Home Forums Chassis & Handling Driving: Slow in Slow out

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  • #10882

    Ray Lovestead
    Participant

    So I think I’ve been taking the slow in fast out idea too far.  After reviewing my Mychron GPS data I found a few corners that I could take way faster.
    My question is – do you experienced drivers really subscribe to the slow in-fast out philosophy?  I find that when I go slow in I’m on the fast pedal WAY before the apex.  Seems like I should only be able to be on the gas once at (or past) the apex.  If I’m truly at the limit, it should be fast in, faster out.

    Ray

    #10898

    James McMahon
    Participant

    You nailed it, fast in faster out. Slow in fast out is a great tip when you are starting out however.

    In terms of power vs apex, really depends on the turn and the line you take, but if you are wayyyy early then yeah, you might simply be coming in too slow.

    #10902

    Greg Wright
    Participant

    I prefer the term “Cool in, Hot out” but I subscribe to the general idea and always have. It depends on what you consider to be “Slow in”. That doesn’t mean creeping but there is a lot of time to be lost charging in too hard and a lot of time to be gained with a good fast exit.

      You definitely should be hard on the gas before the apex of the corner, if you aren’t picking up the throttle until the apex you are giving up time and straightaway speed.

    #10907

    Ray Lovestead
    Participant

    So you are saying that after the initial threshold brake I should immediately begin picking up some throttle (until max throttle at the apex)?

    How is this for another vague question:  Should you threshold brake every time you brake?  Or are there times when you can be lazy with the brake?

    To me it seems like the brake should 100% if you need it, otherwise you’d lose time getting back on the throttle..

    Ray

    #10926

    Greg Wright
    Participant

    <div class=”d4p-bbp-quote-title”>Ray Lovestead wrote:</div>
    So you are saying that after the initial threshold brake I should immediately begin picking up some throttle (until max throttle at the apex)?Once you have turned in yes you should be getting after the throttle. Depending on the corner you often will be at WFO throttle before the apex.

      Regarding braking, My style (Cool in, Hot out) doesn’t include a lot of threshold type braking. I prefer to concentrate on getting through the middle and exit of the corner as fast as possible in order to maximize speed down the following straight. Very hard braking can unsettle the kart badly and result in poor mid corner performance.

    Lazy on the brakes? I didn’t say that.

     
     

    /div>

    #10928

    TJ Koyen
    Participant

    I think Greg’s definition of “cool in, hot out” is more accurate than “slow in, fast out”. You really want to be “fast in, fast out”.

    The definition of “racecraft”, as opposed to just being able to drive, is knowing how and when to attack the entry or exit of a corner depending on the situation.

    Ray,

    Minimizing the amount of time you’re on the brakes (in other words, braking as hard and as quickly as possible) obviously will be the fastest way to slow down. So in hard braking situations you’ll want to be on the brakes hard and fast as much as you can. But in racing situations or times where you aren’t slowing down that much, maybe you’re going to be more strategic with your braking force. Sometimes all it takes is a little graze of the brakes in a long corner to set the kart nicely. Or if you’re trying to set a guy up into the corner, maybe you’ll really slow down your entry and go nice and easy to fully maximize your exit.

    #11327

    Brian Degulis
    Participant

    I did the same thing. At first I would charge into the corners way to hard brake way to late and come out way to slow. Then I got some advice and I started coming in to slow. I found the best way to figure it out is to follow someone that’s fast. You’ll be able to see exactly what your doing wrong.

    After being in this for a year now I am throughly amazed at how much there is to “racecraft”. It’s pretty easy to show up on a track day and do what most are doing. After a few months I was able to run the average times pretty easily. Getting up to where the really good guys are is a whole diffrent story.

    Someone mentioned it earlier on another thread. I think a drving or “racecraft” section in this forum would be a very good idea and probably generate a lot of participation.

    Brian

    #13264

    Paul Kish
    Participant

    edit up front:

    The whole point of what follows is because I think if you know why you are physically able to increase your speed through the apex, it will put an objective to the different techniques being discussed.

     

    Hi Ray,

    You have learned to understand how entry can effect the next phase of any turn.  And what I have read in the discussion is a debate about when and how to accelerate.  I think when reading through the responses you have seen there is still something mysterious being talked about.  You have seen and others have responded about how there is something you can do to be faster through the apex.  You have experienced it and it’s being debated and argued the magic originates, either because of entry or how you intend to exit.  The magic appears to be showing itself as increased speed during the apex.

    If you too are now seeing the end result of the magic, maybe after reading what I wrote, as an increased apex speed, I can tell you exactly why it is able to occur.  But before I can explain why it can happen, I must slightly have to re-define the apex or where the magic can occur.  I think anywhere you read will define the apex as a point in a turn.  I think the point will relate to most often as a transition, from one portion of a turn to another.  I also see the apex that way.

    Before I can go on, if we are not on the same page so far the rest will only confuse.  So to go on I must ask if you or anyone is at least pretty much understanding the apex the same?

     

    _______________________

    I also must throw something else in here now so we all can include it in thoughts later.  Usually if not always when you see a drawing of the apex, the apex will occur at the inside limit of where you can drive.  Lets expand the track a little.  Before I can explain why the magic can occur, we must throw out an “inside of track” limit to where the apex will occur.  For the magic to occur we will still define a turn from a point ‘A’ to a point ‘B’, but the driving line will not necessarily make the apex occur at the inside limit of where you can drive.  I know a purest will only want to see the apex as normally defined, but you did not ask about a purest mathematical concept.  You, if I’m reading you correctly, are asking why does entry effect what you can do not only through the rest of the turn, but why specifically can one entry ‘speed’ cause quicker times through a turn.  And what’s the magic condition your trying to hit to be fast.  If you will notice I did NOT mention the line taken during entry, your question relates to speed through the turn and what is it that makes you able to have more ‘speed’ or less time through the turn.

    I’m going to stop for now because if nobody is following me or nobody is interested in exactly why the magic can occur to be faster in a turn, I’m just wasting my time and your time.  I also realize I wandered off a bit.  It’s my nature and it is especially likely to happen when trying to describe magic. … :)

    #13297

    Rob Kozakowski
    Participant

    Paul, not sure if my response is (1) wtf?; or (2) keep going, I’m curious.  And even if it’s (2), I’m not sure if it’s because of (a) I want to learn something; or (b) I want to see if this is ever going to make any sense.

    Seriously, I’d like to hear about the magic, but I’m really having trouble following…so far!

     

     

     

    #13308

    Ray Lovestead
    Participant

    I wasn’t going to go there Rob, but I’m more confused now than I was before I knew what the question was.

    Here is what I found very useful.  Following closely behind someone who is JUST a little faster than me.  Following someone 2 seconds faster than me is useless because they just walk away.  But I found I learned what speed was possible by following someone JUST ahead of me.

    Ray

    #13338

    Rob Kozakowski
    Participant

    The other thing that cannot be overlooked in all of this is how the kart is setup, how it’s handling, and general grip levels will have a MAJOR impact on the ability to attack a corner vs. “easing” around a corner, and the resulting ability to carry speed into, through, and out of a corner.

    As the most extreme example I’ve experienced, (quite) a few years back, I went from a final practice session where I was a full 2 seconds off the pace on well-worn tires, to setting a track record in qualifying an hour later with new tires.  It was also a lesson on how pointless it can be to try to tune a chassis unless you’ve got decent rubber under you.  The only change I made between practice and qualifying was changing old rubber for new because it really was all tires that were slowing me down and giving me no grip whatsoever.

    #13400

    Paul Kish
    Participant

    To continue on I have to state what I consider to be facts for a straight. On a straight, “Maximum resulting speed no matter what the entry speed or gearing, involves having just enough grip to put all available hp to the track with the least conflict for control of direction from the tires. To do so you would be operating your rear tires at there maximum slip ratio.”.

    Then comes the complex turn which has available grip, available hp, need to maintain momentum, driver input and racing needs; to set limits and limitations.

    The turn starts with turn in which is simply the need to be able to start the process or you would continue straight. Were still racing and were still interested in what will provide us with the ability to carry or obtain the highest speed from the straight. Beyond turn in what will allow us to carry the most speed is to be able to operate our tires with the least slip angle, occurring equally at all four tires and the least conflict for control of direction. And that will occur in all parts of a corner, weather you are decelerating, accelerating or rolling in the corner. I’ve never written it exactly like that before; but I think if there is a goal for how to use your tires for speed in a corner, it may be a very good goal.

    I do realize “real race cars”, as opposed to LTO(left turn only) racers,  needs are to turn both left and right.  And depending on rear axle and differential configuration, it especially limits your ability to control slip angle at the inside rear.  And I realize were talking about racing karts with a solid axle and how it is necessary to unload the inside rear in a corner.  But aside from those limitations I think I stated fairly well what is needed to negotiate a corner at the highest possible speed.  Your goal to be fast, racing something which turns both left and right and has a solid axle, is still to be able to use the inside rear as much as possible.  I suspect I will instantly get thoughts about how any use of the inside rear in a turn will reduce times through the corner.  But weather or not it’s use will reduce or enhance times depends on if you are decelerating, accelerating or rolling in the corner.  And at the start of my getting involved in this thread, I had one particular thing which I now feel is totally a driver function in mind.  I feel it is the major reason a driver can reduce time through a corner.  At least I now think it’s the major reason for reduced time beyond entry speed, entry line and how soon they can apply final acceleration out of the corner.  It’s specifically a skill all drivers need to learn, much the same as a driver needs to learn the function of and the skill to trail brake.

     

     

    #13402

    Matt Dixon
    Participant

    15XG’sXRadius=( )the square root of = Max MPH

    #13413

    Paul Kish
    Participant

    <div class=”d4p-bbp-quote-title”>Matt Dixon wrote:</div>
    15XG’sXRadius=( )the square root of = Max MPH

    <hr />

    Very interesting.  Does it pertain to any point in a turn or does it assume your racing in a perfectly round circle?  I have a very hard time following equation’s let alone being able to solve them.  Would you please explain your concept further or where you learned about it?

    I’m trying to pass on to Ray and anyone else who may be interested a concept of why a particular portion of a turn can be taken and maintained at a higher speed then entry speed.  I think when Ray sees it he will instantly be able to put it into the perspective of why entry speed and exit speed do not necessarily relate to each other.   It’s a simple matter of being able to take the middle portion of a turn at a higher speed then entry, to the point of all out acceleration.

    What generally prevents a driver from doing it is there lack of ability to keep their foot from slamming down the go pedal prematurely.  I’m leading in to showing a physical reason why you may not want to have the pedal to the floor all through a turn.  I’ve heard so often how drivers and others have said slow down to go fast.  It’s a learning process for drivers and when they do slow down and go faster, it’s usually a magical experience.  I’m simply putting a physical reason to why slowing down to go faster can occur.

    I’m looking forward to additional input on your formula.  I hope it will help Ray as I think I am trying to help.  Ray states in his signature he has been a karting expert since 2014.  That and my dry sense of humor makes me want to do all I can to help.  Can I help?  I don’t know but if I do or do not Ray and I will both learn something.  I hope to learn more from you too.

    #13422

    Matt Dixon
    Participant

    With Rays GPS he knows his speed and G’s through any corner and can figure the radius of said corner. When he goes over the data to see if he can change his speed at any point in said corner to lower his split time through said corner.  He can use that formula to see where he is to hot.

     

    To keep the numbers simple We will use 1G and 100ft radius.

    15×1=15×100=1500sq root of that = 38.72mph

     

    So remove magic insert number, if Ray is going faster then 38mph he is loosing time in that corner.

    #13432

    Paul Kish
    Participant

    <div class=”d4p-bbp-quote-title”>Matt Dixon wrote:</div>
    With Rays GPS he knows his speed and G’s through any corner and can figure the radius of said corner. When he goes over the data to see if he can change his speed at any point in said corner to lower his split time through said corner. He can use that formula to see where he is to hot. To keep the numbers simple We will use 1G and 100ft radius. 15×1=15×100=1500sq root of that = 38.72mph So remove magic insert number, if Ray is going faster then 38mph he is loosing time in that corner.

    Thank you.  I think I partially or maybe mostly understand your reply.

    To get a better understanding without hijacking Ray’s thread, may I start another thread and reference your reply to gain a better understanding?

    #13439

    Mike Clark
    Participant

    Paul,

    I keep waiting for you quit leading up to saying “it” and come out and say “it”.

    One physical reason is radius needs to open up as speed increases. Another is tires can only do so much work. A lot of this stuff overlaps. It’s all time & distance.

    So I am officially saying I am ready to get the ‘Magic’. Or did I miss it?

     

    #13499

    Paul Kish
    Participant

    Because of deceleration and loads moving to the outside front your entry speed is limited by the gripping ability of the outside front tire.  Once in a corner and prior to full acceleration, there is an opportunity to roll or maintain entry momentum plus additional speed, above entry speed.  The driver skill required is to realize once corner entry is completed, transferred weight to the outside will be distributed more evenly between both outside tires, reducing the load on the outside front tire.  It provides the opportunity for the driver to slightly increase their rolling corner speed above entry speed and maintain it over a distance.  It’s an obvious thing to do, but a tough skill for a driver to learn.  Most any corner will provide the opportunity for some additional rolling of the corner at a speed beyond entry.   The point is the distance traveled at the enhanced speed of entry momentum plus some acceleration, which is only possible because of grip re-distribution after entry, can be taken in less time, then attempting to accelerate or maintain entry speed over the same distance.  How much the advantage will be depends on the turn configuration and the drivers choice in driving line.

    It takes specific input and skill by a driver to enter, know when grip redistributes, slightly increase speed, roll with the increases speed and then lead into turn exit and full acceleration.  The portion of the turn which can be rolled at increased speed will be taken quicker then if only maintaining entry speed or if trying to accelerate too early, through the same part of the turn.

    Yes this is an obvious thing we see happen every day at the races and it’s just one of those obvious not much thought about things.  But I think if you think about it a little and compare in your memory good and not so good drivers.   I think your memory will be seeing more skilled drivers doing more of it and it’s just one of those un named picture things of higher quality in your mind.  We see it every day when watching a skilled driver on the track and I’m now describing a point of why one driver appears to just be better.

     

    ?

     

    ps… I have to add, how much you are able to relate to what I described, also depends on the available hp of what your use to watching out on the track.  In general you will see it show more with higher hp.   It is because with higher available hp, you will more likely be running closer to the limit of grip.

     

     

     

     

    #13503

    Eric Alexander
    Participant

    I’m going to try to explain this first with words, then I’ll point to a website that has some decent graphics and some geometrical calculations.

    The basic premise in “Slow in-Fast out” is to back the corner up as far as track out is concerned.  The idea is while the corner itself can be taken faster using an ideal line, you’re going to sacrifice entry speed, turn-in sooner, push the “apex” later and essentially give yourself an more gradual track-out.  This enables you to get back on the throttle earlier (well before the apex), and accelerate faster, thus carrying more speed down the ensuing straight.

    I find the turn-in point, depending on the actual corner geometry, may actually go deeper and more to the outside of the corner entry.  Instead of carrying speed to the actual corner apex, you brake a bit more slowing the kart down well before the actual apex.  This is the “Slow in” part.

    You can see in the graphic above the arch is modified from the ideal line.  The ideal line would allow more speed to be carried into the corner, but less speed on exit.  You can also see how the apex is pushed somewhat later, but acceleration has begun well before the modified apex.  The track-out is more gradual allowing far greater acceleration.

    Here’s a website with more info and some math.  LOL!

    http://phors.locost7.info/phors17.htm

     

    Also, it would be beneficial to point out this is best used on corners that empty onto long straights.  There are times when its best to be fast in- Slow out.  For example at the end of a long straight when the corner connects onto another corner (like an esse) or a small straight followed by another corner.  In this case, you may be better off carrying the speed you’ve got on the long straight deep into the corner and sacrificing exit speed.  Let the stopwatch be the judge.

    #13515

    Paul Kish
    Participant

    thanks, lol and :)

     

    I just realized I had no clue what Ray was asking about when I got in on here.

     

    Oh well, hope what I wrote made some sense to someone.  and… I should just say…

    nevermind … :)

     

    #13556

    Paul Kish
    Participant

    ok just can’t keep my mind shut… :)

    Eric, I understand now what was originally asked about when “slow in fast out” was referenced.

    Butt… :)  in addition, not arguing, just trying to show a concept…

    I can see with slow in speeds during the ‘red’ portion of the line will be below the limit of grip.  Because your below the limit of grip it will allow for some acceleration prior to the apex.  And the whole intent I think is to be able to start your acceleration early.  But the line shown in the art work also creates a racing vulnerability.  It leaves open a line under you which when taken by another competitor will more then likely interfere with your intended acceleration.  It sets up the classic battle of a two grove track and an inside and outside  competition.

    In the scenario I was trying to propose(not very well but trying), the outside racer would end the ‘red’ area and enter the ‘yellow’ area, at a higher speed and at the limit of grip.  All out acceleration could not then begin as soon, as in the “slow in fast out” scenario, but the ‘yellow’ portion could be taken per my discussion at a speed slightly higher then entry.  The line would also be a more rounded line and place the racer more toward the inside of the turn and able to apply more hp if available because of then traveling in a straighter line.   It’s a win win situation over the “slow in fast out” scenario.  First because the ‘red’ and early on ‘yellow’ portions of the line would be at higher speeds because of the higher entry speed and it will be much easier to hold the racer toward the inside of the turn protecting the exit line.

     

    well… ?   I don’t think I argued with anything written on here, but instead proposed what I think is a better scenario.

     

     

     

    #13567

    Ray Lovestead
    Participant

    Paul I was thinking a similar thing, just with less words..  hehe.

    Simply put – that may be the fastest line, but it very vulnerable to being dive bombed by the gent behind you.

    Ray

    #13575

    Eric Alexander
    Participant

    @ Paul:  By all means, this is an open discussion.

    For me, the line driven is still on the edge.  The braking is hard and you should be near the limit at turn in.  I think that is what T.J. means early on in this thread when he says “you want to be fast in and fast out”.  In that graphic, you still want to be at the limit during the red and yellow portions of the line.   I think where you’re going be less at the limit of grip is under acceleration and track-out because you’ve lessened the arc – in theory.

    But the real point is how to back the corner up to be faster on exit and thus carry that additional speed down the following straight.

    Also, I think that embedded graphic might be over-exaggerating the line somewhat to show the concept.   I think the linked-to page has better theoretical graphics exploring the concept mathematically.  But personally, I find the math tough to digest and only like it because it explains what I feel I ‘m trying to do.

    #13576

    Paul Kish
    Participant

    The math does not and never has dealt with the redistribution of grip.  That is the basic problem with the math and where book knowledge falls on it’s face.

    IMHO, the fastest line is always on the edge.  But to get to the edge you have to have the luxury of time to increase speed, limit grip or increase hp.  Most of what everyone races can only get to the edge by limiting grip.  To limit grip it is mandatory to take into consideration the redistribution of grip.

    or it don’t… ?   :)   I ain’t never sure about anything, I just once in awhile try to talk like it.

     

     

    #13649

    Greg Wright
    Participant

    Wow, Has this become complicated or what, I’m sure that there’s a newbie reading this while his head explodes. Somebody want to try it again but this time in English?

     

    There is no MAGIC!!

     

    Greg Wright

    Rapid Racing Inc.

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