Chassis Setup

[Scott_AZ]

So I asked the question recently regarding tire cutting/siping/grooving and got some amazing advice thanks to all who contributed.

My next question is regarding chassis setup. I would venture to guess you'd want to be as close to 25% weight bias on all 4 corners, wet and ready to rock but what about all the little things such as caster, camber, steering axis inclination, anti-squat, ackermann, etc.? I don't intend to make this topic too nasty deep-dive (I have the milliken book) but I think you can talk about the principles of what should/could/does work well on shortcourse without having EXACT percentages or degrees of your configuration. I also get that this is the secret sauce to any chassis builder's reputation/career and don't want to rip anyone else's work off.

Specific to my truck (stock full), I am not allowed to change much, but anyone who has seen my truck from the outside can attest to the fact it needs some love lol. Right now, I have absolutely no idea the degrees of caster or camber, toe is pretty neutral to maybe a couple degrees of toe-in. This part hasn't gotten much love because we wanted to LAST an entire race before tuning.

What are some general safe guidelines to being successful in shortcourse?

For camber, I would guess a pretty big range and this should change depending on track conditions but negative 5-20 degrees seems reasonable.
Would you ever bias camber? At speedworld, it's mostly left turns and I could see adding a little more (1-2 deg) neg camber on the right being advantageous (just a theory)

Caster, I would guess would be pretty stood up for some of the tight turns. 5-20 degrees of caster would seems reasonable. Again with the bias question because of all the left turns. Circle track guys bias their caster quite a bit (20-50% in some cases).

Toe, I would guess you'd want zero to maybe up to 5 degrees of toe in. Please speak up if this is wrong. Toe and caster can make a car really "twitchy" which you wouldn't want because of the limited traction.

Tire pressure, we currently are running all the same tire pressure. Mostly focused on consistency for now, this is considered a fine-tuning thing for later in the game after the chassis is setup.

Most of the other stuff, I can't really control but the principles from those building a chassis (hopefully a successful one) would be good info to see the ballpark of where things in a world without constraints should be so we can target the totals (ie. SAI+caster).

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[Coastal]

Would love to hear some guidelines for this too....come on pro's help us out!

[Kyle Green]

Put about a half inch of tow out in the truck and bring it out for practice on saturday

[movindirt]

What truck are you running?

Each type of suspension will have it's own unique settings to get it to work.

[Scott_AZ]

85 chevy 2wd short bed is the make and model. We've replaced the frame side mounts with heims, and it has big balljoints. When we did that, we just slapped em back on and called it good enough and more focused on durability than tuning. It's strong as hell but not exactly "high performance" hehe.

Thanks for the offer Kyle, not sure if we can make it this weekend or not. I still need to focus on getting a bigger cooling system on it if I plan to make the race coming up. I didn't plan on going to Kingman and moving it here put on a little more pressure than anticipated. Right now, we plan on going but that may change.

Another thing I didn't really discuss would be weight jacking. Us stockers cannot adjust weight jacks but you coilover guys have it easy.

[Desert68]

Might this thread get more hits in the Shop - Suspension & Steering forum?

[Scott_AZ]

Someone has to have some general numbers they wouldn't mind sharing! Shoot me a PM, I'll swear to secrecy, sign an NDA, and free cold beer if you come to my pit. Hell if the price is right, I'll paypal ya.


Scott

[PDANK Racing]

My camber is set at -2deg(ride height) and seems to handle pretty well. Not sure if that will work for you, but cambers easy to adjust.