Quote from tristancliffe :

Posting the torque curve isn't really all that helpful for an LFS discussion (if you just want torque curves for personal use then do it via PM), what's more important is turbo behaviour. Is it possible to extract any data from LFS about the turbo that can be compared to real life data?

At the moment it might be that we have a perfect power curve (I know we don't, but bear with me) but the boost modelling is so far off that we rarely get to see that perfect curve (i.e. we're rarely running at full boost, which is where a torque curve print out ould ususally be carried out (as rolling roads rarely know what they're doing))

Absolutely correct.

I don't have too much idea of how to analyze LFS Turbochargers....
I guess the easiest thing to do would be to look at the CFM requirements of the engine running the outputs it does in LFS and peek at a compressor map of a turbocharger that would produce similar results on an engine of said size IRL. There's so many more variables and we really don't know what the fundamental problem is, although it seems to me that the "positive feedback" effect is missing. Once the turbocharger is in it's efficiency ranage, all hell should break loose... I am still stumped about how much worse the RAC is even than the other cars, and I can't imagine why. It runs lower boost, and has the same size engine, but lag is far worse than the XRT which runs more pressure.....

Quote from atledreier :

Here's one from a stock and tuned 2.0T from the new Golf GTI:
http://www.bsrab.se/bilder/_/ev_862_1_l.png/

Here's one for my car (1.8T):
http://www.bsrab.se/bilder/_/ev_616_1%2B_l.png/

Volvo 2.0T:
http://www.bsrab.se/bilder/_/ev_808_1_l.png/

The Golf GTI torque curve is a particularly good example because the stage 1 thing they have on it has its top end power right over 240bhp. Close enough to LFS TBO class IMO

That said, don't expect any turbo modeling changes in the near future. I don't even expect to see that before S2 final, even tho I hope I'm wrong.

Quote from Jamexing :

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?

The RB4 is a replicate of the Celica GT4 and it have only five gears!

Well, as long as the torque band improves, 5 gears are just fine. They are just a solution for peakiness. Well, RB4 is not a direct copy of GT4, though the majority of its styling is. At least the RB4 has better suspension. The XR GTT on the other hand is an almost carbon copy of the Mitsubishi Satrion, down to the exact suspension design, engine type and weight distribution. Only the powerband is missing, and the current one does it no justice.

Good point, Nick II. The Stage 1 Gti has a brilliant midrange, which is obviously the main emphasis of the upgrade kit. 240hp and 6500rpm redline is only slightly of the mark for RB4 use. The only tweaks it needs for RB4 use are slightly higher redline (7000rpm) and better high end power. A rise to about 250hp@6500rpm would be ideal as long as the other parameters remain relatively constant. And the current 9000rpm max rev is a bit silly too. Spooling the ridiculously high inertia turbo at 9000rpm... So much for decent engine life. It would be much more realistic if it was rev limited to 7500rpm, but first things first.

Hopefully they would fix or at least significantly reduce the spool times and powerbands for Rb4 and XR GTT soon, but I get your point, Nick II. the current tire physics are brilliant, though this powerband and turbo spooling issue has remained completely neglected.

For now, keep the quality posts and votes rolling in. Lets just hope that they'll actually take this as seriously as they should. All quality posts and votes will be highly appreciated.

It's been a while, and there's been quite a bit of talk on turbo behaviour and powerbands. It is pretty certain that turbo modelling problems are at the heart of the issue, since the NA cars in LFS have beautiful powerbands. All we can hope for now is that they'll try to fix the problem soon.

Now on to the tire problem. The RB4 driver of today faces 2 major problems that make any race against the FXO of decent length completely uncompetitive. The RB4's relatively skinny tires handicap its ultimate grip, making it impossible to lap anywhere near as quickly as the FXO. The second problem is also a result of undersized tires. To have ANY chance of keeping up with the FXO, one is forced to drive its wheels off, which means using the tires' full potential constantly. Imagine doing this over a 10 lap race at Aston GP. To survive constant peak ussage, one is forced to use 40+psi pressures, slowing the car down EVEN MORE. Or one could run tire pressures that generate good grip such 36psi (setup dependant to a point, of course), only to suffer from greasy oerheated tires as the race progresses. Or one could slow down and abandon all chances of winning.

To have any chance against an well driven FXO, one must push both the RB4 and XR GTT amazingly hard. But to do so only kills tires in the long run. Hence my recommendation for a slight tire upgrade for both cars so none of the TBO cars suffer from serious tire issues.

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

I think everything that can be said about this has been said. Now I suggest you spend a little of your forum posting time actually playing the game online!

Just went online and again it's either:

1.Lack of good races(end up driving alone)
2.Too much lag(I use cable!)
3.There MIGHT be good races, though they all seem to be private sessions.

Hello guys sorry for reviving an aging tread, but 38 + 8 = 46, a small sample size indeed. Wish there are more quality votes so we can have a better look at the larger picture.

IMO, chunk up RB4 tyres, shrink FXO tyres, suck another 10hp from the FXO.

Once the turbo spool physics are sorted the powerbands should automatically get wider.

And see how things go from there.

Also it's rumoured the next incompatible patch (whenever that is, months away by the sound of things) will include aero physics improvements, I'm hoping the cars will finally get different CdA figures, rather than the shared values we have atm.

How have there been roumors about new physics to the next patch? I'm quite sure you just made that up.
(No offense intended, if you have other sources than I do, please say so.)

Vain

For now, I believe that the best course of action is to focus on fixing the undersized Rb4 tire problem. Once turbo spool and other turbo related physics are fixed, then we can tweak the powerbands even better. Nevertheless, my initially suggested powerband stands as a rough target.

Checked me emails, and there's nothing on there, so must be something I read on the forum. We need a sticky of all of Scawen's posts.

Quote from Bob Smith :

We need a sticky of all of Scawen's posts.

Magic