Ken Ji's super-smooth 2:26.3 Onboard Lap Video at the 2010 Time To Attack Finale

[Tom]

Time To Attack superstar Ken Ji shaves 2 seconds off at the Finale last Sunday with his HKS Time Attack Nissan Silvia S15. Best Lap: 2m 26.3s : After struggling with oversteer at 'ZTH TTAS: The Final Call', some setup changes were made to the car to give the rear end more stability. Unexpectedly, handling was dogged by understeer from turn-in to apex today - cornering speeds at T5-6, T7-8 and T-12 weren't fantastic. But more importantly, the strong understeer (even when trail braking into corners) meant that i either had to back off to let the nose hang on, or open up the throttle and deal with oversteer.

YouTube - HKS Time Attack Silvia @ ZTH Time to Attack Sepang: Finale

The high track temperatures may have contributed to the lack of grip (it was measured at 44 deg C at 5pm!) - tail started skating around under braking in the 2nd session, and i overshot my turn-in points for T1 and T9 pretty bad heheh.

Post-mortem with Denis Lian at day's end suggests that I may have gone the wrong with with damper adjustments... oh well, live and learn ;-)

Still, it was good enough for a new personal best time of 2m 26.3s today. Many thanks to all at Onward Motorsports (OMS) and HKS Garage R for their tireless efforts in getting the Silvia to where it's at. Faster times to come! :)

 

[E3newbie]

Super smooth? Doesn't seem like it. Powerfull car though...

 

[6UE5t]

He was pushing quite hard and therefore having some oversteer on the edge moments, but that's how it should be if you're pushing to the limit and overall still a pretty much in control lap hence the good lap time. Notice he was pulling almost 1.3-1.5g on some corners.

 

[shiroitenshi]

at the speeds he's going, seem like the G sensor reading is a bit off.. can't trust the g-sensor if the car bodyrolls too much.

 

[kairigi]

his gearchanges werent that smooth too, could use more heeltoe action, plus the turbine lags a bit. just a bit.

 

[shiroitenshi]

true about the lag and heeltoe, then again driving a car with full racing overall in malaysian weather ain't comfy so it's natural to make mistakes but like the driver said, live and learn.

 

[Laptimer]

is no g sensor error lah!!! dis one is use gps one not afect when roll!

nice laptime n drifting but no need say car say setting
is your car for quite long alrdy
you drive many lap can feel car feel how its change lap by lap
so you drive that time if miss point tail slid all these is jus driver mistake
dirver mus know the car mus ajus to car
exampel if 3 lap brake not so bite alrdy den driver must ajus braking to earlyer

 

[shiroitenshi]

wow a gps that detects g forces, that a first. Considering gps in malaysia are not even supporting MSAS/WAAS.

G force is measured via accelerometers, and due to their design, they are also affected by gravity and tilt, that's why always got to calibrate when using it the first time.

Personally, i'm using Innovate Motorsports one. The only way I can pull 1g below 100kmh is by using it on a car with excessive body roll. Most of the time, hardly hits 1g. If exceed 1g even the front end traction will be so so already.

Btw, I wonder if you know what kind of g's cars pull on a skidpad. It's really not that high. Even a friends skyline only manages 1.3 before loosing traction. And only at higher speeds.

 

[Laptimer]

brudder shrioitenshit you dunno how gps get the speed or gforce?
gps onli see the position
the speed is calculate from position n time
go one more step n calcultae the acceleration aka gforce from the speed and the time
i primaryy skool onli also understand these
dun compare skidpad to track lah
the big turn at the track the steering angle can be small n speed higher so better grips
den oso the track got cambre
plus elevasion change
plus rubber from other car
plus car like dis have the aerodynamic to help
plus car weight low
all combine can make the high g of 1.4
not say is cannot do one

 

[shiroitenshi]

Bro, g force not same with speed la. Gps of course can read speed, like you explained but NOT gforce la. I can confirm motec, haltech, even the nismo r mfd use accelerometers, not to mention many more telemetry systems. There is NO WAY a gps can read gforce, I should know, i'm a GPS user and a contributor to malaysian mapping community. Lol, I think my post on gps still sits in the zth gps forums. Though my datalog on g forces already tenggelam deep into zth forums.

And you're right about the camber on the turns. That's why I said, "can't trust the g sensor when there's bodyroll.". After all, I did say that accelerometers are affected by tilt.. Btw, my driving skills pretty lousy, so since you obviously drive better than me, why never compete against these guys. Eh?

I'm only interested in the technical aspect, and from what I can see, it looks like the car having excessive body roll, so that might be the cause of understeer. But can't trust the g sensor fully either, it's still up to the driver and his crew to interpret the datalogs.

Driver skill can't improve a badly setup car.

 

[kairigi]

Guys don't fight la.. we're here to discuss and not fight over opinions.. accept or correct but don't flame..

Good start for the S15 driver if he's still new, don't have to be that shy on the corners :)

 

[faisal]

wa... KenJi put up his lap vidoe for us to view.. you fellas start discussing gps, WAAS, G force etc... relax la..

Give credit to KenJi la.

Even though he had the car pretty long, it's been constantly improved since he had it.

And even he admits the car and his driving still far from perfect.

 

[Laptimer]

There is NO WAY a gps can read gforce

brudder dun so corky act gps expert lah
nowsadays got many these kind system one
from many year ago got alrdy!!

pls read properly and learn!!!
MaxQData
VBOX
http://www.md.kth.se/body/edu/mme/4F1530/Problems2005/Honda Track Data For Formula Student.pdf
AIM My Tach GPS/Data Logging Watch
Direct Racing Supplies AIM - GPS Module

oso the car roll not same as road camber

ok good job to ken ki
sure can go faster

 

[E3newbie]

No one's saying that driving is not good but it's not super smooth like the title suggests. Would have clocked a better time if he was super smooth....

 

[shiroitenshi]

brudder dun so corky act gps expert lah
nowsadays got many these kind system one
from many year ago got alrdy!!

pls read properly and learn!!!
MaxQData
VBOX
http://www.md.kth.se/body/edu/mme/4F1530/Problems2005/Honda Track Data For Formula Student.pdf
AIM My Tach GPS/Data Logging Watch
Direct Racing Supplies AIM - GPS Module

oso the car roll not same as road camber

ok good job to ken ki
sure can go faster

Lol, those GPS systems include accelerometers la... some even use speed vs distance to calculate acceleration g-force, not lateral g forces..
You're the one who should go study what accelerometers are. Don't simply claim people don't have knowledge and is simply is keyboard warrior when you are one.

Who's being cocky lol.
I'm still learning btw, but I don't claim to know everything...heck, right now I'm working on a K-series dash harness.. it's been done to death by the americans, but practical knowledge is where it counts in real life.. check my posts lol.. Simple matter to see who's a keyboard warrior and who's not, isn't it?

After all, I'm not a keyboard warrior like you, I actually have to work on cars than post on zth all day long.. if you bothered to check, I don't post all the time lol. so if I don't answer, it just means I'm busy with work.

Oh, road camber doesn't cause bodyroll at high speeds? which physics world do you come from? I was answering the earlier post where the poster said he was pushing 1.3-1.5g, but in real life, g-forces are affected by other factors, including bodyroll, so it's not a given that high g forces reflect how hard the driver is pushing.

Don't want to argue with you anymore, Theory is good to know, but need practical experience as well. Unless you start sharing what you know, with pictures and videos, I'll regard you as a keyboard warrior who knows theory only.

Afterall, Off topic already, want to discuss GPS, come join the GPS forum.. :P

 

[Laptimer]

i never meet before pple like dis dunno so much but tok like so sure one
you see the 5 link i posted
all 5 is oni gps
read all very carefully
no accelerometer at all
i know what is call accelerometer i got use b4 n oso got use gps b4

you dun belive me den ask kengi straight lah
ask garager n axis straight lah
nothing more to talk alredy

i dun care wat harness what gps forum
here is here
your word your word
wrong word is wrong
right is right

you
are
wrong

 

[E3newbie]

To be honest, I would really like to know how a GPS system could be used to measure lateral G.

 

[shiroitenshi]

i never meet before pple like dis dunno so much but tok like so sure one
you see the 5 link i posted
all 5 is oni gps
read all very carefully
no accelerometer at all
i know what is call accelerometer i got use b4 n oso got use gps b4

you dun belive me den ask kengi straight lah
ask garager n axis straight lah
nothing more to talk alredy

i dun care wat harness what gps forum
here is here
your word your word
wrong word is wrong
right is right

you
are
wrong

Up to you lah, win in forum only.. troll.

---------- Post added at 08:07 PM ---------- 6 hour anti-bump limit - Previous post was at 08:06 PM ----------

To be honest, I would really like to know how a GPS system could be used to measure lateral G.

Ask laptimer la.. he seems to know.. lol.. love to hear his technical explanation on it.. hahaha.

Ground station also don't have in malaysia, and suddenly can estimate
lateral acceleration at sepang track using geolocation data...

From his own article. Seems like he is epic keyboard warrior but never read the articles he quote.

Do remember the word is 'estimated.' not 'measured'

Maximum lateral acceleration is in the order of just under 2g, but this is probably slightly overestimated by the GPS measurements and is not corrected for vehicle roll. There is a similar case for longitudinal accelerations, but even so, the vehicle is still negotiating the course at very high levels of acceleration compared to the average road car (maximum lateral acceleration for a road car is around 0.8g).

From his quoted article.
http://www.md.kth.se/body/edu/mme/4F1530/Problems2005/Honda Track Data For Formula Student.pdf

Waste my time only. I thought can actually measure with some magic GPS function, but in the end, it just uses high frequency tracklogs and estimate. Cannot read / measure g's directly lol.

Theory =/= real life.

 

[LS1]

LAPTIMER is a [email protected] said...ok guys....
the way he talked i already knew this loser got no car...he is just a ps3 driver"and i dont think this loser got money to buy a ps3....hahhahahaha...maybe try out at sony store"freeloader"...driving sim expert wannabe...kakakakakak
I Vote LAPTIMER AS "ZEROTOHUNDRED Biggest LOSER"No.1":)

 

[afariq]

I Vote LAPTIMER AS "ZEROTOHUNDRED Biggest LOSER"No.1":)

Number 2.. Number 1 was (or is? he could still be around) from penang.. Kendrick?

 

[Laptimer]

Ask laptimer la.. he seems to know.. lol.. love to hear his technical explanation on it.. hahaha.

Ground station also don't have in malaysia, and suddenly can estimate
lateral acceleration at sepang track using geolocation data...

you so rude shiroetinshit!

hello is measure not estimate
dun anyhow say can
ask you your normal car how the speed is know?
is measure from wheel rpm after knowing circumference and derive
you wan to say your normal car speed is onli estimate ??
you knows how de accelerometer work? is by physical move and voltage or capacitance change
so the gforce is derive from de movement hahhahahahahhahahhahahahahhahahahah
so if you tink normal car speed is only estimate
den accelerometer is oso consider estimate
the true is accelerometer gps and normal speed is all measure one!!
ah seng not supid ok! dun anyhow say ting whack me cos my english not power
my understan is not bad ok
not say very good but enuff to see de rubbish ok!!
n i can see your rubbish!!!

gps is see the car position many time in one second
from change in position over time it calculate speed
you understan derivation or you need ah seng teach you??
go one more step and derivation the speed give you acceleration aka gforce
dis one is for gforce longitude

for gfroce lateral is same
with 3 point know de arc n de distance of arc n oso know de radius
with these calculate the gforce oredy by equation below
acceleration (gforce) = speed^2 / radius

don't say what ground station lah
dat one is for accurate compensate for de gps drift dis i oso know
but to calculate gforce while driving and every few 0.1 or 0.05 secon the gps drift is no factor

the pdf tok abt the gps error is actually wrong
you see gps n accelerometer data on same car
the gps usually filter and the lower the hz the more filtering naturally and always less than accelerometer number
oso de car use in the test can do 1.7 sustain lateral gforce on flat smooth skid pad
so on a circuit sure can spike jus under 2
also if the antena is put away from cg of car the number can spike higher oso
g-g trace include spike writer forget is not say sustain unless many point at there
can see there is not many point there most is concentration ard de 1.5

accelerometer oso need calibrate or got error oso
even temperature mus have de compensation table


you charles brudder is it? you all same no thinking style one!!
LS1 even more rude say the dirty word !! can he be ban for saying such work?

 

[shiroitenshi]

you so rude shiroetinshit!

hello is measure not estimate
dun anyhow say can
ask you your normal car how the speed is know?
is measure from wheel rpm after knowing circumference and derive
you wan to say your normal car speed is onli estimate ??
you knows how de accelerometer work? is by physical move and voltage or capacitance change
so the gforce is derive from de movement hahhahahahahhahahhahahahahhahahahah
so if you tink normal car speed is only estimate
den accelerometer is oso consider estimate
the true is accelerometer gps and normal speed is all measure one!!
ah seng not supid ok! dun anyhow say ting whack me cos my english not power
my understan is not bad ok
not say very good but enuff to see de rubbish ok!!
n i can see your rubbish!!!

gps is see the car position many time in one second
from change in position over time it calculate speed
you understan derivation or you need ah seng teach you??
go one more step and derivation the speed give you acceleration aka gforce
dis one is for gforce longitude

for gfroce lateral is same
with 3 point know de arc n de distance of arc n oso know de radius
with these calculate the gforce oredy by equation below
acceleration (gforce) = speed^2 / radius

don't say what ground station lah
dat one is for accurate compensate for de gps drift dis i oso know
but to calculate gforce while driving and every few 0.1 or 0.05 secon the gps drift is no factor

the pdf tok abt the gps error is actually wrong
you see gps n accelerometer data on same car
the gps usually filter and the lower the hz the more filtering naturally and always less than accelerometer number
oso de car use in the test can do 1.7 sustain lateral gforce on flat smooth skid pad
so on a circuit sure can spike jus under 2
also if the antena is put away from cg of car the number can spike higher oso
g-g trace include spike writer forget is not say sustain unless many point at there
can see there is not many point there most is concentration ard de 1.5

accelerometer oso need calibrate or got error oso
even temperature mus have de compensation table


you charles brudder is it? you all same no thinking style one!!
LS1 even more rude say the dirty word !! can he be ban for saying such work?

Whatever bro.. let you win lah.. your article also you say is mistaken.. "compensate for vehicle" roll clearly stated there... and "overestimated by GPS measurements" is quite clear. Your own source, now you twist to fit your needs.

Accelerometers are proven to provide better g-force measurements. They are not affected by satellite reception/minor errors in geolocation.

Even your link about VBOX also shows that there are errors, hence they have products like

VBOX 3i 100Hz
RLVB3i

VBOX 3i is the most powerful GPS data logging system built by Racelogic. Using a new GPS engine, VBOX 3i logs data 100 times a second, and features a 400MHz power PC processor. With IMU integration, USB and Bluetooth connectivity, compact flash card logging, and audio functionality for voice tagging, VBOX 3i represents a flexible solution to a range of testing requirements.

For accurate testing even in areas where view of the sky is obstructed, VBOX 3i has the ability to take the information from a Racelogic IMU (inertial measurement unit), pictured below, and combine this with the GPS data in real time to improve the quality of the measured parameters. The three accelerometers and three gyros inside the IMU are used to keep track of the attitude of the vehicle and will greatly increase the velocity and position accuracy during periods when satellite visibility is poor.

If you say measure also wrong, then everything measure also sure got some error, you also know what instrument error is. The idea is to set up the instrumentation for minimal error. That's why we always do zeroing/calibration, even on lab standard equipment. Suddenly you come in and say everything wrong, and only you is right. Better you become ruler/pembaris of the world.

Never mind, you win lah.. don't want to track this post already.

 

[Laptimer]

Whatever bro.. let you win lah.. your article also you say is mistaken.. "compensate for vehicle" roll clearly stated there... and "overestimated by GPS measurements" is quite clear. Your own source, now you twist to fit your needs.

sometime the doctor stuck in the lab too long study super high theory ting until he no and forget to test real world system in real world never see which always read lower n why

what he say abt gps is true in theory but you mus thinking n cannot anyhow accep whole thing
corner entry n exit where car roll or unroll the lateral acceleration phase and magnitude may not be completely accurate but for mos of de turn where roll is settling or settled already the sustained lateral will be accurate bcos de gps read only single point and that single point is steady alrdy!!

so gps kin of roll compensation is no same as accelerometer
accelerometer mid corner even steady state the roll will add to lateral usually
there are some situation where de roll will minus from lateral
you tinking can see how both can happen and when? :)

is not say i always right lah
the other thread i got say sorry and i am wrong how many time??? at least got 3 4 time leh!!
if you can show where laptimer wrong den laptimer sure say ok i learn and ok i sorry i wrong
dis is de interesting ways to living!!!

actually de racing need both theory and practical
mus balance but everyone will have different idea one
so we tok
then if cannot agree oso ok loh
you do your way i do my way
all is ok one
i never call you troll you dun call me troll loh!! fair right bro??

Accelerometers are proven to provide better g-force measurements. They are not affected by satellite reception/minor errors in geolocation.

true lah i oso use accelerometer but den you should not anyhow say gps NO WAY TO SEE LATERAL G
actually is more than accurate enofff for de normal driver
some normal driver oso install the accelerometer lagi worse and the number all wrong lah den oso signal got so much noise lah super vibration den wire never shelded anyhow run with other wire
for us do time attack gps is alrdy very good and no need compensate for sustain lateral one!!!
i been use the traqmate one is very good!!
http://store.traqmate.com/

of course use both is best lah can compare compare see

 

[shiroitenshi]

is not say i always right lah
the other thread i got say sorry and i am wrong how many time??? at least got 3 4 time leh!!
if you can show where laptimer wrong den laptimer sure say ok i learn and ok i sorry i wrong
dis is de interesting ways to living!!!

actually de racing need both theory and practical
mus balance but everyone will have different idea one
so we tok
then if cannot agree oso ok loh
you do your way i do my way
all is ok one
i never call you troll you dun call me troll loh!! fair right bro??

true lah i oso use accelerometer but den you should not anyhow say gps NO WAY TO SEE LATERAL G
actually is more than accurate enofff for de normal driver
some normal driver oso install the accelerometer lagi worse and the number all wrong lah den oso signal got so much noise lah super vibration den wire never shelded anyhow run with other wire
for us do time attack gps is alrdy very good and no need compensate for sustain lateral one!!!
i been use the traqmate one is very good!!
http://store.traqmate.com/

of course use both is best lah can compare compare see

Ac
[/quote]

If you talk like this, where people find you offensive? talk normally la. Even I also can accept if you discuss your ideas like this rather than simply say wrong, wrong, wrong. If you talk like this, I won't call you troll, fair or not?

Of course if cannot agree it's okay. I also got info from other people, like when I was doing ITB the first time... In the end, the way I did it was totally different from other people in the sense that I didn't use an idle valve. Are they wrong? NO, they did it earlier than me, and sucessfully too, but their way just different than mine. I wouldn't have found out if I never tried it myself. That's why say theory =/= real life or practical experience.

Like you also, you say can use GPS to calculate lateral G, but with accelerometer, it can measure it directly, but only with slight errors due to not compensating for vehicle roll. the 3 axis reduces the errors even further by actually factoring in vehicle roll. With two axis, can measure, but you lose out on the acceleration G.

One argument on gps accuracy is the GPS ground stations, in other countries, they have it to make GPS geolocation more accurate, while malaysia don't have, so our GPS accuracy not so good to make it a good source for lateral g calculations. errors of 3 metre or more is common, that why when you disable LOR on GPS, location sometimes off. What I meant by NO WAY to read G force is measuring it directly. If the data is wrong, then output will be wrong, GIGO (garbage in, garbage out).

But you provided a good alternative, I just think it's not accurate enough compared to using accelerometers.

Of course, using both is better, but not everyone has the dollar to buy high dollar datalogging systems and telemetry, so if have to pick one, better accelerometer.. most common datalogging and race ecu systems use accelerometers due to it's lower error factor.. is it 100% accurate? You also stated the errors common in measurements, so we try to minimize the errors by calibrating the best we can, if cannot reduce it completely.

 

[Laptimer]

as i say your point about measure gforce direct is not right cos accelerometer itself is derive it
can hang stick with heavy weight and use 2 video camera see stick angle as gforce sensor n you would say derive oso
gps derive it different way oni
all is derive you can say how accurate but all 3 actually accurate enough for us!!

i ask you how you know car speed? wheel speed derive? gps derive? radar derive? all is derive! all is accurate if set properly from start! All have GIGO

dun say 3m CEP all dis lah
oni 7 secon go through even the biggest turn
gps drift in 7 second is how many?
you tell me 1 hour 1 day i understan but you talking oni secons leh

i tell you i using both de accelorometer and de gps and both are more than enough for anyone reading dis!!! in fact gps in road car on track wun give so high reading make people read de spike think their car is f1 car oso de signal not so noisy installation not so tricky one

pple here is no need the 500 hz logger and high price very accurate accelerometer for chassis n shock research lah
we not proton lotus or toyota these kind got so much money

gps oso easy do laptime n de track map acceleometr track map always like sai have to ajus ajus to make only ok only
gps first time super liao
so if you acceleromatar onloy den you buy additional sensor for laptime? beacon? for what? use one thing do all loh!
den your real speed how? gps better than wheel speed tyre compress how? tyre grow how?
you go ask all thos pple include ken ji kamaza garager those touring car gt4 gt3 car team at sepang now go throw money buy xtra accelerometer put on the car maybe some will tell you say for what???? unless they do those very deep chassis or shock research n need it but they all never do cos the car n race seres type dun need one

is not lower error factor lah
is easier to use in place where got tall bilding tall tree
easier when look at forces n cmopensate for roll pitch yaw single gps cannot do this but actually multiple spot gps can do it but very accurate enough
but we all here is not doing dis one
oso last time gps tecnolgy no so good but last 10 year improving a lot
now got 10hz 20hz 100hz gps rtk all these ting
got more money oso can get us gov approve n use got some team oversea got approve before but ex

if you wan say ideal ideal den all car will have high qality 3 ax giro 3 ax accelometer n high accurate gps and many many other sensor all install properly all very ex dunno use for what we not f1 right???

tom dun ban me ok?? all these is traffic good for website
no law break no harm