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Restrictions / Turbo cars
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(49 posts, started )
Restrictions / Turbo cars
The restrictions on the Turbo cars should be accomplished via adjusting boost.

It's silly that an FXR is using a "restrictor plate" while still trying to suck 24lbs of boost worth of air, and managing it... Keep the % if possible for simplicity (though it'd be the same as testing different amounts of boost as different percentages) but tie it to boost, not a magic restriction.
As far as I'm aware, the current weight additions and intake restrictions are only temporary until the cars get their values perfected and balanced.
Quote from Dajmin :As far as I'm aware, the current weight additions and intake restrictions are only temporary until the cars get their values perfected and balanced.

People run GT2 class cars on purpose now though.

I'm speaking about the voluntary restrictions, which won't likely go away..
Huh? The only car that has an intake restriction set for the global handicaps is the FOX, which only goes up to 11 lbs of boost. AFAIK, this does not affect the spool time.

As a matter of fact, the FXR is the only car in the GTR class without any global handicaps at all.

EDIT: So... if all the GT2 cars have the same intake restriction and it doesn't affect spool time*, what's the problem?

*if anything it's reduced because you can stay on the throttle more mid-corner
The FOX has boost? (I know you meant FXO),

Again, note, I am talking about the voluntary restrictions.

Bottom line, anyway, you would never put a restrictor plate on a turbo car for obvious reasons - and THAT is the problem.

You would not tune an engine with a specific turbocharger and then screw it up by messing with intake restrictor plates, it simply would not work. In fact, I'm quite certain that putting a plate on would reduce the manifold pressure that's observed anyway since you're not putting enough air through it to maintain the max pressure anymore. I don't even think you could run full pressure if a plate was in there; screwed up turbocharger dynamics notwithstanding.

If you want to handicrap a turbo car, you reduce boost.
Look at FSAE. That series has restrictor plates yet the MRT is (lightly) turbocharged.
Exception to the norm (probably for certain reasons...)

Show me a 20+ PSI car with a plate!
#8 - ajp71
I think it's pretty realistic, restrictor plates are a simple way of controlling an engines output, unlike a turbocharger which is hard to enforce. Without checking I very much doubt that WRC or LMP rules don't have an intake restriction.
You guys are missing the point:

Explain to me how a GT1 FXR and a GT2 FXR (Unrestricted in the former and let's use 25% for the latter) can both run 24lbs of boost and have different outputs. (!)

If you want to keep the plate for some reason, then fine, but the whole point of a restrictor plate is to flow less air - which means the turbo won't be able to force enough air into the manifold to produce the same 24lbs, otherwise the output wouldn't change anyway.

The engine should really run out of boost a lot easier with a plate, at the very least. I'd have to think of how that would work.

You don't take an existing turbo car, and throw a plate on it. Maybe you can redesign one with a plate to meet rules (as in WRC), but that's different. Then you know the flow requirements ahead of time and can attain a suitable turbocharger.
Didn't we (well, me) already agree that the engine restriction is just a slider for top power - it has nothing to do with the "engine physics" or even realism?

I really don't care how it is done as long as the cars are equal. It is just a small feature and it is possible that it can be quite a pain in the axe to make work correctly... limiting boost and all
Quote from Forbin :Huh? The only car that has an intake restriction set for the global handicaps is the FOX, which only goes up to 11 lbs of boost. AFAIK, this does not affect the spool time.

As a matter of fact, the FXR is the only car in the GTR class without any global handicaps at all.

EDIT: So... if all the GT2 cars have the same intake restriction and it doesn't affect spool time*, what's the problem?

*if anything it's reduced because you can stay on the throttle more mid-corner

They Don't have all the same restrictors. The turbocharged require more restriction, as they are forced induction
Quote from Ball Bearing Turbo :You guys are missing the point:

Explain to me how a GT1 FXR and a GT2 FXR (Unrestricted in the former and let's use 25% for the latter) can both run 24lbs of boost and have different outputs. (!)

If you want to keep the plate for some reason, then fine, but the whole point of a restrictor plate is to flow less air - which means the turbo won't be able to force enough air into the manifold to produce the same 24lbs, otherwise the output wouldn't change anyway.

The engine should really run out of boost a lot easier with a plate, at the very least. I'd have to think of how that would work.

You don't take an existing turbo car, and throw a plate on it. Maybe you can redesign one with a plate to meet rules (as in WRC), but that's different. Then you know the flow requirements ahead of time and can attain a suitable turbocharger.

It would seem hard to get your head around it but its possible. boost is not what really creates power. it is quite possible to have the same car running 10psi with one turbo and 10psi with another and having one flow more air. In this situation It really comes down efficiency of the compressor. If your put a plate on the intake in order to get the same manifold pressure. the turbo is going to have to spin faster. in real life if your slapped one on you would prob take the turbo out of its efficiency area on the compressor map resulting in less power.

Now if you've played around with LFSTweak at some point. you can clearly see that LFS Engine Simulation isnt really a simulation, its more of a Formula used to create a torque curve. (With the coefficients being all the variables you play around with.)what that means is just because in game it mentions restrictor dosen't mean thats whats actually happening in LFS. it might just be taking .005 away from general power.
You're absolutely correct, but you hit the nail on the head - the compressor is out of it's efficiency range if you put a plate on. Putting back pressure between the plate and the compressor would affect spool times and make it difficult to get into the proper range given the same unit. Turbines really only like a very narrow operating range and you would be hampering it. I guess one could make the assumption that you're changing the turbocharger along with the intake restriction, but the engine would not behave the same and that's the point.

You'll always need x amount of air (in the actual manifold) for a given engine RPM & throttle position to generate Y amount of positive manifold pressure. That's the whole point of compressor maps, to show you how much air they flow so you can match the application knowing the flow requirements of your engine. Without changing the turbocharger, throwing a plate in there would give you less boost and shitty response.

Quote from lalathegreat :boost is not what really creates power.

From an intake manifold POV it absolutely is, for a given RPM & throttle position.
see your assuming that the turbo can't make the same manifold pressure with the plate on. all you have to do is keep the waste gate closed longer until the desired boost is reached what the plate does it make the turbo have to spin faster to create that kind of pressure
I'm not assuming anything; you said this yourself and it's true:

Quote :in real life if your slapped one on you would prob take the turbo out of its efficiency area on the compressor map resulting in less power.

It's not a matter of "couldn't", as much as "wouldn't" if you want to play semantics

EDIT: I guess I should clarify that I'm talking about reasonably large restrictions BTW. Maybe (just maybe) you could get away with a really minor restriction, but it would still affect response & driveability. Bottom line, it's not the proper way to go about it on an existing car. The cars that have these plates - it's really more about limiting, not restriction. If you had an FXR IRL, and wanted to tone it down, you would adjust the boost controller.
not sure about now but they used to use an inlet restriction plate on group A cars which was mounted not than 50mm before the turbo. toyota got thrown out for running an plate which was designed to leak and allow more air into turbo
If it makes you feel any better: on the whole, I agree with you Jeff.
Quote from Ball Bearing Turbo :If you had an FXR IRL, and wanted to tone it down, you would adjust the boost controller.

i agree 100%

you would not restrict the car with a plate, you would turn down the turbos boost.

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Off topic about gtr's, but the TBO class in general when they tryed to ballence that with extra weight on xrt and fxo. i think they shouldnt of added the weight but instead higherd the boost on the RB4 and XRT to be equal to the FXO.
Pretty sure the XRT has the most boost as it is, IIRC. The RB4 needs wider tires, the FXO needs thinner tires... Just my opinion, although I'm pleased as punch that there is at least balancing going on!
Slightly offtopic, WRC has a 34 mm intake pipe. After that it can be wider, just has to be that wide at some point.
BBT,

I completely get what you are saying but I think you miss the basic point in your argument. For the restrictor plate to work as it would in the real world, by limiting the overall ability of the engine to induct Air and thus burn fuel, you first need to have engines modeled like in the real world where engine power is the result of Air/Fuel induction, compression ratio and displacement, among other things like the power losses from intake flow restriction, exhaust restriction, and engine/drive friction.

Basically before you can have properly modeled intake restriction you need properly modeled engine power generation. Simple as that.
I look forward to driving cars in LFS with engines that have personality. The amount of complexity of engine modelling shown here, which I believe is possible, given the quality of the tyre model, will be great.

At the moment I find LFS's engines a bit too smooth, and linear, and generally artificial. I would imagine with the complexity of the engine sound simulation, and accurate modelling of the engine itself, we will find all sort of behaviours emerge that are hard coded in other games, like a nice burble on the over-run of cars with carbs, and if they can be bothered to model exhaust temperatures and such, backfires and other immersive behaviours, like a little black smoke from an engine that is too hot (don't drive a suzuki bandit 600 hard in a country which is at 40 degrees c! the radiator is far too small!).

I can't wait for the first race I see where the guy in first place blows a turbo flat shifting infront, causing the guy in second to spin out from all the oil deposited on the track, leaving me, tactically in third place, to take all the glory, with non of the effort.... brilliant
Quote from z3r0c00l :I look forward to driving cars in LFS with engines that have personality. The amount of complexity of engine modelling shown here, which I believe is possible, given the quality of the tyre model, will be great.

At the moment I find LFS's engines a bit too smooth, and linear, and generally artificial. I would imagine with the complexity of the engine sound simulation, and accurate modelling of the engine itself, we will find all sort of behaviours emerge that are hard coded in other games, like a nice burble on the over-run of cars with carbs, and if they can be bothered to model exhaust temperatures and such, backfires and other immersive behaviours, like a little black smoke from an engine that is too hot (don't drive a suzuki bandit 600 hard in a country which is at 40 degrees c! the radiator is far too small!).

I can't wait for the first race I see where the guy in first place blows a turbo flat shifting infront, causing the guy in second to spin out from all the oil deposited on the track, leaving me, tactically in third place, to take all the glory, with non of the effort.... brilliant

ive always been pro real time engine sim. but some aren't prospect of having 20 cars coming into t1 all with different sounds and randomly backfiring would warm my heart. problem with lfs is that most people will disagree because they rather something else take higher priority. eg someone wants better aero so they go -1
I'd love real time engine simulation. The fact that decent non-real time engine simulation is only just possible outside of big car companies obviously isn't the point. Anyone here used WAVE? It takes quite a long time to do very basic throttle-power plots, and that's on a single cylinder normally aspirated engine!

So the question is, how close do you go? Closer than now, sure, but not fully accurate which isn't feasible.

I'm sure the engines will get an update at some point in terms of how they produce their power. Coughing and flames, or even backfires, are probably an S3 thing.

But the aero work is weaker than the engine simulation overall, so I'd say that takes priority at the moment. If the basic turbo model could be improved at around the same time I think we'd be a bit happier still.

I'm sure Scawen has already mentally priorities the various options, and he'll get on with it soon. He's very quiet at the moment, so I think he's probably doing AI at the moment quite heavily. Once that's done who knows what he'll do next.
Quote from Gimpster :BBT,

I completely get what you are saying but I think you miss the basic point in your argument. For the restrictor plate to work as it would in the real world ...

Oh, I 100% agree. I didn't miss the point - I am aware of that - I guess where I am coming from is that incongruities ruin immersion (for me). Driving an FXR with 26bs of boost with the exact engine behaviour of an unrestriced FXR, knowing that it's 1xx HP less powerful magically ruins the suspension of disbelief, for me personally. As pointed out, the engine sim will never be able to be 100% perfect, just varying degrees of imperfection - in which case it's never going to cease being about creating an illusion, and things that collapse the illusion ruin the fun.

Quote from z3r0c00l :... what sim heaven would like in 2050...

That would be most excellent, but I have my doubts as to whether this will ever happen in LFS - at least not before cars are obsolete.
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Restrictions / Turbo cars
(49 posts, started )
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