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M157 rev limit

AngryDog

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Jun 19, 2017
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628
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Bucks
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E60 M5
I am wondering, why is the rev limit is 6400rpm on the m157? I understand that there will be a reason for it, but does anyone know what it is? Has anyone ever successfully raised it? Is it even worth raising given the amount of torque it makes?
 
I am wondering, why is the rev limit is 6400rpm on the m157? I understand that there will be a reason for it, but does anyone know what it is? Has anyone ever successfully raised it? Is it even worth raising given the amount of torque it makes?

Yeah you can raise it, you got to put a M156 in it!! The big daddy 😉 release that rpm 💥
 
I am wondering, why is the rev limit is 6400rpm on the m157? I understand that there will be a reason for it, but does anyone know what it is? Has anyone ever successfully raised it? Is it even worth raising given the amount of torque it makes?
Not sure on the reason but I'd have thought little point raising it given the torque lower down the range, as you say. I think Peak power is under 6k rpm and starts to drop off fairly quickly above that as the turbos run out out of puff.
 
I understand that there will be a reason for it, but does anyone know what it is?
Rev limits are imposed to ensure that the engine doesn’t achieve a speed at which something in it lets go. That could be anything from overstressing a con-rod, piston, the crank, or even the valve train losing control of the valves.

The engine designer will know what the limiting factor is. In the alternative you could delete the rev limiter on your engine and run to higher and higher rpm it until it grenades, then let us know what the failure root cause was. You may have to repeat the process on a number of engines to be sure that you correctly identify the limiting component(s) though.
Is it even worth raising given the amount of torque it makes?
No.
 
Yeah you can raise it, you got to put a M156 in it!! The big daddy 😉 release that rpm 💥
Lol. My current car has an engine that revs higher than the M156. I see the M156 as a backwards step.
Not sure on the reason but I'd have thought little point raising it given the torque lower down the range, as you say. I think Peak power is under 6k rpm and starts to drop off fairly quickly above that as the turbos run out out of puff.
Makes sense, but I'd wager running out of puff goes away with a remap. It does seem odd for a modern engine of that capacity to rev so low. It seems old school American like.
 
Makes sense, but I'd wager running out of puff goes away with a remap. It does seem odd for a modern engine of that capacity to rev so low. It seems old school American like.
I think it's a fairly similar curve up top even after remap on this engine. The main difference being the increase in mid range torque. Looking at my dyno plot, peak power is 5750rpm after remap.
Renowned remappers "safely" raise rev limits on other engines I've owned on remapping though.
 
I dont think there's anything to be gained by raising a rev limiter without supporting mods. On an N/A engine everything is designed to achieve most power in a usable range and it will determine the length of intake and exhaust manifold, cam, timing etc. Also bore x stroke is a factor and an over square engine is better for high reving engines where as a longer stroke would be choosen for lower revs higher torque. A road car is designed to get the most of it lower down compared to say a track race car that spends more time high up in the revs. It's a compromise depending what you want to achieve and part of an overall design.

The m157 has so much torque available from so low down in the revs because of the turbo it's pointless raising it more, just change gear.
 
Lol. My current car has an engine that revs higher than the M156. I see the M156 as a backwards step.

Would that be that Mpower plant piece of Garbage your welcome to it 😂😂😂💥

For your information I couldn't care what step I have forward back or sideways. Im over the moon with what the M156 offers. It doesn't seem the case with yourself changing from one brand to another. Get the self imploding m157 it will go well with your self imploding E60 💥😁😁
 
Well, clearly you do, else you wouldn't be posting about it at every opportunity.

Ah yes, the S85 V10. Yes it can be unreliable, but that doesn't make it a bad engine. It won engine of the year twice. The M156 only won it once.

The thing about cars is that it isn't the car that's bad, it's the owner. Owners ruin good cars by being ultracrepidarians. I've noticed a few on here of late, ruins the car. Yourself and sbk844 are the perfect examples of misologists.
 
Why would you want to. The point generally about a turbo (or indeed supercharged ) engine is that it can deliver its performance at lower revs and massive torque way lower down. And actually in every day driving unless you only ever drive with your pants on fire with the needle in the red segment, its torque that really matters. Remember that the M156 , great as it is, was as I remember, introduced because at the time the only 7 speed gearbox in the stable couldnt handle the M113k torque. that said a 6.3 litre V8 that can rev to over 7k was pretty impressive at the time and still is.
 
actually in every day driving unless you only ever drive with your pants on fire with the needle in the red segment, its torque that really matters
Absolutely true. The area under the torque curve is always a good indicator of the relative on-road performance of different engines.
 
Yawn 🥱
 
Well, clearly you do, else you wouldn't be posting about it at every opportunity.

Ah yes, the S85 V10. Yes it can be unreliable, but that doesn't make it a bad engine. It won engine of the year twice. The M156 only won it once.

The thing about cars is that it isn't the car that's bad, it's the owner. Owners ruin good cars by being ultracrepidarians. I've noticed a few on here of late, ruins the car. Yourself and sbk844 are the perfect examples of misologists.

Mate, I couldn't give 500 .UC.s what you think of me and my opinion.

I can say hand on heart I'm well happy with a M156 unit. It has to be experienced if you are a petrol head in a lifetime.

Your on the wrong forum. Go back to your BMW cronies 😉
 
Just been out for a drive in your Jag ?

Unlike you and your friend 350 I don’t need to constantly justify why I bought my car or the merits of its engine.

I adore the M156 6.2 V8, it’s definitely one of the best AMG engines of all time BUT owners who constantly have to compare it to others and try and put others down just seem to let down the community somewhat and it’s pretty tiring and boring to read again and again… 🤷‍♂️🤦‍♂️

This was a totally separate thread about a different AMG engine yet both of you still found a way to come in here and preach about the glories of the M156… it would be like someone asking a question about an OM642 diesel and OM648 owners commenting about how their older engine is better in some ways 🤷‍♂️🤦‍♂️ Just totally irrelevant & tiring to read through.
 
Last edited:
Angry woooof woof dog told lies re m156 i corrected him, simple.
 

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