front setup, rake & height

[911st]

I am all mixed up on how high to set my front height on a stock 86 for DE events.

Conventional wisdom and recommendation is a rear to front rake of 1" or more and about a 25" rear, 25.5" ft fender height.

This is about .75" lower in back and a big 1.75" lower in front.

Any one gone against on this on the track and tried something in the 26-26.5" w around 1/2" rake.

I am hearing the dialing in the rake makes the front bite better but I am suspect.

Could it be a feel thing or is it a real increase in front hold?

Special thanks to everyone that has helped me better understand 911 suspension so far.

[fredmeister]

The rake is only for aerodynamic effects at high speeds. You don't want the front end raked higher than the rear or air catches underneath the front of the car at high speeds, creating lift. It has minor effects on suspension geometry.
Setting the ride heights to recommended fender heights is an approximate guide to make it easy to measure and still get the angles of the suspension arms in the right spots for best geometry. It is better to measure to pivot axis/torsion bar centerlines, but this is harder to do.
Basically you would like to see the front lower A-arm to be parallel with the ground for best handling since any motion of the suspension up or down from this point has least effect on static camber settings. It also has least effect on bump steer provided you account for this by spacing the steering rack (up) to get the steering tie rod parallel as well.
Once all this is done you need to fine tune height again during the corner balance routine.
Hope I helped you.

[911st]

Might be that the 1" neg angle creates a little suction under the car. Of course, the more air you can keep out from under the car the better.

Kind of a third spoiler.

[Mahler9th]

You are in Sacramento? If so, you have many local experts that can help you-- much better than internet experts. Go see Ron Kain. Work through the local PCA. There are lots of resources that would be better for the type of car and tracks in our area (I am in Fremont). If you like the SF Bay area, try SmartRacing Products or WEVO. Up in Reno, Sporthaus. Between the three of those businesses alone, many of the fastest PRC race cars have been set up.

[911st]

Thank you.