Proper revv limiter

[Tim_J_23]

Heya!

This is a little update one for my rotary engine suggestion.
We should have properly jumping revv limiters.
What's my point?

First of all, you should be able to set your shift light at the RPM you like yourself.
It's not the hardest thing to put into LFS I think.

Second is that the actual revv limiter sound.
At the moment it's: wroomwroomwroomwroomwroomwroom.
What I like is: wrooom bababababa BANG bababa BANG babababababa BANG

Hard to write the noise but I think you understand what I mean.
And maybe 2 different ones.

As far as I know there is 2 different revv limiter types IRL, that is one that shuts down the fuel flow the other one is turning off the ignition and adjusts the ignition so it runs bad.

The one that turns off the fuel flow pretty much sounds like this:
Wraaababababababababababababababa

The one that turns off the ignition pretty much sounds like this:

Wraaaabababababa BANG babababa BANG The BANG is misfire which often is a cause by the revv limiter since it turns off the ignition on some cylinders.

I'm not sure if I got the think EXACTLY right but that's how I've understood it.

So in options you can therefor choose between 2 different revv limiters and you should be able to set the shift light.

Inputs?

[evilpimp]

Suggested many times.

I think the ones in LFS right now work just fine. However, I'd like it if we could adjust the limit. :P

[Tim_J_23]

Ok, nah just thought of it since I like sometimes to just go as high up on a gear to the limiter and just stay there for half a second then shift but here I don't like it since nothing is happening.
And when drifting you like to stay on the limiter and give out alot of smoke and at the same time like: WHAAAABABABABA BANG BABABABABA BANG BANG BABABA BANG BANG !! Instead of wroomwroomwroomwroom ... Gets boring after the first time :)

[Woz]

You CAN change the point the shift light comes on, just change your cars gearing.

The shift light in LFS is "dynamic" in that it comes on at the point where you get more power by shifting and not at a preset point. So change your gear ratio settings and you can move the shift point.

No you cant move the rev limiter BUT if you could you would soon find that engine damage starts to occur not far past the limit point so there is actualy NO point moving the limiter higher.

[Tim_J_23]

No you cant move the rev limiter BUT if you could you would soon find that engine damage starts to occur not far past the limit point so there is actualy NO point moving the limiter higher.

ofcourse I can't move the limiter, that's why I made this suggestions...

[asbjoern]

you would soon find that engine damage starts to occur not far past the limit point so there is actualy NO point moving the limiter higher.
actually i think it would be cool if the limiter were moved and engine damage occured, because then youd have to rev it wisely and it gives you more to think about during a race:)

[Bandit77]

actually i think it would be cool if the limiter were moved and engine damage occured, because then youd have to rev it wisely and it gives you more to think about during a race:)

that'd be only one thing of a bunch of engine-related stuff. I don't really know about the "bigger" cars, but the smaller road cars' engines are still quite a step away from the real thing. I don't think that a 1.3 would spill out 115 hp at a certain number of revs, still have 1000 more to go until the red line and have the ideal shift-point before. ideal shift-point would typically be AFTER the red line, mostly because power'd peak just a tad before the red line. (the LX4 comes quite close, iirc)

so then you could trade ideal shiftpoint and best acceleration against endurance... and set your limiter accordingly, maybe with the option to disable it completely during race.

as for the limiter's behavior itself: I don't care too much, as I don't want to hit it anyway. newer cars' limiters are very smooth though.

[Tim_J_23]

My point with the limiter set by yourself is that you can set it to like 5,000 if you want to shift then etc etc. Not so high that you blow the engine ...

[tristancliffe]

that'd be only one thing of a bunch of engine-related stuff. I don't really know about the "bigger" cars, but the smaller road cars' engines are still quite a step away from the real thing. I don't think that a 1.3 would spill out 115 hp at a certain number of revs, still have 1000 more to go until the red line and have the ideal shift-point before. ideal shift-point would typically be AFTER the red line, mostly because power'd peak just a tad before the red line. (the LX4 comes quite close, iirc)

so then you could trade ideal shiftpoint and best acceleration against endurance... and set your limiter accordingly, maybe with the option to disable it completely during race.

as for the limiter's behavior itself: I don't care too much, as I don't want to hit it anyway. newer cars' limiters are very smooth though.

I've race prepared a 1.3l that put out 130hp at 6500rpm, and redlined at 7500. We set the shift light to 7000rpm as that was the overall optimum with the gearing used.

If you don't understand engines or gearing then it's probably best not to try and post technical stuff about them ;)

[ajp71]

that'd be only one thing of a bunch of engine-related stuff. I don't really know about the "bigger" cars, but the smaller road cars' engines are still quite a step away from the real thing. I don't think that a 1.3 would spill out 115 hp at a certain number of revs, still have 1000 more to go until the red line and have the ideal shift-point before. ideal shift-point would typically be AFTER the red line, mostly because power'd peak just a tad before the red line. (the LX4 comes quite close, iirc)


What's your point? We have a lorry that produces peak power at about 2500rpm but it happily revs to over 4000rpm (due to incorrect gearing). A Series engines routinely put out over 130bhp in historic racing series these days (though they never did in period) and there are claims/rumours that someone got over 200bhp out of a naturally aspirated A Series for hillclimbing. Then of course rotary and forced induction engines can easily produce 5 times the power of the XFG for the same capacity. Capacity isn't what defines an engine.

[eight6er]

I'm not saying I have tried every cars limiter but, I have tried more than the average person and I have never come across a rev limiter like the one in lfs. I have come across top speed limiters that behave like the lfs rev limiter tho, but the same cars did have different rev limiters. So the current rev limiter in lfs may not be realistic therefore it should be changed.
Has anyone here experienced a rev limiter like the lfs one?
Also the engine should not be damaged by simply revving it higher than the rpm gauge says is safe.

[Tim_J_23]

I'm not saying I have tried every cars limiter but, I have tried more than the average person and I have never come across a rev limiter like the one in lfs. I have come across top speed limiters that behave like the lfs rev limiter tho, but the same cars did have different rev limiters. So the current rev limiter in lfs may not be realistic therefore it should be changed.
Has anyone here experienced a rev limiter like the lfs one?
Also the engine should not be damaged by simply revving it higher than the rpm gauge says is safe.

Nope I havn't experienced one like the one in LFS, that's why I made this thread ;)

[Bandit77]

I've race prepared a 1.3l that put out 130hp at 6500rpm, and redlined at 7500. We set the shift light to 7000rpm as that was the overall optimum with the gearing used.

with a stroke as short as you would get only in bike-engines or a highly optimistic redline?


If you don't understand engines or gearing then it's probably best not to try and post technical stuff about them ;)

thanks, tristan, for this piece of advice and how respectfully you put it. can I rely on your omniscience in any other areas of life?

We have a lorry that produces peak power at about 2500rpm but it happily revs to over 4000rpm (due to incorrect gearing).

yeah, a lorry has of course a very sporty engine set up for max power...
and for the rest: my point wasn't about capacity at all.


I'm not saying I have tried every cars limiter but, I have tried more than the average person and I have never come across a rev limiter like the one in lfs.

Fiat Punto Mk2b just as one example (kind of to prove that there IS such a limiter IRL). Engine runs into the limiter, stays there without bouncing... quite the way we have it in LFS. But - to be honest - I'd expect something bouncey from a somewhat aged car - which LFS cars mostly are.

[ajp71]

yeah, a lorry has of course a very sporty engine set up for max power...
and for the rest: my point wasn't about capacity at all.

You've missed the point entirely, a lorry engine has as much relevance to this conversation as what you think the XFG has in it, all we know about it is it is a 1300cc 4 cylinder 4 stroke petrol engine, we don't know anything else about it other than peak power and peak torque figures.

[Tim_J_23]

Anyhow, after all this discussion, can everyone agree on that we should get abit better revv limiter sound and revvdrop while it's on the limiter? :)

[eight6er]

I personally would prefer a bouncing rev limiter, because that is what I am used to hearing and feeling in real life, so it would be more realistic to me.

[Tim_J_23]

I personally would prefer a bouncing rev limiter, because that is what I am used to hearing and feeling in real life, so it would be more realistic to me.

That's the point with the thread.
With the "BABABABAAB" it's the jumping/revvdrops ;)

[eight6er]

Yes, I was agreeing with you.

[tristancliffe]

with a stroke as short as you would get only in bike-engines or a highly optimistic redline?No, 1.3l with a 77.6mm bore and a stroke of 69.7mm, from the late 60s. Could have had more if we'd used a full on race cam at the expense of <2500rpm torque.

thanks, tristan, for this piece of advice and how respectfully you put it. can I rely on your omniscience in any other areas of life?Probably

-----

Most road cars have a crappy bouncy limiter because they're cheaper. Most race cars use a soft limiter, only turning into a hard limiter if you haven't changed gear at the first limiter. But there remains a very large quantity of road cars with soft cuts, and plenty of race cars with hard cut. The current one is actually the ideal limiter, is perfectly realistic, and doesn't need to be changed.

[Sueycide_FD]

just keep letting on and off the throttle when you get to redline. at least thats what i do :tilt:

[Tim_J_23]

just keep letting on and off the throttle when you get to redline. at least thats what i do :tilt:

But we want real revv limiter :nod::D

[Woz]

that'd be only one thing of a bunch of engine-related stuff. I don't really know about the "bigger" cars, but the smaller road cars' engines are still quite a step away from the real thing. I don't think that a 1.3 would spill out 115 hp at a certain number of revs, still have 1000 more to go until the red line and have the ideal shift-point before. ideal shift-point would typically be AFTER the red line, mostly because power'd peak just a tad before the red line. (the LX4 comes quite close, iirc)

so then you could trade ideal shiftpoint and best acceleration against endurance... and set your limiter accordingly, maybe with the option to disable it completely during race.

as for the limiter's behavior itself: I don't care too much, as I don't want to hit it anyway. newer cars' limiters are very smooth though.

Ideal shift point has NOTHING, should I repeat that again... NOTHING to do with the redline point of the engine. The ONLY things that determine the perfect shift point is the shape of the powerband and the gear ratios for the various gears.

Create a missmatch between these and the "perfect" shift point will be well below redline.

[Bandit77]

Could have had more if we'd used a full on race cam

Now THAT's a pretty important detail. So your 1.3 wasn't fully optimized and therefore didn't have the characteristic of a fully optimized or at least consistent, sporty small engine.


Ideal shift point has NOTHING[...] to do with the redline point of the engine. The ONLY things that determine the perfect shift point is the shape of the powerband and the gear ratios for the various gears.

Ok, maybe my english is soooooo freaking bad. Did I say anything different apart from that you might not want to constantly shift at the ideal shift point if it lies 2000 rpm beyond the redline?

Am I the whipping boy? The more you guys (tristan, woz, ajp71 for the most part) write, the more I realize that my points are valid although you disagree. But I will put on some rose tinted glasses and just pretend it's all because I didn't make my points clear, because finally I don't want to write novels here trying to make my points clear to people who don't want to understand and I don't care about. There's no benefit to me - it won't change MY life or the way I see it.

[ajp71]

As I understand it your initial comments were:

1. The redlines are too high for a 1.3 - total nonsense you could produce a 1.3 litre engine that redlined at 18000rpm if you wanted to, likewise you could build one that struggled to rev beyond 4000rpm. Typical redlines for small sporty road engines are probably between 7000-10000rpm, though that is often a long way above peak power/indicated max revs or the rev limiter.

2. Ideal shifting points should come after the redline - If they do then the gearing is wrong

[Daviticus]

Just to comment on the "realism" of the current limiter ...

My '97 VW Jetta VR6 has a soft-limiter almost identical to LFS' at 6500revs. Also, several CA18DET-equipped Nissans I've driven have had such a limiter, albeit with a bit more POP in the pipes from running stupid-rich. :thumb:

I think what most people are looking for in LFS is a forceful ignition-cut style limiter. While it's common and widely-used in the standalone-engine-management world, it's not common in standard-ECU-equipped road cars [they use a fuel-cut limiter].

Just food for thought.

[CrAbStEr DrIfTeR]

i think the cars should all originally have rev limiter's built into them - i know of this in reality as i go to drifts, autotests, rallies and all different things and when hitting high revs any car hits the limiter, even my micra can!!! (equivalent to xrg)

[tristancliffe]

Now THAT's a pretty important detail. So your 1.3 wasn't fully optimized and therefore didn't have the characteristic of a fully optimized or at least consistent, sporty small engine.Well, we could have had 150hp, but it would have taken a VERY skilled driver to make use of it. At clubman level there is more time to be found in drivability than in headline power figures.

Your point was that 1.3s shouldn't produce much power I believe. They can and do.

I don't think that a 1.3 would spill out 115 hp at a certain number of revs, still have 1000 more to go until the red line and have the ideal shift-point before.Easy. We had 130hp at 6500. If you think our 7500 self-imposed rev limit was too high (it wasn't), then let's say 7000 is more 'sensible'. With a slightly milder cam, or a tweak to the induction/exhaust system it would be EASILY possible to get 115hp at 6000rpm, probably even lower. The engine would be even less peaky, and optimum gear change points would be around 6600rpm as a guess with our gearing.
ideal shift-point would typically be AFTER the red line, mostly because power'd peak just a tad before the red line.Not necessarily.

So, as I said before, don't make claims that you can't back up.

so then you could trade ideal shiftpoint and best acceleration against endurance... and set your limiter accordingly, maybe with the option to disable it completely during race.

as for the limiter's behavior itself: I don't care too much, as I don't want to hit it anyway. newer cars' limiters are very smooth though.[/quote]

[eight6er]

Just to comment on the "realism" of the current limiter ...

My '97 VW Jetta VR6 has a soft-limiter almost identical to LFS' at 6500revs. Also, several CA18DET-equipped Nissans I've driven have had such a limiter, albeit with a bit more POP in the pipes from running stupid-rich. :thumb:

I think what most people are looking for in LFS is a forceful ignition-cut style limiter. While it's common and widely-used in the standalone-engine-management world, it's not common in standard-ECU-equipped road cars [they use a fuel-cut limiter].

Just food for thought.

The limiter you speak of in the VR6 and Nissan are similar to the lfs limiter but, they do not just stay exactly on the limit and stay there with no change in revs what so ever, no matter what the conditions. These are two cars I have tried so I know this from experience.
I know the limiter in lfs is probably the perfect limiter for a racing car but most road cars do not have this.

[Crashgate3]

Heya!
The one that turns off the ignition pretty much sounds like this:

Wraaaabababababa BANG babababa BANG The BANG is misfire which often is a cause by the revv limiter since it turns off the ignition on some cylinders.

Is this why a lot of racing cars misfire as they approach corners? Because the rev limiter cuts in as they change down a gear?

[fraghetti]

As i've heard its just the big drop/raise(?) in RPM, not any guarantee though.

[Tim_J_23]

Is this why a lot of racing cars misfire as they approach corners? Because the rev limiter cuts in as they change down a gear?

Nope, that's because of the heel/toe teqniuqe if I'm not mistaking.

[ajp71]

Is this why a lot of racing cars misfire as they approach corners? Because the rev limiter cuts in as they change down a gear?

No that is after fire caused by unburnt fuel getting into the exhaust and igniting, and is often accompanied by a visual display of flames. If the rev limiter was hit in the process of a downshift then the shift would have been far too early and would only audibly engage the limiter during the throttle blip, which is only momentary.

[Crashgate3]

Ah, k :)

How come unburt fuel gets into the exhaust in the first place?

[tristancliffe]

Race engines run a lot of overlap (inlet and exhaust valves open at the same time near top dead centre on the inlet/exhaust strokes), and tend to maintain fuelling on the overrun (off the gas) to keep exhaust gas temperatures and valve/cylinder temperatures under control (and because it improves pick-up a bit too). The fuel can go straight in the inlet valve and straight out of the exhaust valve, where the temperatures can be enough to ignite the fuel and cause pops and flames.

Ideally you don't really want it, if only because the shock waves aren't great for exhaust longevity, but some people reckon the gains are worth the costs. I tend towards no popping and coughing if I can help it, but sometimes throttle response degrades too far (in a track environment - you'd never EVER notice it on the roads) to get rid of it completely.

[Daviticus]

The limiter you speak of in the VR6 and Nissan are similar to the lfs limiter but, they do not just stay exactly on the limit and stay there with no change in revs what so ever, no matter what the conditions. These are two cars I have tried so I know this from experience.
I know the limiter in lfs is probably the perfect limiter for a racing car but most road cars do not have this.

http://s64.photobucket.com/albums/h167/daviticus/?action=view&current=101_0142.flv

Listen closely when I tag the limiter in 1st gear. It's just for a slight moment, before I shift. Burbles right off 6500. It's also audibly noticeable by the change in engine tone [it becomes rough in quick succession, not smooth]. Never once has this car dipped-then-revved while hitting the limiter, it's always a smooth 6500 revs, no more, no less.

Now, go into LFS and redline the XRT, for example. Sounds pretty close to identical, to me. Maybe it's my driving habits at the limiter that create this difference in opinion [trust me, I spend a LOT of time on the limiter, 3rd gear is too tall for some of the twisty roads I tackle and 2nd is just too short :D].

[Mikey Monkfish]

Is this why a lot of racing cars misfire as they approach corners? Because the rev limiter cuts in as they change down a gear?

Because they're highly tuned and run unrestrictive exhaust systems.

Myself, I'd like to see flames out of the exhaust and random pops and bangs on gear changes and when braking. Makes for more atmosphere and realism. :thumb:

[sampax]

actually i would like a proper rev limiter too, it gives these cars more realistic feeling, i don't even think they sound now that they have a rev limiter at all!
it's like: wrooorrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr rrrrrrrrrrrrrrrrrrrrrrrrrrrr.
Sounds like that, it's not realistic at all.
it should go like wroooootoootootootoootootototootootootootootootoo. :D
(funny)
And in racing cars like xrr and so one would have a racing limiter, like real fast misfiring sound, wrototototototototototototototototototo...
:)

[Kerodal]

About those rev limiters... cars have different type of limiters.. lfs has many different cars... so why should not limiter be different between different cars in LFS...
just my 5cents

[G!NhO]

actually i would like a proper rev limiter too, it gives these cars more realistic feeling, i don't even think they sound now that they have a rev limiter at all!
it's like: wrooorrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr rrrrrrrrrrrrrrrrrrrrrrrrrrrr.
Sounds like that, it's not realistic at all.
it should go like wroooootoootootootoootootototootootootootootootoo. :D
(funny)
And in racing cars like xrr and so one would have a racing limiter, like real fast misfiring sound, wrototototototototototototototototototo...
:)

Yes or like N AGNH GAWD GAWG DGBANW BNBGD GA while PAPAPAPAPAPAPAPPAPAPAPNG sounds good too.

[azza14]

http://www.lfsforum.net/showthread.php?t=44137&page=7

:nod:

-rev limiter mod

[assntitties]

Because they're highly tuned and run unrestrictive exhaust systems.

Myself, I'd like to see flames out of the exhaust and random pops and bangs on gear changes and when braking. Makes for more atmosphere and realism. :thumb:

Mini Coopers (the new ones) actually adjust their engine timing when you're off the throttle above 2500 RPM, and the same effect is achieved. You can hear it quite clearly in this video - I blew my exhaust apart taking the fabled Dragon too hard, and the "burbles" sound like gunshots :P
http://www.facebook.com/v/163194687361

Mini Coopers also have a newer type of rev limiter, similar to what the new Fiat Punto has - it's referred to as a "soft" limiter. BMW employed this on the MINI because it has an electronic throttle, and it's much more forgiving when shifting at the limit. Example: the prequel to the video above. You'll hear the MINI hit redline several times in this video...
http://www.facebook.com/v/163005357361

[Ca18Slider]

I think the entire point of this topic was to request an annoying limiter like that noisy Bee*R one, can we just let the LFS cars be LFS cars? They have the perfect limiter, if you're going through a corner sideways ideally you shouldn't even need to be hitting your redline.

[Furiously-Fast]

+1 to a proper rev limiter. I don't really like the current one much, it just sounds like it doesn't have a rev limited just at lower revs. Burnouts and drifts would sound so much rice-ier better with rev limiter sounds. :)

[Ca18Slider]

No, not better. Just more annoying. :P

[Qvarnis]

Bump!

+1 to new rev limiter types. The "BAAAAAAAAAAAAAAA" type is just too diesel like for cars which apparently are petrol powered.

Ignition cut type rev limiters are not in standard cars, but they should be in the R cars. (FZR, XRR, FXR)

And the typical fuel cut limiters should be in normal vehicles...


Here`s a good example of the fuel cut type limiter:

http://www.youtube.com/watch?v=Wrq2c4OA9jQ


Ignition cut limiter:

http://www.youtube.com/watch?v=81GPj-oOoY0

[pärtan]

Just get the "Universal Rev bouncer"
It works awesomely for that type of fuel cut limiter

For the ignition cut limiters, maybe LFS should get backfires first. Would be a good first step.