different bhp same torque? (1 Viewer)

[CazPaul]

Peugeot Boxer 2.0 blue, buying but not sure which base to choose.

130bhp 350nm at 1750rpm

160bhp 350nm at 1750rpm

Can anyone explain the torque, surely the higher bhp should have more torque? As both are the same.

 

[rosalan]

Isn't this a case of different mapping?

 

[DBK]

You can't look at a single point on the graph. The bhp figure is derived from torque multiplied by revs. So the 160 bhp engine will generate more torque above 1750 revs than the 130bhp engine. Typically, bhp peaks at higher revs than torque peaks.

You need to see a graph showing torque and bhp against revs. Ideally, for a relaxed drive, you want a long flat torque curve, this will mean less gear changing.

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[Two on Tour]

Try this for a better understanding of what bhp and torque are and the relationship between them.

 

[Yorick]

HP = Torque x RPM ÷ 5252

So there's something wrong with those figures

 

[funflair]

The 160's torque curve bust be a bit flattter then the 130's so sitll making torque at higher revs means more BHP Power=rpmxtorque,

Max power does not have to be at max torque speed.

Martin

EDIT basically what @DBK says, I got a phone call half way through posting, so a bit late.

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[CazPaul]

HP = Torque x RPM ÷ 5252

So there's something wrong with those figures

Any idea what is wrong though, same 2.0 blue engine in both, same torque figures too.

 

[CazPaul]

Need to try and get my head around it and study more what it means.

 

[andy63]

Peugeot Boxer 2.0 blue, buying but not sure which base to choose.

130bhp 350nm at 1750rpm

160bhp 350nm at 1750rpm

Can anyone explain the torque, surely the higher bhp should have more torque? As both are the same.

its late and I've had a few but I had a quick think and thought the same as you possibly..
to produce 160bhp from the same engine it would have to be reving higher so how they say they both produce their given bhp's at the same revs confuses me... but I'm easily confused
andy

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[Lenny HB]

On the info I found 130, 340 Nm, 160, 350Nm.

 

[2657]

Try this for a better understanding of what bhp and torque are and the relationship between them.

Well that cleared that up then

 

[DBK]

Any idea what is wrong though, same 2.0 blue engine in both, same torque figures too.

There's nothing wrong with the figures you quote. They are as usual a weird mix of imperial and ISO units* but the basics are correct. I am sure both engines generate the same torque at 1750 rpm but the 160 bhp engine will generate more torque than the 130 bhp engine at higher revs. At a certain rpm, I don't know what it is, the 160 bhp engine will generate 160 bhp. The only thing you can be sure of is this won't be at 1750 rpm. Might be 2,200 for example.

Somewhere there will be graphs showing torque/power curves against revs. If you can find them it should make things clearer.

*Forget the divide by 5232 in the video as a result.

This is a blurry image but it might help. The blue curve is torque and the red is bhp. The difference between the 160 and 130 bhp engines will be the red line on the 160 bhp engine will reach a higher peak. At 1750 rpm the 130 and 160 engines will be generating the same torque. I suspect 1750 rpm is on the part of the torque curve which is flat.

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[funflair]

Any idea what is wrong though, same 2.0 blue engine in both, same torque figures too.

Noting wrong its just as DBK say's max power will be at higher revs than maximum torque so as long as the torque curve goes on a bit even below max figure it makes more power than a curve that drops too quick.

Martin

 

[CazPaul]

On the info I found 130, 340 Nm, 160, 350Nm.

Not on the brochure I have, both 350nm at 1750rp, I think you maybe looking at the figures when the 2.0 blue first came out.

 

[CazPaul]

There you go Lenny, dead same torque figures.

7.1 KNOW EVERYTHING ABOUT YOUR BOXER
2.0 BlueHDi 110 2.0 BlueHDi 130
2.0 BlueHDi 130 Stop/Start
2.0 BlueHDi 160
2.0 BlueHDi 160 Stop/Start
DRIVETRAIN Cubic capacity 1997 1997 1997 1997 1997
Number of cylinders 4 4 4 4 4
Maximum power bhp (KW) @ rpm 109 (81) @ 3750rpm 131 (96) @ 3750rpm 131 (96) @ 3750rpm 161 (120) @ 3750rpm 161 (120) @ 3750rpm
Maximum torque Nm @ rpm 304Nm @ 1500rpm 350Nm @ 1750rpm 350Nm @ 1750rpm 350Nm @ 1750rpm 350Nm @ 1750rpm
Bore and Stroke 85 x 88 85 x 88 85 x 88 85 x 88 85 x 88
6 speed manual
Driven Wheels Front Front Front Front Front
BRAKES Ventilated front discs
Rear discs
Rear Drum
ABS with EBFD
SUSPENSION & TYRES
Front Suspension
Rear Suspension
Tyre size: 330 & 333 Models
Tyre size: 335 Models
Tyre size: 435 & 440 Models
STEERING Power Assistance
Rack and Pinion
Vehicle speed and variable rate power assistance

Turns from lock to lock
Turning circle between kerbs/walls (m) L1 Turning circle between kerbs/walls (m) L2 Turning circle between kerbs/walls (m) L3 & L4
ELECTRICAL Alternator
FUEL TANK
Capacity (litres)
FUEL CONSUMPTION L1 versions
Urban MPG (L/100km) 43.5 (6.5) 43.5 (6.5)
Extra urban MPG (L/100km) 49.6 (5.7) 49.6 (5.7)
Combined MPG (L/100km) 47.1 (6.0) 47.1 (6.0)
CO2 Emissions (g/km) 158 158
L2 versions Urban MPG (L/100km) 42.2 (6.7) 42.2 (6.7)
Extra urban MPG (L/100km) 47.9 (5.9) 47.9 (5.9)
Combined MPG (L/100km) 45.6 (6.2) 45.6 (6.2)
CO2 Emissions (g/km) 163 163
L3 versions
Urban MPG (L/100km) 42.2 (6.7)
333 - 42.2 (6.7) 335 - 42.2 (6.7) 435 - 40.9 (6.9)
43.5 (6.5) 435 - 40.9 (6.9)
Extra urban MPG (L/100km) 47.9 (5.9)
333 - 47.9 (5.9) 335 - 47.9 (5.9) 435 - 46.3 (6.1)
49.6 (5.7) 435 - 46.3 (6.1)
Combined MPG (L/100km) 45.6 (6.2)
333 - 45.6 (6.2) 335 - 45.6 (6.2) 435 - 44.1 (6.4)
47.1 (6.0) 435 - 44.1 (6.4)
CO2 Emissions (g/km) 163
333 - 163 335 - 163 435 - 168
159 435 - 168
L4 versions
Urban MPG (L/100km)
435 - 40.9 (6.9) 440 - N/A
440 - N/A
Extra urban MPG (L/100km)
435 - 46.3 (6.1) 440 - N/A
440 - N/A
Combined MPG (L/100km)
435 - 44.1 (6.4) 440 - N/A
440 - N/A
CO2 Emissions (g/km)
435 - 168 440 - N/A
440 - N/A

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[Enword]

Horsepower is how fast you hit the wall. Torque is how far you take the wall with you.

 

[jongood]

IMhO 2 litres is not enough for 3500kgs.

 

[CazPaul]

IMhO 2 litres is not enough for 3500kgs.

I thought that was the trend, engines were getting smaller, cleaner, more efficient, more powerful etc.

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[CazPaul]

You can't look at a single point on the graph. The bhp figure is derived from torque multiplied by revs. So the 160 bhp engine will generate more torque above 1750 revs than the 130bhp engine. Typically, bhp peaks at higher revs than torque peaks.

You need to see a graph showing torque and bhp against revs. Ideally, for a relaxed drive, you want a long flat torque curve, this will mean less gear changing.

Thankyou, but if the 160bhp will generate more torque at a higher rpm shouldn't they quote this figure.
They are both the dead same 2.0 engine.

 

[DBK]

Thankyou, but if the 160bhp will generate more torque at a higher rpm shouldn't they quote this figure.
They are both the dead same 2.0 engine.

I think it would be easier to explain if you could find torque/power curves for these two engines. However, it isn't strange that both produce the same torque at the same speed especially as they are the same engine. But the 160bhp engine must generate more torque than the 130 at higher revs. To do this it probably has a bigger turbocharger or something like that. It won't be generating more than 3500nm as that is the maximum both engines generate. For example the 160 engine might develop 320nm at 3,500 rpm but the 130 engine generate the same 320nm but at lower revs of 2,900rpm. I'm just guessing those figures, which are maximum power points, but they illustrate the difference between the engines. The figures you originally quoted will be the maximum power and maximum torque. What's missing is at what revs the maximum power is generated because it won't be at 1,750rpm. At 1,750 rpm both engines actually generate the same horsepower which is 86 according to this converter: http://ncalculators.com/electrical/torque-to-horsepower-calculator.htm

 

[funflair]

OK it's been a long long since HNC in Mechanical Engineering BUT I will give it a go I am sure @DBK will check and keep me right

The only forumla you need to start as long as you know two of the three variables, the variables being Power (watts), Engine speed (RPM), and torque (nm), is Power = 2 x Pi x n x t/60
The thing that looks like a stonehenge symbol is Pi which we are using at 3.14 it is used in this formula to convert Revs Per Minute (RPM) to radians per second, there are 2Pi radians in 360deg.

Using this information we can calculate Power at the maximum torque figure and torque at the maximum power figure. 120kw = 160 BHP so you can see that at maximum torque point the power is only 50% of max.

Enjoy

Martin

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[CazPaul]

I think it would be easier to explain if you could find torque/power curves for these two engines. However, it isn't strange that both produce the same torque at the same speed especially as they are the same engine. But the 160bhp engine must generate more torque than the 130 at higher revs. To do this it probably has a bigger turbocharger or something like that. It won't be generating more than 3500nm as that is the maximum both engines generate. For example the 160 engine might develop 320nm at 3,500 rpm but the 130 engine generate the same 320nm but at lower revs of 2,900rpm. I'm just guessing those figures, which are maximum power points, but they illustrate the difference between the engines. The figures you originally quoted will be the maximum power and maximum torque. What's missing is at what revs the maximum power is generated because it won't be at 1,750rpm. At 1,750 rpm both engines actually generate the same horsepower which is 86 according to this converter: http://ncalculators.com/electrical/torque-to-horsepower-calculator.htm

That's really useful, many thanks for that. I do understand it a bit better now.

 

[CazPaul]

OK it's been a long long since HNC in Mechanical Engineering BUT I will give it a go I am sure @DBK will check and keep me right

The only forumla you need to start as long as you know two of the three variables, the variables being Power (watts), Engine speed (RPM), and torque (nm), is Power = 2 x Pi x n x t/60
The thing that looks like a stonehenge symbol is Pi which we are using at 3.14 it is used in this formula to convert Revs Per Minute (RPM) to radians per second, there are 2Pi radians in 360deg.

Using this information we can calculate Power at the maximum torque figure and torque at the maximum power figure. 120kw = 160 BHP so you can see that at maximum torque point the power is only 50% of max.

Enjoy

View attachment 193806

Martin

Makes a bit more sense Martin especially coupled with @DBK post. Its still essentially the dead same engine though so will it be more stressed and wear out quicker due to more bhp and more torque.

 

[funflair]

Makes a bit more sense Martin especially coupled with @DBK post. Its still essentially the dead same engine though so will it be more stressed and wear out quicker due to more bhp and more torque.

The simple answer to that could be YES but I don't think it's quite that simple you say its the same engine but there could be subtle differences, I think you are looking a bit too deep.

Martin

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[lawry]

Blimey my brain hurts !

 

[Lorryman100]

Not much help but I remember having this conversation with the head mechanic when I was serving my time as a Diesel mechanic about the whole BHP v Torque arguments. His quote summed it up for me

 

[jongood]

Makes a bit more sense Martin especially coupled with @DBK post. Its still essentially the dead same engine though so will it be more stressed and wear out quicker due to more bhp and more torque.

Thats my point. When you think how advanced modern engines already are I think this is asking for trouble. I have the same issue with 180hp out of the 2.3 Fiat engines.

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[CazPaul]

Thats my point. When you think how advanced modern engines already are I think this is asking for trouble. I have the same issue with 180hp out of the 2.3 Fiat engines.

Yes you could be right but they are all doing it, Merc had the big V6 3.0 190 bhp, now they have gone to 2.2 engines with different power outputs, Fiat 3.0 to 2.3 as you say, VW the same now 2.0, if you want a new van there is not much option I am afraid.
I think it needs someone more qualified than me to say if it is asking for trouble or not.

 

[DBK]

Yes you could be right but they are all doing it, Merc had the big V6 3.0 190 bhp, now they have gone to 2.2 engines with different power outputs, Fiat 3.0 to 2.3 as you say, VW the same now 2.0, if you want a new van there is not much option I am afraid.
I think it needs someone more qualified than me to say if it is asking for trouble or not.

How many miles are you planning to do in your MH? If there is a longevity issue with these new "small" engines I doubt they will show up in a typical MH until it has done 100,000+ miles.

 

[funflair]

Thats my point. When you think how advanced modern engines already are I think this is asking for trouble. I have the same issue with 180hp out of the 2.3 Fiat engines.

MAN 4.6l and 850nm Jon, would that be OK

Martin

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