That's why its worth the bother to tweak the cars until they are reasonably balanced. Being an excellent sim that LFS strives to be, realism should always be the first priority, so cars of the same class but radically different drivetrains should NEVER be too equal. Its LFS, not NASCAR after all. The same arguments I lend to the turbo road cars apply here. To be realistically fair, XRT shuld have a SLIGHT overall edge on tarmac whilst the FF should have the edge on mixed surfaces (Rallycross) to show the stability benefits of FWD.

Absolute equality won't bring better racing. It'll just degenerate to boredom and mediocrity in the end. Why master RWD and FWD if both their strengths don't shine through?

Honestly, none of those 2 are anywhere fast enough to challenge the turbo road cars, so that is a relative non-issue. The gap between a the LX6 and GTR cars to the TBO cars is still massive, so is again a non-issue. There is no danger of a clash bertween the classes at all at this point. If i remember correctly, the XF lost a massive 10hp. Another overcompensation indeed. Don't make the XF ridiculously fast. Just fast enough to have some decent fun. The XR just feels too lazy at the moment, so a slight speedup wouldn't threaten the proper order of things. I believed we would be much closer to ideal balance if the XF power was adjusted in smaller increments (say 5hp) instead of the almost 10%. Don't worry, those 2 aren't anywhere near the turbo cars.

As for XRT and RB4, a 250hp Rb4 and 260hp XRT would't come close to the LX6 interms of sheer laptime anyway.

Guys, I happen to a BIG fan of our favourite racing sim and I must sincerely disagree with this idea of needless exclusivity.

One of LFS's chief strengths is its accesibility, which goes a LONG way to explain why it has such a large long term following despite of its unfinished state and LONG development. I couldn't care less if you're a demo or fully licnesed racer. As long as one has something useful to say, one should not be barred by any artificial restrictions.

Besides, this gives the demo racers an excellent idea of what they're missing from the lack of a full license. Last thing we need is to lose potential LFS licnese sales due to inaccessibility of game information.

This openness of the LFS forum is an example for all other developers wishing to become the ultimate PC racing sim title that LFS aims to achieve. Last thing we need is to lose our chief strength against those monolithic corporate glorifications of mediocrity (NFS:U being the prime example).

No, we do not have a need for speed. We LIVE FOR SPEED.

I've just emailed the deveopers about my ideas on power band and tire size(grip) enhancements for the RB4 and XRT. However, I suggested that the FXO ramains as it to avoid the same downward fate of the XF, which is now depowered to a pig like level of slowness. I miss the exciting to drive XF from the older vesions of LFS2 alpha. If any more performance issues occur, we can simply tweak the performance parameters of the XRT and RB4 until the proper balance for the TBO class is reached. We've not even reached beta, so this shouldn't be a real problem. Hopefully, they'll tweak the balnce to near perfection once S2 is finished. If left untouched, things would simply remain as they are.

I'll try to simplify what should be the order of things for the TBO class. The RB4 should be approximately 0.5 second faster per minute on average than the FXO. It should dominate the rallycross to accurately depict 4WD superiority for rally events.

The XRT should be approximately 0.3-0.4 second faster per lap than RB4 on average, with slightly graeter advantage for the higher speed tracks to accurately show the suitability of RWD for high speed circuits. Its lower weight and lesser drivetrain losses should be displayed with its dominance of high speed tracks. However, for shorter and more technical circuits, the RB4 should have a slight edge (0.2-0.3 seconds faster as a rough guide). This showcases the differing advantages and disadvantages of both layouts.

The FXO is already unusually devoid of typical FWD problems such as excessive front tire wear, so its not too disfranchised. The relative ease to drive it consistantly fast should make up for its slightly slower ultimate performance, especially for endurance races.

Please post some valid comments and opinions about this. I thank anyone who posts a serious and reasonable opinion on this.

I said this before, though more clearification would be nice.

What I wish to attain with the RB4 is more realistic power curve, not PEAK power. No, I do not wish for 300+bhp. I'm only asking for a realistic power curve. As I've suggested earlier, something along the lines of 320nm@3500 and 250bhp@6500 with a 7500rpm rev limit would be close to the ideal compromise. And unless significant improvements to peak power are made (say to 320bhp!), top speed will not rise significantly. Top speed is proportional to the square root of power increase(i.e. Original power / Revised power). I do agree that its current weight should be maintained. And more tire too to stop this ridiculous FXO ownage.

I think I should change the thread title a bit and add "XRT defeciency" as well. Anyway, I also wish to improve the XRTs power curve to its realistic 4G63 glory as well. That would make sure that the overall acceleration of the XRT would improve markedly as well. A little more peak power (say 260bp @6500) makes for slightly more top speed as well. As some of us said too, the strengths and weaknesses of all drivetrains must be realistically and fairly represented. The XRT should beat the FXO if it was properly represented.

Here's the order of things if things were as realistically represented as possible:

XRT should top most of the tarmac lap times. The RB4 should top a few of the tarmac tracks as well. This makes sure the XRT has its place in LFS.

Rallycross is where the RB4 should own every other car. Its physics. No car could power out of corners and 4-wheel drift as well the RB4 on low grip surfaces. The better torque curve and hybrid tires should see to that.

As for the FXO. Its present popularity within the TBO class among many LFS players has a LOT to do with its ease to drive. Its ownage of other 2 cars despite of their harder to drive natures is a MASSIVE and unfair bonus. Well, it doesn't even have front tire wear problems! The exact oppostie of RL FWDs.

Driving RWDs and 4WDs tuned to the max at their peak lap after lap isn't exactly noob level ease. The FXO is just too easy to drive consistantly fast. No doubt, that has a lot to do with its surprising lack of FWD problems. Last time I tried the FXO, it demolished my XRT Blackwood times by more than half as second! A car I don't drive nearly as much as the other 2. If it's THIS easy on a casual personal hotlap with an endurance biased setup, imagine how it'll destroy the XRT and RB4 in a clash between the best drivers of each car. With the RELATIVE ease of pulling out error free laps with the FXO its not even funny.

Still, I believe there is no need to nerf the FXO(just trying to avoid unfairly penalizing those who bother to truely master it). Just compensate by making the other 2 as fast as they should be.

Last edited by Jamexing, Tue 18 Jul 2006, 13:57.

At least that little miswording and misunderstanding is out of the way.

Now, some more serious discussions of the theme at hand would be highly desirable.

I should have said "misrepresenting" to more precisely convey my true meaning. Anyway, LFS bashing's not the aim of this thread. Its the discussion of the issue at hand (need for better represention of RB4 type cars via better a torque curve and tire package) that counts. Like any genuinely serious driving sim user, I just want the most of what LFS could potentially offer.

If loving LFS for what it intends to achieve (the ULTIMATE racing sim), I plead guilty.

Last edited by Jamexing, Tue 18 Jul 2006, 12:13.

FWD + massive torque curve of turbodiesel = 3 minutes of front tire life

Exactly one of my points. There is simply no good representation of 4WD in LFS YET(hopefully). I apologize if some of you think some of my posts are excessively lengthy. I'm just trying to be thorough and clear .

The FZ50 is ultra fast. The chief reason is its weight distribution, which happens to be IDEAL for the aero balance we're given. If the FR and 4WD GTRs were given matching aero kits instead of the current generic aero, it would be a MUCH closer race. I still find it hard that such differing bodyshapes had identical aero. Read any aero text and you'll discover that the subtlest changes in shape generate the most significant of changes. For instance, a simple flat endplate design would massively increase L/D ratios for a given aerofoil. Any way, its still alpha so theres hope yet. Well, at least the FZ50 suffers excessive rear tire wear thanks to rear tire overloading (rear heaviness does have a price). Being a relative gas guzler evens things out a bit on Lemans length races.

No, we don't have a need for speed. We LIVE FOR SPEED!

Thanks ajp71 for a much clearer and reasonable description of RWD opinions. Yes, no car forces drivers to baby the throttle more than an overpowered RWD.

However, there is still the severe misconception that other drivetrains require less skill to master. I am fully aware that FWD and 4WD cars are easier to start with. But to master them is a different thing altogether.

For instance, FWD. The inherent front heaviness and power understeer (LSD or not) forces a driver to master advanced weight shift techniques to cope with the understeer. Left foot braking being one of them. LSDs only reduce, not eliminate power understeer, by proportioning more power to the more loaded outside tire while reducing inner wheelspin. Please don't nerf the FXO by removing its clutch pack LSD. FYI, its VERY easy to acquire and install Torque Biasing (usually Quaife) LSD that are ideal for severely limiting the classic FWD power undrsteer, especially for very popular cars like Honda Civics and Integras. These diffs are ideal for FWD and 4WD front ends. Their unavailability in LFS isn't too important since Clutch based LSDs are extremely effective anyway. For raced tuned FWDs with oversteer off throttle, keeping them precisely on the apex and tracking straight on bumpy circuits certainly require attention. Not too disimiliar from the delicate throttle control required for overpowered RWDs. Keeping the heavily worked front tires happy whilst maintaining sufficient pace isn't exactly noob stuff IRL, though the FXO is well tired enough to avoid that pitfall even at 36psi as long as one doesn't go over 10/10ths. Of course, this assumes a relatively smooth and skilled driver with a well developed setup.

The truth is, many overpowered MRs are setup to understeer heavily, with the Ferrari F50 being a classic example. Its lack of traction control and rear traction (relative to its peaky and massive output) makes a neutral setup undrivable, even for Ferrari's professional test drivers. The F50 was notorious for snap oversteer in its teasting days, until it was finally decided to set it for HEAVY understeer. Older RWD porsches are also set this way to maintain controllability. In fact, older race Porsches are known for inability to turn in all whilst on throttle, though they turned in very well off throttle. A well tuned and balanced powerful RWD should understeer progressively as its limits are approached, understeering heavily if its limits are exceeded. Throttle steerability is crucial for correcting understeer and exiting corners efficiently.

Finally, 4WD. Unfortunately, most drivers would simply think all 2L turbo 4WDs are understeering, laggy and slow pigs, and thanks to the RB4 this unrealistic steoreotype is perpetuated. Yes, they USED to understeer like pigs when they were relatively new, with the older Subarus and Lancer Evolutions being the classic examples. With excellent LSDs, improved suspension technology and tuning, that problem will soon be absolutely consigned to the history. Try the EVO VIII MR. Significant understeer simply doesn't exist in its dictionary(unless you try to drive it the same way you drive a V8 musclecar). Its known for almost neutral mid corner balance through 2nd gear hairpins. And no well setup RWD in existance could turn in as ferociously as the EVO MR. Due to the 4WD traction and exit stability, moderately oversteering setups are vey viable.
The EVO VIII MR can accelerate from 0-60mph in 4.3 seconds despite of its relatively low power to weight ratio (276hp and approx.3050lb). The power of 4WD traction and the 4G63's beautiful powerband. So much for 2L turbos must be laggy. So much for the powerband=unimportant detail argument. Even older 4G63s have very wide powerbands.

No skill? Tell that to Tommi Makinen (4 times WRC champion in Lancer Evolutions). Try 4-wheel drifting the RB4 with its unrealistically narrow powerband. Again, left foot braking and precise weight shifting are absolutely crucial. A Group B 4WD car setup to be almost neutral most of the time is one of the most difficult to drive cars in existance. Throttle control for 4WDs is a very speciallized technique which very few can master. Brutal yet smooth and precise.

A more likely reason for 4WD bashing is its rather unique handling characterisitics that require very different techniques to RWDs to master.

As I've said, 6 speeds for RB4 are superflous but not absolutely necessary as long as its power band is realistically modeled. I like the XRT a lot too, thus my recomendation of a realistic 4G63 powerband. The FWD nature of FXO makes its revvy , peaky and narrow powerband ideal. Low torque down low limits traction issues. Plus its realtively light weight and massive tires, it puts even the XRTs lap times to shame. So much for realistic performance representaion of the 3 drivetrains.

Please understand that I'm very happy as long as the XRT and RB4's powerbands are rectified with a slight increase in RB4 tire size and grip to realistically represent the stengths of RWD and 4WD. Since LFS2 is only in alpha stage (not even beta!), it is not too unreasonable to ask for a corective patch some time in the future. It's far from complete, so lets make the most of LFS before it is finallized. I would never have acqured the S2 license if LFS never had the potential to be the ultimate driving simulation (e.g.NFS:U).

No, we don't have a need for speed. WE LIVE FOR SPEED!

Last edited by Jamexing, Tue 18 Jul 2006, 09:10.

Firstly, lets correct the myth that contact area is directly proportional to pressure. That is absolutely untrue, unless tour tyre has no plies, no sidewall belts.... all the RL structures that exist in real tire. There seems to be a belief that tyres behave like your totally elastic rubber balloon. This is very untrue due to the presence of relatively stiff components such as steel plies, etc. Am extreme example is a runflat, where contact area is very unproportional to pressure.

As for greater contact area, that is also a non myth. If tyres behaved like rubber balloons, wider would only equal wider and shorter patch of the same area. But, being not very balloon like as RL tyres are, that is not true. Again, tyres being notoriously disproportional to inflation pressure when it comes to contact area, that is again untrue. Besides, with the stiff sidewall and tread designs of sports tyres as the 3 turbo cars should be using, the pressure to area relationship is very non linear indeed. So IRL, wider tires gnerally mean bigger areas. I'm happy to explian RL tire physics if need be.

As for 4WD is for nancy boys? I'm so hoping that people act reasonably civilized on this thread. I happen to like making full use of 4WD capabilities, on road, on track, off road, rallies, etc. Gee, 4 wheel drifts on rallycross must be for nancy boys.... I didn't know that making use of 4WD technology is nancy boy behaviour.

More to the point. So, all the WRC and 4WD rally drivers must be nancy boys indeed. A list that includes:

1.Tommi Makinen
2.Marcus Gronholm
3.Sebastian Loeb
.....

So, surviving the Paris Dakar Rally (50 celcuis heat, sand dunes, etc) must be for nancy boys too. Lamborghini Murcielagos must be for nancy boys too. So, FWD mini drivers that demolished their larger, overpowered and overweight RWD cousins in rallies must be nancy boys too.

Need I go on?

Please people, realistic and reasonble opinions and comments only. I hope to not escalate to full out flame war, but facts must be clarified.

As for real cars must be RWD and NA... please consult Group B and WRC cars.

Sorry about that. What you say about the 14.7 stoich A/F ratio is theoretically true. However, one must also consider all the real world factors that properly serviced cars never face. IRL, many owners are notorious for skipping or severely extending routine sevices such as oil changes. Americans (in genegeral, not everyone) have a notorious record of skipping service. So do Malalysians (goes a looong way to explaining why so many diesels smoke so badly there). Asssuming that fuel atomization is near ideal, stoich gives the best power. However, as I've said, fuel happens to be a good combustion chamber cooler. For reliability and safety, OEMs usually err on the safe (aka rich) side. The last thing a car manufacturer needs is to deal with trashed engines.

The restrictive OEM intakes and exhausts to practically eliminate all engine noise doesn't help breathing either. For cars such as Porsche 911 turbos, the ECU is usually setup to run leaner A/Fs at high revs for top end power (if airflow was constant). And again as stated, lower combustion temps are necessary to provide a buffer against typical neglect. But seriously, how many of us would use Mobil 1 5W-30 quality oil on a Toyyta Echo? Lower temps are insurance against such variables.

To seal the point abut rich A/F mixtures, try passing the latest emmsions tests without the cat converter. Your unburnt hydrocarbon concentrations are guaranteed to soar. Emmisions control, even today, is still mostly about after treatment, not ultimate thermal effficiency. Unless your gasoline engine happens to be a GDI or FSI(european manufacturer name for the same tech) running in its lean burn mode, don't expect stoich or close to stoich in anything less highly tuned than the N/A Lotus Exige's engine. Since fuel economy ratings are miles per gallon or liters per 100kms, they are poor pointers when it comes to comparing the power generation efficiencies of engines.

Oh, the GDI ensines run very close to stoich A/Fs when it runs at maximum power mode.

As you all should know, petrols generate maxiumum power efficiency at WOT. But how often can you actually use WOT in your average city traffic? Secondly, even racers don't go WOT whenever on throttle. Try running a WRC Monte Carlo rally stage at WOT only. See you at the bottom of the hill (if we could actually FIND you). Please, don't mistake this as a personal attack. I'm just trying to illustrate a point as clearly as possible.

Thanks for pointing out my oversight, Ball-Bearing Turbo! Hope this lays your doubts to rest. I'll gladly clarify anything that needs clarifying.

I'm glad there are some genuinely realistic arguments generated in this thread. Keep the thread strong and hopefully we can petition and maybe convince Scawen to properly represent the 3 turbo cars. Last thing we need is an LFS vs NFS:U comparison. Honda Civics outracing and outdrifting RX-7s, Subaru stis and Lancer Evolutions? Maybe in reverse physics world. Well, at least the FXO can never outdrift the other 2 in LFS. But as one of you mention, a 1 second faster average lap time for the FXO in a less than 1 minute circuit? Alast, no amount of traction,power and chasis balance could overcome those massively oversized FXO tires. Its just physics. No car can overcome the inherent grip limitations of its tires.

Realistically, I'm fine as long as the the XRT and RB4 powercurves are rectified, with a slightly wider and thus, stickier tires for the RB4. The 6 speed is desirable, especiallly on high speed tracks with slow 2nd gear sections (Ashton GP) but with 4G63 powerbands that might be redundant.

By the way, I congratulate the LFS development team on their success at making one of if not the best sims in computer sim history. LFS has a very strong physics core. Its just the specific parameters that need adjusting to realistically represent the 3 turbo cars.

Finally, some sensible arguments. Yes, IRL 4WDs are unbeatable in rallys. Remember the sheer ownage of all other RWD cars when the AUDI QUATRRO debuted? I miss the Group B era.

Let me clarify that i'm just rying to make LFS as realistic as it could possibly be. To have the RB4 one whole second away from the FXO on the Blackwood WR simply does it no justice.

If XRT had a better power curve instead of the current on-off switch powerband, it needs no more peak power and torque. Smoother power curves guarantee better throttle steering and 4-wheel drifts to make the most of it. For those with aversion to any drifting, consult the great Nuvolari. IRL, tires generate maximum friction coeffiecients at finite slip angles. This can be anything from 2-5 degrees (tire dependnet). Any more would lead to less grip. Even F-1 tires need a small drift angles to operate at their peak. Put simply, a well executed 4-wheel drit exit is the ultimate corner exit. Better top end would equalize it to the FXO in straight line acceleration and speed.

Bring on the REAL 4G63!

Last edited by Jamexing, Mon 17 Jul 2006, 02:42.

I forgot to specify that all the benefits in fuel economy that so called "proper" turbocharging entails the use of low pressure turbos which, for petrols, is about 5-7psi and never more than 10psi. The high pressure turbos such as 1 bar (14.7psi) setups will masssively increase airflow and thus power reliability if compression was lowered (usually to something like 9:1 or LOWER) with the con-rods and pistions replaced with stronger billet/forged units. unfortunately, the lower compression negates some of the thermal effieciency gains of higher intake and effective compression pressure, so from the power per fuel burned point of view, high press. turbos are guaranteed to reduce fuel to power conversion efficiency.

As to why road cars run rich and NOx emmsion concerns. Firstly, one must understand where the NOx comes form.

The NOx is generated due to the fact that air is not pure O2. The spark park ignites the petrol and air mixture, but unfortunately the Nitrogen (air is more than 70% N2!) also gets oxidized in the process, hence NOx. With richer mixtures, there's less oxygen to oxidize N2, thus less NOx. That massively reduces the NOx emmsion problems.

So, how would you deal with the unburnt hydrocarbons? Behold the 3 -way catalytic converter! Catalyses the chemical reactions that change unburnt hydrocarbons, CO and other products of incomplete combustion to much more benign CO2 and H2O.

Another major reason for richness is cylinder cooling and also overall temperature regulation of the combustion chamber. Obviously, regulation of temps is crucial for reliability. Unburnt fuel happens to be a good coolant. The best example I can remember off hand is the 911 turbo engine. It's well known for very rich A/F mixtures at higher revs to stabilize engine temp at the cost of absolute top end performacne. The above reasons of NOx regulation apply too.

One of the problems with lean burn seen in diesels and GDI (aka dieselized petrol) is NOx generation caused by oxygen rich burn. This is currently reduced markedly via NOx scrubbers that deoxidizes NOx to its Nitrogen and oxygen components. The best example of a car with this system is the current 3.5L GDI engine of the European spec Pajero. Obviously, it has also been used and will only bettered for current High Performance Diesels.

As for optimal power, yes, stoich ratios are theoretically ideal, but the real physical limitation is fuel atomization for better fuel to O2 contact and more complete burn. This goes a long way to explaining why diesels benefit so much from high pressure injection sysytems. Practically, just slightly rich ratios are the best compromise for both relability and power. Lets just say I've seen enough dyno shootouts end up in massive engine kabooms due to leaning A/Fs to squeeze that last bhp. As the A/F leans, so does the ignitability, so unless you could massively cool the combustion chamber whilst compression, detonation is inevitable. This is why the GDI engines can run 13:1 comp. ratios and ultra lean 30:1 A/Fs. The direct injection system allows better combustion chamber cooling and avoids preheating fuel at the ports, avoiding detonation.

Ultimately, the otto cycle is limited by the fact that it uses A/F mixtures instead of swuirting fuel at the right moments. Compression can never rise too high since petrol is notorious for spontaneous ignition.

If the current diesel fuel atomizaton improvements continue, the A/F could be adjusted richer and more towards stoich ratios without risk of generating excess soot.

And no, your average econobox does NOT run 14.7:1 comp. ratios, unless it happens to posses diesel like (aka insanely strong) block, head and internals and the aforementioned excellent detination control. More like 10.5:1 on average. For example, the high rev engine that the current NA Lotus Exige uses (from Toyota) has a comp ratio of approx. 11:1 and thats considered on the high side. Don't compare it to your typically weak aluminum alloy econoblocks. That engine block is composed of metal-matrix composites, F-1 technology that was banned with advent of the current V8 engines. If it wasn't banned, redlines would be around 24,000rpm instead of the currently "low" 20,000rpm.

This thread is getting real interesting! Just a bunch sincere opinions and good arguments. No highly uncivilized behaviour yet, so lets keep it that way.

I think it best to clarify myself about the 4WD leads to magical grip increase issue. No , I've not implied in any way that 4WD suddenly gets extra grip with identical tires. Hopefully this clears things up a bit.

My main point is that a properly set 4WD system makes the most out of the tyre's tractive capabilities in a way 2WD can never do, and the RB4 would benefit most from a realistically broad powerband, even with current tires.

If the powerband issue alone was rectified, the Rb4 competitiveness is guaranteed to soar, though it will not magically beat the FXO without a matching upgraded tire set.

By the way, the XRT is NOT traction limited at its current state of tune. It would be acceptable with 5sp if its top end was better, say max power at 6800 with 7500 cutoff. Realistically, there is no point revving beyond 7500rpm for an engine of its design. A well setup XRT should understeer mildly on entry, almost neutral mid corner and oversteer slightly on exit. The only way to kill the rears on the XRT currently is via:

a)Doing silly burnouts
b)Poor setup or throttle control leading to unnecessary wheelspin.

If I'm not mistaken, the XRT is supposed to simulate the Mitsubishi Starion. Well, at least they have similiar exterior and suspension designs. To properly represent this supposedly 4G63 powered car, a better powerband is definitely required. If memory serves me right,it had a similiar power curve to Lancer Evo 4G63s, with 3500rpm peak torque and 6500rpm max power, 7000rpm nominal redline with 7500rpm cutoff. Well, at least the XRT has a 7500rpm nominal redline on the tach(one small token of reality).

As for the top gear argument, yes, I am fully aware of those lap times. What everyone seems to overlook is that the FQ400 has a relativelt horrid powerband compared to the standard EVO. One would be better off if you simply upgrade the intake, exhaust and ECU and boost control for a 350hp peak while maintaining or improving OEM powerband. And secondly, both the 280ps and 400ps EVOs run the SAME tires. The same undertired argument applies here. The only major source of lap time loss for the FQ400 was its massive straightline acceleration. No amount of suspension tune could copensate for lack of tire grip. The EVOs run 235/45/17s vs those massive tires the ultra expensive, relatively lighter and overpriced supercars run. 245/35/19 fronts and 345/35/19 rears for the Ferrari Enzo. Try using properly modding an EVO to use 255/40/17s of appropriate design and tyre compound. Thats at least another 2-3seconds off. Add close ratio sets to cope with that narrow FQ400 powerband and don't be suprised if it drops another second or 2.

Last edited by Jamexing, Sun 16 Jul 2006, 15:13.

Speaking of diesel sounds, I happen to drive an NA Diesel Pajero and it sounds absolutely beautiful. Who needs ridiculously loud exhausts on some tiny ricer engine when the NA 4D56 already emits extremly throaty sounds? A turbo would attenuate some of the NA roughness, but a freer flowing 2.25inch exhaust would restore the throatiness without the rougher higher frequecy sound spectrum, all while improving power, torque, response and fuel efficiency. All this could be done without exceeding 85dB even at full throttle and oad.

Seriously, 4WD and other private use diesel engines are much better representatives of how good diesels could sound. Please, do not lock yourselves into this diesel sound=UPS truck sound dogma.

Go to the Borla or Magnaflow websites and sample a few turbodiesel exhaust notes. Musical.

4WD driverain losses alone do not explain the massive lack of track performance. Anyone with any track experience on road courses would quickly discover that the real secret to speed isn't just power. Its tire grip. To prove that RB4 is unfairly undertired, i've not found a setup that could stop the RB4 from overheating ALL its tire when driven at peak performance continuously, not without ridiculously tire high pressures to degrade grip anyway. I've pushed both the XRT and FXO to their limits for 5 laps non-stop at both Aston GP and Blackwood. No luck trying to overheat their tires, even with 36 psi on both cars (obviously, I did't do silly stuff like unnecessary burnouts, though 4-wheel drifts are common for XRT on the edge).

Second point is that real track performance stems from the powerband, not peak power numbers. FXOs FWD traction chalenged nature would thrive on the current narrow powerbands, but it unfairly disadvantages the XRT and absolutely cripples the RB4, where a realistic powerband would showcase the tractive strength of 4WD. Currently, Rb4 has almost all the 4WD cons (understeer can be dialled out via suspension tuning) and very few of its strengths.

Note: I have nothing against the FWD FXO. I do like to drive it (fun and fast car). Please don't nerf it, just improve the other 2. I'm tired of practically all games nerfing the strong to balance with the weak.

No we don't have a Need For Speed. We LIVE For Speed!

Last edited by Jamexing, Sun 16 Jul 2006, 09:16.

An interesting observation, but easily explained.

Most petrol roadcars IRL run rich due for detonation resistance and easier NOx emmision control. In essence, they have really poor airflow rates for their fuel flow settings. In your case, the turbo simply adds airflow rate to the equation, leaning out the A/F ratios a bit if your fuel rate remains the similiar, causing more complete combustion and thus more power and torque. The lessened need to depress the throttle goes a LONG way to explaining fuel economy increase. Conservation of energy always applies, so there is no free energy, just better extraction of the fuel's potential energy. Hopefully you've not gone TOO lean or massive detonation would result. I've not seen a high pressure turboed petrol car that experiences improved fuel to power conversion efficiency after compression reduction to help the relatively weak petrol blocks and internals to cope with massive cylinder pressures.

Please read the quality post at the top of page 4. Obvioulsy, lower compression reduces thermal efficiency. By the way, high pressure diesel injection improves efficiency by squirting fuel through ultra fine holes(like those many hole in your showerheads but MUCH finer), vastly improving fuel atomization. The true secret to better power effieciency is the more complete burn of diesel. 2 step injection regimes help too.

Conclusion:

Diesel + turbo equals complete synergy.

For already highly tuned petrols running A/F ratios on the leaner side, turbos are guaranteed to reduce efficiency.

Last edited by Jamexing, Sun 16 Jul 2006, 09:17.

The upgrade system was just a suggestion, so don't take it too seriously.

However, my chief reason for buying LFS was for realistic vehicle dynamics and realistic representations of relatively modern vehicles. Yes, I've driven EVOs and none of them lag as badly as some of you here claim. Seriously, why waste 36,000USD on a rallycar based roadcar to run it BELOW 3000? Besides, who needs massive torque at 1500rpm IRL street driving anyway? Low end torque would be great for SUVs, but what cars like RB4 and XRT really need is better midrange and high end (3000-fuel cutoff), not the ultra low range torque of a turbodiesel. For goodness sake, they weigh UNDER 1300kg (real EVOS are about 1500kg).

As to the realism that LFS is supposed to repesent, I'm just too disappointed by the unrealistically low powerbands. And FYI, EVOs are all single turboed, but with ultra light titanium turbines for ridiculously fast spool times.

The best example is the 4G62 form the 1980s Mitsubishi Cordia. 1.8L turbo, no intercooler, old TD04 turbocharger. Max torque at 3500rpm, max power at 6000rpm, usable revs from 3500-6500rpm. I happen to have driven this 80s pocket rocket IRL and anything above 3000rpm is lag free. The 5 speed was sufficient for a 185km/h top speed at 6500rpm. So much for outdated 80s technology argument.

What I'm really trying to say here is that a sim like LFS should strive to realistically represent RL cars, not continue the old turbo engine and drivetrain stereotypes of the 1970s and before. And no, I have nothing against the FXO. FYI, evos adopted 6 speeds LATER than subaru because of its comparitive lack of lag to subarus of similiar tune.

AS for the road to racecar argument, we happen to be living in an era of modification haven. In fact, LFS's dampers and springs are wildly outdated if one follows current motorsport trends, when 4-way adjustables are the norm for teams with decent, not just Ferrari sized budgets. The lack of twin-rate springs really stifles all the cars in rally terms.

Seriously, camber and castor settings in LFS are doable IRL. I happen to align the front end of my Pajero myself. Adjustable shocks for race use are about 10,000AUD per set for 4 way adjustable KONI 2822s, or one could use the 2 way tunable LFS versions for about 1000AUD each(I happen to have talked to Koni distributor Toperformance). If an 80's Cordia (FWD!) could easily be installed with 2 way adjustables, why not the 3 turbocars.

FYI, I've got some pretty interesting keyboard driving lap times for RB4 that I currently don't post. The only reason I'm not using steering is due to lack of good FF wheels. All I've tried suffered form highly unrealistic feel.

Last edited by Jamexing, Sun 16 Jul 2006, 12:08.

Sorry guys, I just forgot to mention something.

In the real world, a wider tire with all else equal is always grippier on tarmac. This is due to a phenomena known as tire load sensitivity. Since wider tires have lower contact pressures, the enjoy higher friction ceoefficients. Besides, if a wider tire were to have the same optimal temps and threadlife, the wider is always grippier since, it is less stressed, allowing the use of softer(stickier) rubber.

So, IRL, wider tire is always superior on Tarmac.

About the 3 turbo cars being non-roadcar, that is absolutely untrue. These days, no race car would be without rollcages, which the 3 lack. So strictly speaking, they are still road cars. As one of you mentioned, all 3 cars suffer from limited suspension travel, a common trait for most road cars. And FYI, they did have 6 speed Celica GT4s. Besides, lets do something with those excess points we accumulate from race victories. Why not allow a points trading system whereby one could upgrade the car if 6 speeds wasn't deemed standard? It is unfair to just nerf a car to hopelessness.

Trust me, once you've tried rallying, circle tracks would seem superbly boring. Bring on the RB4 WRC!

I happen to follow the latest technological trends in racing and current f-1 cars run about 45/55 F/R. In fact, everyone is aiming for more front downforce and more front weight bias. The mprovements to mid corner performance are obvious to anyone who understands physics (tire load sensitivity, etc). And seriously, do check the latest EVO IX specs (max torque at 3000rpm, max power at 6500rpm). Now that is a realsitic power curve.

Lack of six speeds makes it impossible to offset the unrealistically narrow power bands. In fact, both RB4 and the XRT could benefit greatly from this.

But seriously, try finding a current sport compact in the RB4s class with only 5 speeds. As I've said, even a 32,000AUD Toyota Corrolla Sportivo with the 1.8L 191hp engine has 6 speeds. To say a 6 speed is out of the question defies the realism the LFS is supposed to convey. 6 speeds are so common that even the Nissan Pathfinder 2.5L turbodiesel runs a 6 speed manual!

In layman terms, to not have 6 speeds in cars of RB4 and XRT class is highly unrealistic. Seriously, even an 4G63s from the 80s had much better power curves than what LFS endows the RB4 and XRT.

Hopefully, for the sake of realismm, these problems are rectified. If LFS is as sim as it is supposed to be, why not use relistic gearboxes and power curves?

It is unfortunate that LFS currently misrepresents 4WD cars. The poor RB4 is the perfect example.

First thing is the engine. with max torque at 4500 rpm and max power at 6054 or so rpm, this is a horrible power curve, especially for 4WD. In fact, all the turbo road cars in LFS desperately need more realistic (aka better) torque curves. For RB4 I suggest 330nm@3500 and 250hp@6500 with cutoff at 7500rpm.

Second thing is the gearbox. All 3 turbo cars should be given 6 speed manuals, not the horrible 5 speeds that make close ratio sets impossible without ridiculously low top speeds. The unrealisticly narrow powerbands make this an even more pressing issue. For goodness sake, even a 2005 corolla sportivo has a 6sp gearbox.

Third thing is the ridiculously fast FWD, the FXO. Yes, it is realistically supposed to be the lightest of the 3. But its true speed secret is those massivley oversized tires. If the RB4 was tired similiarly with all else unchanged, it would destroy all the other 2 cars on any twisty technical circuit through superior grip and traction. Even with the first 2 alterations mentioned above applied to all 3 cars, the RB4 would be the overall winner even if its power to weight ratio ends up slightly less than the other 2. Curently, the RB4 is relatively undertired.

Finally, please make a proper rally version of the RB4 to eliminate the current neglect experienced by the rallycross circuits. LFS does have the potential to make even rival or beat RBR's realism.

FYI, the Audi A4 was kicked out of GT racing due to the inherent "unfair advantage" their Quattro system presents.

Imagine if F-1 cars were allowed 4wd while maintaining their current weight and power levels. Traction control would be effectively obsolete. The fact is, even the current V8s are massively overpowering the rear tires.

In fact, F-1 specifically banned 4WDs due to the potential unfair advantages of a properly develpoed system. Imagine if F-1 cars had WRC style electronic diffs. Why waste 2 wheels with 2WD when 4WD could make the most out of the tires' potential? With current materials technology, drivetrain weight is a non-issue for 4WD since current cars all run underweight anyway. Weight distribution even closer to the ideal 50/50 helps too.

Last edited by Jamexing, Tue 25 Jul 2006, 10:32.