boqueron

Under a rather long and hard braking at the end of a straight line, at 150 mph which is followed by a corner at 50 mph the car unsettles more than I would like . This happens at the middle to the end of the braking period. The feeling is that the front is struggling to find grip while loosing it's line. Nothing specially worrying but it obviously makes me loose some confidence and makes the entrance of the corner more difficult.

Could be that my car hasn't got the lip under the front bumper ? It will be installed next week, but I understand that it should help at high speeds and not necessarily under braking...

I am using Orange Pagids and steel brakes and Ps'2s with 40 pounds/hot pressure, swaybars to -1F and -2R. Roland's Kussumauls settings with only -1.5 camber on the front.

On the rest of the track I have nothing special to mention about the brakes ...

Could you please help me to get the "perfect" gt3...?

Mr. C4

Hi,

The front lip will for sure have some effect at those speeds so good that you are having it installed. I'm sure a wheel alignment would also help.

Ciao,

930man

had the same thiong when i first got my car ... deffinate alignment fixxed it . there are several post with alignment set up which helped it.

boqueron

I will recheck the alignment, it was done 3 track days ago !! ( aprox. 450 miles ago....)

DanH

If it's not alignment, could possibly just be the track surface at that corner, or you unsettling the car by jumping on the brakes too hard initially. The latter makes a massive difference, both to stability and stopping distance.

enthusiast

Is this a section of the circuit where you are threshold breaking in a straight line, downshifting, off the brakes, and then turning? or One where you are trailbraking into the turn?

Assuming the car and your transition into the corner are fine you may be at the limit of speed you can carry into the beginning of that turn.

GT3 Racer

Do you have toe out dialed in? That will do it. Car turns in great but the front hunts around on the track under heavy braking.

Bob Rouleau

Harry - you NEED the front lip. Iwould also be suspicious of the rear alignment. The GT3 loses rear alignment rather easily. Bumpy roads and or tracks can knock the alignment out rather easily. Several people of this forum have installed different rear control arms to avoid unwanted camber changes.
Regards,

enthusiast

Maybe a mechnical issue... but he said it only acted that way on one braking zone on this circuit.

boqueron

DanH,
the surface there is OK.Could be the braking technique ( I will work on that)...but it does not appear on other corners ( not as fasts as this one BTW)...

Enthusiast,
Threshold breaking in a straight line, downshifting, WHILE BRAKING, and then turning..

GT3 racer,
I do have Front Toe In

Bob,
I will check alignment and install the front lip

THANK YOU ALL !!!!!

zoomzoom

40lbs hot pressure? Sounds high to me! (I normally run around 32 hot on track...)

rodneyr

Car unsettles under strong braking happens with my car all the time, and I had my alignment set using a Hunter machine. A known issue with the car is the Front bias is too high which causes the car to get unsettled. The issue is magnifed on a bumpy or rough surface.

Also, 40lbs hot pressure is fine with stock PS2's.

AW

As far as I know, this is likely:

- too much front negative camber. Try removing 1degree or at least have it checked
- brake bias too much on the rear. I realize there is no brake bias but you could run less aggressive pads in the rear. I understand you feel the front is moving on you but could it be the rear?

I suspect the aero front lip effect is minimal below 100mph (in fact probably above 100mph as well, compared to the weight of the car).

I hope this helps.

AW

boqueron

Thanks again ! Nice to have all this information. It will keep me busy for the next two months ...!!

Mike K.

I had similar issues while in florida. Things you can do to start are to bleed your lines to death and check your alignment( I had excessive front camber). After you can try different brake compounds. I have found that a slightly more aggressive pad in the rear will help with bias .