Got a track related question? I'll try to answer.

[CSG Mike]

Originally Posted by racingfool

I don't understand what you are saying.

The stock car has dynamic geometry that is achieved via asymmetrical bushing deflection. It's quite trick, and allows for the stock car to perform above expectations for the presented geometry based on straight articulation.

[racingfool]

Originally Posted by CSG Mike

The stock car has dynamic geometry that is achieved via asymmetrical bushing deflection.

Bushing that are stiffer on one side or one direction? Sounds interesting.
Is this all common knowledge? Should I search?

Originally Posted by CSG Mike

It's quite trick, and allows for the stock car to perform above expectations for the presented geometry based on straight articulation.

Care to be more specific? You sound like a lawyer.

My initial question was about ackerman.
Without me having to take an engineering class,
can you tell me if the 86 has what at least acts like normal ackerman?

[CSG Mike]

Originally Posted by racingfool

Bushing that are stiffer on one side or one direction? Sounds interesting.
Is this all common knowledge? Should I search?

Care to be more specific? You sound like a lawyer.

My initial question was about ackerman.
Without me having to take an engineering class,
can you tell me if the 86 has what at least acts like normal ackerman?

Pro ackerman under normal conditions, anti-ackerman when heavily loaded.

This behavior is eliminated when the factory asymmetrical bushing is eliminated, but also leads to what most feel to be a more linear car.

[NoHaveMSG]

Originally Posted by CSG Mike

Pro ackerman under normal conditions, anti-ackerman when heavily loaded.

This behavior is eliminated when the factory asymmetrical bushing is eliminated, but also leads to what most feel to be a more linear car.

Are you refering to the front lower control arm bushing? The big bastard up front, bolt mounts vertically.

[Racecomp Engineering]

The rubber one with big voids built into it so it deflects in certain ways intentionally.

- Andrew

[Racecomp Engineering]

I think the MotoIQ sticky at the top of the suspension forum has more details but it's been a while since I looked at that. I'm not sure 100% of the information in that article was correct but it at least has some good info.

- Andrew

[peaches]

I ran Barber today and ran into something I’ve never felt before with the car, in certain corners the steering becomes heavy as if it was not powered. Any other place on the track it works fine. Is this normal for the car? I’m running the tracbox, a friend told me the nannies are still kicking in and it’s expected.

Thoughts? Want to see if it’s ok to keep running the car like this or if it’ll eventually break the rack

[strat61caster]

Failsafe mode where the power steering motor overheats/overloads and shuts down to protect itself.

Less caster can help if you have aftermarket caster adjustment but otherwise most people just power through it iirc.

[Code Monkey]

Happens at Road Atlanta coming out of 5 and going uphill, I just power through it.

[Fschlottau]

Mike, got one for you. New to the forum and somewhat new to the car. My wife runs 86cup in Colorado. We’ve done a ton of HPDE, instructing, and lemons racing in mix of BMW, Camaro, and the BRZ. I do most of the needed wrenching, but this has me a bit stumped:
Her BRZ had 20k miles when we got it and had a bunch of modifications from prior owners (notably Tein Flex A, rear Perrin sway bar, bunch of stiffeners etc.). I don’t think the car had seen the track much before we got it. When she first started tracking we noticed the Left rear wheel nut loosened itself by about 1/2 turn and the bearing also seemed a bit loose. I replaced the hub/bearing assembly with a Subaru part from dealer and installed a fresh nut torqued to 140ftlbs. We did 5 track days since then and I had to re-tighten the axle nut again (was trying to back off even w the dimple, maybe 1/16th of a turn.) I just put the car up and L rear wheel bearing feels loose again!? Very subtle rocking, but it’s only been 1000 miles...

In post 863 you mentioned something about “if you don’t replace the hub, you’ll keep loosing bearings”. We replaced the whole bolt-on unit, but should we be looking at more?

Hope you can point me in the right direction... cheers!

Edit: we usually run w full pedal dance. (I.e. shouldn’t be getting a ton of heat from rear brakes dsc etc... car is running CSG ap racing BBK w/ DTC60s up front, stock callipers w dtc60 out back.

[colobrio]

Originally Posted by strat61caster

Failsafe mode where the power steering motor overheats/overloads and shuts down to protect itself.

Less caster can help if you have aftermarket caster adjustment but otherwise most people just power through it iirc.

This was happening to me a few weeks ago at High Plains Raceway, lap after lap on an uphill, 80 mph sweeper. Glad to hear it isn't a big deal, but is there any way to prevent it? Other than going slower, which isn't really option.

[jflogerzi]

Originally Posted by colobrio

This was happening to me a few weeks ago at High Plains Raceway, lap after lap on an uphill, 80 mph sweeper. Glad to hear it isn't a big deal, but is there any way to prevent it? Other than going slower, which isn't really option.

Someone mentioned a bigger alternator... Fixed it for them

Sent from my GM1915 using Tapatalk

[staples323]

Is there a rough ride height estimate for 2.2-2.5 degrees of rear camber on stock LCA's? Trying to not take the .5 hit in NASA TT5 for replacing control arms.

[itschris]

Originally Posted by staples323

Is there a rough ride height estimate for 2.2-2.5 degrees of rear camber on stock LCA's? Trying to not take the .5 hit in NASA TT5 for replacing control arms.

Mine were in that range with the rear pinch welds at 130mm