steve40th

I have recieved a vast amount of great technical data in regards to making my Vette handle better. Driver is one thing, but what about a set of standards to test your modifications.
A Slalom of 200ft cones/100ft cones?
Skidpad?
45 mph 90 degree turns.
Heck I dont know. An autocross course tells me nothing as every time you go its a different course. Our courses are always short 30-50 seconds.
So, to really see if your car is set up to to really handle well, what can you do to ensure positive or negative results after mods?
Just fishing for ideas.

acrace

I've been fortunate in the past to participate in test and tune sessions. Some of these have been one day affairs and some have been multiple day sessions. One group uses a "standard" course from year to year (well marked so it is easy to reconstruct). So this does give the ability to dial in the car, whether just tire pressures or more complex changes.

Given your location (by the signature), I'm not sure what exists in your area. You may need to organize something or maybe even tag it onto an autocross driver's school or the like.

Then once you start participating in a test n tune, you'll have to set up some disciplines to make sure that your results are meaningful (i.e.: the track conditions are not changing, tires aren't degrading if it's a multiple day session where you're making a ton of runs).

Independent1

^^Skidpad is probably the best because of the consistent conditions. Next best thing is to go the same track under similar conditions and see how the car performs.

ScaryFast

Skidpad is easy to replicate, but of very limited use for what you're looking for. While steady state handling is useful for ultimate grip, you're more interested in the car during dynamic motion - i.e. transitions, handling under braking and accelleration, etc. You don't gain much time optimizing your car for long sweeping corners, unless they lead on to the longest straights (like at Mid-Ohio).

It's a tough question. I have the luxury of running on the same tracks over and over so I can test small changes to see their effect. For Auto-x you have a changing environment.

My suggestion is that you get a data acquisition package, such as a racelogix box or a dynapak. They're about $700 and measure lateral and longitudinal accelleration. You will be able to tell the exact handling capabilities of your car. Then just map out a test course, like a set of roads you drive frequently, and compare the results on your PC after subsequent runs. The ones I use also incorporate GPS positioning to compare different racing lines, which may not be useful to you. I belive you can get just the accelerometers and analytical software package for about half the cost.

steve40th

Here in Hawaii, we just dont have the luxury of a nice area we can utilize all the time other than the back part of a parking lot at Aloha Stadium, which is not flat, or consistent. Better than nothing, though.
We used to be able to run at Barbers Point Naval air station base, then 9/11 and the Navy gave it up to private housing etc etc and there is no way we can use it.

ScaryFast

You could always move over the the lower 50.

I'm sure the weather's comparable!

steve40th

True. That will happen when I retire in 3 years. South Carolina, Summerville area.

Solofast

ACRace is right, you have to pretty much set up a repeatable course that you can come back to a couple of times a year, and it is important also to time segments of the course in 3 or (even better) 4 or more splits. This will tell you exactly where you are gaining time and losing it. A data acquisition system is a huge help too, since you can see if you messed up on one corner and if the changes you made were positive or negative. Times don't lie, but a full lap has so many variables in it that if you don't look at the whole picture you end up developing your car to that course and you won't likely see that course ever again unless you test on it.

We have found that the course you set up doesn't have to be "hard" from a technical diving standpoint. The easier it is the more repeatable the data that you get will be (and you will spend a lot less time chasing cones). You do need all of the basic course elements in there, sweeping turns in both directions, a fast slalom (75-100 ft at least), decreasing and increasing radius turns in both directions and fast transient offsets where you have to do violent steering inputs.

I have been to a couple of test sessions where the people setting up the session didn't understand what was the difference between a practice course that was typical of what you ran every weekend (relatively slow autocross course) and a vehicle dynamics test session. You need the fast slalom and fast transient elements to insure that that the car has stability margin. If you set up the car purely for steady state and slow speed manuevers, you won't have stability margin and you will lose time overall. That is an important difference between a test course and a typical autocross course. That is also why the skidpad is pretty much worthless, since if you are fast on the skidpad you won't have any stability margin.

What you can try to do is set up an "event", limit the entries to about 30 cars at the most and allow folks to run as much as they want and whenever they want. Set up a work schedule and have three or four folks working at any one time ******** cones. Plan to start running at 9:00am and finish at about 5:00 pm. Remember since the course shouldn't be nutty or too tight, you shouldn't hit a lot of cones, and you need to get everybody on the same wavelength, it isn't about killing pylons and time, it is about developing the car and working on setup. We often do it as a two or three day deal, Friday, Saturday and half of Sunday, but some clubs around here also do test session as a Saturday event and then run a normal event on Sunday.

When you can run a lot of runs you can make changes and evaluate them. Try to make a run group of about three runs. That will get you from cool to warm tires and let you get some good data and then go back and digest it. Make changes and do it again, and again, and again. Expect to do at least 30-45 runs in groups of three (10 to 15 setup changes, assuming that some are relatively minor) for each day you are running.

I am sure that if you go to the local Solo committe and offer to chair the event they will let you do it. You may have to find the place, but the key is getting the insurance and equipment. Also don't expect it to be cheap, figure at least $40-$50 per day per car for a reasonable cost and expect to dump all the profits into the local Region....

Good luck

Solofast

One other thing that is critically important is discipline.

Before you test you need a list of things that you want to test, in what order, and why.

You need a data sheet that includes the times for each segment of each run, the total run time, the time of day, the temperature, the number of runs on the tires, the suspension setup, a note of the changes in setup for each run group, the tire temps (Inner Middle and Outer) of each tire after each run, and the pressures before and after each run.

That sounds like a lot of data, but it is really just the start. You need to make sure that your data logging system gets data from each run and you log the data file name of each run on the log sheet so that you can cross correlate what the conditions for each run were and be able to see the effects on the data acquired, that way you can ovelay the plots and see what changes helped the car and where, not just that you got faster.

If you don't gather all the data you will probably get a little bit faster, but you won't know why. And you won't know what kind of changes effect what part of the course.

When I was doing this seriously I had sufficient data that I could walk the course and, after scuffing my shoes on the track to note the surface, could go back to the car and make shock and front sway bar setting changes that while they were pretty subtle, made the difference between first place and the rest of the pack. It takes a lot of time a discipline to get there.

steve40th

Well, We have a test n tune coming up in January, but I will be deployed. So, it will have to be next summer. Oh well, time to lan for the tune and to buy parts that will keep the suspension stable throughout all runs.