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