Wez Track Supra

How did you find towing the car Wez?

I hadnt done any towing before last week, it takes a little getting use too and you certainly know its there

The trailer I hired was fapping massive, I could have put the Hilux on it.

Useful if you go off-roading then, hilux on the trailer and tow it with the Supra!

Are you still considering getting a trailer for yourself and going that route regularly, or sticking with driving it to most track days?

Are you still considering getting a trailer for yourself and going that route regularly, or sticking with driving it to most track days?

Trailering it although a little more hassle means you are not relying on it to get home which is nice. I have been looking into various options and would like one that includes a tool chest and wheel rack etc.

The other option is to buy an older transporter, some can be had for approx £3k which is close to a trailer anyway.

Trailering it although a little more hassle means you are not relying on it to get home which is nice. I have been looking into various options and would like one that includes a tool chest and wheel rack etc.

 

The other option is to buy an older transporter, some can be had for approx £3k which is close to a trailer anyway.

Wez, did you see Konrad's recent thread - he's had a customer trailer built by friends in Poland.

Is that my old 4runner towing it?

Anyway, been reading this thread and got to say I'm impressed;)

Is that my old 4runner towing it?

It is indeed matey, still going strong, great motor that

It is indeed matey, still going strong, great motor that

Glad to hear it, she's a good'un and looks great with a Supra on the back

im sure you old enough, if you passed you test after 1997 your supposed to take a b+e trailer test, stupid i know

how come i can hardly hear you external wastegate?

im sure you old enough, if you passed you test after 1997 your supposed to take a b+e trailer test, stupid i know

Didnt know that but I passed in 95

how come i can hardly hear you external wastegate?

Its not too loud which is good.

Thought I would post up the second part of the video from Brands Hatch on the 25-06-09, I am going to look at mounting the camera somewhere else next time

Erm-oikzyUw

A few pics from BrandsHatch on the 25th June

Here are a couple of pics from BrandsHatch on the 25th, same day as the two video clips above, this was the cars first outing since most of the work in this thread.

That wants more negative camber, a lot more, front and rear. You can probably also up the front spring rates 20% or so. It's rolling too much and it's into positive camber in roll. You can get another second and a half a lap easily if you fiddle with the geo some more. However, you may well need some after market arms to get enough negative.

Whats the geo setup at the moment Wes? Your right Chris, looks like its got positive camber, not good.

That wants more negative camber, a lot more, front and rear. You can probably also up the front spring rates 20% or so. It's rolling too much and it's into positive camber in roll. You can get another second and a half a lap easily if you fiddle with the geo some more. However, you may well need some after market arms to get enough negative.

Great feedback, thanks Chris

Is this a while you wait change or leave the car with you?

Whats the geo setup at the moment Wes?

No idea

I think I gave it pretty much all the front negative the adjusters had, you can have a look at the rear front lower wishbone eccentrics and see for yourself. They need adjusting so as to make the bottom wishbone longer. Castor and toe will need resetting. Not a while you wait job I'm afraid, unless we could do it one weekend when Terry is here to help me.

I think I gave it pretty much all the front negative the adjusters had, you can have a look at the rear front lower wishbone eccentrics and see for yourself. They need adjusting so as to make the bottom wishbone longer. Castor and toe will need resetting. Not a while you wait job I'm afraid, unless we could do it one weekend when Terry is here to help me.

I will get under the motor tonight and have a look and let you know.

If they are already dialled all the way out I guess new arms with more adjustment are they only option or can you get adjustable top mounts that allow camber adjustment?

Now that the exhaust ground clearance is sorted I was thinking about lowering it some more, wouldnt this introduce some more negative camber?

Wez, are you coming on Thursday to Snetterton?

Wez, are you coming on Thursday to Snetterton?

Hoping too although I dont have the time off work yet, should find out tomorrow.

You don't want to lower it any more, it's low enough already. You'll make it understeer like a pig if you lower it more, plus you'll be getting it onto the bump stops, with the rate going through the roof, in corners. The top mounts just hold the top of the spring / damper assembly, it's a double wishbone set up, not a McPherson strut You can move the top mounts in and out, forward and back, but it won't change the geo. If you drop it too low the roll centres move to silly places and the handling will go to pot. "Proper" race cars have the inboard pick up points raised so lowering the car keeps the wishbone angles at a similar to stock angle. To do that on a MKIV would entail mega money, work and time.

This may interest you, it cites some of the gotchas when you lower a production car. The text in quotes is from a customer, the repiles come from Mark Ortiz, a suspension expert in the USA:

"I work with a road-racing RX-8, and recently we have been experiencing high front tire wear. It was never previously an issue, but in preparation for a recent race,^a softer front anti-roll bar was fitted to the car and a bit of rake was added. Our front tire wear was measurably poorer at that event. It is my suspicion that the softer front bar resulted in^less diagonal weight transfer to the rear and consequently, more front tire wear. Do you have any thoughts on the subject?"

Anti-roll bars do not transfer wheel load diagonally in the sense of transferring it from one wheel of a diagonal pair to the other, and they do not transfer it front to rear. We might say they transfer wheel load diagonally in the sense that they transfer it from one diagonal pair to the other diagonal pair. Putting it another way, they change the dynamic diagonal percentage, but not the diagonal front, rear, right, or left percentage.

The RX-8 has double wishbone suspension in front, unlike RX-7’s, correct?

^

A couple of questions back to you: did you increase the rake by raising the rear, or by lowering the front?^ How do your static camber and toe settings compare, before and after the change?^ Where do the front tires wear, i.e. what part of the tread?

^

Ordinarily, a softer front bar, or a stiffer rear, helps front grip and front tire wear.^ Does the car in fact have less understeer?

"The chassis that we are running indeed has a double wishbone front suspension. When we increased the rake, we added height in the rear; we try to run the front as low as possible at all times. We were sure to set the camber and toe to the same setting as before our changes. We are usually able to achieve very high setup accuracy. The tire wear was strikingly even across its full width. As far as the car's balance, we have been experiencing mid-corner understeer for the entire life of the car, and that did not go away with these changes. It didn't get any worse either though."

The fact that the understeer wasn’t affected by the a/r bar change, together with the fact that it is most evident mid-turn, suggests that something in your front end is running out of travel at full roll.^ The coilover or shock could be bottoming, or it could be something else.^ Other things that can happen in lowered cars, particularly when you’ve found a bit more bump travel at the shock, include ball joints (usually upper) running out of travel, and control arms (usually lower) hitting something, like the frame.^ Sometimes tie rods or a/r bars hit things.

Do you have travel indicators on your shocks?^ If so, and if they don’t indicate that the shock is bottoming, take out the springs, disconnect one end of the a/r bar, and move each front suspension through its indicated travel with a jack, then a bit beyond that.^ See if anything binds or hits.^ See if the steering still works freely.

If everything checks out at full compression, try the same thing, for full droop.^ In lowered cars, it is less common for the inside wheel to top out than for something to bottom on the outside one, but this can happen in cases where a shorter shock has been used to get more bump travel.

There is one other possibility, particularly if you are satisfied that nothing is binding or bottoming.

In some cases, mid-turn push can be caused by the brakes failing to release as they should, and dragging for a time following trailbraking.^ This can even be driver-induced, when a left-foot braker unwittingly fails to release the pedal completely.^ If you can rule out the driver-induced situation, it can be a bit hard to tell if the brakes are releasing slowly.^ One quick test is to try hard cornering, not immediately preceded by braking.^ That is, either test on a skidpad, or drive into a turn fast enough to put the car at the limit going through the turn, but approach the turn at that speed so you don’t have to brake.^ If the car still pushes, you can probably rule out the brakes.^ If the push does not appear when you don't brake immediately before, suspect dragging brakes.

You don't want to lower it any more, it's low enough already. You'll make it understeer like a pig if you lower it more, plus you'll be getting it onto the bump stops, with the rate going through the roof, in corners. The top mounts just hold the top of the spring / damper assembly, it's a double wishbone set up, not a McPherson strut You can move the top mounts in and out, forward and back, but it won't change the geo. If you drop it too low the roll centres move to silly places and the handling will go to pot. "Proper" race cars have the inboard pick up points raised so lowering the car keeps the wishbone angles at a similar to stock angle. To do that on a MKIV would entail mega money, work and time.

OK cool, so if I am dialled all the way out already new adjustable arms are the answer, I am guessing this is the Ikeya stuff?

Here's a photo of how I converted my Skyline bottom arm to a rod end.

These are the minimum spec rod ends you should be looking at, ideally NMB ones, but they are probably at least twice the price of Auriora's aerospace range. Goldline also make some decent rod ends, and they are in Telford.

http://www.aurorabearing.com/Files/aircraft.pdf

Chris and Paul, is this the bit you are talking about?

This is from the front passenger side.

Chris and Paul, is this the bit you are talking about?

 

This is from the front passenger side.

 

http://www.zen85016.zen.co.uk/gallery/supraodds2/SupraWork130709-%20005.jpg

Pretty sure thats the castor adjuster? Looks like thats on maximum which seems correct, take a pic of the adjuster on the front of the arm.