Tuning/Setup Tips?

[Just Nasty]

Hey, I was wondering if anyone could direct me to some informative tips on how to properly setup/tune a car for autocross and various circuit events? I know no one will want to put their specific setups out there, so any general info would be great. Camber, tires, weight, ride height, etc etc all that good stuff.

Looking to setup a 95 GSX to be specific, but I'd like to know about all the technical stuff across the board too. I'm really starting to take a big liking to NASA events and the likes and want to broaden my knowledge beyond the general straight line racing.


thanks
(I tried searching but the terms are too general)

 

[everbruin]

look at 2g links http://www.wincom.net/trog/autocross/tech.html

 

[RusherRacing]

I would recommend buying a few books the Carroll Smith Drive to win and Tune to win. How to make your car handle by fred Puhn. I use those as handy references quite often. There are some really big thick engineering books like Race Car Vehicle Dynamics (Milliken sp?)

Tire rack has some good basic tech articles.


Changing this behavior with tire pressures this is the easiest way to change the handling of your vehicle.
http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=58
This tire rack gives you general tips to help

Suspension Components Geometry definitions
http://www.tirerack.com/suspension/tech/techpage.jsp?techid=114
Note a coil over is not a spring with an adjustable perch... but a full spring, shock, bump-stop combo.

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=4
This site is very good explanation of your basics terms when defining the geometry of the suspension.

I will post some more in the handling section later this week.

 

[jtmcinder]

The best book to start with is Puhn's How to Make your Car Handle. A good test of whether you have the math down is to make a spreadsheet that calculates all of the critical values from the simple inputs.

- Jtoby

 

[Slow old poop]

Hey, I was wondering if anyone could direct me to some informative tips on how to properly setup/tune a car for autocross and various circuit events? I know no one will want to put their specific setups out there, so any general info would be great. Camber, tires, weight, ride height, etc etc all that good stuff.

My recommendations:

Tires: 235-17 Toyo Proxes (cheap, sticky, wear like iron--you can drive them to the track)
Wheels: Mustang Cobra SVT 17x9-in. replicas (about $110 each)
Brakes: Carbotech Panther Plus pads (good pads and streetable)
Camber: No adjustment available stock. You'll need camber plates to get 2-3 deg negative camber.
Shocks: Few available out there. KYB AGX are acceptable, Koni adjustables are better.
Ride height: No adjustment available stock. You'll need something like Ground Control suspension to adjust the ride height, or shorter springs.
Bushings: Replace everything with poly
Sway bar: Stock bar is fat enough.

I can't speak for autocross setup, but for circuit events, reliability, instruction and seat time are the most important investments you can make. DO NOT MODIFY THE ENGINE until you have a year of seat time. Otherwise, you may spend the entire event weekend fixing things, such as boost leaks, oil leaks, wiring, loose parts, etc. (been there, done all that). An experienced driver in a stock car can blow the doors off a modded car that is not driven properly.

If you are just getting started with NASA, then I recommend tires, wheels and brakes...and that's all. Get seat time first, pick the TT class you want to run in, and build your car for that class.

Rich

 

[asian312]

Agree with SOP 100%. Setups and adjustments wont do you much with out knowing the affect it has on the car. Books will give you the concepts, but seat time will make make the light bulb glow. Make sure the car is in good running order, slap on some new brake pads and welcome yourself to the addiction.

Further down the road:
- If your car is a '95, new suspension bushings might also be in order.
- my preferance on brakes are stock rotors and Porterfield R4-Es (they eat rotors, but rotors are cheap).
- For front camber changes in the 2-3 deg range check out SPC Front Upper Control Arms (http://www.roadraceengineering.com/eclsuspension.htm).
- As a note on the setup, 17x9-35 are the wheel size you need and can fit up to a 255/40/17. One thing that I should point out is that you would need a stock height suspension setup or stiffer springs with maybe an inch drop max due to the tires extending past the fenders.

 

[vaboys2ndgen]

not to take away from the autocross part of the thread but are these books also helpful for suspension in general or does it mainly focus on roadcourse type events only?