@bpracer any update on the spring measurement?
This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
VoodooBOSS said:Thanks for posting the information. While I wouldn't mind lowering my car just a bit what I'm wondering is how the front R springs will respond on track. The track pack springs felt fine with my stock tires during my track day and at TA. My concern is when I add the sticker Cup2 tires will I get more nose dive? If so maybe the R front springs will be the way to go. Thoughts?
JAJ said:I wouldn't mess with it until you've tried it with the RComps and the stock springs. If you've got data acquisition, it'll tell you how much grip you're getting, and if it's easy to drive and you're pulling north of 1.1g's, I'd be tempted to leave it as is.
The challenge with changing springs is that the R springs are softer at the rear than the TP, and stiffer at the front. That increases loading on the outside front tire in a corner and increases the tendency to understeer. To compensate, the R has a stiffer rear sway bar (same bar, shorter arm length) that presumably restores balance. And of course, we don't know how the mag ride programming figures into this. McLaren implemented four-corner linked damping using hydraulics in the MP4-12C suspension. I think Ford did the same using electronics on the mag ride GT350. The linked damping regime improves handling by managing roll and pitch, something regular independent four-wheel spring and passive damper suspensions can't do. But, in doing that, the dampers become an dynamic part of the weight transfer process on corner entry and exit. What we can't know is how sensitive the mag ride calibration is to changes in spring rates. Could be a little, could be a lot.
So, as I said, I wouldn't mess with it until you've actually tried the RComps and the stock springs.
Yep. I want to install the springs when I install the CC plates but I'll probably wait. I'm also hopeful that Ford Performance has their springs ready to roll by fall and they split the difference between the stock and R springs and they work well with the stock damper calibration.JAJ said:I wouldn't mess with it until you've tried it with the RComps and the stock springs. If you've got data acquisition, it'll tell you how much grip you're getting, and if it's easy to drive and you're pulling north of 1.1g's, I'd be tempted to leave it as is.
The challenge with changing springs is that the R springs are softer at the rear than the TP, and stiffer at the front. That increases loading on the outside front tire in a corner and increases the tendency to understeer. To compensate, the R has a stiffer rear sway bar (same bar, shorter arm length) that presumably restores balance. And of course, we don't know how the mag ride programming figures into this. McLaren implemented four-corner linked damping using hydraulics in the MP4-12C suspension. I think Ford did the same using electronics on the mag ride GT350. The linked damping regime improves handling by managing roll and pitch, something regular independent four-wheel spring and passive damper suspensions can't do. But, in doing that, the dampers become an dynamic part of the weight transfer process on corner entry and exit. What we can't know is how sensitive the mag ride calibration is to changes in spring rates. Could be a little, could be a lot.
So, as I said, I wouldn't mess with it until you've actually tried the RComps and the stock springs.
bpracer said:The R springs are stiffer at both ends. The rear springs sets are not a constant wire diameter and they are a variable rate. The R springs are stiffer initially and end up about the same as the TP springs with the TP spring being the more variable of the two. The R spring free height is 1/2 shorter but the ride height is the same.
The front spring is 10" free height for the R vs 11.25" for the TP.
I'll have to overlay the two charts and take in to account the free height difference, but its been long week...
bpracer said:The rear TP spring is 12.375" (same as "R") not 12.675" as close as I can measure it so maybe a number was transposed. See how that makes the math work.