Quote:
Originally Posted by Richbot
What settings did you play with? Ride height? Camber?
Stiff springs are overrated generally
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There is a certain ride height that I attempt to achieve regardless of what springs are on the car. The ride height itself is not based on super science, but it's one that has worked well for me, so whenever we change something like springs or the weight of the car, we try to get it back there as much as is reasonable. With new springs, there seems to be a small bit of settling that occurs after "breaking" the springs in over a day or two. So, we watch that too.
As far as camber goes, I ALWAYS run with max camber--basically as far as I can slam inwards--on the Vorshlag camber plates. What degree of camber that ends up being is not important to me. The more camber I put, the more I can save the front tire edges. It ends up measuring between -3.9 and -4.1º of camber in the front. (I run about -2.2º rear.) I run such fat front tires, that I always have good braking grip, so I'm not worried much about camber there, and tons of camber seems to stick very nicely in turns. But, the first time on the stiff springs, I had not re-aligned the car. So, I had an alignment done to make sure the settings were where I wanted them. It didn't help at all.
I have my own nitrogen rig, so I can accurately adjust nitrogen pressure in the JRZ remote canisters. With the stiffer springs, I lowered the nitrogen pressure to allow the damper to move more easily. Did not help.
Then, of course, there is the Rebound and Compression settings. You're doing a lot of fighting when a car feels both understeer in the front AND at the same time feels edgy in the rear. Basically, go slow and the rear wants to step out; go fast and the front understeers away from you. I was fighting multiple battles at the same time more than I was with the softer springs.
I decided to concentrate most of my effort on trying to solve the understeer at high speeds. I figured I could manage the throttle enough to deal with low speed step-outs from the rear. But I needed the car to stick on high speed cornering stuff. There's no "adjusting" your driving inputs if the car won't turn at high speed.....you just gotta slow down.
I was trying many things, but mainly, I was gradually backing the rebound down on all 4 corners (more in the front) trying to reduce the edginess/jitteriness. And I was lowering compression in the front more than the rear. So, I was reducing the settings overall, but more in the front. I would try several rounds of adjustment. The lower I went, the more grip I seemed to regain. So, it worked to some extent and I got a bit more speed back on Riverside, but an unpleasant floaty feel appeared. It started to give me a "disconnected" feeling which I did not like at all. I am used to the JRZ giving me a very connected feeling. This connected feeling was reduced as I slowed the dampers down. And, the side effect of trying to solve the understeer at high speeds is that I was making the low speed oversteer possibilities even worse.....so, the whole thing was just not working out....I still wasn't as fast in Riverside at Buttonwillow and I didn't like the feel.
I had hoped that by increasing front and rear spring rates by exactly the same percentage that the car would retain some of it's balance, but it was just an unwieldy beast. Riverside at Buttonwillow is my high speed rounder test. I know the speeds and the feel there. It was ugly entering Riverside and it was just as ugly at apex and ugly again after the apex. The car was just ignoring my steering inputs. I'm like, ok---we're running out of track here....you better turn soon car!
Anyway, returning to the 600 lbs springs in the front was absolutely the right thing to do for me. It was magical when I put them back on. And I'm glad to have 100 lbs more rate in the back. Going from 800 to 900 lbs in the rear is a fairly subtle change, but I like it. I get just a little bit more support back there. I think the 900's hold up a bit better under the wing's downforce and the car feels good on acceleration, so I believe this is where I'll stay for the foreseeable future with spring rates.