BMW Power at Imola

[E46Fanatic]

Ok here's some inside info.. Next major engine evolution will come at Imola which is 2 races away.------New aero package and new engine P86B spec with 22.000 revs in qualifying and 21.000 in race.(about760HP) It`s about 22.500 on test bench and 21.500-22.000 in races and qualifying.---------Current engine is approx 735hp now which is not bad but not in front. The new spec should see the BMW break some nice speed traps. Would love to see the digital revs on TV climb to 22,000 rpms in quali.. Awesome man!

 

[feisaldzul]

go villeneuve!

 

[flash]

22,000 rpms, cool.

Thot FIA had wanted to put a limit on max revs? :dunno: That didn't come about?

 

[3er]

Amazing how F1 revs keep going up while our mere mortal engines have got our redline stuck at 6-8k for the past decade.

 

[E46Fanatic]

Originally posted by flash@Mar 23 2006, 10:52 PM
Thot FIA had wanted to put a limit on max revs? :dunno: That didn't come about?

They only limited the V10s and let the V8's roam within the technical specifications they outlined for them. Its only the um 4th race or so at imola and we will be seeing 22k rpms. Makes u wonder what rpms we'll be hearing the V8 engines scream at during the last race of the season.

 

[fabianyee]

I thot they were saying that the V8 has some inherent vibration problem unlike the V10 which has vibration in the mid range (10k-12k RPM) then it's smooth to redline.. The V8 tends to vibrate more and at most RPM range..
Interesting to know what they did to overcome the vibration.

 

[flash]

Originally posted by fabianyee@Mar 24 2006, 01:48 PM
I thot they were saying that the V8 has some inherent vibration problem unlike the V10 which has vibration in the mid range (10k-12k RPM) then it's smooth to redline.. The V8 tends to vibrate more and at most RPM range..
Interesting to know what they did to overcome the vibration.

Yeah, now I remember reading about that. The V10s tend to be smoother above 15k, hence we were seeing 19+k rpms.

But at 19k rpms, the V8s would have vibrations. FIA thot by going 90 deg V8, we would not be seeing such rarefied RPMs. Perhaps the engineers at BMW have found that by going even higher RPMs, the vibrations would inherently be lesser? :dunno:

Keeps us wondering what the max limits would be.... maybe 25k rpm would be the norm very soon? But I would not want to be around such an engine when it lets go.... won't be pretty.

 

[fabianyee]

Originally posted by 3er@Mar 24 2006, 12:44 PM
Amazing how F1 revs keep going up while our mere mortal engines have got our redline stuck at 6-8k for the past decade.

that's due to the fact that the F1 Engines are using pneumatic valve controllers while the normal street cars are still on camshafts and valve springs.

For the normal engine to reach higher RPMs, it needs to have strong valve springs or else the valves would float.. Stronger valve springs would also mean more friction on the camshaft lobes and wear them out faster.

I don't foresee manufacturer going the route of higher RPMs engines for the sake of fuel economy and wear and tear issues.

 

[E46Fanatic]

Originally posted by fabianyee@Mar 24 2006, 12:48 AM
I thot they were saying that the V8 has some inherent vibration problem unlike the V10 which has vibration in the mid range (10k-12k RPM) then it's smooth to redline.. The V8 tends to vibrate more and at most RPM range..
Interesting to know what they did to overcome the vibration.

The difference is the critical operating range of the V8 vs V10. Yes you are right, that the V8's vibrations happen over a higher rev range compared to the V10s (12-14+k rpms if I remember for the V10 and around 16k for the V8). What this means is that to extract drivability and usability power, the V8 has to ideally operate at higher rpms compared to the V10. Hence you will see the V8s being pushed higher up the rev range away from its critical vibration range to give it better drivability.

 

[fabianyee]

found the article I read

http://www.autospectator.com/modules/news/...hp?storyid=3284

***************************
Differences.
Although the V8 with the now compulsory cylinder angle of 90 degrees may look like a sawn-off V10, technically it is an entirely separate concept with its own specific requirements. The V8 has a distinct firing sequence and demands a fundamentally different crankshaft design. Whereas a 72-degree offset crankshaft was used in BMW's V10 Formula One engine, V8 powerplants can feature crankshafts with either four throws spaced at 90 degrees or four throws spaced at 180 degrees. Standard production engines are fitted with 90-degree crankshaft variants due to their better dynamic attributes, but a 180-degree crankshaft is favoured in racing car engine design. The improved performance this allows offsets the disadvantages in terms of dynamics.

Indeed, mechanical dynamics and vibrations represent a particularly critical area of development for the new generation of Formula One engines. The V8 units have different firing sequences and intervals from their V10 predecessors, which leads to a totally different situation in terms of vibrations. The V10 entered a critical area in terms of vibrations between 12,000 rpm and 14,000 rpm. However, this was not an issue as the engine did not spend much time in this rev band and smoothed itself out again once the driver stepped up the revs. And, since that was where it spent the majority of its time, vibrations were not a worry. A V8, on the other hand, is not so well off. Its vibration curve enters critical territory later than the V10 - from approximately 16,000 rpm - and continues to climb from there. It is therefore no longer possible to think in terms of getting through a difficult patch and everything will be all right. Now, the problem of constantly increasing vibrations has to be confronted head on. If you don't get a handle on vibrations, they will eat into the service life of the engine and multiply the loads exerted on chassis components. In order to get on top of this problem, the calculation and analysis of each individual engine component has to be totally reliable. However, analysis of the individual components is only part of a bigger challenge. Determining how they work with and against each other in simulations of the overall system is the main task.
***************************

 

[E46Fanatic]

Ya, you are rite... I missed the bit of where the V8 continues to vibrate more after its critical range vs. the V10.. Must be an engineering feat then to get the V8's going to 22,000 rpms and beyond!!

 

[naza2]

wow.. 22,000rpm? that's freaking high. one of limits to designing a reliable engine is not to exceed 5000fpm of piston speed. I wonder if they were able to increase this figure to 5500fpm or something by improving the material or design?

if we assume 5000fpm, it looks like the stroke is limited to about 35mm. this would correspond to approx. 104.5mm bore. wow... very much over squared engine huh? producing almost 800hp? impressive.

 

[f8.]

naza2-nice calculations

but making 800hp at 22k rpm implies having torque of about 260Nm at 22k rpm. would be quite a feat for a 2.4L. but man, 260Nm is even less pulling power than what a 328 or 330 can muster.

though i must say the drivers now probably miss the g force off the starting grid moving from the V10 to V8 for displacement alone.

 

[naza2]

f8, can you please explain how u got those numbers?

yeah 260Nm is not much but at max RPM, that is quite okay i guess. the car's aerodynamics must be very efficient to reduce drag at that rpm if it's really only pushing 260Nm.

but true, you can never replace displacement.

 

[E46Fanatic]

260nm sounds about right. Previous V10 3 ltr F1 engines had about as much torque as a road going E46 M3.

 

[E46Fanatic]

Originally posted by naza2@Mar 24 2006, 04:57 AM
if we assume 5000fpm, it looks like the stroke is limited to about 35mm. this would correspond to approx. 104.5mm bore. wow... very much over squared engine huh? producing almost 800hp? impressive.

Gotta love them oversquare engines! Most race engines are oversquare in design, achieving high max rpms and lower piston speeds than long stroke ones. Ever noticed that most long stroke engines even in production cars have typically very low RPM redlines?

 

[tyke]

eitherway the engines sounds sweet and the car looks superb...
now if only they start finishing in the points and prove wht bmw's can really do!!!

no matter wht,i will be an undying fan of BMW....

 

[f8.]

e46fanatic, agreed, thats why i'm not too much of a big fan of the s54 engine in the e46 m3. its dimensions in bore and stroke lends itself better for a turbo application with lower redline. the engine characteristic would be very similar to that of the 4g63 from the lancer evo, being an undersquare engine too.

if you want to look at a company that has consistenly got it right in their stroke for high revs, its honda. for the f20 engine in the s2000, honda gave it a bore:stroke of 87mm:84mm for max of 240ps at 8300 rpm and a 9000rpm redline.

even for the k20 in the integra and civic type r, its 86:86, a square engine as used by many other legendary engines like nissan's sr20det and toyota's 3s-gte in its latest incarnation in the caldina.

naza2: its quite simple. power is product torque and rotational velocity. 260nm * 22,000rpm * 2 * pi/60s= 598.997kW= ~800hp.

and usually for naturally aspirated engines, if its quite ok, it should give 100Nm/L displacement. question is either it makes this figure at high rpm in which case it will get a good hp/L figure, or at low rpm for massive torqueyness. but turbos... thats another story. no replacement for displacement (for the poor man who can't turbocharge-and superchargers for the not quite theres).

 

[ALBundy]

Think BMW has definitely improved their car judging from today's qualifying...Heidfeld did particularly well, finished 3rd in the second session and Villeneuve will have an uphill battle to prove he is worth to drive for BMW next season.