Home Forums Chassis & Handling How to develop skill to understand loose and tight

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This topic contains 11 replies, has 7 voices, and was last updated by  Eric Alexander 5 years, 11 months ago.

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  • #5348

    Jean-Paul
    Participant

    Want to really understand kart handling.

    I’ve been racing a year and am a mid pack club racer (looking to run in the front). I am running consistant (somewhat) lap times and am ready to start making changes to the chassis. I haven’t made many adjustments because my lap times were not really consistent. I have the local shop take care of my kart and the kart set up has not been changed – much.

    But, if I had the best tuner in the world and he asked me if the kart was too tight or loose (on any given track session), I don’t think I have a great feel on what to tell him. Adding to the complexity is entry, mid, and exit. Add to the complexity of maybe 11 turns in about 40-50 seconds, etc. Add to the complexity, brake zones, acceleration, etc, etc. Too much going on …

    Since I really don’t work on my kart much anyway, I really need to start turning some wrenches anyway. I am thinking of intentionally setting up the kart to be the “loosest” it can be and then slowly start adjusting things to a nuetral setup to get a real understanding of “what that feels like”. Conversly, setting up the kart to be “tightest” and work it back to neutral. I think I know what loose feels like. But I’m not sure I know what “tight” or “really tight” feels like.

    Looking for comments and suggestions on excercises to teach “an old dog new tricks”. I want to be able to understand what my kart is trying to tell me as I’m asking it to go around these corners. Is this a good strategy to set the kart up really tight, and then really loose?

  • #5351

    Benn Herr
    Participant

    The easiest thing to change on the kart for us – is the adjustable rear torsion bar. We run a Birel and changing it from straight up (pushy) to angled (not bad) to out (loose, loose, loose!) is a easy deal for us.

    The adjustment that makes the biggest difference though is moving the seat forward and back. An inch either way can make a huge difference. Problem is, moving the seat is usually not a quick and easy thing.

  • #5352

    Tyson Henry
    Participant

    Looking forward to the replies in this thread. I feel I am somewhat in the same boat. I have done quite a bit more “tuning” than you, but I don’t always know if I am tuning in/out the right thing. Meaning, is the kart loosing the rear on exit because I have entry understeer and am therefore turning in to hard, then it catches and causes oversteer. Or, is there simply not enough grip on exit?

    I feel like I have a decent grip on things, but not quite “there yet.”

  • #5357

    Jeff Field
    Participant

    Looking forward to the replies in this thread. I feel I am somewhat in the same boat. I have done quite a bit more “tuning” than you, but I don’t always know if I am tuning in/out the right thing. Meaning, is the kart loosing the rear on exit because I have entry understeer and am therefore turning in to hard, then it catches and causes oversteer. 

    For what it’s worth, I think this is the case at least 80% of the time.

  • #5361

    Ray Lovestead
    Participant

    My advise would be to play with the rear track.  If you go really narrow (like 1.5inch either side) you’ll not lift the rear inside tire and you’ll bind up the chassis.   You’ll probably find that it causes push (understeer) on the entry to the turn and has great grip on the exit (no oversteer at all).

    Doing this will give you some idea of what that bind feels with respect to power and acceleration.  On entry if you take it slow in and then get on the gas early, you’ll likely not get any longitudinal acceleration out of the kart.

    Conversely, if you set it up really loose (max rear, loosen the third bearing, remove struts) you’ll find it will eventually want to hop as you go through the corner.

    This is probably the best reference out there:

    http://www.crg-america.com/pdfs/CRG_Kart_Tuning_Manual.pdf

    read page 5.

     

    Ray

    "Karting Expert Since 2015"

  • #5373

    TJ Koyen
    Moderator

    The best way to learn is have someone who knows tight/loose drive your kart and have them give you some feedback on it’s handling. That way you know how to correlate the feeling you have in the kart to what it’s actually doing.

    A GoPro or camera is also a great tool for this. You can watch your hands on the wheel afterwards to see if you are countersteering or putting in a lot of input.

    If you want to try and create handling issues so you can feel them, I would try going to full front width and running a session, then going to the narrowest front end and running a session and seeing how it feels to you.

    Another common practice if you’ve got a coach or partner to help, is to put either neon duct tape on top of your steering wheel or zip-ties sticking straight up to help your coach see the wheel movement from the grid. Then they can better tell you what you’re doing with your hands when you go into the corner.

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  • #5442

    Eric Alexander
    Participant

    I think it should be mentioned that the key to understanding the kart is to be smooth.  I find most new karters tend to overdrive the kart and that complicates them gaining a feel for what the kart is doing.  Most things like understeer and oversteer can be brought about from overdriving the entry or exit of a corner.  But as one’s technique smoothes out over time, the kart’s handling subtlties will become more apparent.

    If one has a Mychron and the ability to download data into Race Studio, I think that information can be useful in helping a driver smoothly carry speed through corners.  I find slower laps almost aways have a less smooth RPM trace throughout the corners.

    As TJ referenced above, steering input is a great indicator.  Watch some YouTube videos of known fast drivers and note just how little they turn the wheel.  Anytime you turn the wheel more than nessecary, you are effectively binding the kart with friction in some way.  So less is more in this regard.  Once you’ve pefected this, the kart will start talking to you more clearly because what you’re experiencing is more of the kart and less of your corrections.

    Another thing I believe is important is to analyze each corner by three distinct zones: (1) braking/turn-in, (2) apex, and (3) exit.  As you gain a feel for the kart, you should use terms like loose, neutral, push, hop, etc., applied to each of the three zones.  Ask youself questions like: “Is it pushing going into this corner because I’m braking too late?” or “Is the kart getting loose as I go over those bumps on the exit?” or “Is the kart hopping at the apex preventing me from maintaining speed?”  This will help guide you in set-up and what to try.

    Lastly, the easiest changes to a kart are front track and tire pressure, so I’d start there to learn to read the kart as you can make these adjustments quickly and get back out.

  • #5476

    Jean-Paul
    Participant

    … My advise would be to play with the rear track…

    Thanks for the advise. I will try that.

  • #5477

    Jean-Paul
    Participant

    Thanks TJ and Eric for the great advice. I’ll try the front track adjustments.

    “… If one has a Mychron and the ability to download data into Race Studio, I think that information can be useful in helping a driver smoothly carry speed through corners. I find slower laps almost aways have a less smooth RPM trace throughout the corners…”

    I will look at the smoothness of the RPM trace throughout the corners. However, I don’t know how this will help. I try to drive smooth every corner and every lap. Maybe looking at the data will clear that up??

  • #5625

    Eric Alexander
    Participant

    “I will look at the smoothness of the RPM trace throughout the corners. However, I don’t know how this will help. I try to drive smooth every corner and every lap. Maybe looking at the data will clear that up??”

    I’m a big fan of looking over data from my sessions.  I like to overlay various laps against my best lap and see where time is lost and gained.  Typically, time lost is due to pushing too much and having to over-correct.  This typically means lifting the throttle  and shows in the data as larger on/off spikes during cornering.  My fastest laps typically have less of these corrections.

    One can also see how much speed you’re carrying in the corners.  Again, overlaying laps can help you analyse your cornering technique for consistancy.  And when looking at straight-away speed, go back and look at the previous corner to analyze the apex and exit.  Getting used to doing this can help you see  where you’re inconsistant and what the potential ideal lap looks like. 

    I don’t spend alot of time on the data during a day’s sessions.  But rather go over later when I’m able to sit and shift through it.

  • #5630

    Ray Lovestead
    Participant

    Alex

    How are you measuring the on/off spikes in the data?  Throttle sensor?  Just looking at speed (GPS or rear axle)?

    Could you provide an example in a graph to explain how you are doing this?  I’d really appreciate it.

     

    Ray

    "Karting Expert Since 2015"

  • #5643

    Eric Alexander
    Participant

    I’m running a simple Mychron 3 so all I use is the RPM trace.  Here’s an example:

    All three laps are within a tenth of a second to one another.  None are perfect – or really good for that matter.  The red is the fastest.  This section of the plot shows two corners and a chicane – a long sweeping right-hander followed by a right-left chicane, and a tight left (turns 4, 5, and 6 at GoPro Motorplex).

    First corner: BLACK takes the corner best.  YELLOW brakes too late and pushes on entry to the apex.  RED get a little wheelspin and goes loose on exit.

    Chicane: RED takes the chicane best – almost perfect with a slight lift but then back on the throttle.  BLACK enters too fast and must back off.  YELLOW isn’t carrying enough speed as a result of the previous corner’s mistake. 

    Last corner: RED looks good.  A little lock-up (the RPM plateau’s), then braking continues.  Smooth apex and good exit.  BLACK pushes on entry and has to back off.  YELLOW again brakes too late, pushes on entry, overcompensates and gets loose on exit.

    Looking at all three together, you can begin to see how a better lap might benefit from aspects of both BLACK and RED combined.

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