General info for an uneducated AX'r, Primarily tire pressure Options

[jd66921]

Hi,

I've been doing AX's for a little more than a year.

Currently I'm driving Howard's old car "Suzi". She's a pretty much
stock 914 2.0l. She's been lightened a little. She has fiberglass hood and
bumpers. All her heat and ventilation has been removed. Weight is 2050 lbs

The engine is a stock 2 l as far as I know, and has an unmolested MPS.
The transmission is stock.

I do not know what kind of shocks are on her. The rears are yellow and do not
seem to have any adjustments. The rear springs seem fairly soft to me? There
are sway bars front and rear, I do not know what size they are. The fronts are
adjustable with a number of holes in the horizontal arms. They are set to the center.

I typically run about 10-12 seconds behind Corvettes, A Birkin, and a well
setup Mustang Cobra. I am typically 3-4 seconds behind set up Miata's,etc.
This is on courses that I would generally say favors the high powered cars.
Generally, the courses are two 180's at each end, fast stuff down the middle,
and most of the courses I can take flat out or with minimal lifting., except for the
real corners, of course.

Wheels are 5.5 inch Fuchs, with Falken Azeni RT-615's.

My big questions is: I am now running 25 psi front and rear in the tires.
Is that in the right ballpark? Should I go higher/lower, and why? The car
feels good most of the time, with a little bit of mostly controllable oversteer. I
can get some wheel spin off the line, and a little on right hand sweepers.

What will changes to the front swaybar make? I've never understood them! I
would prefer an answer like "increasing the front rate will increase grip" instead of
"decrease over steer".

Anyway, I seem to have reached the limit of my improvements without help, so
I 'd like any help I can get!!

Thanks,

Jeff




My first question is

[PeeGreen 914]

Most of these guys know their tires very well but you should understand why the tire prssure needs to be where it is as well. Do a little reading on tire pressures and contact patch and temps.

The perfect pressure is the one where your tires are heating evenly, using the correct contact, and gaining the most grip. You can tell this by looking at the tires after a run. See where the tires are getting wear. If the scrub area is too much you need more pressure. If the tires are not going far enough use less pressure. Feel if the tires are getting heat evenly across the tire or if it is in one spot.

There is a lot more to this but those few tips give you a good idea what to look for.