Coil over spring rates
06-21-2006, 02:02 AM
#16
Rennlist Member
Several years ago I researched updating the suspension on my 88 Turbo S. I ended up going with the recommendation from Andial for combination Street/Track.
180/410 progressive springs up front.
30mm torsion bars in the rear
Welt Adjustable swaybars
Stock S adjustable Koni's.
Andial was the suspension setup guy for the 917 factory race car.
He said the escort setup everyone was going to at the time was too much for the car on the street. Reminider, 270 rwhp was pretty much the max back then.
My impression was that it was a bit jarring around town but not too bad. Once dialed in I was the one to beat at local autocross events with only welt chips running Yoko A032R's on stock wheels and tire sizes.
David Lindsey bought the car from me and I believe is still running the same suspension setup. With the god like horsepower he has now, it does squat a bit on acceleration.
Today I have an 89 Turbo with the only suspension upgrades so far being Adjustable welt swaybars and 18 inch wheels with 225 front 265 rear. The car is only lowered about 1/2 inch because any lower and my front spoiler drags under braking. To keep tirespin down I run 16# boost dynoing around 350 rwhp. The swaybars took a full second off my autocross times. I look for more as I am cautious and slowly approach new limits after a change. Oh, and that second put me 9/10ths faster than any other car on street tires.
180/410 progressive springs up front.
30mm torsion bars in the rear
Welt Adjustable swaybars
Stock S adjustable Koni's.
Andial was the suspension setup guy for the 917 factory race car.
He said the escort setup everyone was going to at the time was too much for the car on the street. Reminider, 270 rwhp was pretty much the max back then.
My impression was that it was a bit jarring around town but not too bad. Once dialed in I was the one to beat at local autocross events with only welt chips running Yoko A032R's on stock wheels and tire sizes.
David Lindsey bought the car from me and I believe is still running the same suspension setup. With the god like horsepower he has now, it does squat a bit on acceleration.
Today I have an 89 Turbo with the only suspension upgrades so far being Adjustable welt swaybars and 18 inch wheels with 225 front 265 rear. The car is only lowered about 1/2 inch because any lower and my front spoiler drags under braking. To keep tirespin down I run 16# boost dynoing around 350 rwhp. The swaybars took a full second off my autocross times. I look for more as I am cautious and slowly approach new limits after a change. Oh, and that second put me 9/10ths faster than any other car on street tires.
06-21-2006, 08:38 AM
#18
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[QUOTE=951_VAB]Autox951, first of all, I'm no expert, but unless I missed it, you've left some pieces of the puzzle out.
Call Jason at Paragon for the bottom line. On this small issue I disagree with Dave Lindsey if that's his position quoted above. Accounting for deflection and such for the effective rate and NO TBars, 100# bias toward the rear is what was recommended and works great for me. My car with 968 M030 bars and stock bushings all around, Konis all around, rear sway set on middle hole, front shocks set just off soft and rear about same, it handles on rails with the 325/425 setup. Slid it a bit the other day--a bit of understeer on 18s and 265/35s in rear. Could easily dial in some oversteer by tightening up the rear a bit by shock, sway, or springs.
Bottom line is there's more pieces to the puzzle than just beefing up springs. For autocross, you might have a completely different set up than one designed for high speed cruising or comfortable/aggressive street. This setup works for me. Those that have more spring in front than rear AND no tbars... would love to hear how your mileage differs, so to speak. It's physics, and there's formulas. Search more on here, plenty to be found.
.I still have my t-bars they are backed off one tooth per L.R. I also have the 968 frt and rr sway bars.
Call Jason at Paragon for the bottom line. On this small issue I disagree with Dave Lindsey if that's his position quoted above. Accounting for deflection and such for the effective rate and NO TBars, 100# bias toward the rear is what was recommended and works great for me. My car with 968 M030 bars and stock bushings all around, Konis all around, rear sway set on middle hole, front shocks set just off soft and rear about same, it handles on rails with the 325/425 setup. Slid it a bit the other day--a bit of understeer on 18s and 265/35s in rear. Could easily dial in some oversteer by tightening up the rear a bit by shock, sway, or springs.
Bottom line is there's more pieces to the puzzle than just beefing up springs. For autocross, you might have a completely different set up than one designed for high speed cruising or comfortable/aggressive street. This setup works for me. Those that have more spring in front than rear AND no tbars... would love to hear how your mileage differs, so to speak. It's physics, and there's formulas. Search more on here, plenty to be found.
.I still have my t-bars they are backed off one tooth per L.R. I also have the 968 frt and rr sway bars.
06-21-2006, 02:19 PM
#19
Former Vendor
400lbs fronts,825lbs rears,full Leda coil-overs,968 M030 sways,polygraphite/polyurethane bushings,Ground Control camber plates,235-40 & 295-30 / 18 MPS2 N2 tyres. Can't complain,suits both auto-X and track on dry conditions.Too stiff for wet.
