Rev limits - why can't I make an engine rev higher than 10k?

[euniqe]

So yeah, i've never made an engine rev higher than 10k. I've also never noticed the lightweight forged pistons make any difference to peak power at all. Only weight.

Is this because of development? Is it too hard/lengthy at this stage in the development to calculate the mechanical calculations for engines that spin over 10k? Or is it just the dynamics of the engine designer platform itself?

Because i've always wondered why we can choose a rev limit of 12k, yet i've never even been within 2k of that. I've made a less-than-1-litre v8 with minimumn stroke and maximumn bore, lightest possible internals and highest-revs cam setting, yet it still doesn't rev over 10k. When bmw can make a 4.0l v8 that revs to 9k?

What gives? I wanna make a current-day formula one engine (which i can't because of the stroke limit, but that's not the point)

[Juno8]

I have one engine a LCC engine that revs higher than 10k its in the engine section and its that post on the 28th Feb look in there but its an I4 not a V8

[oldgreg]

I've made a less-than-1-litre v8 with minimumn stroke and maximumn bore, lightest possible internals and highest-revs cam setting, yet it still doesn't rev over 10k. When bmw can make a 4.0l v8 that revs to 9k?

I can only assume that what you really mean to say is that it didn't make peak power past 10k rpm. I just built such an engine, and it revved to 12k just fine (ie: with ~39000km mtbf) with peak power at 9600 rpm.

To quote the devs:

We don't really have cam designs that go much past about 9000 as Automation is more focused around Road Car engines than bikes.

[Killrob]

Yes... what oldgreg said. Also, with turbos it does look a bit different, but doesn't change the fact that engines that produce maximum power at over 10k RPM will not be very usable

Over9000.jpg (316.72 KiB) Viewed 6506 times

[Juno8]

KillRob I see what you mean I mean you would have to be hammering along with that engine running for it to be any good and to use all that power....I hope the turbo update is coming out soon I cannot wait for it

[euniqe]

Sorry - yes, I've never made an engine with peak power over 10k - thus giving it a reason to rev above 10k. It doesn't make sense, when you think about motorbike engines, too. Hmm okay so 10500 is a bit higher than i've seen, but it's obviously far short of 12k. And not very usable?

Formula 1 engines spin to over 20k, and they're not exactly "unusable", are they? For a road car, then yes - a plus-10k redline is very unrealistic. But I don't want to build an engine for a road car. I want to build an engine for a race car.

[sc90]

they made it 12k so we could kill engines!

[Juno8]

KillRob can do that because he has access to the Turbo Chargers

[euniqe]

KillRob can do that because he has access to the Turbo Chargers

can do what?

[Juno8]

get that power at that high of the rev band...jeez..

[euniqe]

get that power at that high of the rev band...jeez..

calm down.

Your 1st post implies that you can and have already done the same - make an engine that peaks above 10k. You're also stating that automation needs turbochargers in order to raise where peak power is made. Which makes no sense. If i've misunderstood your first post, and you meant you can make an engine that merely spins to above 10k, not making power above 10k, then whoop-de-doo, so can everyone else if they raise the rev limit enough.

[oldgreg]

You have no-one to blame but yourself for misunderstandings that have arisen as a result of your own poor wording. Saying that an engine "revs to xxxx" is universally understood to refer to the engine's redline. I have literally never, until now, seen it used to refer to the rpm at which peak power is produced nor can I, or most people, even see why anyone would even use it in such a way. The way I, Juno8, and probably everyone else on the forum read your initial post was that you were saying that you couldn't build an engine that would reach 12k rpm without failing. Juno8 was not bragging, because it's not hard to do and we all know it. He was trying to be nice to someone he believed to be an inept newbie by saying "sure you can, here's an example".

And he's stating that peak power cannot currently be produced above 10k rpm in a naturally aspirated engine in Automation. Which is because there are no camshaft profiles in the game that will allow an engine to breathe properly much past 9000 rpm. With the as yet unreleased forced induction update it becomes possible to force the matter somewhat and push the peak power out another ~1000 rpm despite the inadequate cam profile. So yes, as the game currently stands, you need turbochargers to raise the point where peak power is made to above 10k rpm.

[Killrob]

Well spoken oldgreg, this is the case exactly.

[oldgreg]

Speaking of which, are there any plans to include any more aggressive cam profiles in the future? It seems kind of silly to allow 12k rpm redlines but not give us the cam profiles to make it worth doing.

As it stands now, the cam slider set at 100 is just about a perfect match for a 10k rpm redline and if 10k was the max allowable redline I'd think it was really well thought out and well executed. But with a max redline of 12k but cams for 10k there's just this disconnect and, to me, it doesn't feel like good game design. Honestly, I think that if you aren't going to add more cam profiles, you should lower the max rpm to 10k, as it would make for a more polished game.

[1224]

Even if peak power is at 10k doesn't mean a car would have its best acceleration when limiting the revs to 10k. It's seen in a lot of cars that the peak power is not given at the rev limit