Alignment Help Thread

[Norm Peterson]

Originally Posted by The_Stache

Need thoughts on new setup...

Running autox and hpde's (6-9 events a year) and daily driving on 2nd set of wheels/tires..

Hardware is: coilovers, rear and front sway bars, rear trailing arms and toe arms, 305/30r19s (race setup), 285/35 r20 (daily),poly bushes all around... sitting at about 400 rwhp...

Previs setup worked great... but wondering if I'm leaving more grip on the table..

Front:
Camber: -1.4 to -1.6
Caster : fixed
Toe: 1/16 total

Rear: -1.0 to -1.2
Toe: 0.00 total

Thoughts?

Is it understeering or oversteering? I'd start by pushing camber further negative on the end that's giving up first while leaving the other end alone.

If cornering in your daily driving gets enthusiastic enough, often enough, front cambers as high as -2.0° are do-able without getting into wear that's too uneven. Toe that's somewhere between zero and a tiny bit 'in' will definitely make for less 'twitchy' daily driving and may help keep the wear a little more even.

I do remember a Fox-body competitor at autocross who would change front toe to a "competition setting" for autocross and back again for the drive home. I used to do the same thing with front camber on a '79 Malibu. Both of these cars were stick-axle, but the idea of making temporary alignment changes to best suit the situation at hand stays the same.


Killboy - the conversion from degrees to inches for a 28" tall tire is pretty close to 1/2" per degree. Tangent of the toe angle times the tire OD.


Norm

[TWOFORTYZ]

Originally Posted by Info@PeddersUSA.com

Pedders Camaro/G8 Bushing Timing Tech Sheet.pdf
Pedders Camaro/G8 Alignment Tech Sheet.pdf

We have based our align specs for street and track based on professional drivers using telemetry equipment, tire temp monitoring, and recommendations from 3 professional drivers, including Paul Tracy.

The following Aggressive Street settings are recommended based on an average drop of 1 inch:

Front:

Camber to -1.0 degrees
caster 7.4 to 7.8 degrees (requires adding caster Pedders Caster eccentrics to get into this range of caster, which is very benificial
Toe: .1 degrees toe out each wheel.

This amount of toe out will reduce tire scrub and understeer, and will not add to tire wear.

Rear

Camber to -.5 degrees. Reducing the camber to this level will reduce understeer. With a 1 inch drop or lower, you cannot obtain this number without Pedders rear camber eccentrics

Toe to .05 degrees toe in each wheel.

For Aggressive Track

Now these settings are only for a Camaro with a Complete Pedders Track suspension Package. This setup with street performance tires can hit 1.38g's thru the turns, and have great tire temps all across. Paul Tracy said this setup was "PERFECT"

Front

Cambers to -2.4 degrees
Caster 7.5 to 8.0. Requires Pedders Caster eccentrics
Toe .25 degees toe out each wheel. (This setting should not be used for the street)

Rear
Camber -1.2 degrees, Required Pedders rear eccentrics
Toe .05 toe in each wheel.

Here is a video of the Pedders Camaro with these settings, driven by Paul Tracy. Notice the Pedders Camaro being chased by a ZR1, which could not go the same line as the Pedders Camaro.

Here is a video from Chris Fessler, our dealer and sponsor:
http://vimeo.com/8678971

Any questions just ask

thanks
mike
dms

Disclaimer, I am saying this with a grain of salt, but feel very strongly about traffic safety so I am saying this either way. I respect the opinions of others, but do not believe toe out is necessary or beneficial for a street car.

I like everything except the front toe out for aggressive street driving. That causes instability and makes any vehicle less pleasant to mill down the freeway, the improved turn in characteristics are greatly outweighed by the loss in stability from my professional experience. I had no loss in performance when I went with .05 or .10" toe in on any of my cars, and was much more comfortable when running down the freeway and catching potholes and tar snakes. Granted the increased caster helps with stability, I personally will never trade that off by putting toe out up front unless for hypothetical trailered autocross car.

I worked full time as a high end mechanic for several years, and have done dozens of custom alignment experiments with countless hours of testing and tuning on cars with a similar suspension design. Anything I own is driven a LOT and very quickly. I have already put 6000 miles on my SS in 6 weeks. If you are like most people and barely drive, or don't spend much time about 45mph, the twitchy steering may not bother you.

[Norm Peterson]

↑↑↑ You might want to check more recent alignment suggestions by the same entity (under a new name).

The data table in this post was copied directly from "the book" this past September. Read the entire post and post #714 (this will make sense when you do).


FWIW, when one of my previous cars became unreasonably skittish I found some amount of toe out that I no longer remember but could have been as much as 0.2° per side. I've usually aimed for about 0.02" (in) across an 18" wheel on each side, or somewhere around +0.10° total.


Norm

[TWOFORTYZ]

^^

Thanks Norm! I still wouldn't run 0 toe in front, but that's a lot safer than herding cats with a toed out front setup.

I wonder why everyone spec's so much toe in for the rear? The car toes itself slightly in under load due to the rwd design. I may have to do some experiments to see if there is anything to gain, the car does have a bit of snap over steer which will be reduced/more progressive with less rear toe in.

[JusticePete]

Feel free to play with your alignment specs, but we have been doing this since 2009 and have a pretty good idea of where the car needs to be.

[California]

Hey Guys,

I have a 2011 L99 Convertible with Sway Bars and 22" Vossen VVS-CV1 wheels.

Are the below Alignment specs (OEM SS Column) the most ideal for Street Driving?

Thanks,

[JusticePete]

22" wheels wear fast with a lot of negative camber. Use the OEM spec.

[California]

Originally Posted by JusticePete

22" wheels wear fast with a lot of negative camber. Use the OEM spec.

Thanks.

Do you mean these specs?

[JusticePete]

Originally Posted by California

Thanks.

Do you mean these specs?

Those will be fine with your 22s

[suprchrgd]

Opinions on my alignment?
Car is 500whp with btr stg 4 cam. 285/35/20 frt and 305/35/20 rear and is mainly a street car, but may see a few sessions on the road course this summer.
My suspension changes:
Bmr: Trailing arms, Tie rods, upper control arms, 1.4” drop springs, poly cradle bushings, poly differential bushings.

sorry for the huge pic, uploaded from my phone...

[JusticePete]

The rear toe should be in 0.10 per side for high speed stability and stability under hard acceleration.

The front Toe should be at 0.00 to improve on center steering feel and help with turn in.

Front camber issn't wrong, but it also isn't doing much. -1.25 won't create much tire wear and will help with cornering and understeer. Even better at -1.5 but you'll start to see inside shoulder wear faster.

Next time print this and take it with you.

http://www.jpssonline.com/t-camaro-a...fications.aspx

[TXM62SS]

Damn Pete. I wish you were in Texas bud. I would have you handle all my suspension work.

[JusticePete]

Originally Posted by TXM62SS

Damn Pete. I wish you were in Texas bud. I would have you handle all my suspension work.

Plan a bucket list trip to VIR. You can swing by the shop and then pit with us at VIR

[suprchrgd]

Originally Posted by JusticePete

Plan a bucket list trip to VIR. You can swing by the shop and then pit with us at VIR

thanks Pete. I sent you a pm. i may be making a trip to myrtle each this summer and may just drop my car off for a few days while I head further south.