Quote from KeiichiRX7 :

i recognize that view...... are you wearing the helmet cam?

nah, just holding a digicam at eye level. it does end up being the same view.

Quote from dpcars :

i feel like i need to have some real progress on the cars to post about before i post about lfs

but on the subject of lfs, i've been messing with tweaks and things are better. the biggest problem i'm having right now is detecting when the back end is about to step out on a rear-driver. sensing the rear slip rate is totally a seat-of-pants thing and i have not yet figured out how to clue in on it in the sim. trying not to spend TOO much time on it though. been wrapping up some projects for clients so i can get back to the cars. but i'll definitely continue to experiment wth lfs.

and no, you won't see me playing online for quite some time.

This soundpack might help you to sense when a car starts to lose grip...

Quote from dpcars :

but on the subject of lfs, i've been messing with tweaks and things are better. the biggest problem i'm having right now is detecting when the back end is about to step out on a rear-driver. sensing the rear slip rate is totally a seat-of-pants thing and i have not yet figured out how to clue in on it in the sim.

It takes time to get used to a force feedback wheel as a wheel alone will never give the full feedback and feel one gets in a car, there is, however, a surprising amount available to pick up on through the wheel when you get used to it. Ultimately though just like in real life planning ahead and pre-empting what the car is going to do is the best strategy, probably more important in a LFS than RL.

Quote from ajp71 :

Ultimately though just like in real life planning ahead and pre-empting what the car is going to do is the best strategy, probably more important in a LFS than RL.

very true! that is indeed the essense of car control.

just had my first trackday of the year. i must say, there is something almost embarassing about how good a fast lap feels. there is a certain 'g-high', i first experienced it when doing aerobatics but now that i'm going fast enough in cars i get it here too.

this is all very educational. lots of new information, lots of things to ponder. i'm definitely the better for it.

good car

Quote from dpcars :

just had my first trackday of the year.

Yay, finally an update to your page. Having read almost everything of remote interest (to me) in the last weeks, I was really waiting for this .

As this is my first post in this thread, I'd also like to say that your blog and especially the MINI-write-ups, played a relatively large role in triggering my decision to get myself a hothatch this year. So, thx for this opportunity to kill some spare time while being at work .

From reading your mini update (thanks for the tip off Linsen), it would appear you use a DL1 datalogger, which is what I've bought to use on my Reynard. Do you like it? I've had a play with some runs I downloaded off an Australian website, but not my own data as yet.

It seems very powerful, and not THAT hard to set up and analyse the data. I'm still not 100% used to it yet, and am not sure how importing multiple runs on top of each other works.

If you've got a minute or two, and don't mind sharing, would you by any chance be able to send me a copy of your run files (don't really care which car, but I'd love to look at the DP1 telemetry <hint hint>) so that I can play with something interesting.

Nice updates, keep them coming!

yep, it's the DL1. love it. a very good educational tool. i've uploaded some sample data runs:

http://www.dpcars.net/misc/dp1pats.run - dp1 at a kart track
http://www.dpcars.net/misc/dp104.run - this is dp1 first track outing
http://www.dpcars.net/misc/mini132.run - for reference, this is my mini on R compound tires.

if anyone wants to play with the files, the software to do so can be downloaded for free from http://www.race-technology.com

the interesting thing is to compare the dp104 run and the mini132 run. in the mini i'm pretty much dialed in and you can see that when i get clear laps i knock them off pretty consistently. at this pace (1:33-ish) i pass most people on the track including instructors in porsche GT3s and it is a little faster than my best elise time on street tires. on R compounds the elise/exige can do about 1:31 but most i've seen out there run 1:35-ish. the dp1 i'm only trying to get an idea of what it does and i only had one clear lap.

the really educational part comes from looking at various spots on the track. for example it's clear that the dp1, even in prototype 4-cylinder form, with only 30 miles on the engine, accelerates pretty well especially coming off the turns. i'm not using anywhere near the capability and yet already that's where most of the lap time comes from. on the other hand notice i'm very tentative with the brakes and brake way earlier and gentler than in the mini. that whole brake-on-the-diff thing is not in the 'success' column i'm also not using the cornering as much as i could, only 1.3 g whereas on the kart track i've seen up to 1.7 (in the run i uploaded i think it only goes to 1.55).

so the mini is pretty much tapped out but the dp1 is only getting started. i expect i have over 10 sec to gain out there this summer. won't happen all at once though!

here's another set of data - an exige on track tires driven by an experienced driver (he used to race formula atlantic among others).

http://www.dpcars.net/misc/scottexigesolo.run

btw the start/finish line is halfway down the front straight so that is where the lap marker should be drawn. a screen shot of the comparison is at

http://www.dpcars.net/misc/datalog.jpg

Great stuff - the mini and the exige are really comparible, which has surprised me. The dp104.run file says it isn't recognised, so I think something has got corrupted somewhere.

I have the slight advantage of vaguely knowing Portland, from my Indycar Racing days a long while back, and I've watched various car races there, so it means something - all the other run files I've found on the 'net have been tracks that have no meaning to me other than the display in the datalogger...

I can see on the kart track that the DP1 is a pretty mega machine - a peak of about 1.75g, despite a max speed of just 70mph or so...

If you can fix the 104 run file I'd be a really happy bunny

it was a case-sensitivity issue with server and filename - try again now, should work.

here are a bunch more:

for PIR:

- the mini on heavy 17" wheels and kdw2 street tires - wheels/tires make a huge difference! - http://www.dpcars.net/misc/mini135_7.run - best lap 1:35.7
- exige on 048 tires driven by ex formula atlantic racer - http://www.dpcars.net/misc/scottexigesolo.run - best lap 1:32.8
- modified cayman S (suspension, rollcage) on R compounds, exp driver - http://www.dpcars.net/misc/caymans.run - best lap 1:31.1
- national champ level driver in a stohr DSR - http://www.dpcars.net/misc/dsr.run - best lap 1:12.0 (this would qualify 10th for ALMS prototype!)
- mcoupe, coilover suspension and R compounds, exp driver - http://www.dpcars.net/misc/mcoupe.run - best lap 1:31.1
- race-prepped wrx STI, SCCA nationals race qualifying (qualified 2nd) - http://www.dpcars.net/misc/sti.run - best lap 1:27.7
- me driving my elise, stock, goodyear street tires - http://www.dpcars.net/misc/dpelise.run - best lap 1:33.4
- for laughs, my stock scion xB, street tires - http://www.dpcars.net/misc/scion.run - best lap 1:44.4


for pacific raceways (formerly seattle international raceway and kent before then):

- me driving the m5, completely stock, street runflat tires - http://www.dpcars.net/misc/m5.run - best lap 1:39.4
- me driving a honda-powered 245hp atom (someone else's car so taking it reasonably easy) - http://www.dpcars.net/misc/dpatompr.run - best lap 1:44.8
- modified 993tt on race tires, driver unknown to me (but supposedly quite experienced) - http://www.dpcars.net/misc/993tt.run - best lap 1:39.0
- modified elise (200 lbs lighter than stock) on AD07 street tires, exp driver - http://www.dpcars.net/misc/elisead07.run - best lap 1:41.8
- me in my mini, stock, bfg kdw2 street tires http://www.dpcars.net/misc/minipr.run - best lap 1:45.9

That`s a lot of carbonfibre mate, hope you don`t like crashing into walls

Quote from Qvarnis :

That`s a lot of carbonfibre mate, hope you don`t like crashing into walls

Uh, and who exacly does like it?
Cool stuff Dennis. If the software is free to try, then I will download and take a look at some of this.
Still have to get a helmet...

Quote from Hallen :

Uh, and who exacly does like it?
Cool stuff Dennis. If the software is free to try, then I will download and take a look at some of this.
Still have to get a helmet...

the software is free to use and it's a full-featured version - guess they hope you'll buy their hardware. i did.

get that helmet, there are lots of good trackdays coming up. alfa 24th, porsche 27th, lotus 3rd, bmw 6th...

Have had a good little play with the logs, and I'm impressed the the DP1. Yes, I can see how gentle you've been on the brakes, yet still carry a lot of corner speed into and out of each curve, giving you a large advantage over the lap compared to the mini and the exige. Once you get braver on the brakes there is probably 5 - 8 seconds to be found there alone, let alone with additional commitment.

It'll be interesting to see how you and the car develop together, so keep posting your logs (either as run file attachments or as screen grabs in your 'blogs').

And I'm getting better at using the software now that I have something I can relate to to play with - random saloons around random Australian tracks were pretty much meaningless to me.

Edit: As for how it handles, what it's like on the power through a turn? Does it remain fairly neutral, or is there a tendency for it to lean into oversteer or understeer? Having watched the videos again (I want your onboard helmet camera!) it seems as though it doesn't require much correcting, but that might have been because you were easing the car a bit. If anything I detected a smidgen of understeer, but it's hard to be sure...

applying power in corners is very easy. it does tend to straighten the line a little but it's not understeer as such as it is not due to front wheels pushing but to the diffs getting partial lock under power. the car is very controllable on the throttle and you can widen or tighten the line with the right foot. of course the production car will have a lot more power so the effect might be greater, but then the center diff setup will be different too. we'll see.

as far as brakes, unfortunately on the prototype i'll always have to be careful with them due to diff-mounted rotors. braking locks the diffs also therefore the car wants to go straight under brakes. in other words, trailbraking is out unless you enjoy spins production car will have more conventional 4-rotor inboard setup.

In a fit of excitement, I've just popped my DL1 datalogger in my car (MX-5 1.6) and gone for a drive down a road Lotus is near to see if it worked properly.

It does.

My peak speed seems to be 91.8mph during this run, and I managed to generate 0.98g of cornering force a few times on the run (bearing in mind I have the worst tyres I could get my hands on to reduce (dry) grip to a minimum for maximum fun!

I'm quite impressed. Currently watching the run in real time, with my speedo and accelerations shown (no other data because it wasn't wired into the car or anything).

In fact, here is my run file if you want to see what I'm on about...

Tristan isn't that a tiny bit incriminating? Seriously I'd not mention where it was from.

Who would have anything to gain from reporting him like that?

It's not like they would find out his name from that po... oh wait.

myself, i'm not a fan of pushing hard on public roads. too many variables, too much risk. these days i try to minimize my street driving/riding although i would have to admit to occasionally breaking rules. it's getting less and less frequent though. just not worth it to me. fortunately the racetrack is convenient and accessible and there is also karting (and now lfs ). but, we all make our own choices.

for what it's worth, there HAVE been real cases of police prosecuting people for driving that they post online or show in videos - most famous was the japan ferrari club president when he started selling a video showing him going at ridiculous speeds in traffic in his f40... chances of it happening in this case are extremely low of course.

I remember that video, 320km/h on the highway.... eek.

after looking at it a bit more, the hethel run is actually a good illustration of why i don't really like street driving. the car is not getting pushed all that hard - max braking is only about 0.5g and most of the time it's around 0.3g max. max lateral g comes at speeds of around 25 mph. and yet the run is quite risky in legal terms (doesn't look like it was dangerous in any normal sense).

the attached pic shows one of the corners. there is some mild deceleration leading up to it (about 0.1g, maybe engine brakng?) from around 44 mph, then a 0.35g stab of the brakes at 34 mph followed by 0.25g decleration down to 25 mph. at this point there is a right-hand turn building qickly to .94g lateral. at the same time there's about 0.1g acceleration into the turn followed by what looks like a mid-turn shift (a dip in longitudinal accel followed almost immediately by a dip in lateral accel, presumably due to lost traction when clutch is let out? - just guessing here).

all this looks like a pretty entertaining street drive but if this were a racetrack the graph would look very different. one could brake much harder and later, carry sustained lateral g at higher speeds and spend a lot more time at full throttle.... makes me grin just talking about it

Yeah, I've had a look at the log of that run too, and I totally agree with it. You can't push a car anywhere near 'the limit' on a public road. I might have achieved 0.98g, and I might have done 90mph for a few seconds, but only where it was safe to do so. The rest of the time (as the log shows) I'm driving within the traffic flow limitation and the legal posted limit. No point braking hard on the road - I actively try and avoid braking if I can and just use the friction in the engine and wheels to slow myself down....

And yes, I'm grinning thinking about it too

LFS is a lot of fun to push the car in - just the thing after spending a couple days swearing at aeroquip hose ends on the atom. now that i'm getting a bit acclimated to it, i've spent about an hour playing with the UF GTR on the south city long circuit. turns out the car can be pitched in and drifted just like my rl mini - and no fear of consequences! it was so much fun i decided to videotape a bit. got it down to 1:53.21 for the long circuit and decided to call it a day.

just got done making the movie (damn autofocus on the camera keeps hunting, just like on rl cars - ugh ) - you can see it at http://www.dpcars.net/lfs1.mpg (warning, it's an 18M file so can take a while)