Racecar Engineering Vol 9 (Year: 1999) No 4 - Ortiz on Dynamic Load Transfer
Page 44: "The basic rule is that the stiffer end gets the greater load transfer. Load transfer at the softer end is correspondingly reduced. This increases cornering power at the softer end and reduces cornering power at the stiffer end."
Page 48: "If we have a tight-on-slick condition, we can improve the car by creating a setup that produces less wedge when cornering forces are modest, with a greater wedge gain as cornering force increases. To obtain this, we would decrease static wedge, and make overall roll resistance distribution more front-stiff.
For a loose-on-slick car, we would do the opposite: more static wedge, with a more rear-stiff roll distribution"
Rainy Mid Ohio Majors Weekend
#1
Posted 05-30-2019 10:06 PM
For faster reply than PM: miataboxes>>>AT<<<gmail>>DOT<<<com
#2
Posted 05-31-2019 06:03 AM
Racecar Engineering Vol 9 (Year: 1999) No 4 - Ortiz on Dynamic Load Transfer
Page 44: "The basic rule is that the stiffer end gets the greater load transfer. Load transfer at the softer end is correspondingly reduced. This increases cornering power at the softer end and reduces cornering power at the stiffer end."
Page 48: "If we have a tight-on-slick condition, we can improve the car by creating a setup that produces less wedge when cornering forces are modest, with a greater wedge gain as cornering force increases. To obtain this, we would decrease static wedge, and make overall roll resistance distribution more front-stiff.
For a loose-on-slick car, we would do the opposite: more static wedge, with a more rear-stiff roll distribution"
Great info Saul, can you tell me how that translates to adjustments in a Miata for the noobs like me?
2019 SeDIV SMSE Champion
#3
Posted 05-31-2019 07:00 AM
#4
Posted 05-31-2019 11:34 AM
What is tight on slick and loose on slick
1999 Spec Miata
Hilltrux - Roush - V2 Motorsports - ESR
#5
Posted 05-31-2019 02:19 PM
What is tight on slick and loose on slick
My interpretation has been, "the car is tight/loose in low grip conditions" but the opposite handling condition in high-grip conditions. The idea being to set the static wedge for the rain, and tune the car with the bars to add/remove dynamic wedge (more roll = more bar (de)wedge) for the higher grip conditions.
-tch
Build: www.tomhampton.info
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I didn't lose, I just got outspent!
#6
Posted 05-31-2019 03:48 PM
#7
Posted 05-31-2019 06:44 PM
#8
Posted 05-31-2019 06:48 PM
Tight you go head first into the barriers, loose you back it in.
Yes of course, but what question are you answering? From JRHille? I think Tom covered that, which was more about “slick” in conjunction with tight/loose.
#9
Posted 05-31-2019 08:34 PM
I confess, I’m struggling with the idea that everything is reversed when wet/slick.
Yes, I agree. But maybe it's better to think in terms of difference. It doesn't really have to be reversed so much as less loose or more tight in different grip situations. In that case, perhaps with less weight transfer (and total load) and suspension compression there is a change in handling as a result of less camber gain on one end or the other.
Also, the rain line is often more sharp following the typical inside the dry line entry, cross over, turn sharp, cross over type of line. I suppose that could result in a different handling dynamic versus the typical dry line.
-tch
Build: www.tomhampton.info
video: vimeo.com/tomhampton
Support: X-Factor Racing
I didn't lose, I just got outspent!
#10
Posted 05-31-2019 09:37 PM
As for weight transfer, it’s less mostly because speeds and loads are less, but it is slower because roll stiffness is decreased. Is that not correct? In fact, thanks to the less abrupt transfer of weight you may achieve higher sustained lateral Gs in the wet with the bars off, which means you actually end up with greater ultimate weight transfer than with them attached (because you go faster). Am I mistaken on any of that?
#11
Posted 06-01-2019 02:00 AM
Personally we/I, do not adjust for rain, it might just dry up and we/I would prefer to be back to what we/I know in the dry, so we/I race the rain with the dry setup. But of course YMMV, just sayin in case anyone is interested
Danny
Danny Steyn Racing | DSR YouTube Channel
Danny Steyn Photography | Adept Studios | Ocean Machinery | OPM Autosports | Rossini Racing Engines | G-Loc Brakes |
2 x SCCA Runoffs Champ | 1 x NASA National Champ | 6 x June Sprints Champ | 10 x ARRC Champ
1 x SCCA Super Sweep | 2 x Triple Crown | 4 x Hoosier Super Tour Points Champ | 6 x Majors Points Champ | 5 x SEDiv Driver of the Year
#12
Posted 06-01-2019 02:25 AM
Good luck to all at MO - wish we could have been there to join in the fun, but have to earn some $$$ to fund this very addictive habit!!!!
Danny
Danny Steyn Racing | DSR YouTube Channel
Danny Steyn Photography | Adept Studios | Ocean Machinery | OPM Autosports | Rossini Racing Engines | G-Loc Brakes |
2 x SCCA Runoffs Champ | 1 x NASA National Champ | 6 x June Sprints Champ | 10 x ARRC Champ
1 x SCCA Super Sweep | 2 x Triple Crown | 4 x Hoosier Super Tour Points Champ | 6 x Majors Points Champ | 5 x SEDiv Driver of the Year
#13
Posted 06-02-2019 12:18 PM
Congratulations to Jim on a double!
#14
Posted 06-02-2019 01:05 PM
Way to go Jim on the two wins this weekend... Looks like the old guys rule in 2019!!!!!
- Jim Drago and FTodaro like this
#15
Posted 06-02-2019 01:27 PM
#16
Posted 06-03-2019 11:50 AM
#17
Posted 06-03-2019 01:11 PM
Why is provisional shown for Sunday???
Was some passing under yellow reported, no sure if they took any action or not. It was not for 1-2, it was 3-6 I believe
Jim
East Street Auto Parts
Jim@Eaststreet.com
800 700 9080
#18
Posted 06-03-2019 01:54 PM
Now that were assured, great job for a guy who hates Mud Ohio (or does it hate you) and to the other's who didn't beat the yellow flag.
- Jim Drago and lillyweld like this
#19
Posted 06-04-2019 10:27 AM
There was a protest for leaving racing room on Saturday as well, but was not deemed well founded.
There was a lot of Metal to metal this weekend. Nothing really serious but high amount of it. All seemed to be "Leaning" Or "you get 1 car and a inch" or "it was my turn" or "defending"
V2 Motorsports
#20
Posted 06-04-2019 12:36 PM
There was a protest for leaving racing room on Saturday as well, but was not deemed well founded.
There was a lot of Metal to metal this weekend. Nothing really serious but high amount of it. All seemed to be "Leaning" Or "you get 1 car and a inch" or "it was my turn" or "defending"
The more and more I attend SCCA and NASA events...the more I appreciate the current level of oversight that occurs in my region with NASA. I had 2 customers this weekend at our SCCA regional at Laguna Seca. So I watched every SM and group 5(alphabet soup)race. The amount of contact was staggering...at least a dozen cars(34 entries I think) with significant damage...75% were avoidable/idiotic driving. The few that were self induced learned there own lessons I'm sure. Sometimes we(SM group) just have bad weekends...the problem local is this has happened EVERY weekend. NOBODY in SCCA oversee's this large group or has any knowledge of the same guys who are constantly creating problems! Then its he said she said with half the drivers not running video..."racing incident" does no one any favors!
- Mark likes this
Ron
RAmotorsports
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