Massive Understeer At The Track, What To Do?

[Smoke them tyres]

Good stuff. The tyre wear should be much more even front to rear.

Most of those expensive (european) cars are hugely overrated. 180k and no faster. Hmmm.

What?.....180k and no fantastic brakes or adjustable suspension? No wonder they can afford F1 racing.

And for such few mods to a great Aust car. Makes the dollar value of the others ill.

I have fitted some custom King fronts that are halfway between std and the uprated Kings..... to me, they are made for the heavier V8. The heavier springs were certainly "working" on the wear rate of the current tyres.

Still to do some further testing to form a solid conclusion. May move the front sway bar to the stiffer position and see how it responds to that.

The ride on the street is MUCH better as an initial impression. Still as pointy in the front end, but tyre life should improve.

[xr_velocity]

Hmmm, tyre wear would be OK....if I had have researched Nitto recommended pressures first...I ran 35 in the last session, when they recommend 42. The first couple of times out it was up at about 40psi. I put it down because the old tyres responded well to less pressure....but these tyres responded by wearing the outer front edge...I could hear the squeal around corners....and notably more understeer the last session with less pressure. Will have the fronts refitted so the worn edge is on the inside and run 42psi next time!

[Smoke them tyres]

Some of the higher pressures that they ask to run is to try to keep the tyre off it's outer edge IMO. Carcass flex is a real issue, and this is an attempt to combat it (at the expense of ride quality). I have dropped pressures down to that region, and have never had the tyre wear be unusual with it in lighter load use.

I suppose the giveaway of the duress the tyre was under (principally the outer edge) was the understeer and accompanying sounds of protest.

The area I look at is to see if the leading edge of the outer tread blocks is showing signs of tearing/chunking (or ramping). That to me indicates extreme concentration of down load on that point combined with side slip.

The leading edge of each treadblock is the first one to see the cornering load........

-chunking equals geometry issues or point overloading (or low pressure)

-"ramping" with a higher lip on the front edge indicates heavy braking as the tread block squirms under that load.....much like a knobby dirt bike front tyre ridden on the road.

All in the "mix".....

Good to hear the progress your car has made. And for not too many dollars either.

[Kroozin]

How does this look reg. camber, caster and toe?

I just got a wheel alignment after fitting the poly bushs for the uca and lca in the front end. This is how it turned out reg camber and caster.

330mm hub to guard, no spacer in rear of uca but 4mm on the front bolts for the front uca's.

Rear is 330mm also though only diff bushes and blades done so far.

[Smoke them tyres]

That looks reasonably ok.

I would keep an eye on the inner tyre wear as the km's go by.....as a check to see that the toe is suitable (and to make sure that a mechanically illiterate person has not changed it by running it up a gutter or something like that).

If not, it will require more toe in as the bush issue has been resolved with the fitment of the poly bushes.

The thing to remember with the fitment of the spacers at the front and rear of the UCA's is that the less spacers at the rear will give more caster (as the top ball joint is moved rearwards), but will also remove some initial camber at the rate of about 60% of the caster added. This is due to the rear portion/arm of the UCA being straight and it being brought more to a 90 degree position with respect to the vehicle centreline when more caster is added........so there is a trade off with the mix of shim stacks fitted on each control arm.

IMO, it would have been better for Ford to have the straight portion of the UCA's on the front section, and the curved at the rear (or both straight ie triangulated). That way, when removing/lessening shims on the rear UCA mount point, it would add caster AND camber.

I remain convinced that the upper control arms should be lower like the older Falcons as there is not so much angularity of the UCA required to get the same dynamic camber gain (UCA effectively shortens as suspension compressed, combating outward roll of UCA mounting point), and the instantaneous roll centre (theoretical intersection point of the UCA and LCA's) is in a higher position in relation to the fixed c of g. It also means less change in the instantaneous centre as the suspension compresses or droops. As far as I can see, the raising of the UCA is done to give more engine bay room. All the manufacturers seem to go with this style of double wishbone setup these days.

But it is still a better setup than the Macpherson strut. You can see the difference in the Aussie ute series. The Falcons typically have about 5-8km/hr advantage in sustained corner grip over the Commodores....and would need less initial camber to do it (as the strut setup has no/very little camber gain provided by the LCA.....which is all unwanted "scrub" anyway). This will mean the tyre temperature for a double wishbone setup will be much more even across the width of the tyre.

Edited 26/04/13 10:55 PM by Smoke them tyres

[Kroozin]

So I had the car out at the new Sydney Motorsport Park (renamed from Eastern Creek) after about a year break. They have done a whole heap of track building and now have different tracks as well as the original. I was on the South circuit which is the tighter more technical side of the complex.

To say I was amazed after being reluctant and thinking the car would seriously struggle on the tight track is an understatement. Since last year I have fitted NItto NT05 semi slick tyres to the car. These tyres have transformed the car, the amount of grip they have in comparison the the old Falken's that were on the car is outstanding. I was very impressed with them, they only got a little squirmish well into the 20 minute session after admittedly I pushed them too far by being too aggressive.

THe understeer that the car had in spades last year is nearly all gone, the car is more balanced to understeer than oversteer, but that is the safe way to go. I could turn in with confidence, if I was understeering a little I could get on the brake a little to bring the front into line and grip, braking into the hair pins became the norm and let me turn in very quickly and hit the apex. Power down and rear end grip overall is still great, with the Nittos on now it is hard to provoke oversteer without really trying to. The car is soft enough to soak up bumps and hit ripple strips without the car getting unsettled, but firm enough to sit flat through corners. The weight of the car in general makes for a bit more of s struggle around the track but it is what it is, I guess I am happy with the setup at the moment, maybe the only thing I might change is a little more camber on the front, but I need a camber kit to achieve that. Perhaps in the new year, I want to keep it as is for now.

I have an engine oil cooler that I will fit before the next day in December the oil overheated each session, given it was 30+ degrees I am not suprised. Water temp is never an issue on my car, never goes past half way. Ford have done a great job with the radiator.

I was running consistent 1:12 seconds which I was happy with since I had a one year break and was on a brand new circuit. I was trying to keep up with a stripped Silvia in the last session, I was about one second slower. I was happy with that. That driver was pushing like I was. Was also keeping pace with two new BMW M3s which were running semi slicks also, I was very stoked with that.

How did your engine oil cooler go on the track + which one did you end up going with?

Are these any good?

http://www.ebay.com.au/itm/OIL-COOLER-KIT-10-ROW-UNIVERSAL-WITH-ADAPTOR-BRAIDED-HOSES-/170714852908?pt=AU_Car_Parts_Accessories&hash=item27bf65ee2c

[xr_velocity]

Don't know if that one is any good. I got a Speco brand kit but have not yet fitted it.....but looking like I will get some time over the next couple of weeks.....time previous to that has just been my laziness!