What would it be? I'll be talking to a suspension guru soon, and wanted to bring a few questions from the peanut gallery here.
Who's the expert? I can't tell you, but I can say that he plays at a slightly higher level than you or I. Think IMSA racing and you'll be on the right track.
Is bump steer that big of a deal when on a racetrack?
How important is caster in a RWD strut type vehicle?
How much bump steer is considered tolerable in a general sense, on the street or track, power steering or manual steering, FWD, AWD, RWD.
Explain the pros/cons of "soft springs / stiff sway bars" vs. "stiff springs / soft sway bars".
I'm curious from the perspective of a sports car like an RX7 or Miata.
Anti-roll bars on rough surfaces: Yes or no? Why or why not?
What's the most effective change I can make to improve my stock street car's ride and handling?
How the berkeley do I spec out what dampers I need!?
If I have any given custom application what do I need to know to figure out for myself what to order a set of Afco or Bilstein or ... dampers with reasonable ranges for compression/rebound and why is it such a goddamn mystery? I've read a lot of suspension books. I know how it works and what they are supposed to do. I'm missing the whole black magic damper settings/value comparison chart/calculator.
All I have now is the phone number for Bilstein and while that works... it's damn irritating.
What range of suspension frequencies is appropriate for each of the following surfaces in a non/weak aero car: smooth asphalt track, bumpy asphalt track, gravel road, bumpy/rocky dirt road (rally stage)?
Giant Purple Snorklewacker wrote: How the berkeley do I spec out what dampers I need!? If I have any given custom application what do I need to know to figure out for myself what to order a set of Afco or Bilstein or ... dampers with reasonable ranges for compression/rebound and why is it such a goddamn mystery? I've read a lot of suspension books. I know how it works and what they are supposed to do. I'm missing the whole black magic damper settings/value comparison chart/calculator. All I have now is the phone number for Bilstein and while that works... it's damn irritating.
Read this site: http://farnorthracing.com/autocross_secrets19.html
The tl;dr is:
If your shocks are set up to provide 65% critical damping over the 0-3 in/sec range, you will be very much in the ballpark - and the only way to get any better is to do suspension velocity histograms.
You can PM me for more better resources on making those calculations -- e.g. if you don't know how to calculate 65% critical damping and can't use the dynamics calculator on that site for some reason.
I would state what i had and what I wanted and ask: what do you recommend and why?, and then record what they said carefully.
Assuming my geometry is benign, how do I go about establishing best compromise for spring/damper rates for each end?
The handling on my wife's car sucks. How do you make it suck less.
How do the relative angles in both in the vertical and horizontal of the upper and lower control arms effect the suspension geometry? Example: if I'm building a locost and for some reason I need large amounts of camber gain, whats an optimum placement?
amg_rx7 wrote: Explain the pros/cons of "soft springs / stiff sway bars" vs. "stiff springs / soft sway bars". I'm curious from the perspective of a sports car like an RX7 or Miata.
This from me as well.
Also, is there any rule of thumb for acceptable body roll, i.e. expressed as a percentage of suspension travel?
Explain corner weighting and its benefits and how you would go about corner weighting a car.
How do I choose an ideal camber curve when setting the suspension pivot points? (for example, the front suspension on a Locost Seven-style car with double A-arms).
amg_rx7 wrote: Explain the pros/cons of "soft springs / stiff sway bars" vs. "stiff springs / soft sway bars". I'm curious from the perspective of a sports car like an RX7 or Miata.
"The peculiar case of the large sedan", as one of my handling books puts it.
For those asking about designing your own geometry, have you read your Adams?
I agree, soft springs/big bars vs stiff springs/soft bars would make an excellent single question discussion as it applies to pretty much every application.
dean1484 wrote: Explain corner weighting and its benefits and how you would go about corner weighting a car.
Psst! Chapter 9.
http://www.amazon.com/Build-High-Performance-Mazda-Motorbooks-Workshop/dp/0760337055/
codrus wrote: How do I choose an ideal camber curve when setting the suspension pivot points? (for example, the front suspension on a Locost Seven-style car with double A-arms).
First you get tire data, I have some for FSAE sized tires but otherwise its more or less impossible to get unless you test it yourself (on a rig) or are a big dollar pro-team. Data basically gives you optimum slip angles, and camber at the slip angles and stuff. Then you input it into optimum K, then take that and put it into optimum G... It ends up being a trade off between what you can actually package, and cornering vs accelerating/braking. Even non-dot slicks that only want a small amount of camber are hard to keep in their happy camber zone during roll while still having the camber not go all silly during braking.
Camber curve is related to body roll. Less roll, less camber gain needed.
iceracer wrote: Camber curve is related to body roll. Less roll, less camber gain needed.
No its related to what the tires want. Keep the tire at its optimal camber (relative to the ground) for the amount of slip angle its seeing to maximize grip. Yeah you need more gain for more roll, but tire XYZ might want to end up at zero or positive camber laterially, while tire QPR wants to be at 2° when loaded up.
Giant Purple Snorklewacker wrote: How the berkeley do I spec out what dampers I need!? If I have any given custom application what do I need to know to figure out for myself what to order a set of Afco or Bilstein or ... dampers with reasonable ranges for compression/rebound and why is it such a goddamn mystery? I've read a lot of suspension books. I know how it works and what they are supposed to do. I'm missing the whole black magic damper settings/value comparison chart/calculator. All I have now is the phone number for Bilstein and while that works... it's damn irritating.
This. Also how to determine spring rates in a custom application.
How much is "too much bumpsteer" varies from person to person. How much is too much - for you?
Caster is caster, doesn't matter the type of suspension.
Hard/soft springs versus hard/soft anti-roll bars, what is your driving style? What combination is fastest for you (and likely different than others).
Shocks, adjust them until they suit you. Asking others what's best is like asking what color you should like....
The smoother the track, the stiffer the suspension can be - it all depends what your definition of "tolerable ride" is.
"My wife's car's suspension sucks." Define "sucks" in detail.
Corner weighing a car is done so that it corners the same turning left or right.
Ideal camber curve - there isn't one. Do you want the tire optimum under braking and acceleration OR in cornering. You cannot have both, or you can have half as much as you want in both cases. It's a compromise.
"First, obtain tire data." Ahahahahahaha, that's pretty funny. Seriously, unless you produce the data yourself, you won't find any.
You guys are asking black-and-white questions with answers that are 50 shades of gray.
In reply to kb58:
Hey now, I'm not in to bdsm.
kb58 wrote: "My wife's car's suspension sucks." Define "sucks" in detail.
The detailed explanation is that I intend it to be joke. It was a the most vague, subjective, unanswerable question I could think of for suspension guru. The kind of thing that used to show up regularly on Honda-Tech back in the day.
In reply to kb58:
So you don't have a question?
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