23 replies to this topic

[Jamz14]

What can be expected for max Gs under braking on Toyo?

[Tom Sager]

A suggestion...

Next time you are on the track, apply the brakes in a practice session very hard, even to the point of locking a wheel. Take a look at your data after the session.

[Jamz14]

Tom,

That is exactly what I was going to do. I was asking so I knew whether my data was correct or not. Thought I would calibrate with guys that might have known good data.

Thanks though, ill go get the answer.

[Randy Thieme]

Sometimes other drivers in your paddock are willing to share data files so looking at another driver's data is another option. Not that unusual so don't be afraid to ask drivers you know. Don't expect to see the same numbers in longitudal G as lateral G. The famous friction circle ain't exactly a circle, more like an ellipse. Just a hint of what you might find.

[Jim Boemler]

Strictly from memory, I think the highest braking G's I've seen is about 0.6 -- less than half the lateral value.

[Danny Steyn]

What can be expected for max Gs under braking on Toyo?

Jamz14 - it all depends on the track, and what the condition of the braking zone is, tire condition etc. Also track temp will have a significant effect. Loaded or unloaded braking zone. And a lot of turns are not pure braking turns, many have lateral G's involved as you are in the turn while under braking.

Looking at pure braking turns on my Traqmate data shows

• In an upward sloping braking zone, where suspension is loaded/compressed, you should get around 1.5G possibly more (T11 at Barber)
• On most flat braking zones with decent grip you should see around 1.1 - 1.2G's (T7 at Sebring)
• On unloaded corners you will see less.
• Generally takes around 900PSI to get full threshold braking

YMMV

[MPR22]

Jamz14 - it all depends on the track, and what the condition of the braking zone is, tire condition etc. Also track temp will have a significant effect. Loaded or unloaded braking zone. And a lot of turns are not pure braking turns, many have lateral G's involved as you are in the turn while under braking.

Looking at pure braking turns on my Traqmate data shows

• In an upward sloping braking zone, where suspension is loaded/compressed, you should get around 1.5G possibly more (T11 at Barber)
• On most flat braking zones with decent grip you should see around 1.1 - 1.2G's (T7 at Sebring)
• On unloaded corners you will see less.
• Generally takes around 900PSI to get full threshold braking

YMMV

Great information Danny. I bet a lot of people will go back and look at their data and see they are not threshold braking.

[Jim Drago]

Great information Danny. I bet a lot of people will go back and look at their data and see they are not threshold braking.

Perhaps even more enlightening... some may wonder why they are threshold braking in certain corners

[MPR22]

Perhaps even more enlightening... some may wonder why they are threshold braking in certain corners

I learned that very thing last year. Results have improved. Now if i could find the push to pass button.

[Jamz14]

Thanks guys. Very good info!!!!! I was looking at straightline threshold braking just as a reference knowing that I would different numbers for different types of corners and brake zones. Looking at last race though, never saw long g exceed .8g . Thought that was a bit low for a straightline brake zone type corner.

[Cnj]

I learned that very thing last year. Results have improved. Now if i could find the push to pass button.

I preferred it when you were threshold braking more corners.

Cnj

[screaming monkey]

I learned that very thing last year. Results have improved. Now if i could find the push to pass button.

I think it's located on the center of the front bumper NOT recommended for use though

[SaulSpeedwell]

Perhaps even more enlightening... some may wonder why they are threshold braking in certain corners

No $4 trophy or 8 day festivus in Elkhart Lake exists for the highest longitudinal acceleration possible? Brake for 1.0g for 100 ms longer than the the guy who broke at 0.9g, and enter/exit slower while you are doing it, and you still lose the lap and lose the race.

You can't get peak decel (or highest average decel over n*100 ms) AND get the lowest split time through the corner at the same time ... which is why divebombs are what they are (position plays at expense of laptime) and qually laps are what they are (fastest lap possible wth no regard to position).

Getting on the brakes harder and later is good .... only if the split time is better. If not, you are robbing Peter of $1 to pay Paul $0.80.

(And this is where 50% of the "Ohhhhh, I'm killing him under braking and into the corners and he just motors me on the straights ..." B.S. comes from, with the other 50% being that people simply don't comprehend that cars cutting identical lap times will be really close when they are going 25 mph and relatively far apart at 120 mph ... because time and speed are related by .... well .... distance).

[Jim Boemler]

[Muda]

Probably more important max G is that the shape of the long. G line looks like a Christmas tree.
Release is pretty important.

[Jim Drago]

No $4 trophy or 8 day festivus in Elkhart Lake exists for the highest longitudinal acceleration possible? Brake for 1.0g for 100 ms longer than the the guy who broke at 0.9g, and enter/exit slower while you are doing it, and you still lose the lap and lose the race.

You can't get peak decel (or highest average decel over n*100 ms) AND get the lowest split time through the corner at the same time ... which is why divebombs are what they are (position plays at expense of laptime) and qually laps are what they are (fastest lap possible wth no regard to position).

Getting on the brakes harder and later is good .... only if the split time is better. If not, you are robbing Peter of $1 to pay Paul $0.80.

(And this is where 50% of the "Ohhhhh, I'm killing him under braking and into the corners and he just motors me on the straights ..." B.S. comes from, with the other 50% being that people simply don't comprehend that cars cutting identical lap times will be really close when they are going 25 mph and relatively far apart at 120 mph ... because time and speed are related by .... well .... distance).

I love when Saul stops by

BTW, I am playing Justin Timberlakes course tomorrow morning.. Miramichi ...One of the only, if not the only totally green courses ( like pollution, not fairways in the country. Supposed to be nice.. we'll see.

[Danny Steyn]

Perhaps even more enlightening... some may wonder why they are threshold braking in certain corners

hmmmmm
The question was - what are the max G's under braking???? Not how to cut fast laps
Max G's occur at threshold

[Nsparks]

In an upward sloping braking zone, where suspension is loaded/compressed, you should get around 1.5G possibly more (T11 at Barber)

Who brakes at T11???

I'm just nit picking here, Isn't the right up the hill 12?
+1 for post count and I agree with Danny. My data shows very similar numbers to his.

[Danny Steyn]

Thanks for the correction Nate - its T12 at Barber - uphill compressed zone. T11 is the downhill left hander
No-one brakes at T11!!!!

[Jim Drago]

hmmmmm
The question was - what are the max G's under braking???? Not how to cut fast laps
Max G's occur at threshold

apples and oranges!!! correct.

I quoted Ross' comments about people going home checking there max G for comparison... just stating the obvious.. Many of those people who are threshold braking in certain corners probably shouldn't be, especially in a SM. Just another point made.. didn't feel it needed it's own thread, nothing to do with your data