Quote from qwejibo :

Weight transfer is created by lateral + longitudinal forces generated by the tyres. The only factors in the equation are the cars weight, CoG height and track/wheelbase.

Yeah, well, for some rather obvious reasons that isn't completely true. Big hint: The centroids don't stay in the same place as the car rolls. My previous hint about drag cars should have made that rather obvious. Soft springs don't just help the launch, they help the whole run down the track compared to a vehicle with a similar static rideheight and stiff springs.

Also, there being antiroll linkages, weight transfer is affected by another set of forces. Importantly, I'm talking about weight transfer between the left and right tires. Other frames of reference are pointless.

Quote :

What is affected is how long it takes for the weight transfer to occur. 100% rigid suspension will transfer the weight instantaneously - OTOH, soft suspensions take time to move to their new position. This is why stiff suspensions feel more responsive, because the car will react more quickly to weight transfers.

This is all well understood.

Quote :

You state that "Stiffer springs result in less weight transfer" - if this is true, then to increase the grip of the front end of a car during cornering, would I stiffen the front springs?

Only if you could subsequently stiffen the rear springs in a rather equal proportion.

The fastest car will have the stiffest suspension system that can still manage the bumps in the road. This is why third spring systems exist.

This particular misconception of yours is completely off topic anyways. Importantly, anti-roll-bars INCREASE weight transfer.

Quote from qwejibo :

Generally, I don't think that body roll has any effect on weight transfer - a car with 100% rigid suspension(thus no body roll at all) would still transfer the same weight as one with soft springs + bars. You could test this in LFS by driving in circles at the same speed/G load with both soft + stiff suspensions, weight transfer (from one side to the other) should be identical.

Quote from Bob :

They do indeed connect together the wheels from one axle, and offer resistance to the wheels moving apart, reducing body roll (and the subsequent weight transfer).

This is not true. I highly suggest you read a layman's treatise on the physics of this. Tune to Win by Carroll Smith is old but very good.

Hint: If what you said were true, two vehicles with similar ride heights would have similar drag strip performance with any spring setup. Clearly not the case.

Stiffer springs result in less weight transfer. Outside of considerations in dynamic camber control, softer antiroll linkages are better.

To be clear, increasing the stiffness of the anti-roll linkage INCREASES weight transfer. Tire adhesion available is not linearly related to the vertical component of force on the tire (twice the force doesn't result in twice the grip), so less weight transfer is always better.

Quote from Bob Smith :

As described, I can't see how an anti-roll bar could be attached to a non-independant suspension system (solid rear axle for example) and still be of any use.

As Fonnybone pointed out, antiroll linkages were developed for and remain more necessary on live axles.

My Wrangler comes stock with a 30.5mm front ARB. It needs it. It breaks the endlinks every couple of years.

Quote from Gabelhirsch :

I doubt that the cold engine can be turn up to 10000 rpm and will stay undamaged. temperature control of the engine is missing in the game. It'd be interesting to see overheating engine and their failure as a result of it. Also some gearbox failure is missing as a result of bad way of driveing or car accidents.

and sorry for my english

Excellent points. Particularly on gearbox failure. Many series tend to have more retirements from gearbox failure than engine failure. Someone mentioned recently that once an engine starts to overheat you rarely see the car last the rest of the race, despite whatever actions are taken to remedy the situation. Without getting too technical, this is because of something called Departure from Nucleatic Boiling. It rapidly makes matters worse.

Also, your English is notably better than that of many posters on a car forum I frequent. They are native speakers. I wish I could write in my second language as well as you do.

Quote from Gunn :

To add such measures for spectator appeal is really sad. With push to pass, overtaking becomes just a ritual. I want to see them earn their positions, I want to know the true winner.

:tup:

Great set of posts.

Montoya past Schumacher last year at Spa still remains in my mind one of the best passes I've seen in a long time. If he did it with "push to pass", he would have done it on a straight, or somewhere similarly boring.

Quote from Cue-Ball :

And how many cars do you know of that use a fuel cut-off as a rev limiter? I can think of none. Every factory rev limiter i've ever seen was spark cut-off. You slow down the engine and prevent over-revving by preventing the fuel from igniting, not by leaning out the engine. Cutting off fuel and still trying to fire the cylinder would be begging for detonation. I hope no modern car manufacturer is that stupid.

I can think of more than a few from the last 25 years. Some were even turbocharged. Bad combo. In the last 5 years, practically none. The reason for a fuel-cut instead of a spark cut is simple. Its cheaper.

Quote :

Now, i'm not going to go out and bury the needle while in neutral, but I've driven a lot of cars and bikes over the years and they have all been redlined daily.

Maybe you should learn how to shift. Running the motor up against the limiter is slow, makes you look like an idiot, and makes guessing what the car/bike is going to handle like a wee bit hard. I get a real kick out of the squids that ride their bikes to the revlimiter in first next to me on public roads. Apparently thats the only way they can bring the wheel down reliably.

Note that there is a huge difference between revving the motor past the line on the tach, and revving the motor into the limiter.

Quote :

I've never blown up an engine. Never thrown a rod. Never bent a valve, punctured a block, cracked a rocker, etc. Not once.

The only possibilities here are:
-You don't like screwing with motors
-You've never driven anything seriously powerful, or highly tuned

I've seen rods break themselves in grocery getter motors that were abused. More commonly I've seen rod-bearings fail.

I've personally windowed a block by running the thing near redline up a canyon at 120mph....daily. #6 rod gave up, probably after the bearing did.

Quote :

The chances of breaking an engine by momentarily going deep into the red zone is very, very small.

Bullshit. Particularly when talking about real race engines a la LFS, not the apparent grocery-getters you've had experience with. 1000-2000 rpms over the line is more than enough to "test the strength of the oil pan" on more than a few designs.

Its all a bit different if your only experience is with motors put in consumer products like road cars and bikes. The windowed block above was running at about 7300rpms in fourth gear at the time it failed. Stock "redline" is at 7000 rpms, but the fuel cut is at 7500, which actually shows on the tach as about 8000.

Car companies aren't stupid. They aren't going to place the redline at the limit on your typical grocery getter.

This is not the same as where the engine builder places the sparkcut on the motor in say, an "FV8" motor, where the driver can be reasonably expected to know how to shift and drive. The redline will be placed at the very limit of safety and durability. Indeed, failures will occur with only minor excursions past the limit.

Some incredibly high-profile examples of engine failure from minor excursions near/at the redline exist. I suggest you educate yourself as to the situation BMW ran into when the E46 M3 motor decided to start eating rod-bearings and throwing rods.

http://members.roadfly.com/jason/m3engines.htm

They've issued at least two campaigns to deal with this, and the problems came down to poor tolerancing in the oilpump, underspecified or poorly manufactured rod bearings, and a design NEAR THE LIMITS of reliability in the high RPM range.

Check out how high the maximum piston accelerations are for those beasts. Fifteen years ago (as in, when most of the grocery getters you've driven were probably engineered), engineering literature would have claimed such a motor was not feasible for production. Apparently, its marginally feasible.

Quote :

I think that LFS needs better engine damage modeling, but it definitely does not need engine damage caused by hitting red line for a few seconds during a race. Instead, I'd say we need to model overheating, damage due to physical contact, etc.

All of those aspects are being worked on. I assume the temp. gauge isn't just permanently there for looks.

Engine damage should reflect reality. In reality, overrevving a race motor will tend to kill it, with a few exceptions. Those exceptions are often classes in which the engine's induction is the limiting factor, and therefore bottom ends/valvetrains tend to be quite reliable. MRT5 comes to mind. Note that the appropriately placed redline is far beyond the powerband.

Last edited by skiingman, Sat 1 Oct 2005, 01:41.

Quote from XCNuse :

er... you might want to reread about it then, because it was in fact made exactly for that reason and for strategy..

What are you talking about?

The sole reason it exists is to artificially increase the number of times overtaking occurs.

Quote from Fonnybone :

You can't
deny the fact that things cost money and that you need people to pay
for that. Publicity/sponsoring is one of the most used way to get money
in racing. The cars themselves are a shame to any tree-hugging anti-
globalization hippie. Covered in stickers from various companies, who's
only intend is to 1-get attention to 2-eventually make more money.

Fine. They can do all this without changing it from "racing" to "spectacle".

Quote :

Now, considering YOU are the spectator, can you at least appreciate the
fact that someone actually cares about you enough to find ways to make
it more enjoyable for you ? We can contest the validity of 'enjoyable', but
not it's intentions.

No, I don't appreciate it. None of these spectacles are designed to be interesting to race fans. They are designed to be interesting to people NOT INTERESTED IN WATCHING A REAL RACE.

The financial issues involved aren't my problem. When men were men, no one complained about the race team being a money loser. Now some series have teams that EXPECT to profit. Silly. Winners should profit...losers should lose. Cost of racing.

Quote :

As much as 'Push-2-Pass' sounds ricey to me and scares the conservative
geezer in me, i find all arguments valid and have a hard time finding fault in
something meant to increase the strategic side of racing.

Strategic side?

As in, NASCAR "strategically" guaranteeing you are given an entire free lap on the competition so the race can be artificially closer? Bullshit.

Strategy is ensuring you don't end up a lap down in the first place.

Quote :

What IS racing?

A contest of speed betwen vehicles innovatively built to a common standard. With a minimum of rules to interfere with the contest to see who finishes first.

Quote :

All i know, is it sure
seems to depend on your perspective.

I disagree. I think pure racing is inherently simple. Run around the track without going off, attempt to pass the white line before the other guy. Complexities abound when the road is wet (GASP! Racing in the wet? Southerners...er...NASCAR drivers can't do that!) or the car needs repair, fuel, adjustments, whatever.

Race fans enjoy racing. Promoters are not happy with just "race fans", they want to put on a spectacle to attract more people. How popular is real wrestling? How popular is "pro" wrestling?

NASCAR, CART, IRL, et. al. are all forms of "pro" racing, where the fans often don't acknowledge they aren't seeing the genuine article.

Very, very sad.

I do think its a sport where men are men and I hope there isn't an overreaction for safety either.

The spectator accidents are largely up to the spectators....I guarantee most of them were someplace they shouldn't have been.

Quote from bobvanvliet :

I don't really agree with that. First of all, more overtaking also produces more exciting racing imho, not just better watching. Secondly and more importantly, it adds a tactical element I think could be fun. This button will not magically teleport you in front of the car in front of you, it requires skill to use (and can be countered with skill by the defending driver).

Do you ever run KY Oval in the FV8?

The massive drafting effect is similar to "push to pass" and it encourages blocking and otherwise unclean racing. Its fun...for about 20 minutes. It would be much more interesting if that effect was more realistic IMO.

Maybe I don't join the uber-cool servers, but in the Formula cars I'm rarely involved in a race that's close enough for such a concept to make a difference anyhow. As noted, the massive drafting effect already serves the same purpose of what you are talking about, and I'm kind of annoyed by it.

Quote :

... would increase LFS' ability to recreate as many forms of RL racing as possible. I don't really see what can be wrong with that.

I don't agree that those "real life" classes are actually exhibiting racing, I believe they are mere shows put on to draw crowds and make money. Real racing tends to be more expensive.

Quote from Fonnybone :

Ok, let me turn my intelligent discussion meter down a few notches here.
There's no need to throw out the baby with the bath water. YOU are the
one saying we should throw out the setups, don't dumb this down.

By implying that performance altering settings changes put people at a disadvantage, one is also implying that the existing settings that do such are likewise a disadvantage to those who don't care to understand.

I'm glad it is that way. Keeps the kids away.

Quote :

This comment is as unintelligent as the message it tries to express.
Please don't be a d!k by insulting whole continents for no reason.

Perhaps you could drop your self importance for a moment and notice my location. Yup. Right here in uhmerryca.

Quote :

The fact that some american racing chose to respect the fans, a concept
F1 has obviously no clue of, and offer them a closer more personal feel
is something that has no relation with this post imo. No oil on the fire please.

"Respecting the fans" is a pleasant way of stating "sham showboat racing" and hardcore racing fans will never appreciate it.

Being that I am forced to endure hours of NASCAR coverage on Speed each week, I find it rather annoying when guys like XCNuse show up and no longer have the capability to comprehend racing in an unmolested format.

Since the majority of LFS patrons are likely bigtime race fans, and a majority are not from North America, I highly doubt anyone thinks a "green white checker" finish is appropriate for LFS. "Push to pass" is inappropriate for similar reasons. It has nothing to do with racing, and everything to do with selling television coverage.

Quote :

There's no setup for it, it just works. Hey, if you want a
button with 'HiPower FuelMap', THEN we'd have something to compare with

If the car simulated should have the capability to change maps on the fly, then an implementation should consider that.

Quote :

Why are you taking any of this personally anyways ?!.

I'm not taking it personally. I just vehemently oppose turning LFS into an arcade game, or a simulation of "racing" in the modern North American tradition, which isn't racing at all.

Call me crazy, but I had a lot more fun watching the Canadian GP last summer than I did watching the NASCAR "race" at the Glen. I'd rather see a contest of unmitigated racing than a show of fancy rules leading to "close" racing. I'd prefer my simulation approximates the former, as I'm sure much of the rest of the world does as well.

Quote from XCNuse :

i have same opinion on this with the cam adjustment.. small or large... i still think its an unadvantage for people that have no idea what they are doing

An unadvantage? WTF is that?

People that have no idea can use the stock map, or cherrypick one off of someone else.

Perhaps you think we should drop setups completely, because they give those without a knowledge of chassis dynamics an "unadvantage"?

Quote :

plus.. i dont think it would matter, cause on long distances.. im sure there would be required pitstops anyway, so you'd have to pit .. anyway..

You've obviously been rendered clueless by watching American forms of "racing" that artificially level the field.

In real racing, pitstops aren't required by rule, but by circumstance. If you burn less fuel, you spend less time fueling in the pit, spend more time driving around the track with a lighter car, wear out your tires at a slower pace, or any combination of the above.

Even if a stop is required, the comments about carrying less around for faster laptimes and less tirewear are still valid.

Bizarrely, you think "push to pass" is a good idea, which is just another way of changing the amount of fuel the motor burns and produces energy with.

Its exactly the same concept, except "push to pass" doesn't require any knowledge at all, and only makes sense for turbocharged vehicles that can make loads more power for a short period, something not generally possible in NA applications.

Quote from XCNuse :

okay.. well if you dont know what this is, its in the champ car racing series here in the US.

Stupid idea.

Driving faster will get you a lot more.

Its something for good spectating, not good racing. Silly, silly.

Last edited by skiingman, Wed 28 Sep 2005, 06:35.

Quote from Cue-Ball :

This has been discussed a few times. I never played S1 but it's not realistic at all for engine damage to occur simply by hitting redline on the tach. If that were the case my car's engine would have been blown up many years ago and several thousand times over.

Depends on the vehicle and the method of imposing the rev-limit.

Run a turbocharged car up against a factory-like fuel cut rev limit and you will put a hole in a piston eventually, sooner rather than later with big boost.

I love how the idle is 9k....


I also love how current F1 cars sound like they will explode at any moment when the traction control is working overtime and the foot is to the floor in a increasing radius turn out of a slow corner. Some driver/car combos feather the throttle there, others just mash it and let traction contol do its work. The sound is like nothing I've ever heard from an internal combustion engine.

Watching it on TV just doesn't do it justice...the mics are all in front of the exhaust. Its mindblowing in person. I'm going to try and hit both the Canadian and US GP this year...didn't last summer, but I guess I'm glad I missed the US GP lol.

Quote from tristancliffe :

and cam timing are set at 'optimum' values before the engine is run on track (unless the engine builder was an idiot (most of them) in which case you see people fiddling in the paddock).

Untrue. Changing cam timing without changing cam profile will effect the character of the engine, and may be a way to gain an advantage at X track if the same cam profile is mandated for the entire season. At some tracks, area under the torque curve will be more important than peak numbers, and vice versa.

Quote :

The only worthwhile change to adjust performance would be to change the cam profiles, but thats a big change, and tends to require a bit of an engine strip down.

I guess it depends on your idea of worthwhile. I've seen parameters as seemingly "not worthwhile" as valve lash adjusted to take maximum advantage of X rule mandated valvetrain. Tradeoff component life for a wee bit of extra torque at a certain critical point.

Quote :

Either way, I think LFS would benefit by NOT having adjustable cams or ignition timing.

And I think LFS would benefit by having realistic setup values. i.e., you can't miraculously remove the sway bar in the cockpit and subsequently add it again with near infinite stiffness.

I think the gear ratios chosen ought to approximate the available ratios for real world gearboxes...or at least not be infinite. If you put a 1.6:1 final drive in the puppy, you should be prepared to have a lower MTBF than the guy with the 2.77.

I find it bizarre that people enjoy and want the ability to screw around with every aspect of the car in a decidedly non-realistic fashion EXCEPT for the engine.

It might make things interesting if the XF had to decide if the race at WE Int'l was worth throwing that peaky 292 cam in that they wouldn't want to bog out of T1 at BLGP with.

Right now we're given a car, and an almost infinite selection of suspension components to play around with and adjust to be optimal at a given track. While an optimal BLGP setup for an XF will be fast anywhere, it won't be as fast at FE Club as a setup optimized for FE Club.

Whats wrong with allowing the same infinite number of choices for tuning the engine? Like suspension components, everything is a tradeoff. A 1.6 liter DOHC four banger isn't going to magically make mucho power if I can suddenly adjust silly little things like cam timing and fuel mapping. Just think....I could have an endurance map and a sprint map.

If some person doesn't want to have to adjust those things, they can just use the known good default setup, or cherrypick a setup off of someone who put the work in...just like they do now.

Quote from Bob Smith :

While I would enjoy tinkering, there is at least some benefit to knowing the straight line performance of all the cars is always identical. This isn't an engineering sim after all.

That logic baffles me.

It seems to suggest that allowing for any setup changes is a disadvantage. Allowing the user to select from an INFINITE set of gear ratios, for instance, is very much engineering simulation...not race car at the track simulation.

If I can vary the anti-roll at both ends from zero to "solid axle conversion kit" while driving, why is it ridiculous to be able to tweak realistically adjustable parameters like cam timing in the pits?

Not that I particularly care if engines ever become adjustable...I just think your logic is a bit off.

The people complaining about "having a disadvantage for not being in the know" similarly baffle me. Putting together a driveable and optimal setup for a given track/car is no easy task, and requires a plethora of knowledge and careful testing.

If X user doesn't know what tradeoff he could make by adjusting cam timing for KY Oval vs. SO sprint, X user probably doesn't put together his own setups anyways.

Quote from tristancliffe :

Left and Right arrows.

Well then, what is special about my keyboard that this won't work?

I know it needs to be in multiplayer.....although that does seem dumb, I do know that.

Compaq R4000...

Stupid n00b question likely:

I can bring up the live settings and pit settings menus, I can even scroll between the different lines with the arrow keys.

I can't find out which key is bound to actually incrementing/decrementing the settings. I've done this before on my PC, don't remember it being difficult. Now I'm using a Compaq R4000 notebook.

Thanks