Post by tasilloracing76 on Mar 6, 2006 18:54:39 GMT -5
Tech Tip # 9 – The Setup Sheet
As you can see in the Tech section of this board, Matt was kind enough to post the set up sheet we use in our racing program. There are many different examples of these available on the internet. I like this one because it is simple and captures most of the information appropriate to the Slingshot. Many thanks to Steve Tinker at T & J Motorsports for providing this.
This tech tip will deal with the set up sheet and how to use it. The next tech tip will get into scaling the car and how to work that information into your set up. And finally, we’ll get into some basic set up philosophies that made a difference for us.
Regarding set up, I’ve watched many of our fellow Slingers show up at a track they’ve never been to and then dominate. In many cases, these are folks who have been involved in motorsports for a long time in many different classes and venues.
We weren’t so lucky. We started racing Microds 10 years ago with absolutely no knowledge of mechanics much less motorsports. For this reason, we learned by mistake…. And the only way to learn by mistake is to run the ‘same’ thing under ‘different’ conditions AND change ‘one’ thing at a time under the ‘same’ conditions AND AND AND keep good records of everything you’ve done and the results.
The set up sheet is our number one tool to accomplish this. We also keep a detailed notebook which has entries for every race we’ve been in for the last 10 years. We fill out a set up sheet anytime we try a new approach or visit a new track. At tracks we go to regularly, the same sheet may be appropriate everytime and then any small changes we make are logged in our notebook. Or for instance, if the track is unusually wet, or rough, or something out of the ordinary one night, our set up may change significantly and we note the specifics in the notebook. Sometimes the results are spectacular so we go home and fill out a new set up sheet including a description of the unusual conditions. Or sometimes, we hit the wall, but we still take notes on what DIDN’T work.
If you are new to this, I would photocopy a stack of the set up sheets and fill one out everytime you got into the car.
Now then…. how to use it ! Print out a copy of the one that Matt provided on this board so you can follow along . . .
First off, note the track, the weather, and perhaps the track condition. Although we don’t bring along a weather station like the NASCAR guys, we approximate the temperature, whether its dry or humid, whether the track is dusty, tacky or wet, and so on.
The 4 boxes on the top left of the sheet represent the 4 corners of the car. The tire circumference at the inflation specified along with the spring type and the coil setting. For instance; The right front ( RF) might be 48 7/8 inch tire size with 10 pounds of air pressure, a 60 pound spring set at 6 ¾ inches. Note the little shock diagram to the right. It shows the reference points for the spring setting measurement; the top of the shock clamp which the spring rest on to the center of the stationary heim joint. We use adjustable shock collars. The shock collar sits on the shock clamp and the measurement we make is from the adjustable part of the collar that the spring sits on down to the stationary heim. Make sure you use the same references every time and make sure that the spring or adjustable collar is resting on the shock collar when you take your measurement since many times, the set up may have the bottom of the spring ( or adjustable collar) floating above the clamp as the car is sitting in place.
LR and RR hub offset is the measurement in inches from the end of the axle to the hub plate to which the wheel is against. It is not uncommon for us to change the offsets dependent on how tight or loose the car is, the size of the track, and the stagger we’re working with.
The track bar (panhard) position, and it’s length defines how square the rear axle is to the chassis. The squareness is a dynamic thing. As the car rolls over, the panhard will steer the rear wheels.
The highest of the 4 holes on the chassis will make you loose in and tight out. The lowest of the 4 holes will make you tight in and loose out. We move this around a lot even though we always have a starting point on our set up sheet. We establish that starting point by measuring the distance from the rear axle, forward to the chassis crossbar ( which the swing arm heim is attached to), on each side of the car. The panhard length which causes these measurements to be equal is considered neutral. If you lengthen the panhard, the rear wheels will tend to steer the rear of the car to the left. If you shorten the panhard, the rear wheels will tend to steer the rear of the car to the right. When we first started, we used to over steer the rear wheels left when the car was loose and over steer the rear wheels to the right when the car was tight. Over the years we found that this was a crutch and if the car was set up properly, statically steering the rear wheels to fix tight or loose was working against us overall.
Don’t forget to enter your gear ratio. That would be 5.5 for a 55 gear. Our choice of gear has a lot to do with track conditions, where we start in a race, among other things. In general, we select a gear that peaks our tach around 6K RPMs. Sometimes in a race that we know is going to have a lot of restarts, we may use a bigger gear for more torque on the restarts. Sometimes on the big tracks where we know we’ll have plenty of room, and lots of opportunity to pass, we’ll use a smaller gear. It’s generally a crap shoot and it has a lot to do with what’s going on, on the track and with the car.
At the bottom of the form is the max temp / max RPM reading you can enter for hotlaps, heats, and feature. Since I’m generally timing his laps, we enter the average lap time on the form. Keep your eye on max temps since as I mentioned in a previous tech tip, high readings could indicate problems such as a head gasket leak. The bottom of the form is generally full of all kinds of observations including who the big guns are, who may be driving nuts, and various aspects on how the car handled.
Additionally on the sheet we indicate the toe out we’re using along with a number of other factors such as carb mixture setting, sparkplug type, etc,etc,etc.
And as I mentioned, when we scale the car, we generally put our cross weight, left side weight, and rear weight percentages on the form. More on this later. Along with a whole lot more discussion on set up.
Regards, Ed
As you can see in the Tech section of this board, Matt was kind enough to post the set up sheet we use in our racing program. There are many different examples of these available on the internet. I like this one because it is simple and captures most of the information appropriate to the Slingshot. Many thanks to Steve Tinker at T & J Motorsports for providing this.
This tech tip will deal with the set up sheet and how to use it. The next tech tip will get into scaling the car and how to work that information into your set up. And finally, we’ll get into some basic set up philosophies that made a difference for us.
Regarding set up, I’ve watched many of our fellow Slingers show up at a track they’ve never been to and then dominate. In many cases, these are folks who have been involved in motorsports for a long time in many different classes and venues.
We weren’t so lucky. We started racing Microds 10 years ago with absolutely no knowledge of mechanics much less motorsports. For this reason, we learned by mistake…. And the only way to learn by mistake is to run the ‘same’ thing under ‘different’ conditions AND change ‘one’ thing at a time under the ‘same’ conditions AND AND AND keep good records of everything you’ve done and the results.
The set up sheet is our number one tool to accomplish this. We also keep a detailed notebook which has entries for every race we’ve been in for the last 10 years. We fill out a set up sheet anytime we try a new approach or visit a new track. At tracks we go to regularly, the same sheet may be appropriate everytime and then any small changes we make are logged in our notebook. Or for instance, if the track is unusually wet, or rough, or something out of the ordinary one night, our set up may change significantly and we note the specifics in the notebook. Sometimes the results are spectacular so we go home and fill out a new set up sheet including a description of the unusual conditions. Or sometimes, we hit the wall, but we still take notes on what DIDN’T work.
If you are new to this, I would photocopy a stack of the set up sheets and fill one out everytime you got into the car.
Now then…. how to use it ! Print out a copy of the one that Matt provided on this board so you can follow along . . .
First off, note the track, the weather, and perhaps the track condition. Although we don’t bring along a weather station like the NASCAR guys, we approximate the temperature, whether its dry or humid, whether the track is dusty, tacky or wet, and so on.
The 4 boxes on the top left of the sheet represent the 4 corners of the car. The tire circumference at the inflation specified along with the spring type and the coil setting. For instance; The right front ( RF) might be 48 7/8 inch tire size with 10 pounds of air pressure, a 60 pound spring set at 6 ¾ inches. Note the little shock diagram to the right. It shows the reference points for the spring setting measurement; the top of the shock clamp which the spring rest on to the center of the stationary heim joint. We use adjustable shock collars. The shock collar sits on the shock clamp and the measurement we make is from the adjustable part of the collar that the spring sits on down to the stationary heim. Make sure you use the same references every time and make sure that the spring or adjustable collar is resting on the shock collar when you take your measurement since many times, the set up may have the bottom of the spring ( or adjustable collar) floating above the clamp as the car is sitting in place.
LR and RR hub offset is the measurement in inches from the end of the axle to the hub plate to which the wheel is against. It is not uncommon for us to change the offsets dependent on how tight or loose the car is, the size of the track, and the stagger we’re working with.
The track bar (panhard) position, and it’s length defines how square the rear axle is to the chassis. The squareness is a dynamic thing. As the car rolls over, the panhard will steer the rear wheels.
The highest of the 4 holes on the chassis will make you loose in and tight out. The lowest of the 4 holes will make you tight in and loose out. We move this around a lot even though we always have a starting point on our set up sheet. We establish that starting point by measuring the distance from the rear axle, forward to the chassis crossbar ( which the swing arm heim is attached to), on each side of the car. The panhard length which causes these measurements to be equal is considered neutral. If you lengthen the panhard, the rear wheels will tend to steer the rear of the car to the left. If you shorten the panhard, the rear wheels will tend to steer the rear of the car to the right. When we first started, we used to over steer the rear wheels left when the car was loose and over steer the rear wheels to the right when the car was tight. Over the years we found that this was a crutch and if the car was set up properly, statically steering the rear wheels to fix tight or loose was working against us overall.
Don’t forget to enter your gear ratio. That would be 5.5 for a 55 gear. Our choice of gear has a lot to do with track conditions, where we start in a race, among other things. In general, we select a gear that peaks our tach around 6K RPMs. Sometimes in a race that we know is going to have a lot of restarts, we may use a bigger gear for more torque on the restarts. Sometimes on the big tracks where we know we’ll have plenty of room, and lots of opportunity to pass, we’ll use a smaller gear. It’s generally a crap shoot and it has a lot to do with what’s going on, on the track and with the car.
At the bottom of the form is the max temp / max RPM reading you can enter for hotlaps, heats, and feature. Since I’m generally timing his laps, we enter the average lap time on the form. Keep your eye on max temps since as I mentioned in a previous tech tip, high readings could indicate problems such as a head gasket leak. The bottom of the form is generally full of all kinds of observations including who the big guns are, who may be driving nuts, and various aspects on how the car handled.
Additionally on the sheet we indicate the toe out we’re using along with a number of other factors such as carb mixture setting, sparkplug type, etc,etc,etc.
And as I mentioned, when we scale the car, we generally put our cross weight, left side weight, and rear weight percentages on the form. More on this later. Along with a whole lot more discussion on set up.
Regards, Ed