xXDavidCXx
Autocross Champion
- Location
- AZ
- Car(s)
- 2017 GTI SE DSG
I was born that year, and in my circles I'm oldI went to the University of Arizona for college...I see that you are from AZ. That was in 1979.
I was born that year, and in my circles I'm oldI went to the University of Arizona for college...I see that you are from AZ. That was in 1979.
...well, then I am decomposingI was born that year, and in my circles I'm old![]()
Changing rear roll stiffness does not translate to what stiffer front roll stiffness feels like.Adjusting the RSB to a stiffer setting should give me a feel for what to expect working with the large FSB
I've never fully compressed (to my knowledge) a spring. I have run into the front bump stops due to too low of a ride height for the shock.xXDavidCXx,
Lazy question for you...I just searched the Hypercoil coilover springs - thank you! The block height or completely compressed height of a 7" 400 in/lb spring is 2.625 inches and the 650 in/lb is 3.129. Have you ever experience this heavier spring to reach block height in track conditions? I realize the spring is heavier, but it's also the same length as the lighter spring at 7"...I am guessing the spring length now. but I will measure them.
To me this says, too much front roll stiffness.Here's a pic from back in July.h&r 26mm front bar, full stiff, plus front spring rubbers. You can see the lift on the inside even with not a lot of lean on the outside. Not a lot of steering input at this moment either.
And I overdrove the turnaround a couple times and managed to deform the inside tire with a nice longitudinal scar down the center. Ouch.
Doesn't prove much other than the inside lift can matter, perhaps more on an open diff car
...but it will reduce understeer...and more to my concerns are that increasing spring and damping and SB rates essentially reduce grip through an increase in wheel rate. I feel as though I have to work around this 26mm front bar...Changing rear roll stiffness does not translate to what stiffer front roll stiffness feels like.
The rear bar does not reduce understeer, it increases oversteer before the understeer can happen...but it will reduce understeer...and more to my concerns are that increasing spring and damping and SB rates essentially reduce grip through an increase in wheel rate. I feel as though I have to work around this 26mm front bar...
Those tires aren't great either, most of us who have a well sorted grippy car run 200TW tires.I also realize, as you pointed out, that I am on the wrong tires...but it's fall and the summer tires are in the basement. So perhaps my comments should be taken with a grain of salt...until the pilot 4S tires are back on the car.
Based on this, you should go back to the OEM rear bar, because it already can pick up the rear tire, which is why I don't recommend a rear bar for a stock car, or soft setting front and rear bar on modified cars.The correct balance is reached when the inside rear tire just barely leaves the ground - on our cars. Which can mean slightly different tuning for different tracks, or public roads. I simply wish to achieve this balance using the lightest springs and swaybars possible, while achieving the best grip levels.
...but it's all a learning experience...and unfortunately, I cannot tune my car without a track...I don't look good in orange![]()
Isn't this a bit of semantics? Which ever bar is strongest - not a technical term - will dominate the balance characteristics. A rear bar increases oversteer, a front bar increases understeer...whichever is the dominant in a given setup, determines the balance characteristics - all else equal...ideally, a little slow speed oversteer leading to a little high speed understeer...this is the balance that I am after. Unfortunately, I cannot really push the car on the street...The rear bar does not reduce understeer, it increases oversteer before the understeer can happen
...except, the front wasn't lacking front end grip before installing the larger front bar - this is relative to my given setup. My option here - all else equal - is to go back to the stock front bar. There is something else at work here too; I installed 15mm spacers on the front, 10mm on the rear, as an experiment a while back. Increasing the front track width - all else equal - increases front roll stiffness - more understeer...raises the front roll center - also softens the camber (compensation) curve. So, I'll remove those first so that I can begin base line my changes. The front bar and the wavetrac were installed together, so I've no way to understand either might work on their own.I find it better to work on the side of the car with the grip issue, the front.
The 4Ss are my DD tire in summer...always had a dedicated wheel and track tire package. Pilot Sport 2...?Those tires aren't great either, most of us who have a well sorted grippy car run 200TW tires.
This makes no sense to me, and I'm not challenging you, but my experiences are completely different. A stiffer front bar will at some point lift the inside front wheel off the ground (why we can see track focused RWD cars lifting the inside front wheel just a hair as the larger front bar helps to keep the rear tires planted ) as is transfers energy diagonally across the car to the rear. The rear bar does the exact opposite by keeping the front wheels on the ground, the nuances of alignment and spring/wheel rates aside. If I go back to a stock rear bar while using the larger H&R bar, the car will understeer more, more than it is now...and I for sure understand that stickier tires will help, but the balance will remain the same.Based on this, you should go back to the OEM rear bar, because it already can pick up the rear tire, which is why I don't recommend a rear bar for a stock car, or soft setting front and rear bar on modified cars.
FWIW:
26mm H&R front (on stiff setting)
26mm H&R rear bar (non-adjustable)
Stock springs w/ Koni SAs
Powerflex LCA bushings and 034 camber plates for adding camber
Kumho V730s
This looks like fun, and well balanced...I should be clear that I am not autocrossing this car, road courses only. I autocrossed a fair amount in the early to mid 80s...never went very far with it because I began to go to road courses and dual setups were tedious...but I very much enjoyed autocrossing...maybe I should give it try again...
The car has no problem just lightly picking up an inside rear. IMO this is a really well balanced setup overall.
You definitely need to have grippy 200TW tires for the front bar to work well on stiff. The car pushes a bit on the first run until they get some heat in them.
...you can create a high cornering beast, but the attitude of the car will either be understeer, neutral or oversteer. Is the car oversteering at 1g or understeering at 1g...? ...as I wrote way above, I am also trying to learn how to drive with the new FSB and LSD...it's a completely different animal going into a turn and mid-corner; slow in is noticeably slower, mid-corner, noticeably faster...Call me a dumbass but when folks talk about under and over steer I think of tires and driver inputs first. Want to reduce understeer in a given corner at a given speed? Get stickier tires.