Antidive, how to adjust it... Options

[Mike T]

Certainly not -3°.

If -1.75 is still too much I guess I need to do some homework.

I've spent the last 2 seasons just getting the engine/trans to work correctly I have neglected the rest. As you can tell.


The ride height is set so the control arms are just parallel to the ground, front and rear. In jounce they will go past parallel which is probably bad.

Mike T

[brant]

Mike,
is the picture on page one under HARD acceleration.
its certainly nose up.

does it sit "nose down" when static?

I'm still betting that its the rear brake bias.
brant

[Don Wohlfarth]

Too much rear brake, add in a little rear toe, might want to dail out a little of existing front toe, forget trail braking.
Get your car slowed down in a straight line, turn in, get on the power. There are very few turns in ax where you will benefit from trailbraking, instead concentrate on the other turns.
Trying to trailbrake a car with too much rear brake will put you in the weeds.

[Mike T]

Brant- That was a slalom. 28 paces between cones. may have been at the end leading into a short straight to the finish lights so I may have been accelerating at that point.



Here is hard acceleration.

Mike T

[Brett W]

raise the car up until the trailing arms are angle down slightly. Same goes for the front, but I would start with the reaer only and see how the car handles. Problem with the front when you lower it you increase the distance between the roll center and height of the CG, thus causing the car to roll more in a turn, not less like common sense would lead you to beleive.

Plus you have other problems.

[Mike T]

Mike,
is the picture on page one under HARD acceleration.
its certainly nose up.

does it sit "nose down" when static?

I'm still betting that its the rear brake bias.
brant

Brant;

I just went through your Vintage Racer thread.

I am inspired.

Thanks;

Mike T

[brant]

[Brant;

I just went through your Vintage Racer thread.

I am inspired.

Thanks;

Mike T
[/quote]


thats mighty kind of you sir!

[Mike T]

Over the weekend I discovered some things that were not so good. Basically my chassis is twisted. I always thought it sat funny. I read Andy's "celette bench" thread and followed the links there. I got the same problem. Set ride height so the car looks right and the corner weights are way off. Set corner weights and it look crooked.

http://www.914world.com/bbs2/index.php?show...515&hl=bend

Not sure what I'm going to do now.

Mike T

[brant]

been there done that..
let it look crooked... (its only appearance)
and go with the correct corner balancing!

it will handle well still.

brant

[Mike T]

been there done that..
let it look crooked... (its only appearance)
and go with the correct corner balancing!

it will handle well still.

brant

When the corner weights are right the twist of the chassis causes the front control arms to be at different angles. The passenger side control arm is parallel to the ground but the drivers side goes uphill from the balljoint to the torsion bar. The inner pivot points are nearly 1" different heights from the ground. Causes it to handle differently in right and left corners. I bet the roll center is migrating around like crazy.

I'd just bent it all back to where it belongs if i didn't have all the roll cage and front reinforcments welded in there already.

How about if I space the drivers side of the torsion subframe down untill everything is in the same plane again? I mean it's bent up now I'll just bring it back down where it belongs.

Mike T

[brant]

ouch...
sounds more serious than mine was.
you sure you can't cut the cage and pull the chassis a little.

brant

[Mike T]

That is a possibility. This whole thing started as a campaign to lighten the car more. I intend to do something similar to URY914's car. After I cut the bent nose off I'll have a better chance at straightening out what's bent. I'll be adding more tubing so replacing 2 at the same time won't be an issue.

For sure something has to be done.

Mike T

[Mike T]

An update to the overhaul of my car.

http://www.914world.com/bbs2/index.php?showtopic=59712

I found one unusual thing; the drivers side threaded shock sleeve had slid down over the support lip on the Koni Red shock. When I installed the sleeves in 2004 they would not slide down over the lip even though there was a counterbore in the sleeve evidently for that purpose. They just rested on the lip. I figured I had the wrong part. I decided to use them anyway. The passenger sleeve was still resting on the lip.

So the perch on the drivers side was 3/8" lower than when I corner balanced the car. It's all I found that could account for the sudden unstable handling I was experiencing. The wedge I inadvertantly had dialed in made the car loose in one direction and tight in the other.

I deburred everything and now both sleeves are sitting properly on the shocks and are reinstalled on the car.

I expect to set the ride height, set the corner weights, toe, caster, camber next week.

My next AX is Sept 17th.

Mike T