Quote from Fonnybone :

I loved my Scirocco BTW, it's 1 'r' and 3 'c' .

Reminds me, i had a 'race' with an old 84ish camaro the other day and i
was an even match with my 1988 325ix, thats an inline6 with 170hp btw.
What engine do you camaro guys think he had ? It had a tailpipe on
each side (2 in total) a bit like Mustangs have sometimes.

In 84, the Z28 had the 350 V8 with a Quadra-jet (or Quadra-junk) carbed engine. Due to GM not having a clue how to deal with emissions, it made about 200 hp at 5000 rpm stock. Yea, real POS. :P I think that was before the Camaro started coming with the 2.8 V6 and the RS engine was the 305 carbed engine with something like 160 hp. They didnt start using fuel-injection until about 86 with the Camaros, and then they started making more power again, something like 230 or so.

Funny thing, my 2000 Camaro has the 3800 V6, I've done a lot of modifications and it will run with the older LT1 Z28's and is capable of getting 36 mpg on the highway. Still, my poor old 84 Scirocco is more fun to drive, blown shocks and all. She's not stock though, either. Has headers, full exhaust, no cat, Audi TB with ported intake manifold. Stock factory limited slip and the "4k" close-ratio transmission. I bet it would give my Camaro a run for it's money. I had a couple of guys in a Prelude scratching their heads because they just got spanked stoplight to stoplight in some funny looking old Volkswagen. :P

I'm trying to sell my Camaro, as the VW is going to get all of the attention here soon.

Brendan

Quote from wheel4hummer :

Camaro's handle pretty good! Any FWD car cannot compare with the handling of a Camaro!

LOL what Camaro have you been driving?? My 2000 V6 (which handles better than the V8's just due to less weight over the front axle) is a decent handler, but my VW Scirocco with blown shocks and 175-75-13 tires (and no power steering) could out-handle it without any trouble at all! I could probably drive it one-handed (shifting and all) and do better than I could with both hands on the Camaro. There's a reason why almost all Camaro's end up on the drag strip, that's about all they can do well.

And, I use the locked diff a lot on most of my UFR setups, it helps the car pull out of turns with more throttle and keeps from burning the tires up. I've heard of auto-X and rally Volkswagens that use 85% or more LSD in the front for exactly the same reason.

Brendan

Quote from Slartibartfast :

Did it come around right at 1.10Gs, or after a your foot had been down a while?

Came right around immediately. And notice if I kept the G's a little lower than what the car's maximum was (close to 1.25) which means it should not have a problem accelerating (albeit slowly at 2k in 5th gear) or making the front end wash out due to weight transfer.

I understand the "traction circle" perfectly, but I think there is a problem with what the "traction circle" looks like in LFS, maybe more like a "traction hexagon". :P Also, traction circles for different tire types will look different than others. For example, put some drag slicks on your car and try to run an autocross track with it- probably wont work too well. Likewise, the tires that they use in Nascar probably arent the best for drag racing. Heck, they even have special tires that they use for drifting now a days. illepall

But in thinking about it more, it makes me think that LFS uses a traction circle type of model for the tire dynamics, but really I think having separate models for longitudinal vs. lateral grip might work a little better. I just know that I've had my big brick of a Camaro (which are known to be "tail happy" anyway) with crappy street tires on the edge of lateral traction many times, and pushing the throttle will not snap the car around. In fact, most of the time the car will push understeer a little. I really have to jerk the car hard or use an excessive amount of throttle going into the turn to bring it sideways. Now, if I'm on rain or snow, that is a COMPLETELY different story.....

Brendan

Quote from jtw62074 :

If the weight transfer is actually "wrong," that would most likely be due to a vastly goofy center of gravity height. I doubt very much that's the case with LFS though.

Hmm, I was playing around with the "slickmod" and made the mistake of putting slicks on the UF1000. First turn in FEClub and the car flipped right over! Noticed that the GTI would do the same thing. Does that mean that if I put slicks on my Scirocco it would flip? And I dont even think it's that the slicks have too much grip- I think I saw a max of 1.3G's at the moment of "flippage". I know of a Race-prepped Scirocco with slicks that can turn 1.2 G's in a turn and it doesnt flip. Not the best comparison but it's all I got right now.

On another note, I put slicks on the LX6 and boy what a ride. Also makes me think that the physics on slicks are better than they are on the road tires. I know there was a bit of placebo effect because of the grip but I found that I had a lot more warning when I was getting out of line before it started to slide. Also, I never got into a slide that I couldnt get myself out of. Arent slicks supposed to generally brake free a lot more suddenly than street tires? I dont know because I've never driven anything with slicks before in real life.

So I guess that is another factor to ponder. I just hope there is a GTR LX4 with slicks and some aero parts for S3.

Brendan

Quote from jtw62074 :

And even at the limit, the results aren't really right either. As soon as you hit 0.10-0.15 slip ratio or whatever, you have zero lateral force capacity. This isn't how it works in reality. Sims are harder to drive than real cars in my opinion primarily because of the commonly faulty approach used to model tires.

Yeah, after reading your post a few times it makes sense to me. Logically that really seems like the only way to explain what's going on. I've noticed when driving the LX6 on a track, sometimes I will keep the car in a higher gear until out of the turn before I downshift, but even then, the car could be at oh, -.55 or so lateral G's in a corner, and pushing the throttle even a little in a higher gear will cause the car to snap around.

I've posted the setup that I made here too. Made for left-hand drive, which will even out the camber all around. I've used about 40 different combinations of diffs on this setup on a lot of the tracks, and really the only difference I notice is that when using the locked diff, it helps the car remain stable under braking or trail braking, and it seems like it helps catch the car if you get in a spin, at least for me it does. :P The times I tried the open diff, it just made the car harder to launch and it would still snap oversteer long before the inside rear wheel would spin. Good in theory, but not in LFS world.

Quote from jtw62074 :

I've figured out how to beat this though, and no, I'm not telling

Yeah, I'm curious. Have you released any type of playable demo of that project you are working on yet? The vids looked pretty great.

Now that I think about it, this behaviour of slip ratio limit vs. lateral force capacity does show up in the FWD cars as well but for some reason not as severe. (besides the obvious, when your fronts are slipping at least the car is still pointed in the right general direction) My real life experience tells me when I had a somewhat lightweight, high torque V6 FWD car, when coming out of a turn and flooring it, the wheels would spin some, the car would tend to understeer a little, but for the most part, would still go in the right direction. Only in extreme situations, like snow, would the car just go off in a straight line. But this is what the LFS cars seem to do, even with the slightest amount of wheelspin, the cars will violently at times jerk back and fourth between grip/slip. Now, the good side is that diff settings in the front really make a difference here, unlike the RWD cars. I've noticed too on rally tracks, with a stiff front diff and the right setup, the FWD cars can actually oversteer a little under power in a turn, just like my VW Scirocco does on dirt roads.

So maybe it's not so much weight transfer. Although I know it still feels funny launching the cars, the suspension does not compress as much as I think it should and there is way too much wheelspin going on, FWD or RWD.

Just stating the obvious here, I'm not complaining about the game or whining about anything, I just really enjoy hearing intelligent conversations about what's going on in this game and why it does the things it does.

Brendan

There was some good reading on the "experiments in tire physics" thread, but I wanted to report some testing of my own. I was on the skidpad, basically I removed all of my setups and started over. I did the UFGTR first, since it's probably the car I use the most, and made a really great setup for it. Ok, on to a RWD car, better start easy, used the LX4. So I make a "baseline" setup, and take it for a spin on the skidpad. Basically I was heating up the tires evenly, (burnouts, full front wheel lock, etc..) then going around in a circle to see what happens and measure my max sustained G's around the turn. When I noticed something strange. I held the car at about 1.25 G's or so, then pushed on the gas just a little more and the car did a 180 on me. Hmm. Did the same thing again, only this time in 5th gear (somewhere around 2000 rpms) at about 40 mph, held at 1.10 or so G's, then pushed on the throttle again. Once again, around she came. What the heck? I know the car doesnt have enough power at 2000 rpms in 5th to spin the wheels. I did the same test with the same setup, and used about 20 different diff settings, all with identical results. Ok, time to switch cars. Used the XRG non turbo, surely it is low power enough, it barely spins the wheels in 1st!! Did the same basic test, got it near 1.0 G's, put it in 5th, pushed on the gas, around it came. I think this is what makes the RWD cars so tricky to drive. Really I think the tire physics are done quite well. In the FWD cars, they do feel pretty darn good, especially the RB4, it feels great. On dirt too, the tires feel quite good- maybe a little too "slippy"- almost like wet grass than gravel, but the car reacts the way it should. This makes me think that the tire physics are quite close, but it's the weight transfer that is off.

I ended up running a new PB at a few tracks with the LX6 with a new setup. And suprisingly enough, it has 0 front swaybar and about 10 rear swaybar. I found that the front end will not turn as long as the rears have traction until I took the swaybar setting WAY down. Diff settings didnt matter a whole lot either. Now, the setup is a bit twitchy, but I can actually hold the car in a semi-drift if it gets too loose instead of snapping around like usual. Only problem now, the fronts will not heat up. This setup follows most of my standard setup rules in real life, keep the lower control arms slightly above parallel with the ground and run stiff enough springs to keep them that way. My new UFR setup is done the same way, zero front bar, and only about 15 rear but VERY stiff springs. Seems to work for me as I beat my BL1 PB by about 1.5 seconds by the third lap.


Anyhow, try out these experiments for yourselves- I think the weight transfer is what is causing the RWD cars so much grief. Sure, the tire physics arent perfect but I think they are a lot better than most people give them credit for.

Brendan

Say what?? Well, the TDI is a 1.9 and is quite old technology. The head design is pretty much the same as all of VW's older IDI diesels from the 80's. Direct injection is nothing new, but I guess you could call the fancy computer controls "new technology". And you think the 1.8T is old?? Name another 4-cylinder car with 20 valves and progressive-intake timing?? I worked for VW for two years, I dont think you are going to sneak any VW facts past me.

Point is, every car in the world is compared to every car in the world. Sure, some might have advantages in other areas, but why do you think Honda Civics race Camaros on the drag strip? Not the smartest idea for the Honda driver but I've seen a few Civics beat Camaros. (my Camaro, for example)

I know a rally team here in the states that races a tuned TDI FWD Golf. They are competing in classes with SRT4 Neons, and Mitsu EVO's, and a few others, some turbo, some AWD, and they are winning many events. Some would say that there is no chance against the EVO but they are making it work somehow.

Brendan

Quote from AlfaLover :

Off course, 2 reasons because Golf 150 bhp Diesel is faster than Petrol One,

1- Diesel has Turbocharged, try petrol unit with a turbocharger mmm more than 200 bhp easy , is not at same level of technology.

2- At city and daily use the planar torque curve of a diesel is more easy to take it power than a petrol one, that you need to move engine to rev high to take all its power.

I think introduce diesel cars in lfs is not logical.

Well, 1, the 150 bhp golf IS TURBO, the 1.8t to be exact. It did come in a 150hp version. Actually, the 150PD diesel "TDI-GTI" is faster than the 180 hp GTI if I remember correctly.

And 2nd, Diesels can rev to 6000 rpm + if tuned properly. The 1.8T, even modified, doesnt do much past 6000 rpm.

Diesels have been showing up in various forms of motorsports lately and are VERY competitive. Also, the fuel economy savings over a long race really play into the strategy and make for some interesting results.

I say go for it.

Brendan

Hell yeah, add a diesel car! I'm all for it. Probaby strange to hear from someone in the States, but I'm a big diesel head. Back in S1 days, I used LFSTweak to "create" a TDI-style engine for the XF, with a very similar power curve. It was a blast to drive! Lots of shortshifting and powering out of turns with torque.

And to counter the Diesel vs. petrol argument, I've seen Naturally-Aspirated Diesels make more hp than a similar size Petrol engine. A VW Rabbit with a 1.5 N/A diesel with a modified injection pump made about 77 crank hp, when it started with 53. Still had stock exhaust, intake, manifolds, etc... and it makes power all the way up to 6000 rpm. Compare the hp/torque curves to a 1.5 petrol engine, and the diesel will win with total "area under the curve" which is what counts.

For a final kick in the pants to you petrol heads, check out this truck that Gail Banks is making- a truck to compete in 24-hour road racing!!!!!

http://www.bankspower.com/DmaxTypeR.cfm

Diesels rule. Imagine a monster like that truck in LFS against the GTR cars. Hehe.

Brendan