Proton Persil: v1.2 available 2008-12-05

Tomte wrote:no loadsens,

it's back in D2...which was called D1 in carname, just changed that... just did 2:20 at Rocky Pass, not sure how that compares.
I may need to re-examine the xbow now, I'm suspicious of myself.

I dont want to debate reality with the much brighter people than I working on this but.....

081127 D2 rides like its on a sheet of ice for me. It skids in curves at at 60 mph.... certainly that cant be right?

DANDY wrote:

Tomte wrote:no loadsens,

it's back in D2...which was called D1 in carname, just changed that... just did 2:20 at Rocky Pass, not sure how that compares.
I may need to re-examine the xbow now, I'm suspicious of myself.

I just had some sweet rides with what I tought was a rear loadsens on -0.07 on one of my versions... it turned out to be -0.7.... I guess I ned to back off that a bit
I think a RP time of 2:10 or there abouts is ok for the KTM, given how quick other cars are ont this track. 2:20 is definitely slow.
Come to think of it, 2:15 on Mountainside is a good time as well, faster than say Don's early saloons, 911 (I think), M Coupe, but not as fast as the really quick supercars.

Tomte wrote:Do you think this car produces any kind of lift to speak about? The air should go straight through it

Where there's turbulence, there's suction. The direction of the vector is yet to be determined, though. If anyone has a toy model of this car: Please put the car on your floor, position a fan in front of it, light a match and record a video of how the smoke moves around the car's body. We need that data!

Last one....2:12.8 fear-restricted@Rocky Pass
Changed suspension, heaped on the loadsensitivity, weighted the wheels, minor adjustments here and there...probably as far as I can push it. Throttle control is key.

I did not follow all development steps, to be honest...

For me the car is much more difficult than the one Tomte originally released. I understand that this was intended and we might have a comparabla class with the xbow now.
The 20081128D1 version needs much attention but is controllable. I like it - but its not easy anymore.

would need to do some timed tests, but won't do that right now...
for me a release i can find fun with...

alphonse

Dandy wrote:3. Based on LOA, I have -0.21142 at 38/62

I honestly think that the CoG position in your .car files is off. I'm certain that the CoG is dependant on where the model is placed in the 3D environment. As the wheel position is taken from the model in it's specific cordinate system, the CoG needs to adhere to that system.
That means in this case: in the old model, the one you are using, the front axle is at 0.93 and the rear at -1.41 (or there abouts). Therefore, the 50% mark is at -0.24. You placed the CoG to -0.21, which would mean a forward weight distribution of 51.5/48.9.
According to this topic, the weight distribution will be based on the axle positions in the .car.
The tread also sais that as long as CoG, wheel position and collision boxes are set accordingly, the model could also be places some 1000m out in Z direction without changing the handling.
This of course should also include the intertia calculations.

I will continue to use the replaced model

Code:


model "ArielAtom_Frame_v1.2.mdl"
interiorModel "ArielAtom_Interior_v1.2.mdl"
shadowModel "ArielAtom_Shadow_v1.2.mdl"
driverPos {-0.287, 0.34, -0.20}


with all the Z coordinated adjusted accordingly (even the lights). This is already done since 081127b. I wouldn't know why except for the changed inertias, but the Atom does feel different and a tad easier to handle.

There was the undrivable 081127 D1 I think
and now the modified 081127 D

This is almost as hard as the 911 ! With this build I cant do anything under 1.03 on HSL. The car feels ok but it seems as if it's always hitting a patch of oil on the road. Real slippery, I even managed to lose the back end simply by full throttle in third gear?

Dont know what to say but ... it's really hard to drive now. Same comment as before, at speeds of 60 MPH, does not seem it should be so slippery unless it's rainning.

SF

First things first: I have to thank Dandy, who spend quite some time trying to find a setup for the Atom. I really appreciate that (even if we differ on some points).

After a week of fiddling and trying, I could not get the 'no swaybar' option to work without some serious amount of loadsensitivity (>0.3). Even with that, the car just didn't feel right or interesting or fun to drive.
So, with a heavy heart I went back to the 'with swaybar' option. For me, it appears to be the lesser cheat with improved feel and understanding of the car. Call me weak...

Anyway, here's my last attempt. If I don't hear anything negative (which I can't discuss away ), I'd like to release that as v1.2. In any case, if one of you finds a setting that works on most tracks, I'm happy to incorporate it.

Dandy, I think the KTM is fine as it is, I don't see a need to change it . The way it handles is believable, the brakes are astonishing, but there is nothing wrong with that.

Atom 081204

Tomte wrote:I'm certain that the CoG is dependant on where the model is placed in the 3D environment. As the wheel position is taken from the model in it's specific cordinate system, the CoG needs to adhere to that system.

Isn't everything relative to the origin of the 3D model?

NoNameBrand wrote:Isn't everything relative to the origin of the 3D model?

Yes it is. I was just discussing the position of the CoG in one of Dandy's .car files.

081204;
This version is fun to drive but is pretty tough. Feels right on the edge... pretty safe.. and bam... spin out of control
It's not slippery like one of D's .car mods. Feels more like suspension making it tough. There is on twist on black forest, in the cliffs, that I spin out 7 out of ten times if I try to get top speed. I really have to slow down and the only thing that seems to happen different then otherc curves is there is a drop in the road.

Going uphill on limerock is also quite tricky... harder than downhill

I think it's a good match, will do better than Xbow on certain tracks, flatter ones. Just as Radical will do best on real flat tracks but will be damn hard on tracks like black.

Best time I got on Black was 2.34.94

I cant tell anymore when you guys are happy with your work or not.

RP in 2:08'58 in 3 laps. Well, surely is the better then old version. This new build approaching the hardest parts of the track with a sensible high speed. She has behavior and is not flat. She need to be drove carefully. Yes, I like it.

The latest version is much more like version 1.0 in its handling, which means that I like it.

The oversteer/understeer behavior seems to solely depend upon if the weight transfer is to the front (braking into a corner) or to the rear (accellerating out of a corner). I don't know if that's the definition of a perfectly balanced car, or if it's an indication that one variable may be out of proportion in the .car file. You seem to have tried very many approaches, so I think it's best to leave things as they are now that they work OK.

In both my incarnations of the Top Gear Test Track, I get times between 1:17 and 1:18.5 - Not the 1:19.5 of the Ariel Atom 2 300 driven by The Stig. First of all, you shouldn't trust that I've been completely accurate in my measurements and track layouts. Second, most Redline plug-in cars are much faster than their real life comparisons, sometimes as much as 10% faster. I take your 3% faster as a sign that you're within the right range.

Since I think this car handles well, if you are to do any performance adjustments compared to other similar Redline cars, then only do so by changing the mass and changing the body's rotational inertia. That's probably the most consistent way to do it, just like how FIA uses their weight penalty system to balance the field.

Thanks a lot for all your replies.

@SeeFlat: your assertion sounds reasonable. It's a mid-rear engined car, which will be tricky and bite your head off when you try too hard. Once the rear end loses grip, you will be hard pressed to control it with opposite lock.
There are certainly tracks where it has a hard time to match the speed of the X-Bow, especially everything with sudden elevation changes.

@DonaemouS: 2:08 is astonishing, I never manage below 2:13 on Rocky Pass. There is only a very narrow path at WALT and the following turn, despite that the road is so wide there. You really need to know what you're doing (which you do).

@C14ru5. The Atom is far from perfectly balanced. I mean, with the engine that far in the back and not much weight, I wonder how they get the car to work in real life in first place.
I read somewhere that the Atom 2 with the singular springs at each end was sometimes tricky to figure out. One did not know if the Atom would understeer or oversteer in the next moment. In this aspect, my car is easier to read and understand.
When the rear wheels get light under braking, the back wants to come around. When you accelerate and take load off the front tires, it understeers. Powerslides are hard to do or impossible, only as a reaction of sudden load transfer.
All that reminds me of the M Coupe... I agree that a way to adjust the speed/competitiveness would be to adjust the weight.

Anyway, I'm happy with what I have now. A bit more throttle response in corners (off-throttle/trailing) would be nice, but that might get in the way of keyboard players.

Expect the release soon.

Oh, one more thing: I hope that the KTM won't change! From what I read it is easy, somehow unspectacular to drive compared to the Atom or Caterham et al. I think this is what we have with the current car. The tests I read compared the KTM with the 300 hp version of the Atom, which is faster than what we have. That's why I made the 245 in the first place.

Ok, I hope this one sticks.
Compared to last night, I changed nothing in the .car apart from some housekeeping.
Version 1.2 is now up at Legacy:
Ariel Atom v1.2

i just get a lap on monaco and Atom. If you hit the pool right turn kerb, the car flip on herself...

well well, I finally worked on the Atom again.

What always bugged me about the setup was the always present understeer. The front was just not responsive enough, the rear too stable.

I hope I have changed that somehow with the current beta. The front should bite just a little bit better with the rear being a tad more loose. I hope it's also a bit less distubed by curbs, but I'm not too certain about that.

Still, the 1.3 beta doesn't like all the tracks, Watkins is tricky at places.

I'd like to have some comments especially from keyboard players, as I've set up this version mainly on the wheel. I think the Atom reponds quite well to stabilizing corner entry with the throttle, but I found that downshifting at corner entry is deadly, as can be downshifts in mid corner.
This is probably due to the raised rear wheel friction.

Finally, Ariel Atom v1.3b.car.zip

Don't shout, and not all at the same time...

Gawd,

NOISE IN HERE!

i downloaded the testversion but forgot to test it.
will do that this evening and hopefully feedback you then...

alf