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front sway bars

meb58

New member
Location
Wappingers Falls, NY
Car(s)
2015 MK7 GTi
I was born that year, and in my circles I'm old :ROFLMAO:
...well, then I am decomposing 😞 ...better than the alternative;)

So my goals then are to try a bit more static neg camber and higher rear spring rates. Adjusting the RSB to a stiffer setting should give me a feel for what to expect working with the large FSB
 

meb58

New member
Location
Wappingers Falls, NY
Car(s)
2015 MK7 GTi
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.
 

xXDavidCXx

Autocross Champion
Location
AZ
Car(s)
2017 GTI SE DSG

xXDavidCXx

Autocross Champion
Location
AZ
Car(s)
2017 GTI SE DSG
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.
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.
 

odessa.filez

Autocross Champion
Location
Roswell, GA
Car(s)
2016 GSW 1.8tsi auto
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
 

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xXDavidCXx

Autocross Champion
Location
AZ
Car(s)
2017 GTI SE DSG
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
To me this says, too much front roll stiffness.

I have experienced similar results with my front bar on full stiff. I run both front Hotchkis and rear 034 bars on soft.
 

odessa.filez

Autocross Champion
Location
Roswell, GA
Car(s)
2016 GSW 1.8tsi auto
My thought was too much from the bar. I went back to softest setting and increased the durometer on one of my spring rubbers.
 

meb58

New member
Location
Wappingers Falls, NY
Car(s)
2015 MK7 GTi
Changing rear roll stiffness does not translate to what stiffer front roll stiffness feels like.
...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...

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.

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:)
 
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xXDavidCXx

Autocross Champion
Location
AZ
Car(s)
2017 GTI SE DSG
...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...
The rear bar does not reduce understeer, it increases oversteer before the understeer can happen

I find it better to work on the side of the car with the grip issue, the front.
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.
Those tires aren't great either, most of us who have a well sorted grippy car run 200TW tires.
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:)
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.
 
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DerHase

Autocross Champion
Location
Hampton Roads, VA
Car(s)
2019 GTI Rabbit
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


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.
 

meb58

New member
Location
Wappingers Falls, NY
Car(s)
2015 MK7 GTi
The rear bar does not reduce understeer, it increases oversteer before the understeer can happen
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...
I find it better to work on the side of the car with the grip issue, the front.
...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.
Those tires aren't great either, most of us who have a well sorted grippy car run 200TW tires.
The 4Ss are my DD tire in summer...always had a dedicated wheel and track tire package. Pilot Sport 2...?
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.
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.

I am also focused on this new front bar because the balance clearly isn't working for my current setup. Going back to a more basic path, remove the spacers, increase rear spring rate, then tune with the swaybars...

xXDavidXx, if you are racing competitively, I imagine that you are also testing tire heat across the tread to aid in your setup decisions? I've done no such thing...balance and front end grip...
 
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meb58

New member
Location
Wappingers Falls, NY
Car(s)
2015 MK7 GTi
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
  • 034Motorsport (Soft) - 153% Rate Increase vs. Factory Volkswagen GTI (20mm) Rear Sway Bar ...which is why I plan to increase the rear rate a bit by re-adjusting the 25.4mm rear bar. These rate increases come from 034...
  • 034Motorsport (Stiff) - 174% Rate Increase vs. Factory Volkswagen GTI (20mm) Rear Sway Bar

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.
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...
 
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tigeo

Autocross Champion
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.
 

meb58

New member
Location
Wappingers Falls, NY
Car(s)
2015 MK7 GTi
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.
...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...
 
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