ColorChange

Mark:

OK, let’s continue the discussion. I think you have to agree that if can’t support you viewpoint, you lose the argument. Therefore:

- is wrong. Do we agree that:

1. g analysis is highly valuable for corner analysis and is used by the best racers and teams in the world.
2. g-g graphs are extremely valuable in car development, highly valuable in driver development and in chassis set-up.

Let me point out another mistake. You say that “overdriving the car” generates great g results. This is not true. If you exceed the limits of the car (past the optimum slip of the tires) the g capability drops off, not gets higher.


G data is not only good for braking, it’s great through the whole turn. If this is your time from full accel to full braking, that is fast and excellent compared to a normal car. I can only do it in about 0.6 seconds or more. Now, I am not sure how much of an advantage the down force gives you but I think your time is excellent.

OK, I agree. Are you performing fft (fast Fourier transform – converting to frequency) analysis? Most people look at frequencies slower than 2 Hz as driver induced, faster than that is mechanical (that can be influenced by the driver). If you are, you are well ahead of me here.

Just for clarification, the Aim systems are extremely capable and can perform much the same analysis Motec (and others, stack, pie, etc) system can for MUCH less money. For example, my reservations about installing the displacement sensors was strictly travel/mounting related, not Aim system capability which can handle it easily. The Aim system should not be confused with the g-tech products. If this was the basis for your engineer’s comments about the reduced value of those type systems, I can understand that in that context. If he was talking overall, than you should seek out a new coach as his competence is severely questioned.


Carrera:
The whole point of the DAS is help you drive faster. You really need to get one to understand how useful it can be. For example, if you can see after a session that you are leaving a ton on the table on entry to turn X (looking at g-sum), you know to push it harder there. Your view of a minor tool for suspension tuning only is completely baseless (and wrong).

Sunday:
With regards to “knowing” the limit, maybe we are hung on the details. Yes it is difficult, but the absolute limit value is not critical. From previous testing you know the approximate limits of the car and what your highest g-sum was through that turn. Again, (as I have said earlier and as you have also said) having an “expert” drive your car will be hugely elucidating!

RJay:
Yes, lap time is king. Exit speeds are not the best indicator of fastest lap times. G-sum (or related g analysis and segment times) are far superior. The rev display is primarily used for engine protection (shift lights), not exit speed analysis.

944Turbos, Thanks, you weren’t working with the Redszus gods at RA were you?

Vaughan:
Your implication of the Aim system being low resolution is way wrong. If you want me to get wheel speeds at 400Hz with 8 magnets per revolution I can. Is that fast enough for you? This bias against Aim is largely wrong.

Brian P

Okay... Let me know when you get that G-sum display set up on your dash. In the meanwhile, I'll use my tach to determine how well I'm coming through the corner. I don't see how else you are going to get that instant feedback on what line or technique is better.

ColorChange

Brian:
I agree real-time feedback might be nice and I discussed this in an earlier post. But, real-time feedback is not the only way to go faster. It is often desirable if it can be done in a reasonably non-distracting and safe way. A DAS (non real-time) is a superior approach to driver feedback and training than a real-time tach.

Brian P

I guess it depends on what level you are in your development. For many beginners and intermediate drivers, the tach is going to be a great instrument for determining how well you went through the corner. Basically, higher exit speed is king (for our Type I turns).

After a while, you will be leaving the corner nearly as fast as possible and the rest of the lap time that you can save will be in the other parts of the corner: corner entry, midcorner, and braking. Yes, the tach is relatively useless for those parts of the corner (or, at least it's pretty difficult to look at the tach in those sections).

The Skip Barber book covers this in some detail when it overlays a student's DAS data versus the pro's. I should emphasize that exit speed was still king. I.e., they were trying to figure out why there was about 2 seconds of lap time difference between the pro and the student even though their exit speeds were near identical. In the few cases where the exit speed wasn't the same, it was always viewed that the driver (usually the pro) who had a better exit speed did the corner better.

SundayDriver

I do, in fact, have a gauge - the beauty of the very programable Motec. I can see braek bias and use it 1) In the pits if I know what I want to start with 2) During practice. Too much to look at in qual or race.

I am really relying on feel but the bias reading is helpful at times. The logged pressure data was very helpful in diagnosing problems.

SundayDriver

We don't agree and I am not all that interested in winning an argument. I am interested in winning races. Your statements above (1 & 2) are not things I agree with. I have seen no evidence either is true - though you cite a book I have not seen. Other than that reference, none of the experts I have worked with seem to agree with your statements. The only part that I may agree with is the value of g-g grapshs in vehicle developmenet (vs. tuning). So I would ask you to support your statements, expecially outside of F1. (I think there are far too many issues trying to use F1 techniques in amateur racing as I posted earlier).

I can't prove that g data is worthless, but I have not seen any proof that it has value. That, I think, is the core of what we do not agree on.

SundayDriver

I really don't see how you are in a position to say that - here comes the experience thing again.

I have used the tach approach to improving my lines and exit speeds with great lap time reductions to go with that. Others have done the same - either coaching others to improve or their own improvement. Here is a case where experienced drivers and instructors are saying this is valuable. In my case, I had access to DAS as well and the tach for exit speed resulted in far greater improvements than the data provided.

I would ask how many drivers you have coached to improvements with DAS? How much have you improved yourself with DAS? You have said you have little track experience and I imagine you are not working as a coach either. How can you assert the relative values of these approaches when you lack the experience to back that up?

You have interesting ideas about theory and DAS - anyone with a technical background can go down that path. You lack the real world experience to back up your real world claims.

SundayDriver

I completely agree with that. Repeating something I have posted here many times (from a coaching session with Brian Till):

Speed comes in three steps:
1) Driving the line
2) Exit speed
3) Entry speed

All the data and video you want will no help with #1 anywhere near as well as a coach/instructor. #2 also does not require fance data - tach or speedo is fine. Then you are ready to pick up that last couple of seconds with entry speed. Data can help a lot with that, but so can feel and chasing faster cars.

DE drivers should not even be working on #3, IMO. When you get to the stage of high entry speed, most of you safety margin is gone. From the moment you hit the brakes until exit, you are pretty much committed to the corner. IMO, there is no reason for a DE driver, in a street car, to take the risks associated with that level of driving.

Tim is working this in reverse with a lot of focus on entry speed when he has not yet perfected #1 and #2. That does not work for most people, maybe it will for Tim. I am opne to that possibility, BUT, I think Tim will have to prove it works before anyone (including me) will accept it as a viable way to learn to go fast.

ColorChange

Mark:

A former F1 technical director analyzes the best driver in the world using lat and long g analysis, Milliken, Skip Barber, numerous Race Car Engineering articles, numerous SAE technical papers, professional race car consultants/coaches, etc. etc. etc. and you say you have not seen any proof?

errr... aaah ... open your eyes?

You're right on my inability to say the DAS is a better way for others to learn. I am not qualified to make that statement and stand corrected.

How do you know I don't have the line and exit speed reasonably learned (clearly I don't have the entry portion learned well yet)? You may be right by your standards, but I don't think you're qualified to make the statement (lack of information on my driving ability).

iloveporsches

By the video you posted where you had inconsistant apexs?

If you can't hold damn near identical lines every time around the track, what good is knowing your particular g-sum for an arbitrary line that most likely isn't the fastest line? Once you are able to nail the perfect line every time, maybe DAS will help you improve lap times; I don't know so I won't say one way or another. But if you don't know the limit on the best line (done emperically, which if you can't drive the same line all the time you're going to have a hell of a time doing it), what good is knowing your g-sum? Oh, I got .9 on this line and 1.1 on this line. So what? How do I know which is fastest? How do I know either of those are anywhere near the fastest line? How do I know those are the highest g values for those given lines?

smokey

Mr. Hyde redux.

ColorChange

Brandon:

If you are pushing hard on the entries as I was in the videos, I missed the apexes primarily because of errors on entry (and getting used to a new car). If you asked me to take a reasonable entry speed and back off the trail braking, could I then hit my apexes and exits? The only one who might no that is F1ten. He has seen me and ridden with me at the track. You can't tell that from the videos I have hosted and that's my point.

Secondly, by driving different lines at different g-sums, you can compare segment times (all in the DAS). It really is quite simple.

M758

... and here I thought color was learning...

iloveporsches

But if you need to back off to hit the lines properly, you have no idea what the limit is. Unless you're already at the top of the game, you're not going to be able to drive consistantly enough to determine the best lines, and limits on those lines, to have g-sum be all that valuable. That was my point.

For an amatuer, there's just WAY too many variables to take data like that very seriously. I could go run 50 laps with DAS on the FSAE car and analyze the crap out of it, but I gurantee I'll go faster by just driving an extra 50 laps instead of looking at numbers.

trumperZ06

Quoting from an earlier M758 thread...

" Just a note to the others out there! "

" I believe Color is learning what we are saying. Sure its taken a while, but I think he is being won over slowly! I believe in time he will be a fine driver. Lets all agree to lay off the inflamatory comments. O K "


Patience, Grasshopper!!

Soorriiieee about that, M758 !!!