Fighting understeer in high speed corners

OP
OP
honeybadger

honeybadger

Just don't care
Joined
Apr 20, 2016
Threads
57
Messages
3,355
Reaction score
5,181
Location
Texas
First Name
Kevin
Vehicle(s)
'17 GT350
Front FP Racing (Blue) and BMR Springs in the rear?
For the December event, correct!

With the oem spring location you'll be at a ride frequency of 1.7hz. I'm not sure if that is more or less than you're at now. I'd say raising rear spring rates would be one way to improve the understeer issue
FP springs in right now - they're 565 lb/in rear, so these should make a big difference

 

ShatterPoints

Well-Known Member
Joined
Apr 22, 2020
Threads
3
Messages
141
Reaction score
115
Location
Austin Texas
First Name
James
Vehicle(s)
2017 GT350
For the December event, correct!



FP springs in right now - they're 565 lb/in rear, so these should make a big difference
Yikes, 565 puts you under OEM rates (1.3hz vs 1.55OEM) this will make a massive difference. You'll get more wheel spin in low speed. Not that you need to improve your throttle management. LoL
 
OP
OP
honeybadger

honeybadger

Just don't care
Joined
Apr 20, 2016
Threads
57
Messages
3,355
Reaction score
5,181
Location
Texas
First Name
Kevin
Vehicle(s)
'17 GT350
Yikes, 565 puts you under OEM rates (1.3hz vs 1.55OEM) this will make a massive difference. You'll get more wheel spin in low speed. Not that you need to improve your throttle management. LoL
For sure. Full soft on the rear bar we go. Hehe. Any maybe some more rear wing.

We'll have new 3Rs and a set of Pirelli scrubs for Dec. Should be a good test.
 

ShatterPoints

Well-Known Member
Joined
Apr 22, 2020
Threads
3
Messages
141
Reaction score
115
Location
Austin Texas
First Name
James
Vehicle(s)
2017 GT350
For sure. Full soft on the rear bar we go. Hehe. Any maybe some more rear wing.

We'll have new 3Rs and a set of Pirelli scrubs for Dec. Should be a good test.
Trying to work out my schedule to make the Dec event. Hope to make it, see you there!
 
OP
OP
honeybadger

honeybadger

Just don't care
Joined
Apr 20, 2016
Threads
57
Messages
3,355
Reaction score
5,181
Location
Texas
First Name
Kevin
Vehicle(s)
'17 GT350


drummerboy

Well-Known Member
Joined
Mar 15, 2019
Threads
20
Messages
470
Reaction score
371
Location
SoCal
Vehicle(s)
'19 GT350
Front FP Racing (Blue) and BMR Springs in the rear?
That's what I'm running. Honeybadger is obviously far beyond what I've done to mine, but they're a fantastic pairing on mine. Great balance. From previous tech posts by BMR I read, it sounds like they've said this is the stiffest combo the S550 suspension travel will allow for (and it is by no means very stiff or harsh), so indeed coilovers would be next. FWIW I think the FP and BMR fronts are nearly identical.

Crossing my fingers hoping this is a good improvement, Kevin, and fully expecting it will be. I am running the Steeda bars full soft currently, and I need to play around with those a bit on the next outing. She handles great but could scoot a little faster through the corners with a little less roll and a bit stiffer rear for sure.
 

ShatterPoints

Well-Known Member
Joined
Apr 22, 2020
Threads
3
Messages
141
Reaction score
115
Location
Austin Texas
First Name
James
Vehicle(s)
2017 GT350

drummerboy

Well-Known Member
Joined
Mar 15, 2019
Threads
20
Messages
470
Reaction score
371
Location
SoCal
Vehicle(s)
'19 GT350
Kevin, do you have record of tire temps when it didn't want to turn?
 
OP
OP
honeybadger

honeybadger

Just don't care
Joined
Apr 20, 2016
Threads
57
Messages
3,355
Reaction score
5,181
Location
Texas
First Name
Kevin
Vehicle(s)
'17 GT350
OP
OP
honeybadger

honeybadger

Just don't care
Joined
Apr 20, 2016
Threads
57
Messages
3,355
Reaction score
5,181
Location
Texas
First Name
Kevin
Vehicle(s)
'17 GT350
That's what I'm running. Honeybadger is obviously far beyond what I've done to mine, but they're a fantastic pairing on mine. Great balance. From previous tech posts by BMR I read, it sounds like they've said this is the stiffest combo the S550 suspension travel will allow for (and it is by no means very stiff or harsh), so indeed coilovers would be next. FWIW I think the FP and BMR fronts are nearly identical.

Crossing my fingers hoping this is a good improvement, Kevin, and fully expecting it will be. I am running the Steeda bars full soft currently, and I need to play around with those a bit on the next outing. She handles great but could scoot a little faster through the corners with a little less roll and a bit stiffer rear for sure.
Yep - I remember reading that as well. An OEM R bar might be a good upgrade for you. Excited to try it out. Should be a big change!

wait what?!?! How on earth did that happen? You might want to source a set of 750-800's to try.
Started out when the car was stock aero and focused on upgrading stuff as I broke it. Turns out, I broke this setup and now it's time for me to address. You know how it goes
 

drummerboy

Well-Known Member
Joined
Mar 15, 2019
Threads
20
Messages
470
Reaction score
371
Location
SoCal
Vehicle(s)
'19 GT350
Normal temps 185-195 or there around.
I know you've already got a solution at hand, so I don't mean to bother as it's just satisfying my curiosity, but I'm wondering what it was looking like like this especially the front to back if it's not too much trouble.

tiretemps.jpg
 

BillyJRacing

Well-Known Member
Joined
Oct 30, 2017
Threads
8
Messages
226
Reaction score
779
Location
West Palm
Vehicle(s)
Mustang
As anyone thought about reaching out to @BillyJRacing?

looping the King in.
Thanks for the kind words. I mostly hop in here to help dispel myths and help people in need with fundamental concepts, but detailed setup work (especially for more advanced drivers) is what I make a living doing - from track day guys and performance shops to OEM mfgs and NASCAR Cup teams.

I don't want to come in here being 'that guy' that comes off as "you have to pay me for my help" but Kevin is on the right track and his feedback sounds pretty good based off his changes. As far as free advice goes, let's just say if more rear camber was worse for him... maybe less rear camber would be better ;)

Oh, and EVERYTHING understeers in T16-18 at COTA because it's so long, is off-camber, and increases then decreases in elevation. If it doesn't then it's probably too loose.

0.02

I know you've already got a solution at hand, so I don't mean to bother as it's just satisfying my curiosity, but I'm wondering what it was looking like like this especially the front to back if it's not too much trouble.

tiretemps.jpg
Those numbers are way too low. If you aren't using a PROBE type tire pyrometer, you need to. Make sure to NOT do a cooldown lap and come in as 'hot' as possible, QUICKLY check the temps (a minute will make a big difference in results) and make sure to measure in the proper procedure:

Stick the needle ALL the way in
Stick it in at a 45* angle
Stay away from the edges of tread blocks, measure in the middle of tread blocks
**Stab the tire 3X to 'heat up the needle' before taking your first measurement.

ALWAYS go: OUTSIDE - MIDDLE - INSIDE
(the outside *should* be cooler and the needle should increase in temp with each measurement.
 
OP
OP
honeybadger

honeybadger

Just don't care
Joined
Apr 20, 2016
Threads
57
Messages
3,355
Reaction score
5,181
Location
Texas
First Name
Kevin
Vehicle(s)
'17 GT350
...detailed setup work (especially for more advanced drivers) is what I make a living doing - from track day guys and performance shops to OEM mfgs and NASCAR Cup teams.
Hopefully someday. Got some big plans that I'll make a mess of if I'm left to my own devices (more so than I already have).

As far as free advice goes, let's just say if more rear camber was worse for him... maybe less rear camber would be better ;)

giphy (1).gif
 

 
22 - Velgen Wheels - 1
Top