27 replies to this topic

[Christiaan]

I am surprised I don't remember anyone mentioning this before but you engine boffs tell me... if FIA limited the rpm to say 14,000 wouldn't that effectively limit power? There would be maximum power that a 3L engine with a certain fuel can develop at a rpm ceiling. Engine builders would now concentrate on making more driveable engines with flat power curves. An offspin would also be an in increase reliability since parts are not subjected to the high number of cyclic stress loads. FIA could provide a standard rev limiter and could very easily police teams using the engine's acoustics.

What do you all think?

[AS110]

Very good idea,but it will never work,it's far too simple.
They will smell a rat,if Max can understand it,well,then anyone could.So it will have to be padded out to the size of a small book,maybe a trilogy even.

[JForce]

It wouldnt slow anything down. The power would just become more and more usable, and the cars would still keep getting faster and faster...

[JollyRoger]

I'm pretty sure I've seen articles where they have suggested that this would just give them more time to optimise the engine for the lowered rev range and that they would eventually have just as much power.

I'd prefer complete freedom to the design of the engine, and just a reduction in capacity to 2.5 litres.

This is only if it's necessary however - generally I'd just prefer they had to run with less downforce. I've got no problem with lap times coming down because of higher straightline speeds however.

[Christiaan]

Originally posted by JForce
It wouldnt slow anything down. The power would just become more and more usable, and the cars would still keep getting faster and faster...

It would certainly lower the max power the engines can generate. If Max went really low to say 10,000rpm I'd think F1 cars would be pegged at speeds of around 250-300km.h, just a guess. Besides, as it is mfrs are pumping dosh towards making engines driveable but are still falling short

AS110 wot do you mean? Its very easy to see who is breaking the rules and who's not by analysing the acoustics of an engine.

[AS110]

Does that mean the track marshals would all carry dictaphones,and hold them out as the cars wizz by?

Yes,I would like to see the engine manufacturers working hard to make useable with a lower rev limit,it would change the focus and give some good racing,for a while at least.

I prefer an engine with a big dosh of mid range,than megga in the top end.

[Jezztor]

Even at 10 000 RPM, LM cars manage to to peak 388km/h with 2.5's and 3's, I've seen it. They rev max 10 000....although there are many millions of variables, the one sticking out like a sore thumb is the closed-wheel aspect, sure, but F1 cars don't reach 388 these days...

It is a good idea, however, I agree it is too simple for the FIA to stipulate...the engines are designed for optimum power at high revs, hence rather sluggish comparative acceleration, but it can all change and engines are going to be hell of a radical in 2004...

Jezz

[Halfwitt]

I read an article in Racetech or RCE saying the best F3000 engines (when it was a competitive series) made about 500bhp. This is a V8 at 9000 rpm. So at 10000 rpm, I'm sure that power would be considerably higher than this.

[AS110]

I'm warming to the idea.

If they then removed the number of cylinders rule,then engines could be designed for specific tracks.A 10,000rpm limit would handycap a V12 more than a 6cyl,so we could see everything from 4cyls to 16cyls,just like the good old days.Engines for tight circuits,engines for high speed circuits.In the 50,s,Guzzi had a 500cc single,and a 500cc V8,both had their uses.

Of course this is not going to reduce costs at all,but who cares,it's not our money to spend.But it will sure sound nice - I bags be an acoustics marshal!

[Christiaan]

I don't understand why this rule is difucult/simple for FIA to communicate. All they say is that the crankshaft speed is not allowed to exceed 10,000rpm, or the frequency of the main reciprocating parts is not allowed to exceed 10kHz. Its a rule that cannot be interpreted otherwise. Jezz, what kind of Torque do those cars have and what is their mass and Cd. The Cd of a F1 car is probably twice that of a LM car.

[Pioneer]

Yes the rule would be clear, but policing it would be... difficult.

How would the FIA know if the rev limit was being exceeded while the car is on track? With 2-way radio communication, the rev limit could be raised and lowered without the driver even doing anything.

[Christiaan]

The can have their own rev limiter installed on the engine, or rev counter. Or they could simply listen to the engine, you can tell by the crests in the sound profile of an engine. they are all harmonics of the fundamental engine frequency which should be the cranckshaft rpm...

[Pioneer]

F1 cars weigh 600 kilos.

LM I think you are taking about the prototype Le Mans/ ALMS cars. They weigh 900 kilos and have intake restrictor plates.

All things being equal, any 3 liter unrestricted naturally aspirated engine will have about the same torque. (Torque is essentially purely dependant on how much fuel you can burn per unit time.) Increasing the revs increases the power.


And yes, you can tell RPM by listening... but you can't listen to the engine constantly. I mean whats to stop the teams from bumping up the revs a bit then putting them back again say in the middle stint of a 2 stopper? Its all software. With 2 way radio communication, its also software that is changeable on the fly.

Unless you mean a hardware rev limiter which I guess would be feasible, someone with more knowledge would have to comment on that.

[BRG]

Haven't F3000 cars always been rev-limited? I believe that they have to use a FIA supplied rev-limiter (given out at the start of each meeting, a bit like pop-off valves in CART). There has never been any problem with this arrnagement that I am aware of. It should be possible to police this satisfactorily, even with a bunch of sharks like the F! teams.

The problem with rev-limiters is that continuing engine development for power makes the useable rev range smaller and smaller. We saw this in Super touring, where the 2 litre engines were rev limited to 6,800rpm IIRC. To get the 300+bhp out of them, the rev range was down to a few hundred revs cutting driveability seriously. The use of an intake restrictor is a better route, as seen in F3, WRC and sports-cars. Here the driveability is less affected, the engine just runs out of puff.

[Jezztor]

Christiaan : don't have access to Cd figures etc atm, but F1 would be under double that of an LM car, LM cars are 50% heavier and run restrictor plates. Your point is definitely taken though. As for the FIA, I mean the concept is very basic really, but too basic that it almost becomes complex, ie. it is extremely hard for the FIA to police. Sure, they could put their own rev limitors on, or EMS linking to 22 central computers with 22 or 44 people managing those, but what's to stop the teams making a 'mock' of this, and setting it to a different shaft diameter, therefore it would seem as if the revs were lower...Ferrari could rev 12 000 and make it look like 10 000.

Acoustics as seen on Digital + are not 100% accurate. You don't need anyone to man central computers come to think of it, as soon as the RPM limit is exceeded, a package is sent to a manned PC (race director?), this could happen with an acoustic dial too, or graph, but it is not accurate.

And what happens if a car hits a kerb too hard, the rear wheels lift, if this is done at 9, 10K rpm, the RPM would exceed the limit, and if the team can't prove the wheels 'skipped', they could be disqualified. The other thing, if TC fails on a car, if the car is going round a bend full out, the wheels can spin without the car spinning out...could also be a problem...thats another aspect of policing...

Jezz

[BRG]

Originally posted by Jezztor
And what happens if a car hits a kerb too hard, the rear wheels lift, if this is done at 9, 10K rpm, the RPM would exceed the limit, and if the team can't prove the wheels 'skipped', they could be disqualified.

Not so. If the wheels become unweighted for whatever reason, the revs can rise, but only until the rev-limit is reached when the limiter will cut in as usual. There is no way to over-rev in these circumstances (unless the limiter used is seriously ineffective!).

The danger area is over-revving when changing down through the gears. Here, the engine can conceivably speeded up by the wheels and exceed the rev-limit despite the limiter cutting off the spoarks and/or the fuel. But with the trick electronic gearboxes now used in F1, this is probably effectively impossible.

[Ali_G]

yes it would be easy to limit power using this method.

But no body want to see this done.

Remember last year when CART were thinking of adopting the IRL enine specs. CART fans were crying out to adopt the 3.5 litre engine, but under no cicumstances not to the adopt the rev limiter.

Its seen as completely too low tech. The engine manufacturers probabley wouldn't like it and lobby agains't it.

A much better option IMo would be to just lower the capacity to 2.5 litres.

A change in fuel being used would be an even easier way. Just specify a fuel with a lower combustive energy. It would lower power vey easily.

Niall

[Ben]

There was an article in RCE a few years ago which showed the various rpm profiles relative to the limiter. It was very clear that a blatent violation of the limit looke very different on the trace than a wheel overspeed for example or a spike caused by a crap downshift.

That said, I think a fuel flow meter or an air restrictor would be better.

Ben

[Jezztor]

Sorry, my bad there...been scanning this thread kinda quickly between classes, was under the impression we were simply talking about limiting the revs, not a rev limiter.

I agree with Ben - it's been done in other formulae, if power restriction has to be introduced, air restrictors would be the easiest to police and very effective.

jezz

[desmo]

I had a chat with an F1 engineer about potential rpm limits in F1, just to gauge his reaction to the idea. His feeling is that profound scrutineering issues would be raised- analagous to the problems encountered in the TC morass. Apparently the Monk limiter employed in F3000 prior to the spec powertrains being mandated was fairly easily outwitted by some of the entrants. In his opinion the only workable way to implement rpm limits in F1 with any certainty of compliance would be to use a single system supplier- a solution that the manufacturers would likely never agree to.

Interestingly, he is of the opinion that absolute engine outputs have actually been relatively stagnant for the last 5 years or so and that the apparent gains in outputs are due to the fact that, "drivability and (by implication) torque curve shape, allied to traction capabilities [including tires] have been the major improvement areas over this time period."

It also seems likely that a de facto rpm limit may have already nearly been reached due to the critical natural frequency of current V10 crankshaft designs, and that barring a major development or innovation in crankshaft design- made (barring perhaps steel matrix MMCs) unlikely by the material stipulation- 19K or so may define an upper limit on rpm until the current Concorde Agreement's 10 cylinder stipulation is due to expire in 2007.

I know his contention that peak power has been pretty stagnant in F1 runs counter to commonly held thought, and in fact may not represent the "official" line of the manufacturers, but I believe he is in a position to at least make well-informed guesses. Perhaps it's just his team!

Many of the pros and cons of various power restriction schemes have been pretty thouroughly hashed out in this earlier thread.

[Christiaan]

Lots of great great stuff on this thread. Okay, let me reply one by one

Pioneer wrote
And yes, you can tell RPM by listening... but you can't listen to the engine constantly. I mean whats to stop the teams from bumping up the revs a bit then putting them back again say in the middle stint of a 2 stopper? Its all software. With 2 way radio communication, its also software that is changeable on the fly.

Don't you think Ron Dennis would be monitoring Ferrari's engine noises, and visa versa? Remember how much controversy a spluttering Ilmor engine produced in 1999? The other thing is yes you can listen t engine constantly, if the listening device is on board - FIA's listening device. Also, you can put listening devices on straights or gentle corners where the engine RPM is likely to reach the maximum. You probably wouldn't need more the 10 per track.

Jezztor wrote
1. LM cars are 50% heavier and run restrictor plates. Your point is definitely taken though.

2. what's to stop the teams making a 'mock' of this, and setting it to a different shaft diameter, therefore it would seem as if the revs were lower...Ferrari could rev 12 000 and make it look like 10 000.

3. Acoustics as seen on Digital + are not 100% accurate.

4. if TC fails on a car, if the car is going round a bend full out, the wheels can spin without the car spinning out...could also be a problem...thats another aspect of policing...

1. Come to think of it, weight doesnt affect top speed, rather accelartion. I think you'd find is an F1 car had the staights that a Le-mans car has its top speed whould be much higher. Look at the fundamental aerodynamic equations
Drag Force = 0.5 x Cd x air density x Cross sectional area velocity^2
and
Power = Thrust Force x Velocity
and solve it for velocity you get
Vmax = [ (2 x Power) / (density x Area x Cd) ]^(1/3)

If an engine produces 750Hp Taking the Cd a high speeds to be about 0.75 (to include not only air resistance but frictional drag); air density to be a maximum of 1kg/cubic meter and the cross sectional area to be a maximum of 1.7sqm (approximating using the dimensions given by FIA) the maximum acheivable velocity of an F1 car would be 370 km/h, which is right in LeMans territory using conservative figures.

[Jezztor]

Weight doesn't affect speed at all, I didn't say that. Weight has to do, with as you rightly said, acceleration, it has to do with momentum, inertia (+ and - direction) and forces to overcome them.Nice calculations Christiaan.

Jezz

PS I'm getting those equasions for you stocked up, then i'll mail them.

[Ali_G]

Christian you must remember one thing though.

The best setup for a heavier car will hae the gear ratios set more towards acceleration. Hence a LeMans cars setup compared to an F1 car will have the gear ratios set up for more acceleration (if both are racing on same course)

Hence in that case an F1 car would aways maul a LM car if racing it on a slow to medium. But on places like a very fast circuit, the LM car would have its legs.

Q. Would a LM car lap faster than a CART car at Fontana.

Niall

[Christiaan]

Hmmm, I didn't finish my post coz i woz late for a planer to Joburg (yes Jezz i was in your nieghbourhood on thursday but drove straight down to Durban)

Okay,

Jezztor wrote

1. LM cars are 50% heavier and run restrictor plates. Your point is definitely taken though.

2. what's to stop the teams making a 'mock' of this, and setting it to a different shaft diameter, therefore it would seem as if the revs were lower...Ferrari could rev 12 000 and make it look like 10 000.

3. Acoustics as seen on Digital + are not 100% accurate.

4. if TC fails on a car, if the car is going round a bend full out, the wheels can spin without the car spinning out...could also be a problem...thats another aspect of policing...

1. An addition, i looked at this months SA Car and they say the frontal area is significantly lower than my calc (I forgot the figure) which increases the speed even more

2. don't understand I actually never thought of how rev meters work but surely the diameter should not be an issue

3. The guru at the university says you get about 3% error on the equipment that he has, which is okay for the purposes of policing coz 3% of say 10k rpm would be 300 extra revs which would probably be less than 1% extra power since rpm and power don't have a linear relationship. The thing is if the engine revved at the peak it would only be for a short part of the track anyway.

4. According to Max, if your car is damaged and it breaks the rules it will be penalised. remember when Schuey's Benneton ran into the grass and lowered his ride height making him faster? Charlie Whiting did not hesitate to disqualify Schummy.

[Jezztor]

*sniff* you don't love me any more! You didn't visit!

Don't have much time to reply - shall do so fully at a later stage, but with relevance to the acoustic endeavor, I didn't realise it was that accurate - and I suppose top - of - the - range FIA acoustic equipment could be even better. Nice info there - I'll speak to the sound engineers at wits too.

Lemme know if ur up here & have a few moments

Jezz

[imaginesix]

If the appeal of F1 could be broken down into it's many individual attributes, I think the single greatest attraction to the sport would be the scream of the engines. A rev limiter rule would kill that attraction.

Also, the unlimited regulation of RPM stands as a vestigial pillar supporting F1's original philosophy of 'purebred' racing. Even if we acknowledge that the F1 image has become nothing but a shell around a 'sports-entertainment' package of a race series, unlimited RPM is still sacred ground. Regulating RPM would officially and publicly mark the end of the ideology that gave birth to the formula.

If it ever comes down to that, then long live the GPWC say I!

[desmo]

I couldn't agree more Yelnats, rpm limits and intake restrictors somehow, subjectively for me anyway, are desecretory incursions of the very terra sancta of the formula! And that terra sancta is an endangered piece of real estate as it stands. Swept volume displacement limits for NA engines have always seemed to me the most elegant and straightforward means of limiting motive power in F1. As the "suits" play an inevitably larger role in the regulation of the sport, some ineffable dimunition of the sport's "soul" seems a grave risk- and utterly unnecessarily IMO. There are innumerable lesser formulae for such things it seems to me.

[Christiaan]

Originally posted by desmo
It also seems likely that a de facto rpm limit may have already nearly been reached due to the critical natural frequency of current V10 crankshaft designs, and that barring a major development or innovation in crankshaft design- made (barring perhaps steel matrix MMCs) unlikely by the material stipulation- 19K or so may define an upper limit on rpm until the current Concorde Agreement's 10 cylinder stipulation is due to expire in 2007.

Desmo this interests me greatly. What are the factors affecting this natural limit? I remember that when Renualt proposed the V10 concept mfrs said it would impossible because of the vibrations, but things don't seem so now. I believe that Renualt's wide angle V10 was trying to counter that problem but found vibrations lower down in the spectrum. They seem to have their little problems solved now but I wonder in they will be able to rev higher than the rest.

The thing is I don't know how relevant air restrictors would be road cars, but I know an RPM limit would make designers pursue driveability of engines, and that is about a s relevant as you can get.