video.google.com/videoplay?docid ... 6000773883

[Speedy]

Looks good - how was the balance of the car ? - naturally understeery / oversteery? - what tyres / sizes were you running?

[Romanv]

In the morning when it was wet, it was very understeery.

But this was partially because I was taking the TOTALLY wrong line.

It felt really well balanced, the only time I wasnt happy with it was hard braking from high speeds. It felt very twitchy in the rear.

I'm only running 205s all round.

I think if I came back next time with wider tires in the rear, rear strut brace, harder rear suspension, and perhaps a big xxxx off wing on the back, to help with high speed stability under braking, I'd do much better.

I'm only running standard gen 3 rear suspension, I'll have my harder rear springs + adjustable shocks by next track day.

[Speedy]

You might find that going harder at the back will increase it's tendency to be twitchy at the back, and that you'll need to go harder at the front to try and resist some of the diving under braking unloading the rear, although you might find that it promotes even more understeer in the wet.

Being a little twitchy at the back under braking isn't all bad (on the track anyway), makes it useful to get the car sliding through the corners (if that's what you want) - plus, on a track, you can (usually) get all your braking done in a straight line.

I suppose that one thing to mention might be to check that the front brakes are working 100%, and that you've got decent(ish) rubber on the rear of the car..

Really good videos though, I like the first one, first lap, sliding through that hairpin

[Romanv]

Yep another person told me the same thing, but it doesnt seem to make sense.

At the moment, under braking, all of the weight shift is happening at the *rear* of the vehicle.

When I brake hard, it feels like the rear of the car is lifting off the ground.

If I stiffened up the rear relative to the front, it would feel like the nose is diving down instead.... Which seems like a good thing to me!

Yep tires all round are virtually brand new toyo proxes T1Rs.

It wasnt just under braking, if I would under rev match, it would compression lock the rear, WAY easier than I thought it should. I think wider tires at the back will help with this, as I'm only running 205s at the moment.

Then again, it was pouring down the night before, raining in the morning, and fineish by afternoon. So it wasnt exactly the grippiest track ever I suppose.

[Speedy]

All the weight is moving from over the rear wheels to over teh front wheels, and the front of the car is already dipping down (although you might not notice it from inside the car, if you had video of it from the outside, you'd be able to see it) - I suppose you could think about it as a see-saw, as you brake, you move the weight from the middle of the see-saw to the end, lifting the other end up in the process.

If you put your soft spring under the see-saw end where you are moving the weight to, then the spring will compress, and the see-saw will stop moving.

If you put a stiffer spring there (which requires more Nm to make it compress the same distance as the softer spring), then it won't compress as much, and the see-saw will be more level than with the soft-spring - therefor, the rear of your car will appear to lift less, and should be more stable under braking.

Although, as you say, if it's been wet and it's greasy, and you're giving it some beans, then the car is going to move around, no matter what you do!

[Romanv]

I think your seesaw analogy is flawed.
How I see it, is that by adjusting the ratio of hardness front/rear, you're shifting the axis on which the seesaw pivots, more towards the front and rear.
How my setup currently is, is that the pivot point is more towards the front of the seesaw... By putting in harder suspension, I'm moving the pivot point back more towards the middle.

Please dont take anything I say the wrong way. I dont know you, or your background at all, you may very well know better, and/or be far more experienced than me, these are just my thoughts on the matter.
I have an open mind on the topic, I just dont understand your point of view at the moment.

IMO Weight transfer under braking is NOT a good thing.

Although the weight distribution between the four contact points on the track changes, the inertia distribution of the car is always equal to the static weight distribution.
Eg. You have a static weight distribution of 45/55.

When a car spins under braking, it's because there isnt enough rear grip to prevent the inertia of the rear of the car from wanting to overtake the front. (Unless they were doing something silly)

When you're braking hard, lets say it's 60/40. Now you've still got 55% of the weight of the car in the back, and only 40% of the cars weight giving grip over the rear to stop the extra inertia from wanting to overtake the front of the car.
If you can stiffen the suspension to lessen this effect, you can brake harder, as you've still got a larger proportion of the grip holding the rear of the car to the ground.
If when braking hard, your nose is ducking down, and the tail is lifting a little, thats' fine.
However with my current setup, the front suspension is significantly harder at the front.
When braking hard, the front resists the weight transfer, but the rear doesnt.

This means that the rear lifts higher than it would otherwise....
Which is definitely bad! The Centre of gravity of the rear of the car gets higher, as opposed to the centre of gravity at the front getting lower.
Now with all of that weight in the back, with less mechanical grip holding it to the ground, the last thing I want/need is a higher COG there!
Imagine a long pole attached to the centreline of the rear suspension. when you corner, it's like someone is pushing on the end of this pole sideways, with a force proportional to how fast you are cornering.
If you have a higher COG, it's like having a longer pole... the same amount of force (cornering speed/inertia) wants to tip the car over more, without more effort being applied.

This obviously unloads the inside wheel, making it more likely to spin up.
Now on track day, when I had an LSD, was having fun on the hairpin, this was great.
However if I wanted to go faster, I need to lower the COG, keep more weight on the inside wheel, and keep the rear from lifting as much (and disproportionally to the front) under hard braking.
Now dont get me wrong, my current setup is great on the street, I'd never know the difference otherwise, because you're never going that fast.
But after having a look/think about how my car behaved, I've concluded that harder rear suspension would have made my car more stable on the track.

Now you may very well be more experiencd on the matter than me, and you may very well be right. But next track day, I'll be going with stiffer rear suspension.
Which may, or may not improve my situation... But that's the fun of it IMO... making some changes, seeing how it affects the cars handling etc.

[jonb-]

Stiffer rear suspension will cause a looser rear (ie more oversteer) because the suspension with the higher roll stiffness will receive the largest portion of weight transfer caused by bodyroll.

I wouldn't upset the balance Toyota designed into the suspension by just fitting harder rears, if you want more mechanical rear grip i'd advise start by adding a bit of negative camber and see where that gets you. A degree and a half negative can make the world of difference.

Edit: The correct balance of tyres would help your cause no end (ie 205f /225r) and a 'big spoiler' will do nothing on a track like that, you really need 100mph+ corners to notice aero changes.