The season is nearly here – in fact for some people it has already started. So that means that you should have already set the data logger up so that it gives you no trouble when you actually hit the circuits. It won’t take very long to do and will pay for itself many times over when the time comes.

The AIM system is very robust and reliable and gives fewer problems than many other much more expensive systems. In fact, it’s the reason that I’m writing this blog. The only other systems that I have seen that are as dependable as the AIM literally cost several thousand pounds more. It is a real bummer when you get to the end of a run and find that you cannot download the data. That has happened to me too often with other systems so now I use AIM. With one of these, I have never had a problem and that means a great deal if you want to run competitively. But you do need to ensure that the system is properly installed and looked after.

The mechanical bits need to be safely attached with decent, properly engineered mountings and the electrical bits need to be kept cool and dry and mounted on rubber to minimise the effect of vibration.

Speed sensors have a hard life unless they are mounted rigidly so that they cannot vibrate and the cable is very vulnerable to accidental damage either in the case of an accident or from a bit of ham-fistedness when changing wheels or doing other essential repairs and maintenance.

One good tip relates to mounting pressure sensors on the engine. The high frequency vibration can destroy a sensor in a very short time. I know one team where the mechanic refused to listen to the advice and they have now installed their third sensor after just one season of racing. The mechanic (whose day job is as a road car mechanic) would not believe that there could be a problem. Because race engines are often mounted rigidly on the chassis, the vibration level is much higher than when the engine has rubber mounts and it literally shakes even the best quality sensors to pieces.

The AIM uses good quality plugs and sockets for all the connectors but make sure that they are firmly located and that the joints are not under any strain. Cable ties are your friend here. It is also worthwhile looking at all the wiring to see that it has not been abraded or overheated.

Keeping the electrics dry can be a problem and it is worth thinking about whether you can mount the system into a sandwich box. The sort with a clip on lid is ideal. There are a few problems to be overcome, like sealing the leads where they go into the box (silicon sealer will do the job) but if you do it properly your expensive logger stays dry forever. Get it wrong and you will end up in a plastic container full of water so do be careful.

When you are happy with the hardware side of your set-up, think about the software. Use Race Studio to get things how you want them. It’s simple enough and I will cover it in my next blog entry

In the last post, I showed you how to create a maths channel. The one that I chose was mph per 1000rpm. Now it’s worth looking at what that channel can show you.

The first screenshot shows a nice controlled car with no identifiable problems. The trace highlighted in the blue circles is the inevitable effects of changing gear. It is never synchronised perfectly so small spikes here cannot be avoided. Bigger disturbances here would indicate poor driving technique that would need to be discussed.

The area in the red ellipse shows the speed and the engine rpm increasing and reducing as the driver negotiates the series of bends at the end of the main straight but the mph/1000rpm trace remains constant because the driver stays in the same gear and so the ratio that you calculated remains the same.

You can also see what gears were used simply by counting them. Without knowing the gearing, we can assume that the driver was in top gear and went down two gears for Turns 1 2 and 3. One more up-shift dealt with the long sweeping bend and another downshift was made for Turn 5.

A better way of visualising what gear the driver is using is with the track report function. Get at this via the menu (VIEW  -  TRACK REPORT). The default set up shows rpm so you will need to use the settings button to show the dialogue box. Select only the mph/1000rpm channel in all of the places where you get the choice and also do not ask for any extra information to be shown.

You may also have to fiddle with the slider bar shown in the red ellipse to get the map to look reasonable, but it is easy enough to do. The end product looks like this

You can clearly see where each gear was used on the circuit.

Finally, this screenshot shows a much more powerful car. The speed and mph are shown in the top half of the screen and the rpm in the bottom half. In addition there is the throttle trace so that you can see what the driver is doing.

The trace in the blue circle has been magnified slightly and it shows that the mph/1000rpm ratio is decreasing. It is not the nice controlled trace of the first set of data. This car is much more powerful and wheelspin is abit of a problem. The fact that the trace is not horizontal, but falling away indicates shows wheelspin. This is confirmed if you look at the throttle trace (Orange, along the bottom of the screenshot) and you can see that the driver is having to be careful with the gas and in fact backs out towards the end of the bend. A close look at the other two slow corners shows similar, but milder symptoms. Some work here for the engineers!

Maths Channels

Sooner or later, you are going to want to use a maths channel in your data logging, so now is as good a time as any to learn how to do it.

You can use a maths channel to record what gearing your were using on a particular day and show it either as a gear ratio or as miles per hour per 1000rpm. You can calculate braking force  by calculating longitudinal g force and, once you have got the hang of things, you can even create a maths channel to measure understeer or oversteer. The possibilities are pretty well endless.

To create a maths channel you need to be in the Math Channel dialogue box. You get there through the menu system (Modify ¦ Math Channel) or by pressing the  Alt and F8 keys. The box looks something like this. (Click on to the image below for a better view.)

The stages that you have to go through are

·        Open the dialogue box

·        When you click on the Insert button the words “new channel” appears in the box on the left.

·        Select this name (using a mouse click)

·        Click on to the button that contains the three dots to the left of the word Name under channel parameters and you can then put in whatever name you choose.

·        In this case we can use mph per 1000rpm so type it in.

At this point we have a new channel that doesn’t do anything. To make it work, we need to put a formula into the Formula box in the bottom left hand corner. You do this by typing in what you want. For mph per 1000rpm we need to divide speed by rpm. Don’t forget that you are using a computer program that is very picky about giving precise names for everything, so in the case  shown in the picture, speed is called Speed­_1 and rpm are recorded using the AIM conventional name of Engine. The formula needs to be

Speed_1/Engine

So long as you use the exact names (the correct capital letters are important) and leave no spaces you will have calculated mph per rpm. This gives a pretty big number, so it is conventional to convert the answer to ‘per thousand rpm’ by dividing rpm by 1000. This means that you are doing two calculations in your formula so it is better to separate them by using brackets. Otherwise you can end up with not quite the answer that you were expecting. It would look like this.

Speed/(Engine/1000).

Click on the Test channel button to check that your formula works. If it does, the channel will now appear in your list of channels but probably not in your charts. The likely reason for this is that the AIM default scale is for some reason, -1 to zero. For this sort of gearing calculation, the answer is likely to be in the range zero to 30 miles per hour per 1000 rpm. You can scale your channel using the buttons in the dialogue box.

Had you ever thought about sharing your data with your competitors? If your immediate reaction is “No chance!” think about it for a moment because there are circumstances where it can pay dividends. If there are two cars in a team, the team can learn twice as quickly. So why not try to get some of the benefits by sharing data in the same way that Lewis and Heikki obviously do.

Most club racing is done in one-car teams so it will be necessary to find someone with whom you think that data sharing would be mutually useful. A good starting point is someone who is at the same level of competitiveness as you because a competitor who has already figured out the secrets is unlikely to want to give them away too easily. But pooling your knowledge with someone at the same level can help you both make progress more quickly.

 Take the data shown in the chart. It comes from two separate cars running in the same class. The two drivers prepare their own cars and are currently running just behind the leaders and both need to make the step up to become consistent front runners. By sharing data they can learn from each other and make progress towards the front of the field. When they get there, their natural competitive instincts will kick in and they are pretty well certain to let the arrangement drop. But until then they know that it is in both their interests to play the game of “I’ll show you mine if you show me yours”

The data shows Speed at the top, Lateral g (cornering force) in the middle and Time slip at the bottom.

 Although the red car (well, red trace) is faster over a lap, the bits that I have circled show where the blue car was making up time. The blue car carried more speed through Turn 1 and this can be explained by the Lateral g trace. In the yellow circles, we can see that the blue car turned in slightly later and maintained a constant line through the bend. The red car turned in more sharply (shown by the higher and erratic lateral g) and was a tenth or so slower. The dip in the red trace is probably indicative of mid corner oversteer.

 The blue circles show that the blue car was more ragged through Turn 2 and was a few miles per hour slower on the exit. For some reason the blue car was able to make up this deficit before the end of the straight.The green circles show that there were definite differences of line and speed between the two cars. The red car turned in earlier and used a tighter line than the blue car.

 So the driver of the blue car gives away secrets about the lines through Turns 1 and 5 but learns that he really must do something about his braking. It is not shown on the chart, but in the three big braking zones (Turn 2, 3 and 7) his time-slip line heads upwards indicating that he is losing time. Both drivers left the circuit with something to think about! That seems to be a reasonable reward for sharing some of your secrets.

Okay, it’s a fair cop. When I started this blog I intended to update it whenever something interesting came along. But then, somehow too many things came along and the blog sort of took second place. So now it’s time for a New Years Resolution and so I’m going to try to update the blog on a much more regular basis. So here goes!

The first piece of news is that I will be presenting a seminar about the use of AIM loggers in Karting. It will take place at the PFI meeting on Saturday 28 ^th Feb 2009. (EDIT Please note the date change from 7th to 28th Feb.) It starts at 6.30pm and will go on to 8.30pm (and possibly a bit later if we are enjoying ourselves!) The cost will be £25 and drivers under 16 will be admitted free if accompanied by parent or team manager.

The session will cover the basics of setting up and using an AIM logger and show you how to use the Race Studio Analysis software to understand what is happening on track. If you already use a logger you should learn how to get better quality information, more quickly. If you are thinking about buying a system, we can show you what you can expect to get out of your investment. In either case it will be money well spent.

The contents will include

• choosing and setting up a logger
• using the software to create and use maps, XY and measures graphs
• what the data can tell you about handling, gearing, traction and braking
• improving the driver and improving the team

Further information and a booking form can be found elsewhere on this site, but you should try to book up quickly because numbers will be strictly limited. If people find the Seminar useful, we will be repeating it at various kart circuits around the country at race weekends through the racing season.

The Mytach GPS Watch is making a big splash in the motor racing world and is being picked up by karters already! Karting1 have given it test run already and have used it to produce some very impressive reults showing track mapping, speed and g traces and some nice google earth overlays.

Take a look at the mytach article here

The mytach is available in the aim shop here and the mytach website is here

It’s a beginner’s mistake that I thought that I had grown out of years ago. When we got back to base and unloaded the van, the beacon was not in its usual place. It was where we left it. On the pit wall. Fortunately it was our local track and a thirty mile round trip and a visit to the circuit office got the thing back where it belongs.

We now have a laminated A4 sheet that simply says ‘BEACON’ in large print and a system that requires whoever puts out the beacon to hang the sheet on the van steering wheel. It is usually my job to put out the beacon because I’m so fussy about where it goes. I know that its not absolutely essential that it is in the same place every time but I make sure that it is because although you can shift the lap marker using the software, who needs the extra work on race or test days?

I have devised a simple method to ensure that we are consistent in our beacon placing. The marshals (track workers) at UK circuits always occupy the first part of the pit wall. This part of the wall is normally fenced off and they naturally don’t like beacons being put there. So our beacon always goes on the first available piece of pit wall after the marshals. I always ask politely whether our chosen spot is ok and I feel that this prompts them to keep a bit of an eye on it. It’s not just an anonymous bit of equipment, but it belongs to that nice bloke who always stops to chat and show appreciation of the voluntary work that they do.

The other way round the placing and fetching the beacon problem is to buy the GPS based system that AIM sell and you will never have to bother with a beacon again. You need to train the system to recognise where you want to time your laps from but this involves going into a set-up routine on the dash and pressing a button at the appropriate place. The easy way to do this is to get the car into the pit lane in line with the Start / Finish line and press the button there. Once set, the system remembers this forever. Better than that, because it knows where it is on the planet, it associates this place with a particular track and writes it into your filenames.

You get other benefits with a beacon system as well. You don’t need to measure wheel speed although the very slight time delay with a GPS system gives small differences that you can see on the data but which are not significant for interpretation purposes. The GPS module provides a collection of spin-off data besides speed. Track maps are obviously excellent and v2.30 of Race Studio Analysis enables you to colour the track map according to any parameter you want. The screenshot shows long g and gives a good idea where the heavy braking areas are

The GPS system provides lateral and longitudinal g, gyro, slope and heading data. Most useful of these is the long g data because that makes it possible for you to analyse braking performance which in my experience can be the single most cost effective way of improving lap times. And using GPS data saves you the cost of an additional g sensor and, if you are running with a limited number of channels, saves a channel as well.

Version 2.30 of the Race Studio Analysis software makes creating your own user profiles much easier than it was before, and because it’s easier, it is more likely to be useful.

A profile is simply a set of graphs and statistics that you use frequently and can save for future use. So, for example, if the first thing you look after a run is the engine health, you could set up a profile that brings up all the things that you are interested in. You could create a measures graph that shows engine rpm, and all the relevant temperatures and pressures on one screen Plot this against time so you can see if any time was spent in the pits. An XY chart could be used to plot oil pressure on the Y (vertical) axis and lateral g on the X (horizontal) axis. This will show whether there is any oil surge in the corners. A Channels report that shows the minimum pressures, maximum temperatures and averages of all engine parameters will give instant warning of anything that is out of range.

Clearing away all the other graphs and setting this lot up will take a few minutes, so it makes sense to save it as a Profile. This means that you can access this layout instantly the next time you get data. Get all the data set up in precisely the way that you want it – for instance, even when doing engine health, you might want to show throttle and rpm histograms and it is always a good idea to have the lap times available.

Creating a profile is easy. If your charts are set full screen, press the space bar to make the measures tabs appear. Then select the Profiles tab, and the Save Button. Give your profile a suitable name. The next time you want to look at engine health go to Profiles and select your engine health profile and the graphs and tables that you set up originally will appear using your new set of data.

If the next stage in your data analysis to investigate the handling , then no doubt by now you have worked out that you can do exactly the same thing with charts showing speed, lateral g and corner radius. It makes life at the track simpler and anything that does that is to be welcomed. Engine health, driver / rider inputs and handling profiles cover much of what you will want to know at the track.

If you have never bothered much with the XY Plot feature in Race Studio Analysis, you should give it a go. It can present data in a way that you had probably not thought of before. An XY Plot, shows one variable plotted against another. For example, you can plot speed against rpm to look at gear ratios and gear change points.

To create a plot, Select the XY Plot menu option or button and select one variable in the measures toolbar. For a gear chart it needs to be Engine Speed (rpm). This will be shown on the Y (vertical) axis of the XY plot. Then right-click somewhere on the chart and the pop-up menu will offer you a range of options from which you choose ‘settings’. This then presents you with a dialogue box from which you select Speed. At this point you can choose whether to have the points plotted lines joined together or as dots or circles.

There are other things that you can do using this technique. You can evaluate your driving technique by creating a Friction Circle by plotting longitudinal g on the Y axis and lateral g on the X axis. Any good book on race technique will tell you what the chart shows and how to interpret your driving or riding style.

Another useful plot is to plot oil or fuel pressure on the y axis and lateral or longitudinal g on the x axis. This will give you an idea of whether or not you are suffering from surge during cornering or under braking. Oil surge is indicated if the cloud of points is mushroom shaped. If the oil pressure readings are clustered together and do not drift downwards under high g forces then there is no problem. A quick look at the two charts shown here will give you an idea of what to look for. The first chart shows a car where the pressure stays within bounds during cornering but the second one shows that pressure can fall during hard cornering in either direction.

If the scaling is not quite what you wanted, the things to look out for is that if the Y variable has a number immediately to its left in the measures toolbar, this needs to be a 1. If the X scale is compressed then it is simply a matter of changing the plotting scaling using the Modify Test Channels menu options.

It can be a real pain if you are at an event and you laptop goes down. One way round this is to borrow one from someone else, but whatever you borrow is unlikely to have the Race Studio Suite loaded on to it. A good way round this is to copy the whole directory on to a 4Gb USB stick and to run the program off that.

It sounds like it shouldn’t work and no doubt there are occasions when it won’t, but this trick has got us out of trouble several times. Open Windows Explorer, find the Program Files folder and drag the whole AIM folder onto your memory stick. The program can then be run by selecting the RaceStudio2.exe file and double clicking. The program runs quite slowly but it is a big improvement on not being able to run anything at all and it saves having to install your program on to someone else’s computer.

You might have to install the USB driver on to the new host computer to enable you to download and if you want to run the analysis program you will need to use Windows Explorer to transfer any older data files on to the hard disk of the borrowed machine. It also works if you want to show your data to someone away from the track.