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View Full Version : Torque graphs of the new Valvetronic Inline-6 engines


Alex Baumann
01-18-2005, 02:52 PM
Courtesy of BMW AG

Alex Baumann
01-18-2005, 02:52 PM
325i left - 330i right

STEVE46
01-18-2005, 02:57 PM
Does BMW try to make it's torque output equal its engine displacement? Or is that just an odd coincidence?

Jspeed
01-20-2005, 10:50 PM
Does BMW try to make it's torque output equal its engine displacement? Or is that just an odd coincidence?
Most efficient street car engines nowadays generate around 100 N-m of torque per liter.

andy_thomas
01-21-2005, 03:50 AM
Most efficient street car engines nowadays generate around 100 N-m of torque per liter.
BMW's 2.0 litre inline petrol four: 200 Nm

Yup :). But this only applies to petrol engines. BMW's diesels kick out anywhere from 170-190 Nm per litre.

Plaz
01-21-2005, 05:31 AM
Nice to see that dip eliminated!

Patrick
01-21-2005, 06:04 AM
You Europeans with your newton meters and killowatts and such... :tsk:

:p


I love the Metric System!


.

Staszek
01-21-2005, 06:55 AM
You Europeans with your newton meters and killowatts and such... :tsk:

:p


:rofl: :rofl:

kyfdx
01-21-2005, 07:24 AM
Does BMW try to make it's torque output equal its engine displacement? Or is that just an odd coincidence?


Well.. It can't be an odd coincidence... I thought both engines were 3.0 litres?

Alex Baumann
01-21-2005, 07:27 AM
I thought both engines were 3.0 litres?

Not the European spec cars. It looks like the US spec cars will be getting the same engine (with different output) according to the order guides that's been mentioned here.

dynosor
01-21-2005, 05:28 PM
BMW's 2.0 litre inline petrol four: 200 Nm

Yup :). But this only applies to petrol engines. BMW's diesels kick out anywhere from 170-190 Nm per litre.

The diesels are all turbo charged. If they were normally aspirated their torque would be lower than the petrol engines.

JAWJr
01-21-2005, 05:34 PM
Not the European spec cars. It looks like the US spec cars will be getting the same engine (with different output) according to the order guides that's been mentioned here.

Maybe a dumb question but if the displacement is the same, what do they change on the engine itself to get a different output out of both? Very confused. :dunno:

Wouldn't that make it easy to mod a lower output car up to the higher output ones? People always say there's no substitute for displacement...

~Jon

philippek
01-21-2005, 05:37 PM
That is quite impressive. 80% of peak torque available at 1100 rpm? Wow.

dynosor
01-21-2005, 06:54 PM
It is very common to use different cams for different applications. These affect the breathing of the engine and determine the torque characteristics. Usually, a light car would get more top end power at the expense of low end torque, and a heavier vehicle (SUV/RV/Truck) would get more torque at low speed at the expense of top end power.

BMW had an eta line of engines in the '80s that were optimized for torque and fuel efficiency. The 528e for example, had its power peak at about 4000 RPM and had no high RPM punch at all.

With double vanos (variable valve timing) and variable inlet track length or resonance there is much less need to make this compromise, and torque can be optimized through a much wider engine speed range. The valvetronic engines have so much torque at low speed that they would work well for SUVs and good top end power too.

It would be possible to limit power and torque by means of the engine controller software, but that would be silly. Even sillier than limiting the performance of a particular model by using very long gearing (low revving).

I seriously doubt that the US will get two derivatives of the 3 liter engine, with one called a "325" in that car. The graphs above strongly suggest displacement of about 2.5 and 3 liters. That does not mean there won't be two 3 liter engines with slightly different characteristics; like with the ZHP engine we have now.

Before variable valve timing it was common for hot rodders to replace the stock cams in their engines for ones that improved top end breathing. Today you have the best of both worlds, but it can still be done. The ZHP is BMW's version of such an engine.


Maybe a dumb question but if the displacement is the same, what do they change on the engine itself to get a different output out of both? Very confused. :dunno:

Wouldn't that make it easy to mod a lower output car up to the higher output ones? People always say there's no substitute for displacement...


~Jon

numbersguy
01-21-2005, 11:05 PM
I seriously doubt that the US will get two derivatives of the 3 liter engine, with one called a "325" in that car.

It's in the ordering guide. Two three liter motors, one producing 185 lbs/ft peak torque and the other 220.

Maybe somebody can explain to me the advantages of a 325i motor that has been so drastically detuned from the 330i. It still runs on premium, according to the guide, so it won't save money at the pump.

Kaz
01-21-2005, 11:22 PM
It's in the ordering guide. Two three liter motors, one producing 185 lbs/ft peak torque and the other 220.

Maybe somebody can explain to me the advantages of a 325i motor that has been so drastically detuned from the 330i. It still runs on premium, according to the guide, so it won't save money at the pump.

If this is really going to be the case, it's probably because displacement sells in this country. The general carbuying public in America will buy a 160hp 4.0l V6 over a 160hp 2.0l 4cyl, even if every other characteristic between the two were exactly the same.

dynosor
01-21-2005, 11:53 PM
It's in the ordering guide. Two three liter motors, one producing 185 lbs/ft peak torque and the other 220.

Maybe somebody can explain to me the advantages of a 325i motor that has been so drastically detuned from the 330i. It still runs on premium, according to the guide, so it won't save money at the pump.

Australian brosure shows 2, 2.5 and 3 liter engines.

http://carpoint.ninemsn.com.au/Tig/UI/ArticlePopup.aspx?market=car&articleid=6431&Alias=carpointau


I believe two three liter engines is a typo, but if this is correct, the only reason to do it is economy of scale:

You cover two marketing price points with only one investment in hardware. Same block, crank , head, etc. That suggests the differences are in cams, because if it is only in software, hacks will be selling cheap upgrades in a hurry.

Kaz
01-22-2005, 12:04 AM
You cover two marketing price points with only one investment in hardware. Same block, crank , head, etc. That suggests the differences are in cams, because if it is only in software, hacks will be selling cheap upgrades in a hurry.

But other markets worldwide will get the other displacements.

dynosor
01-22-2005, 12:06 AM
But other markets worldwide will get the other displacements.

That means the money has already been invested for other engines, so why not use them. The US drops the 2 liter engine; that is enough deviation.

Kaz
01-22-2005, 12:15 AM
That means the money has already been invested for other engines, so why not use them. The US drops the 2 liter engine; that is enough deviation.

Er, you just contradicted yourself. First you say it's economies of scale so they can use the same block/heads/etc. Then next you say they've already made the investment in the different parts. So which is it? :dunno:

dynosor
01-22-2005, 12:16 AM
Based on this info from BMW on the 5 series, who knows...

http://www.bmwusa.com/bmwexperience/buzz/news.htm?article=152

http://66.102.7.104/search?q=cache:_1wOgGXF7WwJ:www.bmwusa.com/bmwexperience/buzz/news.htm%3Farticle%3D152+the+525i+and+525xi+will+o ffer+a+3.0-liter+engine+which+produces+215+hp+&hl=en

"In order to offer improved performance while at the same time improving fuel efficiency and meeting ever more challenging emissions requirements, two 3.0-liter engines will be offered. In the U.S., the 525i and 525xi will offer a 3.0-liter engine which produces 215 hp (SAE net) and 185 lb-ft of torque at 2,750 rpm. Responsiveness in everyday driving situations is outstanding. Nearly 85 percent of peak torque is available from 1000 rpm all the way to 7000. The 530i and 530xi models will feature a 3.0-liter engine which produces 255 hp (SAE net) and 220 lb-ft of torque. Peak torque is available between 2750 and 4000 rpm. Here fully 90 percent of peak torque is available between 1500 and 6700 rpm."

dynosor
01-22-2005, 12:39 AM
Er, you just contradicted yourself. First you say it's economies of scale so they can use the same block/heads/etc. Then next you say they've already made the investment in the different parts. So which is it? :dunno:


Ok, let me make my position clear. I don't know if BMW will offer two versions of the 3 liter engine, but I am trying to find evidence one way or the other.

I think that detuning the 3 liter engine could make sense if it allowed you to build more of the same engine, and not a 2.5 liter engine. As the rest of the world will be getting a range of engines, including a 2.5, offering two 3 liter engines is not being done for economy of scale.

Perhaps I should delete my previous posts or edit them as my opinion develops and new facts come into play. On the other hand, I think I have already edited some and thereby seem to be contradicting myself.

I was offering a potential reason for doing something, not stating that as fact. It seems the facts point away from economy of scale, in this instance.

numbersguy
01-22-2005, 06:36 AM
Detuning might make sense if the detuned motor would run on regular. Which BMW owners would rejoice over a savings of $.25 per gallon? Many of the same ones who drive 325s and 525s with slushboxes. Yet the ordering guide says premium for both motors. Maybe THAT is the typo.

Jalli
01-22-2005, 11:50 AM
or they could just be putting it in there for bragging rights... look even our base model has a 3.0 liter engine...

It is not surprising to me at all that the US would get a 3 liter in both cars. The reason is that competition from other brands is so tough here .

kyfdx
01-22-2005, 12:53 PM
I still don't get it..

I see that Europe is getting a 2.5 litre engine.. But, they are saying that the U.S. 325i will have a 3.0 litre engine..

And, yet.. coincidentally... The power specs for the 2.5 litre and the "de-tuned" 3.0 in the U.S. model are identical?

This just doesn't seem right.. I can't believe they will be building these cars in the next few weeks.. and, no one seems to know for sure..

dynosor
01-22-2005, 01:42 PM
or they could just be putting it in there for bragging rights... look even our base model has a 3.0 liter engine...

It is not surprising to me at all that the US would get a 3 liter in both cars. The reason is that competition from other brands is so tough here .


The same people who would want a bigger number for displacement would want a bigger number for power, compared to competitors. All this silliness, when the only thing that really matters is real world everyday driving performance.

dynosor
01-23-2005, 03:25 AM
http://www.germancarfans.com/news.cfm/newsid/2050118.013/page/1/lang/eng/bmw/1.html

Spec sheet on page 12


"Six-cylinder with extra-light magnesium crankcase.
Developing maximum output of 190 kW/258 bhp, the six-cylinder in the top-of-the-range model outperforms its predecessor by a significant 20 kW/27 bhp. Maximum torque of 300 Nm (221 lb-ft) comes consistently between 2,500 and 4,000 rpm. This is the most powerful and lightest six-cylinder in its segment.
To reduce the weight of the engine to an absolute minimum, BMW is using magnesium for the first time in volume production, with weight down by 30 per cent versus aluminium. Both the crankcase as well as the crankshaft bearings and the cylinder head cover are all made of this sophisticated ultra-light material.

Another new feature in the six-cylinder is VALVETRONIC masterminding the opening times and lift of the intake valves infinitely as a function of the gas pedal position. The result is even more efficient use of the fuel injected into the engine, with engine response being even more spontaneous than before. This technology comes hand-in-hand with double-VANOS variable camshaft adjustment for the intake and outlet valves. The new BMW 330i accelerates to 100 km/h in 6.3 seconds and its top speed is limited to 250 km/h or 155 mph. Fuel consumption in the composite EU cycle is 8.7 litres/100 km equal to 32.5 mpg Imp.

The BMW 325i is also making its debut in spring 2005: Maximum output is 160 kW/218 bhp at 6,500 rpm, maximum torque 250 Nm/184 lb-ft between 2,750 and 4,250 rpm. Engine displacement, as the model designation indicates, is 2.5 litres. "

DaveH
01-24-2005, 08:48 AM
I don't know if you guys have looked closely at the numbers and the shape of the curves, but the specs on the new E90 "325" engine is about the same as the current 330i in the E46-but with a better (flatter) torque curve.

FYI:
KW x 1.3410 = Hp
N-m x 0.7376 = Lb-ft

If you look at the curves side-by-side (Alex Baumann, can you post these?) for the E46 330, the E90 325 and the E90 330, you will see a progression in engine power and consistancy. The older engines, especially the ZHP, had peaks and valleys in the torque which felt like a "hole" in the power output.

I don't know why you think the new 325 is "detuned". It is clearly an improvement over the current 3.0L engine available today. The newer engines are also 22lbs. lighter. I would be very interested to hear more about the fuel injection system (Alex?) on the new cars. These published engine numbers are extraordinary accomplishments in power output

andy_thomas
01-24-2005, 11:30 AM
I don't know why you think the new 325 is "detuned". It is clearly an improvement over the current 3.0L engine available today. The newer engines are also 22lbs. lighter.
Peak power for the "detuned" engine (that's if it turns out to be a 3-litre, and who knows?) is 40 bhp below the 255 bhp version, and 40 lb-ft down also. That sounds like detuning to me.

The outgoing engine has a higher peak than our mystery 215 bhp/184 lb-ft engine, and more power. As you say, it is heavier too. But the comments about detuning are only about the two new engines in isolation. The new Valvetronic units have very little to do with the old; this is not the comparison being made (not intentionally, anyway).

And doesn't 215 bhp/184 lb-ft sound a bit highly strung for a lazy 3-litre? Especially a BMW? The torque/litre figure is very old-hat, even if it has a plateau...

numbersguy
01-24-2005, 11:47 AM
I don't know why you think the new 325 is "detuned". It is clearly an improvement over the current 3.0L engine available today.

I mean detuned in relation to the 330i version of the new 3 liter. Because that version has much greater torque and horsepower and it shares its design with the 325i version I assumed that the higher output version represented a development target for BMW and the lesser version was an adaptation of it. That is also suggested by the use of the 3 liter motor in the 325i for the US market only.

DaveH
01-24-2005, 12:51 PM
The E90 engines will be 2.5L and 3.0L according to the enclosed Spec sheet from you know who:

http://www.autospies.com/images/1-20/bmw/sec12_technicalspecifications.pdf

By the way, I also read in the BMW Interior section that the E90 will be able to house 19" run flats on 199 cast aluminum and 179 2-piece Star spoke rims. 225/35 tires on the front and 255/30 on the rears will be factory approved on the 3 series. The sport seats in the ZSP package will also have the adjustable side bolster like the M3

http://www.autospies.com/images/1-20/bmw/sec8-9_interior,equipmnt,accessories.pdf

Rob325_in_AZ
01-24-2005, 12:58 PM
The E90 engines will be 2.5L and 3.0L according to the enclosed Spec sheet from you know who:
[/url]

It seems this controversy won't go away until the first ones arrive here :dunno:

dynosor
01-24-2005, 07:45 PM
If you look at the curves side-by-side (Alex Baumann, can you post these?) for the E46 330, the E90 325 and the E90 330, you will see a progression in engine power and consistancy. The older engines, especially the ZHP, had peaks and valleys in the torque which felt like a "hole" in the power output.


The graph shown at
http://www.bimmerfest.com/forums/attachment.php?attachmentid=43063
is not a plot taken directly from a dyno. It is a graph with only a few data points from the spec. The curve may very well have dips in it that have not been shown.

Real dyno plots are never completely smooth and ripple-free.

kyfdx
01-25-2005, 07:40 AM
and, I'm not sure why..but...

I really think the U.S. market E90 325i will have the 2.5 litre engine.. And, it has nothing to do with the nomenclature..

Why the heck would they bother to put a 3.0 litre engine in the 325i for the U.S. market, if it has the same torque/horsepower as the 2.5 litre engine that is available in every other market?

Logic will prevail.. I think..

Note.. I'm not betting on this applying to the new engines in the 525i.. since it is a heavier car.. And, if it uses a 3.0 litre, I'll guess that the horsepower/torque stats won't be the same as the 2.5 litre.

regards,
kyfdx

Chris90
01-28-2005, 01:23 PM
(sorry, this is mostly a repost)

Canadiandriver.com new preview also confirms the 3.0L in 325i rumor, and it also says the difference in the two 3.0L engines is intake and software.

In Canada, we'll receive two 3 Series sedans for a mid-year introduction (early summer). The 325i is powered by a 3.0-litre engine with a new magnesium crankshaft making 215-horsepower and 185 lb.-ft. of torque. Like all BMW six-cylinder engines, it's an inline cylinder configuration mounted longitudinally.

The 330i (which we drove at the press introduction) is equipped with the same 3.0 litre engine, but with a different intake and computer management system. It makes 255-horsepower and 220 lb.-ft torque.



http://www.canadiandriver.com/articles/pw/06_bmw_3.htm