jid2 - I didn't realize you had all your stuff hooked up. Very interesting stuff!

 

I don't have the downforce stuff hooked up yet - so not everything is up and running yet.

I have "black" to take out of my laps for sure. I just need a little more seat time to get comfortable with more speed in the gnarly sections. The fastest cars at Pacific Raceways seem to be running lap times of 1:35 to 1:36, right now my fastest lap is a 1:41 - so I've got 6 seconds to shed. This is a hard track to drive at the limit - at least in my opinion. I've ran on a few flat, easy tracks like Portland, and Miller and it's easy to drive the car at the limit on those flat suckas with their plush new pavement.

Nathan - what sort of steady state G's are you pulling in the corners. Throw up some lateral G plots for that lap. You do a good job of braking for the corner and then putting the power back down through the corner itself.... you were all green in them.

 

I need a data set up.......

 

+100 lol

 

guys the racelogic performance box's can give detailed 'G' forces of braking, acceleration and lateral cornering G as well as all other speed / time / distance
data recording. all from a box plugged into your cigarette ligher.
you can also analyse the line you took thro a corner and compare which line makes it thru the fastest.
all good stuff.
here is a thread of a day at a circuit with several cars including a gtr that we got performance box data from so you can see some stuff it can do.
http://www.lancerregister.com/showthread.php?t=237274

 

Looks like on this track I was seeing 1.15-1.20 in most corners. I added the friction circle to the map to better show this. The inside ring is .5 and the outside is 1.5g. I left the cursor on a 1.2g corner where I was at 80mph:



Keep in mind that if the track is angled/cambered or if you go over a burm/gater that is distorts the data. Like there's instances on some tracks where I'll see a 1.5 or 1.6g load, which usually means I ran over the burm on corner exit.

 

Ok, now it's kinda fun! Here's a different track that I'm more comfortable with. You can see the lateral curves are more rounded - ie steady.
Here's a comparison of 2 different weekends. Drastically different temps and tires; I'm also running different tunes hp wise. One is with 245 Dunlop's and the other with 245 Hoosier R6's. Bet you can tell which is which just by looking at the friction circle! You can look at the track map and see that I'm gassing and braking nearly the same. But with just extra sustained corner speed I end up nearly 5 seconds faster with the better tires. Which is why I say build the car around the tires in a limited budget or pts (aka NASA TT) type event.

 

Excellent post JID2. I really appreciate your 'analytical' approach to things ...Just reading the thread makes me want to get back on the track again - last race season for me was 1995 ...

Where do you guys recommend buying this datalogger ? Any models you recommend, or is there just 1 ?

 

Glad you posted the friction circle - you do a nice job of painting the sustainable friction limit around the the top half of the circle; which is what you want. There are very few data points inside that main friction arc, which means you keep the tires at the limit while going from braking to turning.

As you can see in my circle I'm not sweet yet. I'm nowhere near carring the limit across the front arc - all my points are in that inner "wuse" section And with the amount of black I have I paint the middle up pretty good as well. I'm going to try and put the logger into some of the faster guys cars and see what they come up with for data.



Both boomn29 and I use Traqmate. http://store.traqmate.com/ProductDet...uctCode=930001

I researched this stuff about a year ago when I bought this, there are other systems out there, which are similar - but the Traqmate software is the most user friendly, and most powerful in my mind. They make frequent upgrades and are continually making improvements.

Other systems include:

http://www.racepak.com/Road_Racing/index.php

http://www.race-technology.com/home_8.html

http://www.vboxusa.com/performancedrift/compare.php

 

And for a cheaper solution there is the MaxQ data system.

http://www.maxqdata.com/

 

i need one as well.... interesting data nonetheless

 

This is quite interesting....more! Pete

 

That's the one I want to buy, if I ever save enough $. More important things like roll bar, belts, rotors, pads, tires always seem to take precedence.... sigh...

Last year, when I looked at that, they had an DYI option for only ~$50 if you already have all the hardware (compatible GPS & smartphone).

 

This is the way to go. I got an open box blue tooth PDA for <100. Blue tooth differential GPS receiver for $45, and the software download. Add in a case and another GOPRO suction cup and the whole setup was under $250.

That being said, I will be buying a traqmate or similar for my next car. It took a little while before I got it set up right, and all the bugs worked out. But for the DIYer thats not afraid of software go for it.

 

Jid2's power must be pretty impressive, 135 before the kink is pretty good. As reference I have topped out at 145 way down after turn 1. That takes a lot of wot on my car. 135 is what I typically get to before turn 2. Jid2 is doing 135 about three hundred yards before my car.