Harry's Lap Timer: iPhone 5 video at Sepang

[guy013]

[video=youtube_share;ONJs9uXQ9fQ]http://youtu.be/ONJs9uXQ9fQ[/video]

Here's a little video I took today at BMW-SG track day at Sepang. It was a great day with few cars which means lots of track time! Pretty happy with my timing (2:36.83) although I'm sure there's plenty of room for improvement with my extremely erratic driving

Also my 1st time out playing with this new app I purchased, pretty cool!

I hooked the iPhone 5 up to an external DUALAV GPS for greater accuracy. As you can see the preset start/ stop line in the app is about 20m in front of the actual, so that's where the app starts/ stops the timing.

Just some background info on the car setup, hopefully the real track lao jiaos can chime in on how I can improve my timing further:

TE37SL 18x9.5 & 18x10.5
Michelin Pilot Super Sports 265/35/18 & 285/35/18
Akrapovic evolution exhaust
Bilstein PSS10
Camber Fr 1.7 Rr 2.0
ESS Tune

 

[Meek]

Re: Harry's Lap Timer: iPhone 5 video at Sepang

Cool app! Nice run too.

Share more info on the app please.

 

[guy013]

Re: Harry's Lap Timer: iPhone 5 video at Sepang

Harry's Lap Timer
http://www.gps-laptimer.de/

download for iOs or Android

few different versions, all cost money and has different features.

Worldwide review is that the timing vs actual average error is less than 0.1 sec

I'm using an external GPS connected by bluetooth but apparently the iPhone 5 GPS module on its own works pretty well too. But i', kiasu

Phone must be mounted securely. I'm using RAM MOUNT system

 

[guy013]

Re: Harry's Lap Timer: iPhone 5 video at Sepang

Couple more videos

Cruising around the track
[video=youtube_share;yXSmnkY7amY]http://youtu.be/yXSmnkY7amY[/video]

TRYING to chase a GTR
[video=youtube_share;ks353U9493E]http://youtu.be/ks353U9493E[/video]

 

[totoseow]

Re: Harry's Lap Timer: iPhone 5 video at Sepang

almost got the GTR....but u wobbled....stick up his ass maybe he makes a mistake.

 

[guy013]

Re: Harry's Lap Timer: iPhone 5 video at Sepang

almost got the GTR....but u wobbled....stick up his ass maybe he makes a mistake.

haha ALMOST caught him is being extremely optimistic. at the start of the video can see how he went past me at the straight like I was standing still.

 

[Shaun]

Re: Harry's Lap Timer: iPhone 5 video at Sepang

Aiyoh that GTR so beng and poorly driven Who was driving it? Admit it..
Chow bengs relying only on technology to go "fast"!

 

[Gerald81]

Re: Harry's Lap Timer: iPhone 5 video at Sepang

Thanks for sharing, very nice driving. What sort of horsepower is your M3 punching out?

Also, noticed that in your 2:36 hotlap video, the g-plot appears to be working fine but the speed and lap time seems out of sync?

 

[guy013]

Re: Harry's Lap Timer: iPhone 5 video at Sepang

Thanks for sharing, very nice driving. What sort of horsepower is your M3 punching out?

Also, noticed that in your 2:36 hotlap video, the g-plot appears to be working fine but the speed and lap time seems out of sync?

Hmm I didn't notice the out of sync speed and timing.

Will check it out later when I get home. Unfortunately didn't have transponder numbers to compare to this time round.

Have not done a dyno so I don't want to guesstimate what my HP is or it will lead to another can of worms.

What I have done performance wise is full akra EVO exhaust and ESS tune.

 

[Gerald81]

Re: Harry's Lap Timer: iPhone 5 video at Sepang

Hmm I didn't notice the out of sync speed and timing.

Will check it out later when I get home. Unfortunately didn't have transponder numbers to compare to this time round.

Have not done a dyno so I don't want to guesstimate what my HP is or it will lead to another can of worms.

What I have done performance wise is full akra EVO exhaust and ESS tune.

If you look at the 7 second mark, in the g-plot and video it appears that you are still accelerating, but the speed shows that you are decelerating, so I'm guessing the speed displayed is about 2 seconds ahead of the g-plot and video. Also the lap timer seemed to start about 2 seconds ahead of the point in the video where you crossed the start/finish line. I think the lap time is accurate though, just that the speed display and lap timer are out of sync with the rest of the video. Your other video seems to be well synced up though. I stopped using transponders too once I started using data acquisition systems, never looked back!

 

[guy013]

Re: Harry's Lap Timer: iPhone 5 video at Sepang

I guess that's the drawback of using a cheap app like this vs a full fledge standalone like performance box

I noticed the start stop timer also starts before the actual start stop line, to me as long as the start stop point is consistent then the lap timings should not vary too much from actual.

I'll try to overlay some other laps and upload so see if the problem still exists. Takes along time to upload though. Haha

 

[Gerald81]

Re: Harry's Lap Timer: iPhone 5 video at Sepang

Is there a way to adjust the syncing of the data and video for your iPhone lap timer, or does it automatically sync itself? For myself I'm using Pbox for data, video from a bullet camera and I use Dashware from Chasecam which allows me to sync it up. I think most of the popular data/video editing software like Dashware, Trackvision, etc. will allow you to adjust the syncing of data and video.

 

[Shaun]

Re: Harry's Lap Timer: iPhone 5 video at Sepang

To go quicker I would say you can stop overspeeding some entries and over scrubbing the front tires.

Where control inconsistency has caused you to overspeed an entry or miss it altogether, learn to recognize early when you've already oversped the entry, so that you can quickly abandon trying to make the apex and focus on reaching the trackout at a good speed. This is the best recovery you can possibly make after missing or overspeeding an entry. It's the early recognition that will prevent you from pinching the exits and allow you to make the best of the proceeding straight.

It's good to know what is ideal and to drive around it, but human and car variance will mean often drivers end up in non ideal situations. Once there it is important to know what best recovery is to make the most of the situation. Next turn, sector, or lap can be corrected based on what just happened.

 

[guy013]

Re: Harry's Lap Timer: iPhone 5 video at Sepang

Is there a way to adjust the syncing of the data and video for your iPhone lap timer, or does it automatically sync itself? For myself I'm using Pbox for data, video from a bullet camera and I use Dashware from Chasecam which allows me to sync it up. I think most of the popular data/video editing software like Dashware, Trackvision, etc. will allow you to adjust the syncing of data and video.

for this app, the overlaying of data is done automatically.

To go quicker I would say you can stop overspeeding some entries and over scrubbing the front tires.

Where control inconsistency has caused you to overspeed an entry or miss it altogether, learn to recognize early when you've already oversped the entry, so that you can quickly abandon trying to make the apex and focus on reaching the trackout at a good speed. This is the best recovery you can possibly make after missing or overspeeding an entry. It's the early recognition that will prevent you from pinching the exits and allow you to make the best of the proceeding straight.

It's good to know what is ideal and to drive around it, but human and car variance will mean often drivers end up in non ideal situations. Once there it is important to know what best recovery is to make the most of the situation. Next turn, sector, or lap can be corrected based on what just happened.

thanks for the tips. i realised also that the harder i pushed ie later braking etc, would result in slower lap times.

 

[Shaun]

Re: Harry's Lap Timer: iPhone 5 video at Sepang

You need to kind of reverse your braking signature as shown in your G-G plot.
Your brake point are actually too early still. What's off is the braking decisiveness (0.4 sec from start of brake event to max decel) and aggression (10% down from max lateral). Both will cause you to use up more time and distance in the braking zones.
You need high initial pressure to threshold before trailing off at turn entry. Currently it is opposite.. starts light, gets heaviest by turn entry which hurts turn in.

 

[guy013]

Re: Harry's Lap Timer: iPhone 5 video at Sepang

Wow u can see that from the g plot!

That's exactly what I'm doing now. In fact before I brake I even coast a little but off the throttle before applying. I've got lack of confidence under braking and find the car a bit unstable if I press too hard on the brakes. That's why I start light then progressively heavier. Will try the other way round next time.

 

[Shaun]

Re: Harry's Lap Timer: iPhone 5 video at Sepang

If the instability is minor, deal with it, sometimes it is inherent. Try making sure no one is behind you on track, move to the center of the track width, brake 30m or so early, but really nail it quickly in a big brake zone. Feel how unstable it is (or isn't). That exercise run a few times may give you confidence when it comes to your hotlaps. Many times a rear end can move around a little but is self correcting. This is not dangerous, just unnerving. It's the rear ends that need actual driver correction to catch, even in dead straight braking on flat, level, smooth sections of the track, where something is wrong.

If the instability is major to the point of near loss of control in dead straight braking, make sure your dampers are symmetric on settings and the rear ride height is not too high. Alignment and tire pressures should be ballpark right. Typical road car aftermarket spring and damper rates are not high or low enough to create problems. It's usually setup.

 

[guy013]

Re: Harry's Lap Timer: iPhone 5 video at Sepang

added 2 more videos, i don't know why it doesn't start at 0:

2:36.89
[video=youtube;b3BHALeqVME]http://www.youtube.com/watch?v=b3BHALeqVME[/video]

2:37.30
[video=youtube;3wMqEAYUaKE]http://www.youtube.com/watch?v=3wMqEAYUaKE[/video]

 

[Jetpilot]

Re: Harry's Lap Timer: iPhone 5 video at Sepang

Is there a way to adjust the syncing of the data and video for your iPhone lap timer, or does it automatically sync itself? For myself I'm using Pbox for data, video from a bullet camera and I use Dashware from Chasecam which allows me to sync it up. I think most of the popular data/video editing software like Dashware, Trackvision, etc. will allow you to adjust the syncing of data and video.

are you Gerald Tan, ex-SMU?