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The BMW M5/6 engine

Shadowness

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I was just wondering if anyone knew what happens when the engine goes from 400 bhp to 507bhp? I would imagine it would be something similar to the VVT technology in the japanese cars. Any ideas?
Thanks
 
I think it's just the engine mapping. A different software setup gets in, and it injects more fuel and air, and adjusts injection and ignition times. IMHO.
 
yup, good ol computers, I still wonder why they did it though.. Was it because they don't expect the v10 at 100hp a litter to last as long as their old m5 i6's and v8's?
 
A car with such aggressive mappings can get tiresome when in traffic, or when just hawling around.
 
bihus said:
A car with such aggressive mappings can get tiresome when in traffic, or when just hawling around.


I?m with bihus here. Of course I?ve never driven them, but probably when you?re using the mapping with "only" 400 you have more torque in low revs or a smoother powerband, wich sometimes is good, afterall it?s still a car you should be able to use everyday.
 
Yep, most likely the engine setting for 400HP is easier to drive in traffic due to the power characteristics of the engine.
 
bihus said:
A car with such aggressive mappings can get tiresome when in traffic, or when just hawling around.

that wasn't the reason though.

to get the extra 100hp, the car uses about twice the amounth of fuell it needs at 400hp...
 
so it is all ignition/fuel control vs. "multiple displacement" like honda engines? (it is perhaps the one redeeming feature of my sister-in-law's honda minivan-when not necessary (aka cruising) 3 of the 6 cylinders shut off)


VVT could easily cause the change in hp, but it seems like variable/multi displacement with VVT would be more energy efficient.....
 
It's also because the engine is stressed a lot more when producing 507 bhp. There are a lot of rumours going around about blowed M5/M6 engines.
 
freerider said:
It's also because the engine is stressed a lot more when producing 507 bhp. There are a lot of rumours going around about blowed M5/M6 engines.

If that's true, I guess it's got something to do with keeping with the tradition. M3's engines also have an habit to blow out. :mrgreen:
 
It was mostly their first production run of the engines... They had main berrings that weren't made right, They attributed it to a bad supplier. M3 engines were going left and right, but replaced them under warrenty mostly. I saw it everywhere on the bmw board atleast.
 
I always assumed it was different cam timing/lift and fuel/air mapping.

There are many people who run standalone fuel systems with turbocharged engines. They use different air/fuel mapping for city, highway, or track use.
They also vary it according to boost pressure. The changes in performance and economy are huge.

For example, you can have a 200hp engine that gets over 30mpg on the highway. You can have that same engine pumping out over 400hp and get single digit mpg figures.

For a non-turbocharged engine, all you can do is change the cam lift and timing.
Cam lift/timing can vary the revband--give it a wide torque range or give it high end peaky powerband. The fuel/air mixture would be adjusted accordingly.

I've been too lazy to google and figure this one out for sure though.
There should be articles about it somewhere . . .
 
They also vary it according to boost pressure.

i sure hope so!
or you would get a lean condition, resulting in a !BANG!
 
Z Draci said:
I always assumed it was different cam timing/lift and fuel/air mapping.

There are many people who run standalone fuel systems with turbocharged engines. They use different air/fuel mapping for city, highway, or track use.
They also vary it according to boost pressure. The changes in performance and economy are huge.

For example, you can have a 200hp engine that gets over 30mpg on the highway. You can have that same engine pumping out over 400hp and get single digit mpg figures.

For a non-turbocharged engine, all you can do is change the cam lift and timing.
Cam lift/timing can vary the revband--give it a wide torque range or give it high end peaky powerband. The fuel/air mixture would be adjusted accordingly.

I've been too lazy to google and figure this one out for sure though.
There should be articles about it somewhere . . .


what you are saying is *very* true for FI vehicles, but NA vehicles will have much less of a performance boost due to remapping and VVT (something that a stock 5 series has anyway) think of how little gain one gets from a new ECU chip (18-20 hp max??)

The M5 is NA, and while it may be able to get a 107 hp boost mainly on remapped FI and VVT, i find this harder to believe. but if it has a variable displacement system, a 20% decrease/increase in power could be easy if they simply cut out 20% of the displacement (shut off 2 of the 10 cylinders)



Im not stating this as fact though, now i just really want to know HOW BMW does it :p
 
sandor_ said:
Z Draci said:
I always assumed it was different cam timing/lift and fuel/air mapping.

There are many people who run standalone fuel systems with turbocharged engines. They use different air/fuel mapping for city, highway, or track use.
They also vary it according to boost pressure. The changes in performance and economy are huge.

For example, you can have a 200hp engine that gets over 30mpg on the highway. You can have that same engine pumping out over 400hp and get single digit mpg figures.

For a non-turbocharged engine, all you can do is change the cam lift and timing.
Cam lift/timing can vary the revband--give it a wide torque range or give it high end peaky powerband. The fuel/air mixture would be adjusted accordingly.

I've been too lazy to google and figure this one out for sure though.
There should be articles about it somewhere . . .


what you are saying is *very* true for FI vehicles, but NA vehicles will have much less of a performance boost due to remapping and VVT (something that a stock 5 series has anyway) think of how little gain one gets from a new ECU chip (18-20 hp max??)

The M5 is NA, and while it may be able to get a 107 hp boost mainly on remapped FI and VVT, i find this harder to believe. but if it has a variable displacement system, a 20% decrease/increase in power could be easy if they simply cut out 20% of the displacement (shut off 2 of the 10 cylinders)



Im not stating this as fact though, now i just really want to know HOW BMW does it :p

I agree with you to a certain extent, but I think its the other way around: you?re not trying to boost power, you?re reducing power, and 100BHP/liter is not so special when concerning modern BMW engines. BUT, I?m just guessing, I also don?t know how it works, but never heard it?s a variable displacement engine.

On a side note: This thread remembered me a motorcycle prototype I read about a few years ago, where they had an engine with variable compression and displacement. It would automaticaly vary between 600cc and 750cc and/or 7:1 and 12:1 (if I remember correctly) depending on a lot of sensors (RPM, throttle position, etc...) so you would theoreticly have economy or power whenever needed. Seems interesting and I will stop my off-topic now. :oops:
 
Re: The BMW M5/6 engine

Shadowness said:
I was just wondering if anyone knew what happens when the engine goes from 400 bhp to 507bhp? I would imagine it would be something similar to the VVT technology in the japanese cars. Any ideas?
Thanks

weird, I was wondering the same thing yesterday and nearly wrote a topic about it =)
 
then that would've been a repost, caus this topic is already 3 days old :p
 
Hey while we are on the topic of the M6, after watching Top Gear, i was wondering why Richard said the car had 501BHP. I thought it was 507BHP (in M5 atleast) or is there some weird diffrence between the engines??
 
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