53 replies to this topic

[F1Champion]

I had a feeling the magical barrier would be broken but not this soon that's for sure.
Everyone was talking about the 19,000 RPM BMW qualifying engine and Gerhard Berger and Mario Theissen both admitted how good they felt at breaking this barrier.

Mario Theissen's comments

The BMW V10s in the back of the Williams FW24s both reached engine speeds of 19,050rpm, as against the 17,000rpm that was clocked when BMW made its F1 return at Melbourne in March 2000.

"With this record figure we have once again raised the threshold in terms of our engine performance," said Theissen. "For an engineer it is thrilling to see figures which not so long ago were considered unattainable, suddenly becoming reality."

Werner Laurenz's comments

Werner Laurenz, the man responsible for the development of the P82 engine, added: "During the race at Monza the rev counter won't yet hit the 19,000 rpm mark. But in principle we don't develop special qualifying engines. Each development stage is ultimately destined for the race, following its successful deployment in qualifying and the completion of endurance testing."

Since BMW's Formula One comeback, engine speed - and with it power output - has been steadily increasing - from 17,000 rpm (at the start of the 2000 season) to 18,000 (start of 2001) and 18,500 (start of 2002), all the way to the first figure in excess of the 19,000 rpm mark at Monza.


I wonder how long it will take before we will see race trim engines clocking 19,000 RPM. I guess next year will be the engines manufacturers last chance before the one engine per race weekend rule but I'd like to think Ferrari and BMW will get pretty close before the end of 2003.

What are your views?

[Chui]

Well, if anyone recalls it was I who said that they would not reach 20,000 rpm some time ago. I stand corrected.

I don't recall my train of thought now. But I believe it was something to do with increasing revs increase friction [it varies with the cube of engine operating speed]; bore stroke ratio and the time required to burn 90% of the charge.

The latter one is "easy": No turbulence in the combustion chamber. However one loses combustion efficiency at lower engine speeds. This may not be a concern with a modern race car/engine thoughl.

Shell and Honda wrote an SAE Paper describing how they improved the output of the V-12 F1 engine 100 bhp with lower octane fuel over the course of the season. I'll look it up and post the paper number. The lessons learned in this paper would apply to current engines as it deals with burn rates of the fuels used.

[Bluehair]

Congratulations BMW!!! Not only did they turn 19k RPM, but they went ahead and told us about it as well. There are other ways to produce additional horsepower, but increasing the rev limit creates a little more excitement. Now if we could just get an accurate horsepower quote!

[eoin]

"Congratulations BMW!!! Not only did they turn 19k RPM, but they went ahead and told us about it as well."

I think it is possible to find the figure out by analysising the sound,so why not tell us.
BTW has anyone the Revs from the other engines?

[marion5drsn]

One must remember they did not win the race, therefore rpms mean nothing!!! M.L. Anderson

[Jhope]

But they didn`t race it. They only qualifyed it.

[Ray Bell]

And we used to think it was a big deal when the Cosworth DFVs ran to 12,500 rpm!

Would airspeeds in the inlet tracts reaching sonic levels become a problem too?

As they do in F3 cars with their restrictors...

[desmo]

No Ray, due to the very long rod ratios and the generous port cross sections, intake velocities are still remarkably prosaic in these high rpm F1 engines- see the WAVE code thread's graphs I posted for some idea of port velocities before it falls off the bottom of the page due to indifference. Exhaust velocities might be another matter...

I believe that BMW's rpms are the result of some really innovative materials technologies.

[Mark Beckman]

Originally posted by desmo

I believe that BMW's rpms are the result of some really innovative materials technologies.

Are you saying lighter materials or stronger ?

Is it mass or strength that's limiting rpm in F1 ?

Of course theres 10 of thousands of motorbikes running around the roads that do 20000 rpm but these are somewhat smaller in cyl size but they do use common metals for engine parts.

I wonder what bore/stroke ratio BMW used for this one.

I wonder what innovative materials, ceramics ? Leftovers from Roswell ?

I wonder if my dinners ready ?

[Yelnats]

Mark, what are these 20k road bikes that are running the roads by the thousands. I thought even GP bikes didn't reach that rpm but I don't follow this field very closely so I wouldn't bet on it.

About inlet and exhaust velocities. The route to effective power has always been maintaining reasonable levels of volumetric efficiencies at ever increasing rpms. This sets upper limits on inlet and exhaust velocities which is why they haven't changed significantly in the last 30 years and won't in the future unless F1 were to do something silly like restricting valve area to limit maximum power. It's always easier to design larger valves than to increase rpms and this is the route designers will take.

As for increasing friction providing a upper limit, shorter strokes have maintained piston speeds at a reasonable level over the same periods and seem likely to do so for the near future until dinner plate sized pistons become too fragile to endure the heat and accelerative forces at 20k plus rpms.

[wawawa]

Over 150 ignitions per second per cylinder

[Nathan]

Originally posted by eoin
"Congratulations BMW!!! Not only did they turn 19k RPM, but they went ahead and told us about it as well."

I have never understood why numbers like this are so secrative. Its not like Ferrari and Illmor are now going to go 'oh, well if they are pushing 19k then so will we'

[desmo]

Originally posted by Mark Beckman


Are you saying lighter materials or stronger ?

Is it mass or strength that's limiting rpm in F1 ?

Of course theres 10 of thousands of motorbikes running around the roads that do 20000 rpm but these are somewhat smaller in cyl size but they do use common metals for engine parts.

I wonder what bore/stroke ratio BMW used for this one.

I wonder what innovative materials, ceramics ? Leftovers from Roswell ?

I wonder if my dinners ready ?

Lighter and stronger, think specific properties. Stronger and heavier is easy, as is lighter and weaker or less stiff.

Reciprocating masses or crankshaft elastic modulus, since increasing journal diameters is apparently not an option due to oil cavitation in the big end bearings at a critical relative velocities- perhaps developments in lubricants have played a part as well.

Somewhat smaller? Those motorbikes don't have 95mm+ bores!

The S/B must be made more oversquare as rpm climb to maintain piston speeds, an engine used solely as a qualifying engine might be able to "cheat" a little in this respect.

Since the specific modulus limit on metallic materials, the push is on to develop ceramic reinforced MMCs to circumvent the rule.

[eoin]

have never understood why numbers like this are so secrative. Its not like Ferrari and Illmor are now going to go 'oh, well if they are pushing 19k then so will we'

It gives the other teams something to target,and also tells them where they are lacking.

[Mark Beckman]

Originally posted by Yelnats
Mark, what are these 20k road bikes that are running the roads by the thousands. I thought even GP bikes didn't reach that rpm but I don't follow this field very closely so I wouldn't bet on it.

.

Honda CBR250RR is the highest, redlines at 18 or 19 but spins easily past that.

Yamaha FZ250 would be next about 1000 rpm lower.

Both these bikes and the Suzuki 250 have been around going on 10 years now and are readily available everywhere.

Weird riding them sitting at the speed limit of 100 kph at around 10000 rpm !

[Mark Beckman]

Originally posted by desmo


Lighter and stronger, think specific properties. Stronger and heavier is easy, as is lighter and weaker or less stiff.

The S/B must be made more oversquare as rpm climb to maintain piston speeds, an engine used solely as a qualifying engine might be able to "cheat" a little in this respect.

It all goes hand in hand, if they can lighten a component ie; in this case piston, rod, bearing or hardware, while retaining its strength then the rpm/piston speed limit can be raised as well.

Any guesses of cam timing ??

[desmo]

http://members.atlas...io-velocity.bmp

[FNG]

Hey Mark

Are those bikes that you listed two strokes? Just curious?

[VAR1016]

On the subject of motor-cycle engine speeds, at the Goodwood Festival of Speed this year, there was a 1965 Honda: 125CC, five cylinders, each with four valves. This was supposed to have run at 22,000 rpm.

Now of course, like all racers, it would not have been designed to last very long, but given the lubricant , electronic and fuelling technologies of 37 years ago, it must rate as a staggering achievement - even with 25cc cylinders!

PdeRL

[daSilvium]

Originally posted by wawawa
Over 150 ignitions per second per cylinder

Surely it's actually 316 ignitions per second per cylinder.

(If this is referring to 19,000rpm)

[MRC]

Divde that number by two and you'll be spot on. 19,000rpm=316rev/sec, but only 1cycle per 2revs, so 158.3 cylces per second. How many sparks there are might be much higher as good chance they use some kind of mutliple strike spark.

[desmo]

I was actually looking at a graph showing mean reaction rate v CAD published in an SAE paper on F1 engines the other day and IIRC there were two distinct spikes in the reaction rate, one at initial spark (c 55 & 60 degrees BTDC in the examples cited!) and another about 10 degrees later. Again IIRC, there was NO corresponding second spike in mass fraction burned. My initial impulse was to read it as a two event spark per ignition. Does that sound plausible?

Yes I checked again. The paper is #980126 "The Influence of S/B and Combustion Chamber Design on F1 Engine Performance" authors Bianchi, Cantore, Materelli, Guerrini and Papetti (why is it only Ferrari will let their engineers publish?), page 8, figure 16.

[Mark Beckman]

Originally posted by FNG
Hey Mark

Are those bikes that you listed two strokes? Just curious?

No, all 4 strokes.

Contrary to popular belief, 2 strokes dont rev very high in comparison to 4 strokes.

Honda 250cc 2 stroke is around 55 hp at 6000rpm/ aprox 6800 redline
Honda 450cc 4 stroke is around 55 hp at 9000rpm/ aprox 11000 redline

[Mark Beckman]

Originally posted by desmo

My initial impulse was to read it as a two event spark per ignition. Does that sound plausible?

I know that some systems use twin fire in order to keep plugs from fouling and help prevent misfires.

Mazda used a twin point distributor in their domestic VC 1800cc engine (Mazda 929) that fired the plug twice about 5 degrees apart, this was at the peak of anti - pollution equipment on older style carburated 60's - 70's designed engines so I am thinking it helped in the combustion process for cleaner emissions.

[desmo]

That makes sense Mark. Being so oversquare, anything one could do to encourage more complete combustion in in an F1 engine would help thermal conversion efficiency with the side effect of lower unburned hyddrocarbons and perhaps nitrogen oxides as well. I understand F1 engines do have relatively low emissions for being non cat-conned.

2 strokes do, in my experience, tend to be higher revving than 4 strokes. How many cylinders do the engines you cite for comparison have? Our old 100cc kart engines were turning 17krpm back in the '70s, I'm not sure it would have been feasible to make a 17k 100cc 4 stroke single back then. At least one anyone could afford.

[ebin]

Could someone do the math for me (i'm bad at math) and tell me how fast those pistons are going when they rev to 19000 rpm? Or what type of distance they are covering or the g loads they are encountering.

[Scoots]

I remember 10+ years ago RC car 2-stroke engines were approaching 40000 rpm.

[VAR1016]

Originally posted by ebin
Could someone do the math for me (i'm bad at math) and tell me how fast those pistons are going when they rev to 19000 rpm? Or what type of distance they are covering or the g loads they are encountering.

That's easy - all you need to know is the stroke and the mass of the piston/rod assembly!

Best e-mail Patrick Head ;)

PdeRL

[MRC]

Desmo, I took a look at that paper you mentioned. I'm guessing that the mean reaction rate curve spike is more due to how the code handles the energy release for spark modeling, but not sure. It does appear to be right at the spark advance number they give.

VAR1016, you don't need mass to compute g's. You do need stroke and rod length (and any offsets, if you want to get really accurate).

Ebin, I think 96mm for the bore would be a reasonable guess nowadays. That makes the stroke about 41.4mm or .0414m. Average piston speed = 2*Stroke*(revs per second).

So, you get 2*(.0414)*(19,000/60) = 26.22 m/s.

[VAR1016]

Originally posted by MRC
VAR1016, you don't need mass to compute g's. You do need stroke and rod length (and any offsets, if you want to get really accurate).

Ebin, I think 96mm for the bore would be a reasonable guess nowadays. That makes the stroke about 41.4mm or .0414m. Average piston speed = 2*Stroke*(revs per second).

So, you get 2*(.0414)*(19,000/60) = 26.22 m/s.

Quite so - but I have an excuse: it was my birthday, it was late and there had been BEER.

There is also the issue of corrected piston speed - I have forgotten the reason for it but the basic speed is multiplied by the square root of the bore/stroke ratio - originally devised by George Lanchester, this would be very significant in the case of such an extreme short-stroke example.

I prefer ft/min so 26.22M/S = 5161.407 ft/sec

The square root of the bore/stroke ratio (2.3188) is 1.523, so the corrected piston speed is: 7860.8 ft/sec or for the metric folk, 39.93 M/Sec.

These numbers are staggering!

PdeRL

[Mark Beckman]

Originally posted by desmo

2 strokes do, in my experience, tend to be higher revving than 4 strokes. How many cylinders do the engines you cite for comparison have? Our old 100cc kart engines were turning 17krpm back in the '70s, I'm not sure it would have been feasible to make a 17k 100cc 4 stroke single back then. At least one anyone could afford.

I know that Kart engines rev quite high but also there has never been the chance for a 4 stroke to be competitive in that class so no development either and note that the 250 4cylinder production engines go to 20000 and they are 70cc per cylinder so I imagine a 100cc race engine would rev as high as the 17000rpm 2 stroke 100cc Kart engine with ease.

Those engines are off the floor, retail, single cylinder Moto Cross bikes.

I compared equivelent performance bikes, comparison between capacities has a larger difference;

Honda CR 500cc 2 stroke is around 65 hp at 5500rpm/ aprox 6000 redline
Honda CR450cc 4 stroke is around 55 hp at 9000rpm/ aprox 11000 redline
Yamaha YZ426cc 4 stroke is around 55 at 10000rpm/ aprox 12000 redline
Yamaha YZ455cc 4 stroke dynoed at 58 hp at 10500 (modified big bore private bike)

Honda CR250cc 2 stroke is around 55 hp at 6000rpm/ aprox 6800 redline
Yamaha YZ250 4 stroke is around 35 hp at 11000rpm/ aprox 13000 redline

(those Yamaha's are all 5 valve motors)

Again all these are off the floor production MotoCross bikes.

The CR500 motor is basically unchanged now for 15 years because of its massive torque and often I have lowered the exhaust port, lowered the compression to customers CR500's to make them easier to ride and added more flywheel weight for more traction (I hope marion5drsn doesnt see that ).


Even in racing the smaller GP 500cc 4 cylinder 2strokes rev lower than 750cc 4 cylinder 4stroke Superbikes aprox 13000 vs 14000.

What those figures dont tell you though is the awesome mid range torque of modern 2 strokes which often mean its just a waste of time over revving unlike a 4stroke where its of benefit to go past your power peak in order to be as high up the power curve as possible when selecting the next gear, again a myth that 4 strokes make more torque than 2 strokes, myths that were born in the 60's before expansion chambers and reed valves were properly developed and later on exhaust power valves in the early 80's.

[Catalina Park]

I did hear an explanation as to how the Japanese motorcycles reached such high revs.
The story was that they run the tacho off the wrong shaft!

[Mark Beckman]

Originally posted by Catalina Park
I did hear an explanation as to how the Japanese motorcycles reached such high revs.
The story was that they run the tacho off the wrong shaft!

Tachometers on Jap bikes always tend to be a bit exagerated but the tacho on my timing light and the road speed taking the gearing into account gearing says that they are indeed spinning very highly.

By the way the Honda CBR250RR (4stroke 4 cylinder) is rated at 45 hp which is 180 hp per litre, not bad for a production machine that only requires tappet inspection at 20000 kms intervals.

Engine
Configuration Liquid-cooled 4-stroke 16-valve DOHC in-line 4 cylinder Gearbox 6-speed
Bore & Stroke 48.5 x 33.8
Ignition Electronic
Capacity 249cm³
Charging system 12v
Compression Ratio 11.5
Starter Electric
Maximum Power 45PS/15,500rpm
Transmission 6 speed
Maximum Torque 2.6kg-m/12,500rpm
Clutch Wet multiplate
Fuel 4 inline carbs Lubrication

[Top Fuel F1]

I believe it was in a Race Tech "F1 engine development special" magazine over a year ago that Dr. Theissen (BMW F1 Engines) made it quite clear that the door to higher RPM and performance lie in materials developement. Also that that centered primarily with the piston, whether that be a MMC material or something else. If they are now starting to realize the results (.ie Monza practice) they may try to capitalize on this at the USGP and Susuka where (especially at Indy) the long straight(s) exist. The higher RPM could be converted into greater passing ability. Even if a piston were to be virtually weightless other thresholds of limitations (widely discused in other Threads during the past year) that go beyond just materials limitations come into play.

[Electric Sheep]

From Autosport:

With this year's P82 having breached the 19,000rpm mark in qualifying at Monza, the P83 is rumoured to be capable of an astonishing 20,000rpm.

Is this plausible? Can they jump from 19K to 20K like that? It's mighty impressive if they can...

[F1Champion]

I also read that article and I didn't think that it was possible that the P83 could jump to the 20,000 RPM barrier.

I would think that the P82 would be regularly running at over 19,000 RPM because the P83 is going to be better than the P82 qualfying unit. Not sure about 20,000 RPM though.

[Mark Beckman]

Originally posted by Electric Sheep

Is this plausible? Can they jump from 19K to 20K like that? It's mighty impressive if they can...

Think on the lines that the with the P82 they found some things to get it to theorectically get it to 20000 but couldnt because of design limitations which they will be able to free up with a different design, hence the P83.

[Yelnats]

Originally posted by Mark Beckman




Tachometers on Jap bikes always tend to be a bit exagerated but the tacho on my timing light and the road speed taking the gearing into account gearing says that they are indeed spinning very highly.

By the way the Honda CBR250RR (4stroke 4 cylinder) is rated at 45 hp which is 180 hp per litre, not bad for a production machine that only requires tappet inspection at 20000 kms intervals.

Engine
Configuration Liquid-cooled 4-stroke 16-valve DOHC in-line 4 cylinder Gearbox 6-speed
Bore & Stroke 48.5 x 33.8
Ignition Electronic
Capacity 249cm³
Charging system 12v
Compression Ratio 11.5
Starter Electric
Maximum Power 45PS/15,500rpm
Transmission 6 speed
Maximum Torque 2.6kg-m/12,500rpm
Clutch Wet multiplate
Fuel 4 inline carbs Lubrication

Mark, as I suspected 15.5 k peak power is a long way from your statement posted previously......

"Of course theres 10 of thousands of motorbikes running around the roads that do 20000 rpm but these are somewhat smaller in cyl size but they do use common metals for engine parts."

but very impressive all the same. My buddy regularly revs his 1982 Honda Night Hawk to 12 k but no one would call his machine a 12 k road bike as the power peaks at less than 10k.

[H. Eckener]

Mark Beckman,

Are you suggesting that adding weight to the flywheels of your customer's bikes achieve a traction improvement by the same or similar methods put forward by the big bang theory? Fewer pistons from my understanding mean bigger pulses of torque with less crank angle degrees between occurence of said pulses. Bigger flywheels in my mind just resist/dampen fluctuations in the torque coming off the crankshaft.

Which theory does the job in giving you more traction

[Scoots]

Yelnats, in my mind the redline is the redline, the rpm at hp peak is just that. If an engine can spin to 15k without falling apart then it's a 15k engine.

[Mark Beckman]

Originally posted by Yelnats



Mark, as I suspected 15.5 k peak power is a long way from your statement posted previously......

The Honda CBR250RR will rev to 20000 rpm, what has the power peak rpm got to do with maximum rpm ?

Theres hardly an engine in existance that produces max hp at max rpm.

What I suggest you do is go to your Honda motorcycle dealership or whats called a "Grey Import" motorcycle shop and see for yourself.

[Mark Beckman]

Originally posted by H. Eckener
Mark Beckman,

Are you suggesting that adding weight to the flywheels of your customer's bikes achieve a traction improvement by the same or similar methods put forward by the big bang theory? Fewer pistons from my understanding mean bigger pulses of torque with less crank angle degrees between occurence of said pulses. Bigger flywheels in my mind just resist/dampen fluctuations in the torque coming off the crankshaft.

Which theory does the job in giving you more traction

Theory ?? who said theory ?

In the real world, I do something specific, it changes something specific, that is not theory, it is fact and wether or not I can explain it very well or produce a paper on it doesnt change the fact of what it actually does in real time when I operate that machine.

Did you consider what you have yourself said ?

"Bigger flywheels dampen flucuations", did you consider that it may indeed dampen the acceleration of the crankshaft power pulse therefore not breaking traction as abruptly ? and then the extra inertia stops the engine from "bogging" down carrying it to the next pulse.

Kawasaki KX125 2001 new model comments...
"Kawasaki also offers three other flywheels of various weight to fine-tune engine performance to track conditions and riding styles".

Some other reading....
http://www.ardracing...co.uk/page4.htm
http://www.aloop.com/flywheel_info.htm
http://www.cycleworl...vice.xml?body=2


As for the big bang I agree that it seems logical that the increased torque would seem to break traction offsetting the tyre recovery time gain, but in the real world it seems that the extra tyre recovery time wins out.

Both give more traction seperately but you have to pay the price, and that is less power available and note that after winning 5 World 500cc Motorcycle Championships with the big bang motor, Michael Doohan felt that it was worth moving to the 180 degree motor because of the extra hp, but less traction could finally be tamed by the latest tyre technology. (Also they lost about 10 hp because new rules stated the use of unleaded fuel).

[Yelnats]

Originally posted by Mark Beckman


The Honda CBR250RR will rev to 20000 rpm, what has the power peak rpm got to do with maximum rpm ?

Theres hardly an engine in existance that produces max hp at max rpm.

What I suggest you do is go to your Honda motorcycle dealership or whats called a "Grey Import" motorcycle shop and see for yourself.

Your post made no mention of maximum, just before they burst, RPM but instead defined them as 20 k road bikes. A matter of semantics but I'll stick to the manufactures definition and I wouldn't recommend anyone exceed the peak power rev point by 30% on the basis of a BBS recommendation.

[Scoots]

It is not only common, but occasionally makes sense to have a redline (and to shift) beyond the rpm at which maximum hp is achieved. If torque falls slowly after max hp then most of that hp will be available still and there is no reason to shift. On some turbo cars (sorry, don't have dyno graphs available) the boost is reduced steadily to redline (to save the engine and lower peak torque) and the result is a fairly flat graph. I realize that a turbo car is not the same as a 2 or 4 stroke naturally aspirated bike, but it is an example of driving deeper into the revs beyond the hp peak.

[Mark Beckman]

Originally posted by Yelnats


Your post made no mention of maximum, just before they burst, RPM but instead defined them as 20 k road bikes. A matter of semantics but I'll stick to the manufactures definition and I wouldn't recommend anyone exceed the peak power rev point by 30% on the basis of a BBS recommendation.

In the future try reading my posts properly in which I said......

"Honda CBR250RR is the highest, redlines at 18 or 19 but spins easily past that"

And futhermore by "definition" the redline is the manufacturers recommended safe working limit and it doesnt take a rocket scientist to realise that there is a percentage factor past the redline that is still safe or else engines would be going BANG everyday.

Many high performance street or mild racing engines go past the recommended redline with no upgrades to components most likely to suffer from excessive rpm, those components working life are however shortened.

There are hundreds of engine dyno sheets on the net, type in "dyno sheets" into Google and have a study of some noting where peak hp is obtained compared to the maximum rpm obtained.

[H. Eckener]

"Bigger flywheels dampen flucuations", did you consider that it may indeed dampen the acceleration of the crankshaft power pulse therefore not breaking traction as abruptly ? and then the extra inertia stops the engine from "bogging" down carrying it to the next pulse.

Yes that is precisely what I realized and it is at the heart of my question. How can you reconcile the differences between these two methods of improving traction and still keep a straight face? To me the flywheel bit makes sense. Personally, I am skeptical on the big bang theory, especially when people make this one factor out to be so significant. Like the only difference between an I4 bike made by one company and the V2 made by another is the number of torque pulses.

but in the real world it seems that the extra tyre recovery time wins out

So you have proved it in the real world by some means?

[Yelnats]

Originally posted by Mark Beckman


Are you saying lighter materials or stronger ?

Is it mass or strength that's limiting rpm in F1 ?

Of course theres 10 of thousands of motorbikes running around the roads that do 20000 rpm but these are somewhat smaller in cyl size but they do use common metals for engine parts.

I wonder what bore/stroke ratio BMW used for this one.

I wonder what innovative materials, ceramics ? Leftovers from Roswell ?

I wonder if my dinners ready ?

I don't like to belabour this point but this is the post I was responding to. Topic closed!

[Scoots]

Yelnats ... what is your point? That there are not 10,000 motorcycles in existence whose engines can spin to 20000rpm?

Mark B, speaking as a dyno operator I can tell you that many of the dyno charts on-line do indeed lift off right after the power peak, but that is not necesarily a fair representation of redline on those vehicles. My MX-5 redlines at 8500 but I don't dyno beyond 7000.

[Mark Beckman]

Originally posted by Scoots

Mark B, speaking as a dyno operator I can tell you that many of the dyno charts on-line do indeed lift off right after the power peak, but that is not necesarily a fair representation of redline on those vehicles. My MX-5 redlines at 8500 but I don't dyno beyond 7000.

For sure, not much point, after all I guess your main task is to find out what peak horsepower is for most of your clients rather than finding out what the maximum RPM is.

[carlos.maza]

Hi friends:

Formula 1 Technology by Peter Wright, pag 63:

"With RPM continuing to rise steadily and the 19.000 RPM theoretical limit of the V10 within sight, 12 cylinders were inevitably being considered again by engine designers....."

Why a theroretical 19.000 RPM limit for a V10???
Were do these numbers come from?


Thanks

Carlos