Better technique required

27 Oct

Last Sunday, 25 Oct, my kart had the ultimate pleasure
of having James Lee piloting it. For those who do not
know, James was last year RMC champion.

He basically just shaved off about 1.2 second from what
Ivan and I can do with the same machinery without
any adjustment at all... Beat that!

So, anyone who had doubt about his skill and suspect he's just
using a 'better' engine... please wake up and smell his exhaust
smoke!
And if I do hear anyone saying again he may be using a "better"
engine, I will not be hesitate to slap them there and then!


What Ivan and I observed is that he is indeed a very very
smooth operator of the machinery. The line he took is very
neat which basically utilize the entire track possible for his
corner entry, which then in turn give him an superb exit
speed.

There was one lap when Alan was on his Aixro closing in a bit
on James for the 1st hairpin after the start finish.
Alan was close, and I thought Alan will probably just overtake
James on the straight that follow with his 50bhp engine.
Nope!!
James just continue to drive smoothly through the hairpin,
have more momentum for the exit, and shot into the
straight to pull away...!
Darn! That was a sight!

In that moment, I am just inspired and determined to
improve my overall technique. I have to! Because what he
had just showed was that engine power can only do so much,
skill is really what differentiate one driver from the other.

We continue to watch him drive for a few more laps in my
kart before he returned into the pits.
He discussed with us on a few areas that can improve the
handling of the kart, but had 'warned' us that what work
for him may not work for me.
But I will have to make it work!

So, there will be some changes to the kart setup which will
require more track time to be get used to, and fine tune.

I hope I will take the 'lesson' which James freely gave, and
learn well from it.

At the end of the day, Ivan and I had a simple conclusion
to what James had showed us. Which is the simple saying
in motorsports which is 'slow is fast and fast is slow'
Simple to say it out loud but it is not easy to do so at all.

Now, I will be looking forward to go back on the track to
try the kart once again, and applied all I have seen.

my blistered right hand

PS. had a mini race as a finale for the day. Me, James, Alan,
Joey and Louis
I started at the front but ended supposedly last after Alan
retired with a carb issue.
Honestly, I was already tired, and the rear tyres was all shot.
It was fun, but I could not do better than lapping about 1/4 lap
behind Joey and James.

Kart's CG and what it does

24 Oct

Chanced upon this article.
Informative, and relatively easy to understand.
Now, I hope I can fully comprehend and applied the good
knowledge.
----

You hear a lot about center of gravity (CG), when dealing with kart setup.
But what does it mean and what is really going on?

Well hold on, because I am about to tell you.

First off, what exactly is a CG.

Simply put the CG is the point by which all the forces on the kart act through.
It’s an imaginary point where if you attached a string to it the kart would be perfectly balanced and you could rotate it in all directions. In general, this point is somewhere right in front of your stomach or chest. If you flop around in your kart a lot as you drive the point can move which will alter your handling. Some karters will actually move around on purpose to give them an advantage. For instance, you can lean back as you brake to put more weight on the rear tires so you can brake harder.

So what does it mean that all the forces act through this point? Ok, let’s say your rear weight bias is %60. That means that the CG is at %60 of the distance from the front to the rear tires. Now when you go through a turn the lateral forces act through this point so 60 percent of the force goes to the rear tires and 40 percent goes to the front.

This explains the front to rear location of the CG, but there is also a vertical component – how high above the ground the CG is located. There are ways to calculate this based on tilting the kart, but it’s kinda complicated and in my opinion, it’s not necessary to know exactly anyway. What you do need to know about the vertical component of the CG is that it has a profound effect on the grip of the kart. Here is where one of the motorsport oddities unique to karting shows its head. The front of the kart acts as a car, but the rear acts as a motorcycle? Say what? Well it is easier to explain by showing you.


If you remember that the rear of a kart corners on only the outside wheel, you might be able to figure out what I am talking about real quick. The pictures depict the CG acting through the tire. Motorcyclers have a pretty good advantage in this sense in that they can lean to the perfect angle necessary and their tires are round. A kart however has a flat tire and cannot lean. Why does this matter? Well what happens when a motorcycle corners faster. It must lean more. Why is that? Because as the lateral force increases the center of gravity must act at a smaller and smaller angle to the contact patch otherwise the rider will tip over. If he leans too much he will slide the rear tire out. A good rider can naturally feel this balance.

On a kart however, in order to get this maximum amount of grip you must set the kart up properly beforehand to get this ideal angle. So looking at the picture it is pretty obvious you can either move the center of gravity (you) or the tire. Just like the bike, there is a perfect balance point that will give you the maximum grip. If you 'move the tire out' or the CG down you will lose grip and start sliding more. If you move the CG up or 'the tire in' the kart will want to lift up and flip over. This rarely happens for reasons I will explain in a second. The importance of all this is that changing grip levels based on track, tires, and many other things require that you either move the CG or rear tire to maximize grip, which is one of the reasons setting up karts is so specific to drivers and tracks

I also mentioned the rounded profile of the motorcyle tire. Karts have a flat profile, so what happens is that if you move the CG too high or the tire in too much the kart will want to tip over, but as the kart starts to lift, the outside tire is no longer flat and you lose grip really fast and the inside tire comes crashing back down. It then regains grip and the kart starts to lift again. The repeating cycle of this is one of the main causes of hopping karters experience. So my recommendation is to find the balance point where your kart is just shy of wanting to hop. In general This is where you will have maximum grip at the rear.

Ok, so now we understand how the rear of a kart is like a motorcycle, how is the front like a car? Well this is the easy part of kart setup. In order to maximize front grip you want to get the CG as low as possible. Why is that? Well it is all because of load sensitivity, which I explain in my tire article. Basically the lower the CG the less weight transfers the outside tire during cornering and the more evenly loaded the front two tires are. The more evenly loaded the two tires are the more grip they will have.

The take away message is to get your CG as low as possible. This gives maximum grip at the front and at the rear you can just move the tires in until you find your perfect balance point. A side advantage of this is that your rear track will be narrower and you will be able to use more of the track to improve your cornering speed. There are other effects of lowering the CG other than the obvious butt scraping that could occur, that we will address shortly, but these can be tuned around using other methods.

So now we now what moving the CG up and down does, but what about moving it forward and backward. Karters often think there is some magic number for the front to rear percentage that is ideal. Well just like most everything else there is always a compromise. Basically you are compromising between your pure lateral grip (cornering) and longitudinal grip (acceleration and braking). First let’s discuss lateral grip. If you were doing a skidpad competition where you just drive in a circle the ideal front to rear weight percentage would about equal the relative tire contact patch size. Here is where tire load sensitivity comes in again.

Moving weight back creates more relative grip in the front and moving weight forward gives more relative grip in the rear. This is backwards to the way most people think, but nonetheless it is absolutely true. You could optimize your balance by driving in a circle around a 100 foot skidpad and move weight forward or back until you maximized your speed. In fact in the lower powered classes this might be a good strategy because the karts do not have much acceleration potential anyway. In a kart with more power however you could benefit from running a more rearward weight bias. Think of a dragster where all the weight is over the rear tires. This is not just related to the relative power of the kart either, it is also related to the track you are running. Even a very low powered kart can generate some wheelspin coming out of a super tight hairpin and likewise a high powered shifter is not going to be doing much acceleration during a 100 mph corner on a road course. Braking works in a similar manner. On a kart with rear only brakes you want as much weight as possible on the rear so you can brake harder. On a kart with brakes all around you also want a rearward weight bias because during braking weight shifts forward and a rearward weight bias allows the tires to work more evenly and thus create more overall grip. Hopefully you can see the compromises involved in moving weight forward and backward. Go more forward if you are looking for ultimate cornering ability, and go more backwards if you are generating excessive wheelspin on corner exit. If you want to really put your knowledge to use, try leaning forward and backwards at the right time to maximize your grip.

I focus mostly on sprint karting, but for those curious using a leftward bias for circle track racing will generate more grip at front and will allow you to run your rear track narrower. There actually is a point where you can run too much left bias, but in practical use you will probably never reach it.

There is another affect of moving the CG I want to go over and it is related to kart jacking (unloading the inside rear tire). If you look at the photo to the right you will see that I have drawn a line from the left front tire to the right rear. This is depicting a kart in a left hand turn and the way the CG acts on a pivot point created by these two tires. Basically the further to the CG is moved forward the stronger the jacking forces are on the kart and the more the inside rear will unload. This is why a lot of people suggest moving weight forward if you are understeering, you may have not been unloading the inside rear enough and this accomplishes that, but this is not the best way to tune a kart. Move your CG to maximize traction and then alter your jacking through other methods. Now that you understand that I am going to confuse you some more. The higher the CG is, the greater this jacking force as well. If you can picture in three dimensions how the CG is a lever arm attached to this virtual pivot arm you can visualize how this works. You may also notice that moving the tires in and out will change where this virtual pivot arm is.

Lots of things have multiple affects when they are changed, but you can often separate them into overall grip and jacking effects. I always say maximize your grip first because you can almost always tune the proper amount of jacking through other means.

from http://howkartswork.com/?p=299

Strangely Enough

20 Oct

from http://www.grandprix.com/ns/ns21935.html

Did you realise that an English driver, in a Mercedes-engined car bearing the number 22, beat a Brazilian to the World Championship by finishing in fifth place in Interlagos - for the second year running?

Hell of a coincidence...

Button Up !

19 Oct

Yes, Jenson Button had won the F1 Driver Championship
at Interlagos, Brazil !
While he did not win the race, he did race aggressively
to get from 14th to 5th.
That was enough points in the bag for him to be crowned
2009 Driver Champion.
There are talks about if he is indeed a worthy Champion..
Much debate on it but an article from BBC is a good read

http://news.bbc.co.uk/sport2/hi/motorsport/formula_one/8312844.stm

Congrats Jenson, you truly deserved this!!

Better than _e_

19 Oct

Yesterday, me and my friend, Lennie, went to the track bright
and early (we move off from my place at 6.30am!)

One of the tasks is to ascertain if the his new Mychron4 has
a faulty Magnetic Senor.
With an another sensor fitted on to his unit, we managed to
get 'laps times' which effectively told us that he is a unlucky
dude. I don't how many people got their units with a faulty
sensor, but I'm quite sure there isn't that many!
Anyway, a replacement part will arrived soon enough for him.

Still with Lennie's day...

Both of us went out on track together for a second session.
He was in front of me about half a lap, and I was trying to close
in to him. After the 3rd or 4th lap I noticed there was a black
piece of 'something' on the spoon section... I think I avoided it.
Still the next lap, I saw the one piece is now pieces here and
there. So I went back into the pits, and soon after Lennie was
in too.

"Hey, there was something on the track, right? You saw?"
In my thoughts then, I was thinking some part of fun karts may
have fallen off or some items from the fun karters could have
dropped on to the track.

Only then, Lennie realised it was his phone that was on the
track!! GOSH! It was a LG phone which claimed to be almost
indestructible even if it is run over by a car.
But apparently, damage by kart is more serious.
Although the phone do seems to be still 'working' ... barely.
So I told him, the rest of the guys reading this, please
please have your personal belongings in a bag in a locker
and not in your pockets while you are having fun on the track.
With the vibrations and turning forces of the kart, things do
finds its way on to the track surface or anywhere.
If you are fortunate, it's just a phone. If you are not, it can be
passport, house or car keys that gone missing and never to be
found. Or found in pieces... many pieces.

My day at the track was just getting into the kart again,
and trying my painted helmet for the first time!

The HJC AR10 helmet fits well. The air intake gives plenty of
air which keeps me breathing. While the "exhuast" system
of the helmet keeps it firmly on the head and not have the lifting
off feeling which I get sometimes from the MHR.
I'm still waiting for the tinted visor, the clear ones is, well,
too clear!

James Lee was at the track late on. He was going to run in his engine,
which I reckon he is going to use for his participation for the Nov
Invitational race at Sepang. When I went out for my final session,
without me knowing he watched for awhile.
Returning to the pits, he gave me some valuable inputs on how to
get the race line and reduce the lap times.
The gist (i think, if i got it correctly ) is really not to be too eager on
the throttle, be smooth, slow when one need to, and focus on the exit.

Seems easy?
Not so !!
Why? Let me explain.. Begining with this odd analogy:
One of Lennie's friends who tried his kart a few weeks back,
exclaimed that karting is "Better than Sex!"

When we are driving the kart we all experienced the
adrenaline rush. Most times, what we wanted to do is just to
keep the foot down on the throttle, and steer quite wildly.
The feeling of G force give us more rush. It's Shiok!
And then we want more rush, and we go more wild (on track
not some places else)

However, we really have to realised it's not the fastest way
around. I had experienced this a couple of times that when I
feel "slow" that the lap times are actually better, faster.
When we are "slow" I believed we are controlling the kart
better around the track, and hence there's no wastage in
steering and throttle movements. Every little bits power from
the engine is used to move the kart around the track faster.

I hope I understand this and put it to good use.
It's not easy, but I will most certainly do my best to have
more 'slow' laps.
Perhaps in time to come I will too exclaimed it's "Better than
sex!! " at the track

Karting Incidents

15 Oct

I can understand that FIA is trying to root out unsporting
behavior during races, but some of the incidents in the footage
seem very much like just race incidents.

I don't know. You can decide.

No more silly

15 Oct

This morning I suddenly recalled how screwed up my mind

was last Sunday...

Reached the track. Looked at my kart. Sprayed chain lube.
Inspected the rest of the kart and see if there anything to

adjust or tighten. None.
Want to start the engine, just to warm it a little bit on the kart
stand.

Choke Lever Up, Press Ignition Button... Engine not firing..
check battery terminals, nothing odd and try to start again.
Nothing

Thinking WTH...

Wanting to try again, and Jason said "wah lao eh, alamak, did not even
put the switch to 'On' how to start?!?! "

How can I miss that??

I will stop beating myself on the last race, and thinking about
the next one in Nov.

Also something to think about is this:

Race Pics, Oct 09

14 Oct

Some good pics from http://kartingsingapore.com/wp/?p=665
Post some of them here with me (78) in it, click to Enlarge the pics.

Beside the rolling start pic, I can't really pinpoint when the rest
were taken.
I can't even recalled the one when was the one which had most
of us by the pits. Is it an end or a start of the race?

hmmm








Rolling start for Heat 1. See how Louis just peel off to the side even
before the green flag dropped?

Alocholic Driving

12 Oct

Bad race for me. Superbly off colour.
I hope this do not come as an excuse, but a huge lesson
to learn from instead. I really need to write this down for
a stark reminder for myself.
It all started with a full day activities on Saturday,
which ended with more than my fair share of beer intake.
It was a great fun night, but it totally screwed up my race.


I did not even want to wake up. And after I did, I had to
visit washroom more times than usual.

Then my qualifying and Heat 1, I did not know/ realised that
my Power Valve was all the way out which means I had very
poor low end torque. Screwed by someone who thinks he
knows a lot but only talk too much. And that someone had
a huge quarrel with customer who wanted a refund for fun
kart. Now, you likely to know who's the "someone"

Qualified 6th, almost 2 second off James Lee.
Then finished Heat 1, in 6th. With Alan Lange hot on my rear.
Heat 2, finished at 7th.
In a summary, because there was really nothing too much
worth mentioning. Other than 2 bad rolling starts, and
inability to overtake

All I can sum up for the race was not I am not aching at all
today. Nothing. It's like I wasn't even in a race yesterday.
Thinking back, the feeling while I was in the kart is that I
could not do more knowing that I can.
It is like there was something I cannot access to in my brain.


I could see that most of my race line is off, and I still keep
doing it wrong. Likewise for my steering inputs, braking
points and throttle rhythm... I knew everything is out of
sync and yet I still cannot get it right even though I know
how.
It was like I was just going through the motion of driving...
BADLY.
Below, I found an article today which describe the effects
of alcohol to sports performance. If only, I know about it
sooner.

There were a few incidents in the race which deserved
some mention here.

1st, during Heat 1, Mark in front of Leo. Mark's air filter
dislodged and flew past Leo head !!

Please see video at Facebook:
http://www.facebook.com/video/video.php?v=155716381669&ref=nf

The video also show that the 125cc has a huge disadvantage
when the race track has a long straight. Leo is more than
an average driver, with him having much difficulties
in getting past Mark it just goes to show the weight requirement
to have the engine power equalized do not work at all for 4 strokes.
Not to say Mark is slow, but Leo is definitely a much faster driver.
Hence, here horsepower just speaks louder than skill and technique.


Next incident whcih also involved Leo. At the start of Heat 2,
green flag dropped and everyone floored their throttle.
In front of me were Wee How (4th) and Leo (2th).
Leo did not get off quickly and Wee How did. Wee How whacked
into his Leo's right rear tyre and flew over it.
All this happened in front of me and I had to brake to avoid hitting
Leo or Wee How. That cost me at least 3 or 4 positions.
Game over to get a good race.

In the later stage of Heat 2, I had to race with KP and Alan Smith.
It was fun... but I was just angry with myself in the last few laps
to be honest. Way too angry that I actually did not see the
chequered flag and race another lap... what an idiot I am.

All in all, it had been an experience which I sweared I will never
want to feel again.

It's not about getting points or position. It's about me not being
able to push to the limits that I can. DARN....!
I just need to 'think' about the race in Nov, and give it a better
shot then.

Anyway, in Macau over the weekends, CRG using Maxter
engine with Kozlinski piloting it won the World Karting
Championship Super KF, the principal class in world karting.

Enjoy the video and the real superb race

Alcohol and Exercise

Alcohol affects the body's ability to turn food into energy, it slows down reaction times, increases body heat loss and reduces endurance.

If you have alcohol 24 hours before exercising you are more likely to develop muscle cramps.

After exercising the body needs to be rehydrated. It's not helpful to drink alcohol as it will just continue to dehydrate the body further.

What difference can a couple of drinks make

What may surprise you is the number of ways the proverbial couple
of drinks can affect your performance.

If you take your sport seriously, and like to do the best you can for yourself or your team, it's worth knowing the facts and what you can do to drink sensibly.

Endurance

The blood sugar your body needs for energy is produced by the liver releasing glucose into the blood stream. Alcohol reduces your body's ability to produce this sugar, so you have less energy and less endurance capac

Alcohol affects the body's ability to turn food into energy, it slows down reaction times, increases body heat loss and reduces endurance.

If you have alcohol 24 hours before exercising you are more likely to develop muscle cramps.

After exercising the body needs to be rehydrated. It's not helpful to drink alcohol as it will just continue to dehydrate the body further.

What difference can a couple of drinks make

What may surprise you is the number of ways the proverbial couple
of drinks can affect your performance.

If you take your sport seriously, and like to do the best you can for yourself or your team, it's worth knowing the facts and what you can do to drink sensibly.

Endurance

The blood sugar your body needs for energy is produced by the liver releasing glucose into the blood stream. Alcohol reduces your body's ability to produce this sugar, so you have less energy and less endurance capacity.

Remember - if you were drinking the night before, when the time comes to really dig deep, there mightn't be anything there.

It is also important to remember that drinking before or during exercise can lead to injuries. Alcohol in the body can slow down the healing process leading to an increased recovery time from an injury.

Body Heat Loss

If you've ever had that feeling of running hot and cold after a big night, you'll recognise the symptom.

First, alcohol in your system makes you feel feverish, then you lose body heat too fast leading possibly to hypothermia.

The longer you play or train, or the colder the weather, the greater the risk.

Reaction Times

The relaxant properties of alcohol can flow on into your sport even well after you've finished drinking.

Alcohol affects the central nervous system and slows down the information processing ability of the brain. This in turn affects your reactions, co-ordination, accuracy and balance - all the things most important for staying on top in any sport.

from http://www.alcohol.org.nz/Sport.aspx?PostingID=835