track times at Thunderhill
05-14-2005, 12:56 AM
#1
track times at Thunderhill
I finally downloaded a bunch of data from my gtech pro competition, and found a lot of interesting data.
The instantaneous lateral g's I'm reading are up to 1.2g turning left, and 1.1 turning right. It also shows that I can hold about 1.1g for about 2.5 seconds turning left, and about 0.95 turning right. Thunderhill has more long left turn sweepers that allow me to get more consistent readings.
I get just under 1.0g braking, and about 0.47g of accelaration.
My lap times were determined by finding the same spike along the curve that measures lateral g's, which has a consistent pattern to it. In my case, I always hit the berm on T14, which produces a distinct spike before the long straight. My best lap time w/cyclone is 2:20, and 2:21 w/bypass, but I can get 2:22-2:24 75% of the time, which I think is a good indicator that I've gotten consistent.
My foremost goal is to become smoother with the brake/throttle transitions, as I still need work on it, and I think the byproduct should be better average lap times. It would be cool to see some improvement over the course of the year. Any idea what would be considered a good lap time for the Z w/street tires on this track?
The instantaneous lateral g's I'm reading are up to 1.2g turning left, and 1.1 turning right. It also shows that I can hold about 1.1g for about 2.5 seconds turning left, and about 0.95 turning right. Thunderhill has more long left turn sweepers that allow me to get more consistent readings.
I get just under 1.0g braking, and about 0.47g of accelaration.
My lap times were determined by finding the same spike along the curve that measures lateral g's, which has a consistent pattern to it. In my case, I always hit the berm on T14, which produces a distinct spike before the long straight. My best lap time w/cyclone is 2:20, and 2:21 w/bypass, but I can get 2:22-2:24 75% of the time, which I think is a good indicator that I've gotten consistent.
My foremost goal is to become smoother with the brake/throttle transitions, as I still need work on it, and I think the byproduct should be better average lap times. It would be cool to see some improvement over the course of the year. Any idea what would be considered a good lap time for the Z w/street tires on this track?
05-16-2005, 05:15 PM
#3
2 seconds is a lot of time to make up!...I got a long way to go...I've lost it on turn 7 last August, on my first track day; Too much throttle too early, and then lifting when my rear end started coming around. Talk about poor instincts...yet I don't know how to overide that habit without putting myself into those situations. I care more about car control than turning in fast lap times. I figure they are somewhat interlinked anyway. Better car control (to me)--->faster laps.
On another note, I see about 1/3 of the intermediate group running dot R-compounds. I'm not ready for those yet, but maybe another dozen track days, I might consider them. Quite surprisingly, most of the faster drivers are still running on street tires, which basically means they must be much better drivers. But, assuming those really good drivers put on R-compounds, how much would their times improve on Thunderhill?...3 or 4 seconds?
On another note, I see about 1/3 of the intermediate group running dot R-compounds. I'm not ready for those yet, but maybe another dozen track days, I might consider them. Quite surprisingly, most of the faster drivers are still running on street tires, which basically means they must be much better drivers. But, assuming those really good drivers put on R-compounds, how much would their times improve on Thunderhill?...3 or 4 seconds?
05-19-2005, 06:16 AM
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A fast SCCA T2 (Showroom Stock) time for Thunderhill would be in the 2:07-2:08 range with the cyclone. I would think a fast time for a street car with street tires would be 2:18
11-08-2005, 05:03 PM
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Originally Posted by ALong
A fast SCCA T2 (Showroom Stock) time for Thunderhill would be in the 2:07-2:08 range with the cyclone. I would think a fast time for a street car with street tires would be 2:18
Records will be surely broken next season in every class..
11-08-2005, 05:19 PM
#6
Originally Posted by daveh
I was actually able to hit those times last weekend. The new runoff pavement that they've added seems to shave almost 2 seconds off lap times.
Records will be surely broken next season in every class..
Records will be surely broken next season in every class..
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11-09-2005, 11:42 AM
#8
Originally Posted by dnguyent
I finally downloaded a bunch of data from my gtech pro competition, and found a lot of interesting data.
The instantaneous lateral g's I'm reading are up to 1.2g turning left, and 1.1 turning right. It also shows that I can hold about 1.1g for about 2.5 seconds turning left, and about 0.95 turning right. Thunderhill has more long left turn sweepers that allow me to get more consistent readings.
I get just under 1.0g braking, and about 0.47g of accelaration.
My lap times were determined by finding the same spike along the curve that measures lateral g's, which has a consistent pattern to it. In my case, I always hit the berm on T14, which produces a distinct spike before the long straight. My best lap time w/cyclone is 2:20, and 2:21 w/bypass, but I can get 2:22-2:24 75% of the time, which I think is a good indicator that I've gotten consistent.
My foremost goal is to become smoother with the brake/throttle transitions, as I still need work on it, and I think the byproduct should be better average lap times. It would be cool to see some improvement over the course of the year. Any idea what would be considered a good lap time for the Z w/street tires on this track?
The instantaneous lateral g's I'm reading are up to 1.2g turning left, and 1.1 turning right. It also shows that I can hold about 1.1g for about 2.5 seconds turning left, and about 0.95 turning right. Thunderhill has more long left turn sweepers that allow me to get more consistent readings.
I get just under 1.0g braking, and about 0.47g of accelaration.
My lap times were determined by finding the same spike along the curve that measures lateral g's, which has a consistent pattern to it. In my case, I always hit the berm on T14, which produces a distinct spike before the long straight. My best lap time w/cyclone is 2:20, and 2:21 w/bypass, but I can get 2:22-2:24 75% of the time, which I think is a good indicator that I've gotten consistent.
My foremost goal is to become smoother with the brake/throttle transitions, as I still need work on it, and I think the byproduct should be better average lap times. It would be cool to see some improvement over the course of the year. Any idea what would be considered a good lap time for the Z w/street tires on this track?
Anyone know of books on analyzing lap times based on collected data? The G-tech sounds like its a pretty effective setup for the money. I spent a boatload on a video datalogger and I'm not completely sure how to crunch the numbers.
Earlier this year, I manually took the speeds and times off some logged video and created an "average" profile for each corner of my local track. Now, I compare it to when I make a change in driving or upgrade my parts. Worked really well, but it was tedious to crunch the numbers. Since my logger is OBDII and my Diasio has a motorcycle ecu, I cannot use it. So I'm looking for alternatives.
This is a good topic. I'm wondering what type of street tires dnguynet is using? Also, wonder if you are heel/toeing?
11-09-2005, 02:07 PM
#9
Originally Posted by zillinois
Anyone know of books on analyzing lap times based on collected data? The G-tech sounds like its a pretty effective setup for the money. I spent a boatload on a video datalogger and I'm not completely sure how to crunch the numbers.
Earlier this year, I manually took the speeds and times off some logged video and created an "average" profile for each corner of my local track. Now, I compare it to when I make a change in driving or upgrade my parts. Worked really well, but it was tedious to crunch the numbers. Since my logger is OBDII and my Diasio has a motorcycle ecu, I cannot use it. So I'm looking for alternatives.
This is a good topic. I'm wondering what type of street tires dnguynet is using? Also, wonder if you are heel/toeing?
Earlier this year, I manually took the speeds and times off some logged video and created an "average" profile for each corner of my local track. Now, I compare it to when I make a change in driving or upgrade my parts. Worked really well, but it was tedious to crunch the numbers. Since my logger is OBDII and my Diasio has a motorcycle ecu, I cannot use it. So I'm looking for alternatives.
This is a good topic. I'm wondering what type of street tires dnguynet is using? Also, wonder if you are heel/toeing?
The G-tech has a few features that will allow me to compare grip between tires or suspension settings. Now that I have the upper control arms and different tires (SportConti II), I will see if I get more grip or less. The G-tech is still quite limited in capabilities, but you can't expect too much out of a $300 unit. I have to extract my laptimes, which can be a PITA, and I only find out how I've done after the day's over. I have a spreadsheet that I enter my time after hitting the berm at T15, and it basically calculates my lap time. It's probably not accurate enough for a lot of advance level folks, but I'm certain it's accurate for plus/minus 0.5 seconds. At my level, that's good enough. All in all, I extract data similar to how you extracted data. However, I'd have to extract my RPMs and gear to determine speed, but that data will be useless once I put in smaller diameter r-compounds. I guess GPS is one of the only ways to meaure speed that is independent of wheel rpm.
I'll eventually get a lap timer when my times don't vary so much. I do like the friction circle feature of the G-tech, and it gives me an indication of how smooth my transition from braking to turning is. The Speed Secrets book by Ross Bentley had a little blurb about the how to determine whether I'm extracting all the friction that my tires are capable of. The fact that my g's don't follow the friction circle during the braking-to-turning transition indicated that I didn't use all of my tire's capabilities. Apparently trail braking would fix that.
I've also been a member of forums.rennlist.com. The "Racing and Drivers Education Forum" is excellent! They have a large community of track addicts and instructors. Plus, there are discussions on the use of dataloggers and the interpretation of its data. Quite frankly, there's a little bit too much analyzing for someone like me who only DE's 8 times a year.
As for heel/toeing, yes, I do it. I'm not great at it, but my clutch still thanks me for trying.
Originally Posted by daveh
The T2 guys are running at least 4 seconds a lap faster than me. That's a significant distance. (counting to 4 in my head..)
11-10-2005, 06:45 PM
#11
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I know of two good books that cover the subject of Data Acquistion. The best one is called Data Power and was wrirten by Buddy Fey. Unfortunately it is out of print and a bit hard to locate. The second best choice is Competition Car Data Logging by Simon McBeath. It is available on Amazon, among other sources. Good luck!
-Rob
-Rob
11-10-2005, 10:39 PM
#12
Thanks Rob. I found the Data Power book on Amazon. $399 is the used one and the new one goes for $1338. I'm going to have to save my pennies for that one.
Here's an interesting link about data aquisition.
http://www.mitchellsoftware.com/Procedures.htm
Here's an interesting link about data aquisition.
http://www.mitchellsoftware.com/Procedures.htm
Last edited by zillinois; 11-10-2005 at 10:41 PM.
03-13-2006, 09:27 AM
#13
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Just did a track day with my stocker's with 30k miles on them. There was a chance of rain (even though it never did) so I decided to keep my bald toyo's at home. It was a very cold day so I was able to manage tire temps for quite a few laps before overheating the rears (before the real fun started). I certainly felt more power in the cold weather.
So, it looks like a 2:14 is doable on street rubber at t-hill. I also answered the question of how much faster RA-1's are than stock tires. 6-8 seconds at at a long track like thunderhill.
So, it looks like a 2:14 is doable on street rubber at t-hill. I also answered the question of how much faster RA-1's are than stock tires. 6-8 seconds at at a long track like thunderhill.
03-13-2006, 12:38 PM
#14
Originally Posted by daveh
Just did a track day with my stocker's with 30k miles on them. There was a chance of rain (even though it never did) so I decided to keep my bald toyo's at home. It was a very cold day so I was able to manage tire temps for quite a few laps before overheating the rears (before the real fun started). I certainly felt more power in the cold weather.
So, it looks like a 2:14 is doable on street rubber at t-hill. I also answered the question of how much faster RA-1's are than stock tires. 6-8 seconds at at a long track like thunderhill.
So, it looks like a 2:14 is doable on street rubber at t-hill. I also answered the question of how much faster RA-1's are than stock tires. 6-8 seconds at at a long track like thunderhill.
Dave,
Is that time achieved using the newer runoff? Regardless of that, you make me feel like I'm on an leisurely Sunday drive when I'm out there. I'm still 5 seconds slower!
...damn impressive considering those stockers are old and are 225/235 width. Are we going to see you at the NCRC event?
-don
03-13-2006, 03:12 PM
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Dave and Don, it will be interetsing to see in April how we all compare. I had done around a 2:20 (w/ cylcone) on a stock Z (w/ CAI) w/ . I just picked up a set of track wheels - F:255, R:275 toyo RA-1 and have done some suspension mods...I'm hoping the raybesto pads will hold up and that it won't take me too long to get used to them.
Can't wait to see you guys there!
-Peter
Can't wait to see you guys there!
-Peter
03-13-2006, 03:33 PM
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Originally Posted by dnguyent
Dave,
Is that time achieved using the newer runoff?
-don
Is that time achieved using the newer runoff?
-don
I never actually touched the new pavement that was laid out, but I certainly did go through the corners a little harder knowing that it would save my hide if I needed it.
I won't be there for the NCRC event. I've already commited to two other full weekends in April. Have fun.
03-13-2006, 08:06 PM
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since it was briefly touched on, and i'm pondering the possibilties...
anyone know of any real comparos of data acq such as the DL1/g2xtreme/...?
i'm most interested in ease of use of software - the DL1 is universally praised, but i feel like a monkey with a football trying to use their software. secondarily would be a way to integrate video from a miniDV cam. again, i know the dl1 can do this (although i believe it requires an extra cost software option).
my last real qualification is support of reasonably priced additional sensors. ie, it would be nice to have a brake pressure sensor and possibly a steering angle sensor. i doubt i'd be able to parse all that data effectively, but still...
while this is primarily for my miata, it would be nice to be able to move it to the z - so quick install/removal is a plus.
any thoughts?
ahm
anyone know of any real comparos of data acq such as the DL1/g2xtreme/...?
i'm most interested in ease of use of software - the DL1 is universally praised, but i feel like a monkey with a football trying to use their software. secondarily would be a way to integrate video from a miniDV cam. again, i know the dl1 can do this (although i believe it requires an extra cost software option).
my last real qualification is support of reasonably priced additional sensors. ie, it would be nice to have a brake pressure sensor and possibly a steering angle sensor. i doubt i'd be able to parse all that data effectively, but still...
while this is primarily for my miata, it would be nice to be able to move it to the z - so quick install/removal is a plus.
any thoughts?
ahm
03-14-2006, 02:36 AM
#18
Originally Posted by amolaver
since it was briefly touched on, and i'm pondering the possibilties...
anyone know of any real comparos of data acq such as the DL1/g2xtreme/...?
i'm most interested in ease of use of software - the DL1 is universally praised, but i feel like a monkey with a football trying to use their software. secondarily would be a way to integrate video from a miniDV cam. again, i know the dl1 can do this (although i believe it requires an extra cost software option).
my last real qualification is support of reasonably priced additional sensors. ie, it would be nice to have a brake pressure sensor and possibly a steering angle sensor. i doubt i'd be able to parse all that data effectively, but still...
while this is primarily for my miata, it would be nice to be able to move it to the z - so quick install/removal is a plus.
any thoughts?
ahm
anyone know of any real comparos of data acq such as the DL1/g2xtreme/...?
i'm most interested in ease of use of software - the DL1 is universally praised, but i feel like a monkey with a football trying to use their software. secondarily would be a way to integrate video from a miniDV cam. again, i know the dl1 can do this (although i believe it requires an extra cost software option).
my last real qualification is support of reasonably priced additional sensors. ie, it would be nice to have a brake pressure sensor and possibly a steering angle sensor. i doubt i'd be able to parse all that data effectively, but still...
while this is primarily for my miata, it would be nice to be able to move it to the z - so quick install/removal is a plus.
any thoughts?
ahm
I ran the DataCam 2 last year and loved it. It has video overlayed from OBDII. My only complaint was the OBDII doesn't supply data fast enough for decent overlay. It works, its just not ideal.
I just did a bunch of research this winter picking my new system. And I think the Datatraq is probably the one of the best bang for the buck. A guy in the Chicago crew bought the DL1 last year and we tried to install it into my Z and didn't have much luck. I'm pretty computer literate too. In theory, the DL1 is probably the best bang for the buck though. Maybe we got a dud, but we couldn't even get the GPS to work.
I think Stack is probably one of the better ones too. I eventually bought a Veypor2. It has wheels sensor and rpm pickup with 2 axis accelerometer and a helmet mounted HUD with shift indicator light, gear indicator and lots of data logging, lap timer and some advanced graphing features. Its incredibly cheap for what it delievers, but its a work in progress. They are constantly adding new features to it, which you can get for free by downloading new firmware.
03-16-2006, 10:38 AM
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Hey DAVE, its Jason i am in the white G35!
I took a video of myself to see what my times are.
The lap where there was no traffic i got 2:16.
I still have so much room for improvements, PRACTICE PRACTICE!
And bring me for a ride Next time so that i can learn from u!
Hopefully i can bring it down to 2:14s.
Looking forward to see you on April 1st and 2nd!
I took a video of myself to see what my times are.
The lap where there was no traffic i got 2:16.
I still have so much room for improvements, PRACTICE PRACTICE!
And bring me for a ride Next time so that i can learn from u!
Hopefully i can bring it down to 2:14s.
Looking forward to see you on April 1st and 2nd!
Last edited by jaslui119; 03-16-2006 at 10:55 AM.
03-16-2006, 03:39 PM
#20
Originally Posted by jaslui119
Hey DAVE, its Jason i am in the white G35!
I took a video of myself to see what my times are.
The lap where there was no traffic i got 2:16.
I still have so much room for improvements, PRACTICE PRACTICE!
And bring me for a ride Next time so that i can learn from u!
Hopefully i can bring it down to 2:14s.
Looking forward to see you on April 1st and 2nd!
I took a video of myself to see what my times are.
The lap where there was no traffic i got 2:16.
I still have so much room for improvements, PRACTICE PRACTICE!
And bring me for a ride Next time so that i can learn from u!
Hopefully i can bring it down to 2:14s.
Looking forward to see you on April 1st and 2nd!
-Don