Thanks guys!! I think the springs I have are around 400lbs which would explain the loose condition... I'll check the fronts and look at the 3:1 ratios... may not be able to correct before Hallett but all this info will help my decisions in the near future... Check out other issues on other posts... Thanks again you guys are great... you might be kicking you own butts when Jason passes you in 2008......... :twisted:
Last November I got a note in my e-mail box that pitstopusa.com was reducing their spring inventory and was selling AFCO 5.5" pigtail x 11" springs for $29 each in rates starting at 125 lbs and going to 350 lbs in 25 lb increments.
So, I bought several pairs in increasing rates
David, I have a pair of 250s and 275s I would sell you pretty cheap if you'd like them.
Some great information is to be had in this thread. One note of caution - if you work on getting rear grip and make changes to do so, the outcome with a sticky rear will be a Mustang that pushes and plows through a corner. It's a fine balance between having enough or too much rear grip when matching it up with the front. I tend to like a slightly loose condition which can be driven through during corner exit. A push will result in having to lift on exit which will slow ya down... a lot!
Don't forgot the front when changing the rear.
Testing: being consistent enough on corner entrance, apex and exit to know whether or not chang "A" made more of a difference than change "B" is paramount.
I'm always available to help test setups if the price is right. You know.. big glass of ice tea or lemonade.
Most definitely ... testing has to remove as many variables as possible. Be consistent on air pressure, shock settings, fuel load, etc. It all adds up.
And sometimes, you will find that a 25lb change is too much of a change and going back isn't just right either.
There are CMC legal ways to split hairs, like with bushing material or wheel spacers.
David, remember, i used the 3:1 ratio as an example for what works w/ the 4th gen f-body. due to differences in suspension design and geometry i'm sure thats not the correct ratio for a fox ford. yours could be a 2:1 or a 5:1, i just do not know.Originally Posted by David Love AI27
Roberts cars set-up shows about a 4.25:1 ratio. he is also the only one who has posted front and rear rates.
IMHO 900lb front springs are too much. Then again, it all depends on the other 101 things involved when setting up the suspension.
700/225 seemed really close - but again, it all goes along with everything else as a whole.
Example: MSRC 700/225 the car had a huge push and nothing could be done at the time - even with tire pressure. Next MSRC event. Went with the 700/275 setup and the car was wicked loose (no changes to front suspension). With a change to the front suspension, it went from loose to slight oversteer.
Factors involved:
Tire pressure(s)
Front/rear swaybar and bushings
Strut/shock rebound rate
Weight distribution
Chassis flex
Big factor - driver's ability to hit all marks consistently
.02
Just my .02
I would never make changes to the wrong end of the car.
If the front is doing something undesirable, make changes at the front.
Don't take away grip you have at one end just because the other end has less.
jb
Harmony is that elusive pot-o-gold.
that is true for a car that is almost balanced or is balanced. but if you are just way way off (soft) on rear rates and the front is spot on, the car will still push. softening the front will make the push go way, but the car should be faster if you were to stiffen the rear. overall, you have to work the problem. sounds to me like David has way to stiff of a spring on the rear and no idea whats on the front. but guessing from the rears, i would think 900-1000 is what he will find.
Davids best bet for now is the copy another drivers set-up and then work it from there.
Ah but which driver to copy? :lol:
It seems to be common perception that some guys are fast thanks to their cars..but my experience is that its just as likely to be that some guys are fast in spite of their cars. Some guys just aint fast. 8)
My point is, Glenn is right, find some basline from which to start and then experiment from there. There is no "right" answer, and what is fast for you might not be fast for someone else. I've driven some cars that I thought were awful but their owner liked it, knew it, and ran fast with it. I've also driven a few that I thought were fabulous who'se owners thought were completely off the mark.
Al Fernandez
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