Increased front negative camber now oversteering what next

[NoHaveMSG]

I had similar issues when I went to 245 RS3's on my mostly stock suspension. The car would body roll and load up, then the rear would let go under hard cornering. On Flez Z's now, car much more planted.

[finch1750]

Do you run TC on track? Try it off. It is very invasive and actually feels less stable then with TC off imo.

[ZDan]

Originally Posted by Harey

My wheel alignment settings are:
Front Camber -2
Front Toe +0.5
Caster 6 degrees 12 minutes
SAI 17 degrees 18 minutes

Rear Camber -1.3
Rear Toe +1.0

Toe-in is in millimeters I trust? If so, that's fine (about 0.05° front and 0.10° rear), could run zero though.

I'd go with a front sway bar to balance handling, that will take advantage of the added front camber and provide more grip at the rear of the car.

[Harey]

Wow thanks for all the posts, lots of good info there.

I definitely agree that the additional front camber has made my car faster, its not a complaint. Its more of a what to do next question.

The rear toe is +1.0 degree (toe-in) which was intentionally added by the guy who did my wheel alignment to reduce oversteer and add high speed stability (which he does to all of his twins with great success).

I realised I left out some information:
I only get the traction control engaging on the street. I have never had it occur on the track (and mostly turn it off when i remember to). TC engaging occurs in sharp bends on the street with less than ideal surfaces or a few bumps.

On the track the turn in is fantastic, I can always bring the front in but then for the rest of the corner it is about managing the rear traction. It definitely feels like I have way more grip in the front than in the rear. The rear has never kicked out on me but I am not pushing it to the limits.

My previous track car was a Subaru awd and it was a constant battle to turn in. I learnt how to trail brake which helped heaps. Complete opposite to this car which I feel like at the speed the rear can take the corner my front laughs at it.

There is definitely a lot of driver improvement to go. My main focus at the next track day will be feeding in throttle as I unwind the steering. However, I just feel mid corner with zero throttle and trying to balance front and rear grip there isnt as much driving skill (long corner), its more about the car. Corner entry and exit I completely agree that driving skill is massive.

[Harey]

Originally Posted by wparsons

The balance of camber front to rear is actually decent. IMO, it's probably how you're driving that's causing it.

Does it happen if you're off the throttle, or does the rear kick out under power? Are you adding throttle without reducing steering input?

It happens on the street without any throttle but normally on a less than ideal surface sometimes with bumps. With less front end grip I couldnt take the corner as fast so the rear wasnt under the same stress.

I think the question is "Now I have more front end grip, how do I increase rear grip to match"

[strat61caster]

Originally Posted by Harey

I just feel mid corner with zero throttle and trying to balance front and rear grip there isnt as much driving skill (long corner), its more about the car. Corner entry and exit I completely agree that driving skill is massive.

You shouldn't be at zero throttle mid-corner unless you're out for a leisurely Sunday drive or you screwed up.

[Harey]

Originally Posted by why?

are the tires new? Are the rears worn more than the fronts?

Definitely need more rear camber.

All tyres purchased brand new last year with less than 3,000 miles on them. They are worn evenly front to rear.

[Harey]

Originally Posted by strat61caster

You shouldn't be at zero throttle mid-corner unless you're out for a leisurely Sunday drive or you screwed up.

I thought if you are accelerating mid corner then your corner entry speed was too slow?

[Harey]

Originally Posted by ls1ac

I just thought I might mention one other possibility, sometimes at the track we would adjust the front for more bite and the driver would swear we had ruined the back. When in fact he would be turning in faster lap times. The front improved and the back did not ,but with the higher speeds the back was loose. The seat of the pants are not necessarily the best measuring device.

Completely agree with this, this is exactly what is occurring. It is definitely faster with the additional front negative camber.

[NoHaveMSG]

Originally Posted by Harey

I thought if you are accelerating mid corner then your corner entry speed was too slow?

Maintenance throttle.

[johan]

MCA Traction Mod, easy to install and doesn't screw up your alignment. Also you're already in Australia so they're easy to procure.

[ZDan]

Originally Posted by Harey

The rear toe is +1.0 degree (toe-in) which was intentionally added by the guy who did my wheel alignment to reduce oversteer and add high speed stability (which he does to all of his twins with great success).

1° is an absurd amount of rear toe, way way WAY too much. Like 10x too much. And 0.5° is also a stupid high amount up front as well. Are you *sure* that's in degrees? If so, handling is guaranteed to be fuxored with those toe settings. Not to mention tire life...

[strat61caster]

Originally Posted by Harey

I thought if you are accelerating mid corner then your corner entry speed was too slow?

Well at the risk of derailing this thread to hell...

Saying "zero throttle" implies that your foot is off the pedal and the car is coasting and slowing down, maybe we're on the same page and just using different language and you do mean maintaining speed at apex which is something I would agree with and I apologize in advance for the misunderstanding and this wouldn't be new theory for you but it might help others. Most quick drivers are accelerating at or around the apex and using the rwd characteristics to complete the necessary amount of yaw, at a minimum there should be some amount of throttle input to maintain speed in a perfect theoretical corner. Of course some corners will be exceptions depending on what's happening.

2:00-2:30 you can see the throttle being fed in well before the apex of each corner.
[ame="https://www.youtube.com/watch?v=NtaV_cOGgTM"]Schumacher's driving style explainded - YouTube[/ame]

Recent Lewis Hamilton lap:
[ame="https://www.youtube.com/watch?v=zJRh9FG83d0"]F1 2017 v 2016: G-Force Comparison - YouTube[/ame]

There's some amount of throttle being used pre-apex at just about every corner as good drivers are 'balancing' the car and finding the limits, great drivers nail the speed on the braking and are just maintaining until they know they have the grip to accelerate.

But we're not F1 drivers. It's a bit harder to find telemetry of street cars with known good drivers, this should do. The key here is there's no drop in speed after braking is completed, that doesn't happen with your foot off the throttle unless you're using cruise control. Given that we're mostly amateurs doing HPDE's and such, it's safer to brake a little too much and begin picking up speed, but with enough practice we can have data that looks as good as the fast guys.

[ame="https://www.youtube.com/watch?v=38WqRJf7So8"]2013 Subaru BRZ Hot Lap! - 2012 Best Driver's Car Contender - YouTube[/ame]

Or this is a good example too:

[ame="https://www.youtube.com/watch?v=HlwAIb4Zz9Y"]Fastest Lap at Toronto Motorsports Park In a Scion FR-S - YouTube[/ame]


YouTube has a great feature that allows you to slow down the video so you can get a better understanding (in this case) of speed relative to car position.

[Harey]

Originally Posted by ZDan

1° is an absurd amount of rear toe, way way WAY too much. Like 10x too much. And 0.5° is also a stupid high amount up front as well. Are you *sure* that's in degrees? If so, handling is guaranteed to be fuxored with those toe settings. Not to mention tire life...

Woops yeah your right its in mm not degrees.