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The driver "MUST" know what is going on in order to have any idea of what to change or adjust. Thinking that the car is pushing due to an incorrect suspension setup when actually they are driving into a corner waaay too fast leads to nowhere.
A car + 2 seats = priceless
you have to be confident in the car before you are willing to drive it fast.
Instructed many green students? hehe :DQuote:
Originally Posted by GlennCMC70
seafoam green to be exact.
My car just received a second seat for that very reason. :wink:Quote:
Originally Posted by SmackDaddy
Boudy
Me too.
<licks chops>
jb
Guys,
Remember when people start talking about front/rear ratios, the actual wheel rate of the setup may be vastly different.
Since the Mustang front spring is set so far inboard from the wheel and strut, it takes a huge front spring to act the same as what would be on a 4th gen Camaro or AI Mustang which has coilovers.
The same holds true in the rear. The closer to the axle (or behind) you get the spring, the less lb-in rate you will need to get the same effective wheel rate.
Mustang Front Motion Ratio
Conventional = .25
Coil-over = .9
Mustang Rear Motion Ratio
Conventional = .49
Coil-over = 1.1
CMC Mustang with H&R “Race (Red)” springs
Front: 750 lb-in (at spring) = 188 lb-in (wheel rate)
Rear: 260 lb-in (at spring) = 132 lb-in (wheel rate)
= 1.42/1 Front/Rear split
AI Mustang with coilovers and T/A
Front: 450 lb-in (at spring) = 405 lb-in (wheel rate)
Rear: 350 lb-in (at spring) = 385 lb-in (wheel rate)
= 1.05/1 Front/Rear split
As shown above, if you are running a T/A car (AI or Cambird) your front/rear split will be much less than a CMC Mustang which has a bunch of "built in" bind with the 4-link design. The T/A cars need less split (more rear spring rate) due to less rear bind (geometrical and bushings) which will now need to be accounted for by a higher spring rate.
Good info, Marshall.
You are correct in your thoughts about "effective" rate which is dependent upon a lot of differing factors, like wheel offset, bushing material and even air pressure in the tires, which changes dramatically during a 20 minute race.
Factor in lessening fuel load, head wind down force.
However, the suspension pick up points on ANY CMC platform is fixed and a known. So once one figures out where the "balance" is, chassis design plays a lesser role.
I don't know if David's head is spinning, but mine is.
To answer Glenn's question about why I mix n matched spring manufacturers. I knew I had too much rear spring, I had a set of Eibachs laying around, I called Eibach to get an idea about what rate they were, they were much softer than the H&R rears, so I tried them. Pretty scientific - huh? That got me into the gross ballpark (luckily) and now I can tune it in with adjustable shocks, tire pressure, steering strategy, throttle strategy, downshift - upshift strategy, rev limiter strategy, front sway bar end link tension, water leaking from my cool shirt cooler, overaggressive driving, etc., etc., etc.
Get someone else to ride and drive the car at a more relaxed event like TWS Motorsports Club. There is a lot of talent and experience here to help you along. My advice is to set the car up with a bit of a push and work toward the loose condition slowly.
Quote:
Originally Posted by SmackDaddy
I'M SCREWED!!! :( WHERE ARE THESE MARKS YOU SPEAK OF?!?! :shock: ONLY MARK I AM FAMILIAR WITH IS THE BIG YELLOW SQUARE BETWEEN 1 & 2 AT TWS.....
tried to hit that square going CW... didn't work too well :wink:
I kid... I understand what you are saying...