RE: 'Beyond 400hp' Mercedes-AMG A45 caught testing
Discussion
clarki said:
Nonsense. The turbo and feuling set up on an fq400 could easy make 400hp.[quote] Remaps at Owen developments had owners seeing nearer 500hp. Mine was stock and would easy pull on any stock 360/340/320.
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The point is a stock FQ400 did not make 400 or more HP from the showroom, they could not do so without exposing owners at risk of engine damage. .
95-98 RON pump fuel under high boost in small displacement conditions is a recipe for detonation if one factor that helps hold it all together falls short. A tuner burdens the risk of engine failure on YOU if you want more power, there are many examples of tuned cars making high boost, hp per litre for many miles, and many others fail within a few dozen miles.
A manufacturer could not get away with those failure rates with a standard car.
Just because you claim you 'easily pull away' from a lesser FQ model, it doesn't mean your car was legitimately and consistently making 400 hp. Having a mere 30-40 hp advantage makes less of a difference compared to poor gear selection, gear shifting etc
It's most likely out of the factory Mitsubishi EVO flash ecu auto adjusted the boost solenoid duty, as well as ignition and fuel maps based on knock count, ether it begins to kerb power/torque once knock is detected (you no longer make 400 hp, more like 360-380 hp), or the base map is detuned further for UK cars due to fuel quality available at the time.
Edited by TwinExit on Wednesday 7th November 15:30
TwinExit said:
or the base map is detuned further for UK cars due to fuel quality available at the time.
Detuned for the UK market? The UK market was the only market the FQ cars existed! As for ionisation current sensing ignition....it's certainly no marketing. It's a very well established system capable of feeding precise combustion information back to the ECU. Better measurement of in cylinder combustion makes it possible to increase both emissions and power efficiency. As I said previously, modern knock sensing and direct injection greatly help the stability of high power, high specific output engines and the management of in cylinder pressures.
http://bmwmotorcycletech.info/ionization-current-s...
RacerMike said:
Peaky? Since when has peak power at 6000rpm ever been called peaky?
By all means pick holes in the stuff people say, but I don't really get what your point is? The engine makes the power, and whether modern knock detection and direct injection help in that is irrelevant. There's no conspiracy....it's 380bhp+ all day long from a 2L Turbo. If you have any specific information about what else helps achieve that, then by all means go into detail, but it's not witchcraft.
The shape of the power curve peaks near the RPM limit, under 6000 rpm the power figures drop dramatically. The point is peak numbers are good for selling cars, it will offer very little improvement in performance.By all means pick holes in the stuff people say, but I don't really get what your point is? The engine makes the power, and whether modern knock detection and direct injection help in that is irrelevant. There's no conspiracy....it's 380bhp+ all day long from a 2L Turbo. If you have any specific information about what else helps achieve that, then by all means go into detail, but it's not witchcraft.
Any gains in acceleration will be thanks to the 9 speed box rather than the 20 extra horses up top.
To have real gains in engine output, either the rev range increases substantially whilst keeping the torque band high as possible (you stay in a lower gear for longer) or you increase torque everywhere which raises IN-GEAR AVERAGE POWER.
The latter point is Mercedes (or any other manufacturer) could not achieve reliably, due to likely hood of engine knock when boosting small displacement engines.
RacerMike said:
1. The engine in the last car clearly isn't peaky by any normal definition. Peaky would be 7k rpm plus in nearly everyone's understanding. 6k would be peaky for a diesel maybe but....
2. The engine doesn't use charge cooling
3. They don't lie about power....well...they do but they understate the power. The current engine is closer to 400bhp than 380bhp.
Considering neither of your 3 statements you made are true, then there are clearly other ways of making 200hp/L from an engine. Either from knock detection and direct injection.....or by other means.
HP/L is meaningless on performance standpoint, it's important that readers understand how peak power is not the same as average power, the latter is more important. Mercedes marketing have fooled a number of people, including yourself that the peak number is indicative of the car's potential against its rivals.2. The engine doesn't use charge cooling
3. They don't lie about power....well...they do but they understate the power. The current engine is closer to 400bhp than 380bhp.
Considering neither of your 3 statements you made are true, then there are clearly other ways of making 200hp/L from an engine. Either from knock detection and direct injection.....or by other means.
The current engine is not underrated, due to the long piston stroke (92.8 mm), you get artificially high torque reading due to high crank throw leverage. If you measure this torque over a period of time (RPM), you can work out the horsepower which too would be artificially high. This is what happens on certain brands of rolling road.
RacerMike said:
Detuned for the UK market? The UK market was the only market the FQ cars existed!
What I meant was the original mapping that supports "400 HP" could have been detuned for sale in the UK market. It probably ran at this headline power during development however too aggressive for UK fuel. And that they didnt feel a FQ375 would sound as racey as FQ400 would it?RacerMike said:
As for ionisation current sensing ignition....it's certainly no marketing. It's a very well established system capable of feeding precise combustion information back to the ECU. Better measurement of in cylinder combustion makes it possible to increase both emissions and power efficiency. As I said previously, modern knock sensing and direct injection greatly help the stability of high power, high specific output engines and the management of in cylinder pressures.
http://bmwmotorcycletech.info/ionization-current-s...
And yet BMW still needed charge cooling for the 500+ HP M4 GTS, a mere 170 HP/L motor, there are practical limits when playing with garage forecourt fuel, no sensor on earth can push the envelope further. A motor can output 400 lbs/ft from 2 litres one day, another day it will knock. How is an ION sensor going to ensure the fuel and air charge is of sufficient composition of anti-knock additives and low enough temperature so it can be ignited safely near or at MBT to make the claimed big numbers?http://bmwmotorcycletech.info/ionization-current-s...
All this literature tells you is it is a better/cost effective way of preventing significant damage upon detection of knock, whenever an anti-knock system kicks into action, the end result is reduced output.
Additionally no sensor on earth (not yet) can predict the manifestation of knock and super-knock, the point of detonation occurs virtually at any location within the combustion chamber.
Engine builders/tuners can only spec out a motor so that it doesn't run into the typical observed conditions where knock most commonly occurs.
Edited by TwinExit on Wednesday 7th November 16:16
Edited by TwinExit on Wednesday 7th November 16:20
TwinExit said:
HP/L is meaningless on performance standpoint, it's important that readers understand how peak power is not the same as average power, the latter is more important. Mercedes marketing have fooled a number of people, including yourself that the peak number is indicative of the car's potential against its rivals.
The current engine is not underrated, due to the long piston stroke (92.8 mm), you get artificially high torque reading due to high crank throw leverage. If you measure this torque over a period of time (RPM), you can work out the horsepower which too would be artificially high. This is what happens on certain brands of rolling road.
I can assure you I haven't been taken in by any marketing thanks. I have good engineering understanding of how engine design and calibration works.The current engine is not underrated, due to the long piston stroke (92.8 mm), you get artificially high torque reading due to high crank throw leverage. If you measure this torque over a period of time (RPM), you can work out the horsepower which too would be artificially high. This is what happens on certain brands of rolling road.
Average power and peak power are two completely different mathmatical concepts. So I'm not sure how this relates. A car that has a high average over it's rev range but a lower peak power won't be faster than a car that has a higher peak power but lower average. Not int he realms of ICE. To get any significant different in that, you need to look down the route of electric motors. Only then will a relatively low peak power but high average make much of a difference...and ultimately it just results in the car feeling fast in different ways. The higher power car is still ultimately faster more of the time (try racing a Tesla P100D against a 720s from 50mph and see what happens).
And crank throw gives you an artificially high torque value? Eh? It produces a given amount of torque, and at a given engine speed. What's artificial about that? No one is measuring any torque value here apart from the one at the output of the crank. It could have an 18ft crank throw for all anyone cares. If it produces 450Nm, it produces 450Nm.
To me it seems like you have some issue with the philosophy of the engine design, and that you would, for some reason, like an engine that delivers maximum power half way up the rev range. From a customer attribute view point this (IMHO) is as boring as f..... Where's the joy to be had in an engine that just goes flat for the last 2000rpm? I want something (whether it's a manual or a Dual Clutch) that pulls all the way to the limiter. By your own definition, this would suggest it would be 'peaky', but nearly every 'great' engine in history does exactly this.
RacerMike said:
Average power and peak power are two completely different mathmatical concepts. So I'm not sure how this relates. A car that has a high average over it's rev range but a lower peak power won't be faster than a car that has a higher peak power but lower average.
The car with the higher average power across say 5000-7000 RPM will be quicker than a car with a higher peak power and lower average power across the same RPM range.Every successful engine builder, fast drag racer or tuner will support this, only random posters on PH feel this is all wrong.
RacerMike said:
And crank throw gives you an artificially high torque value? Eh? It produces a given amount of torque, and at a given engine speed. What's artificial about that? No one is measuring any torque value here apart from the one at the output of the crank. It could have an 18ft crank throw for all anyone cares. If it produces 450Nm, it produces 450Nm.
Because an engine accelerates a car based on progression from x RPM to y RPM vs time. The faster an engine can reach the end RPM whilst coupled to the transmission and wheels, the higher the performance.A long throw crank/ long stroke motor produces more torque than the same sized motor with a shorter stroke with similar cylinder pressure. If you then multiply the torque value by the rotation speed (RPM) you get an artificially high HP number. This does not translate into more acceleration despite higher 'calculated' figure, as longer stroke needs more time to complete its intake, exhaust and compression phases due to longer piston travel distance.
RacerMike said:
To me it seems like you have some issue with the philosophy of the engine design, and that you would, for some reason, like an engine that delivers maximum power half way up the rev range. From a customer attribute view point this (IMHO) is as boring as f..... Where's the joy to be had in an engine that just goes flat for the last 2000rpm? I want something (whether it's a manual or a Dual Clutch) that pulls all the way to the limiter. By your own definition, this would suggest it would be 'peaky', but nearly every 'great' engine in history does exactly this.
I simply posted 3 likely approaches that Mercedes would take to reliably 'offer' 400 HP from 2 litres with warranty, it is posters like you who appear have an issue with it. Simply because if it is true ..... it somewhat deflates the engineering hyperbole a little.Edited by TwinExit on Wednesday 7th November 17:29
TwinExit said:
RacerMike said:
Average power and peak power are two completely different mathmatical concepts. So I'm not sure how this relates. A car that has a high average over it's rev range but a lower peak power won't be faster than a car that has a higher peak power but lower average.
The car with the higher average power across say 5000-7000 RPM will be quicker than a car with a higher peak power and lower average power across the same RPM range.Every successful engine builder, fast drag racer or tuner will support this, only random posters on PH feel this is all wrong.
RacerMike said:
And crank throw gives you an artificially high torque value? Eh? It produces a given amount of torque, and at a given engine speed. What's artificial about that? No one is measuring any torque value here apart from the one at the output of the crank. It could have an 18ft crank throw for all anyone cares. If it produces 450Nm, it produces 450Nm.
Because an engine accelerates a car based on progression from x RPM to y RPM vs time. The faster an engine can reach the end RPM whilst coupled to the transmission and wheels, the higher the performance.A long throw crank/ long stroke motor produces more torque than the same sized motor with a shorter stroke with similar cylinder pressure. If you then multiply the torque value by the rotation speed (RPM) you get an artificially high HP number. This does not translate into more acceleration despite higher 'calculated' figure, as longer stroke needs more time to complete its intake, exhaust and compression phases due to longer piston travel distance.
RacerMike said:
To me it seems like you have some issue with the philosophy of the engine design, and that you would, for some reason, like an engine that delivers maximum power half way up the rev range. From a customer attribute view point this (IMHO) is as boring as f..... Where's the joy to be had in an engine that just goes flat for the last 2000rpm? I want something (whether it's a manual or a Dual Clutch) that pulls all the way to the limiter. By your own definition, this would suggest it would be 'peaky', but nearly every 'great' engine in history does exactly this.
I simply posted 3 likely approaches that Mercedes would take to reliably 'offer' 400 HP from 2 litres with warranty, it is posters like you who appear have an issue with it. Simply because if it is true ..... it somewhat deflates the engineering hyperbole a little.With a road car engine, the character, driveability, emissions, transient response, off throttle response etc etc are all a considerable influence. As I said previously, a linear power curve that pulls until the limiter is a desirable attribute to have for most drivers, so a flat power curve that peaks a thousand RPM before the limiter is relatively boring to drive.
To be clear, I have no real interest in owning an A45. I've had a Focus RS for the last 2 years and want something a bit less practical, but I think you're seeing this from a very 1D viewpoint which you believe is the only valid one....
Geeze Louise consumers can have their cake and eat into these days -all that feel good luxury and cabin ambience with an demented powertrain.
Struts, aluminium wishbone multilink rear end, torque vectoring, AWD, 2.0 heavily turbocharged, sounds like Bemz are finally cat him up to the 90s Mitsubishi Evo formula
Struts, aluminium wishbone multilink rear end, torque vectoring, AWD, 2.0 heavily turbocharged, sounds like Bemz are finally cat him up to the 90s Mitsubishi Evo formula
TwinExit said:
Because an engine accelerates a car based on progression from x RPM to y RPM vs time. The faster an engine can reach the end RPM whilst coupled to the transmission and wheels, the higher the performance.
A long throw crank/ long stroke motor produces more torque than the same sized motor with a shorter stroke with similar cylinder pressure. If you then multiply the torque value by the rotation speed (RPM) you get an artificially high HP number. This does not translate into more acceleration despite higher 'calculated' figure, as longer stroke needs more time to complete its intake, exhaust and compression phases due to longer piston travel distance.
Euhm. Long story short, a longer stroke engine produces more torque but doesn't rev as high, in the end power is about the same as power = torque x revs. Obviously any difference in revs can be compensated by gearing. A long throw crank/ long stroke motor produces more torque than the same sized motor with a shorter stroke with similar cylinder pressure. If you then multiply the torque value by the rotation speed (RPM) you get an artificially high HP number. This does not translate into more acceleration despite higher 'calculated' figure, as longer stroke needs more time to complete its intake, exhaust and compression phases due to longer piston travel distance.
Or put differently, a longer stroke doesn't need to make the same change in rpm to reach the same increase in power and speed.
I have no clue what you mean by 'an artificially high HP number'. Either the HP is, or it isn't....
To add, longer stroke means higher torque means stronger drivetrain components means higher weight. Lower revs means higher efficiency and higher comfort. Engineers make a balance.
I'll leave it at that.
RacerMike said:
To be clear, I have no real interest in owning an A45. I've had a Focus RS for the last 2 years and want something a bit less practical, but I think you're seeing this from a very 1D viewpoint which you believe is the only valid one....
I too owned a MK3 Focus RS until last May, wasn't really interested in the 350 HP rated power it had, I just wanted to buy into the 'Fast Ford' scene and enjoy the 5 door practicality.When the hype surrounds peak head line power numbers and high HP per Litre, it just sends the wrong message out to less informed punters and brews up unjustifiable hype.
Thornaby said:
I drive past that dealer quite often and I'm sure that it's still sitting there in the showroom, or was until very recently. Onehp said:
Euhm. Long story short, a longer stroke engine produces more torque but doesn't rev as high, in the end power is about the same as power = torque x revs. Obviously any difference in revs can be compensated by gearing.
Or put differently, a longer stroke doesn't need to make the same change in rpm to reach the same increase in power and speed.
A long stroke can be made to rev high, that is not the point. The point is the method of capturing engine output will yield different numbers, which can often mislead owners and tuners, and many stories of 'my new car makes more horses than what the brochure quoted me'. Or put differently, a longer stroke doesn't need to make the same change in rpm to reach the same increase in power and speed.
When placed on a load/cell dyno, when you work out the estimated transmission losses, the calculated power readings are much closer to the manufacturer numbers as they too use the same method to obtain the output (measured direct at the flywheel/crankshaft using a brake).
TwinExit said:
Onehp said:
Euhm. Long story short, a longer stroke engine produces more torque but doesn't rev as high, in the end power is about the same as power = torque x revs. Obviously any difference in revs can be compensated by gearing.
Or put differently, a longer stroke doesn't need to make the same change in rpm to reach the same increase in power and speed.
A long stroke can be made to rev high, that is not the point. The point is the method of capturing engine output will yield different numbers, which can often mislead owners and tuners, and many stories of 'my new car makes more horses than what the brochure quoted me'. Or put differently, a longer stroke doesn't need to make the same change in rpm to reach the same increase in power and speed.
When placed on a load/cell dyno, when you work out the estimated transmission losses, the calculated power readings are much closer to the manufacturer numbers as they too use the same method to obtain the output (measured direct at the flywheel/crankshaft using a brake).
A shorter stroke engine WILL rev further because the piston speed will be lower than the long stroke version. That's why F1 engines have very short stroke and wide bores - to allow them to rev to very high rpm.
TwinExit said:
mwstewart said:
Not technically true. The ion sensing system in one of my cars detects changes in combustion chamber chemistry that are a precursor to pre-ignition.
Sorry but that looks to be marketing nonsense.Firstly Pre-ignition is NOT knock.
Pre-ignition is not a result of 'combustion chamber chemistry', it can be triggered by various factors.
The subject is all too complicated to be discussed on a thread about a hot hatch
Pre-ignition and knock can be considered the same thing for what we are discussing here: a limitation in peak power due to elevated combustion pressure or extremes of temperature.
TwinExit said:
PixelpeepS3 said:
Remember when the Evo FQ-400 came out... had to be serviced every 4000 miles?
think we've progressed rather well since then
The FQ400 rarely proved itself to make the claimed power output on the available pump fuel of the time. Owners reported 340-350 HP.think we've progressed rather well since then
Hard turbocharged engines require frequent oil changes due to thermal break down and fuel dilation.
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