Ultimate Street Sleeper - Mercedes W124 'Superturbodiesel'
Discussion
It's an interesting discussion I think. On the one hand, there are drag racing diesels putting out about 2,000 hp from 6.7 litres, so 500 or so from 3.0 litres doesn't seem beyond the realms of possibility.
On the other hand, I watched the DPUK youtube channel for a bit yesterday. One thing of note in the comments section was one or two guys from Finland who said that flywheel horsepower of 450-470 was about the limit with the mods that had been done to this particular car. (Which is what Max Torque is also saying, in between the lines).
The guy from DPUK effectively laughed at this notion, as they are 'making' 560 at the wheels, kind of suggesting the Finns don't know what they're doing. That's effectively another 200 hp over what the Finns suggest flywheel horsepower could be.
That may of course be true, but I wonder if in fact there's something they're doing wrong with the Dyno setup.
It's a hub dyno, the question in my mind is how it measures power. Is it simply recording the torque at the wheels, and using the wheel speed to arrive at the power figure? Or can it also measure power at the same time?
To me, it's not unfeasible that someone has put a parameter in wrong, which is giving inaccurate figures.
The graphs that are being produced on the computer are showing engine revs against wheel horsepower. It's possible that there's a numerical error with gearing or the way engine revs are being measured. I would be interested to see it on a different dyne for comparison.
Not that any of this detracts from the achievement here, it's still a phenomenal power output from an engine with essentially unmodified internals. It's on the verge of being undriveable if the power is used, but impressive nonetheless.
On the other hand, I watched the DPUK youtube channel for a bit yesterday. One thing of note in the comments section was one or two guys from Finland who said that flywheel horsepower of 450-470 was about the limit with the mods that had been done to this particular car. (Which is what Max Torque is also saying, in between the lines).
The guy from DPUK effectively laughed at this notion, as they are 'making' 560 at the wheels, kind of suggesting the Finns don't know what they're doing. That's effectively another 200 hp over what the Finns suggest flywheel horsepower could be.
That may of course be true, but I wonder if in fact there's something they're doing wrong with the Dyno setup.
It's a hub dyno, the question in my mind is how it measures power. Is it simply recording the torque at the wheels, and using the wheel speed to arrive at the power figure? Or can it also measure power at the same time?
To me, it's not unfeasible that someone has put a parameter in wrong, which is giving inaccurate figures.
The graphs that are being produced on the computer are showing engine revs against wheel horsepower. It's possible that there's a numerical error with gearing or the way engine revs are being measured. I would be interested to see it on a different dyne for comparison.
Not that any of this detracts from the achievement here, it's still a phenomenal power output from an engine with essentially unmodified internals. It's on the verge of being undriveable if the power is used, but impressive nonetheless.
xjay1337 said:
From the casual onlooker how does this look? They wouldn't want to post up and share their projects because people would assume it's BS.
More likely they'd think: "Blimey, it's not as clear as it seems. I wonder if the company selling me this superturbo stuff is telling me the whole truth. Before I splash out the cash, and start shouting about these super-high numbers, perhaps I should find out more."I don't think anyone (inc Max Torque) is slating this car and there certainly hasn't been diesel hate. I too think this is a great sleeper, does exactly what a sleeper should.
I think it would be fair to say that Max came in a little heavy which has put the OP and others noses out. BUT and this is the important bit, what Max does have is 20+ years experience of developing cars/power trains at the highest levels of Motorsport and Road car development. I think that gives him a far greater insight to what is and what isn't possible than about 99% of the other contributors, myself inculded.
There is a reason that Motorsport and Roadcar Manufacturers use MIRA homologation quality dynos for engine development rather than 'Jo Smiths' mobile rolling road. They just aren't accurate enough and there are far too many variables. As Max stated earlier in the thread, when he has benchmarked a well respected rolling road companies product against an engine previously dyno'd on a homologation quality dyno, it was over reading by 20%.
I'll say again, I think this is a great sleeper but I'm afraid I too just cannot believe the figures. 450bhp @ 5500rpm @ the crank yes, 600+ no.
Will it rev to 8000rpm? Who knows, but they certainly didn't bother on that dyno run. Maybe it would as it's an unusual design for a diesel being so under square. What power would it produce at those revs? I'd guess at sub 100 bhp. It certainly sounds like its screaming at very high revs in one of the clips, but I'm pretty sure what you're hearing the the turbine.
So OP, you've bought a great car, I think the builders are a little ambitious with their claims but that shouldn't stop you from enjoying it and surprising a few people.
I think it would be fair to say that Max came in a little heavy which has put the OP and others noses out. BUT and this is the important bit, what Max does have is 20+ years experience of developing cars/power trains at the highest levels of Motorsport and Road car development. I think that gives him a far greater insight to what is and what isn't possible than about 99% of the other contributors, myself inculded.
There is a reason that Motorsport and Roadcar Manufacturers use MIRA homologation quality dynos for engine development rather than 'Jo Smiths' mobile rolling road. They just aren't accurate enough and there are far too many variables. As Max stated earlier in the thread, when he has benchmarked a well respected rolling road companies product against an engine previously dyno'd on a homologation quality dyno, it was over reading by 20%.
I'll say again, I think this is a great sleeper but I'm afraid I too just cannot believe the figures. 450bhp @ 5500rpm @ the crank yes, 600+ no.
Will it rev to 8000rpm? Who knows, but they certainly didn't bother on that dyno run. Maybe it would as it's an unusual design for a diesel being so under square. What power would it produce at those revs? I'd guess at sub 100 bhp. It certainly sounds like its screaming at very high revs in one of the clips, but I'm pretty sure what you're hearing the the turbine.
So OP, you've bought a great car, I think the builders are a little ambitious with their claims but that shouldn't stop you from enjoying it and surprising a few people.
Edited by Mikeeb on Monday 8th February 11:10
xjay1337 said:
dyno proof
I lol'd.(Commercial) rolling roads and dynos are notoriously inconsistent which is why Max torque talks about a calibrated facility like Mira. He's backed it up with an explanation of the theory behind diesel combustion, and sensible reasoning why the figures stated don't stack up.
I don't think anyone has slated the OPs car, indeed most of the feedback has been positive. The technical explanation doesn't take anything away from that.
xjay1337 said:
From the casual onlooker how does this look? They wouldn't want to post up and share their projects because people would assume it's BS.
There is huge amounts of BS in the aftermarket though. I'm all for this being filtered out, and the best way for this to be done is through better educated customers with more knowledge to appraise claims being madexjay1337 said:
Professional engineer can't measure an engines power.
Max Torque may be very smart but he can't measure an engines power over the internet looking down his nose.
As for his calculations about pressure then I see it being poor reasoning that if a BMW 535d is doing 33psi pressure that this Mercedes can't do 38psi of pressure. It is WELL KNOWN that certain engines, usually diesels, can be pushed way beyond their stock power.
1.9 PD Golf engines can safely go to 320-330bhp on stock internals and that's cheap VW tat. You can probably push a bit more but then it gets risky - Infact from memory, Darkside Developments only blew up a PD engine at 430bhp. (these engines are 105, 115, 130, 140 or 150bhp and all share the same internals other than a few select models (eg the PD115) aside from turbo and injectors.
As I said the most frustrating thing for me is that this is clearly hating the little guy, especially when it comes to diesels. Someone comes up with an interesting car (certainly more interesting than a E92 M3 with the CSL pack) which has dyno proof of a lot of power, more than most other cars on here, and people can't just say "well done mate", there's always someone who has to say "I call custard", thinking they are smart/clever.
Then the usual band of arselickers follow suit going "yes, yes I agree with you, it is preposterous" because they look up to an individual smart poster (probably because of daddy issues at a younger age)
From the casual onlooker how does this look? They wouldn't want to post up and share their projects because people would assume it's BS.
The thing that REALLY gets me, is I guarantee, had this been a Ferrari F40, which has what, 470bhp, if someone said they'd change their turbos and it was now 800bhp with a dyno chart to proof, everyone would be wowing it, wanting to sleep with the OP, not calculating engine pressures at max BHP when compared to a Ferrari 458, or saying that it's actually 500bhp.
If you can get the chip off your shoulder, whether it's a Ferrari or Mercedes doesn't matter.Max Torque may be very smart but he can't measure an engines power over the internet looking down his nose.
As for his calculations about pressure then I see it being poor reasoning that if a BMW 535d is doing 33psi pressure that this Mercedes can't do 38psi of pressure. It is WELL KNOWN that certain engines, usually diesels, can be pushed way beyond their stock power.
1.9 PD Golf engines can safely go to 320-330bhp on stock internals and that's cheap VW tat. You can probably push a bit more but then it gets risky - Infact from memory, Darkside Developments only blew up a PD engine at 430bhp. (these engines are 105, 115, 130, 140 or 150bhp and all share the same internals other than a few select models (eg the PD115) aside from turbo and injectors.
As I said the most frustrating thing for me is that this is clearly hating the little guy, especially when it comes to diesels. Someone comes up with an interesting car (certainly more interesting than a E92 M3 with the CSL pack) which has dyno proof of a lot of power, more than most other cars on here, and people can't just say "well done mate", there's always someone who has to say "I call custard", thinking they are smart/clever.
Then the usual band of arselickers follow suit going "yes, yes I agree with you, it is preposterous" because they look up to an individual smart poster (probably because of daddy issues at a younger age)
From the casual onlooker how does this look? They wouldn't want to post up and share their projects because people would assume it's BS.
The thing that REALLY gets me, is I guarantee, had this been a Ferrari F40, which has what, 470bhp, if someone said they'd change their turbos and it was now 800bhp with a dyno chart to proof, everyone would be wowing it, wanting to sleep with the OP, not calculating engine pressures at max BHP when compared to a Ferrari 458, or saying that it's actually 500bhp.
I guarantee that bulls
t performance claims from a Ferrari owner would be scrutinised just as closely on here.And just maybe some people agree with MaxT because they think he's right, not for arselicking reasons.
Not wanting to jump on the bashing band wagon because I like this kind of left field stuff, but I do take exception to being taken for a c**t with regards to power figures generated from dynos.
Dyno operator is claiming the measured 562bhp at the wheels. It was in fact measured at the hubs, this takes out the tyre-roller interface drag which is usually associated with wheel hp figures and is the greatest source of loss in such measurements. The dyno operator then claims that the actual crank shaft power is 680bhp. Are we really expected to believe that the gearbox, diff, drive shafts and rear wheel bearings are absorbing 118hp? Putting that in to SI units 88kW of power.
Given that energy is never lost, it is only changed in to another form, the energy that generated 88kW of power must have changed in to something else, noise and heat within the drivetrain. So, having viewed the video I don’t hear abnormal amounts of noise, so presumably 88kW is being lost to heat. 88kW of heat, think about that? Given the gearbox contains about 2lt of oil, how long would it take to boil?
All claims made by tuners should be taken with a pinch of salt as it is their business to sell their services, and the best way to do this is by having the best performance. Some due diligence on the buyers part can uncover some obvious BS which gives an indication as to the integrity of the tuner themselves.
Dyno operator is claiming the measured 562bhp at the wheels. It was in fact measured at the hubs, this takes out the tyre-roller interface drag which is usually associated with wheel hp figures and is the greatest source of loss in such measurements. The dyno operator then claims that the actual crank shaft power is 680bhp. Are we really expected to believe that the gearbox, diff, drive shafts and rear wheel bearings are absorbing 118hp? Putting that in to SI units 88kW of power.
Given that energy is never lost, it is only changed in to another form, the energy that generated 88kW of power must have changed in to something else, noise and heat within the drivetrain. So, having viewed the video I don’t hear abnormal amounts of noise, so presumably 88kW is being lost to heat. 88kW of heat, think about that? Given the gearbox contains about 2lt of oil, how long would it take to boil?
All claims made by tuners should be taken with a pinch of salt as it is their business to sell their services, and the best way to do this is by having the best performance. Some due diligence on the buyers part can uncover some obvious BS which gives an indication as to the integrity of the tuner themselves.
Whose Dyno was this power run done on ?
Has anyone else run their car on it ?
Also, its a hub dyno, when calculating a figure, its at the hub, as opposed to at the wheels, does that make any difference ? also the losses are impressive.
Also, "Haters", really ? this isn't an American Teenagers Xbox forum, next someone will drop a "Butthurt" in for good measure, nobody hates this car, it is fantastic, it is just some of the figures seem a bit out of the ordinary.
Need a diesel dyno day organising, bring your own respirator
Minor scepticism aside, I love this, OP, have you taken any performance measurements, 1/4 mile etc ?
Has anyone else run their car on it ?
Also, its a hub dyno, when calculating a figure, its at the hub, as opposed to at the wheels, does that make any difference ? also the losses are impressive.
Also, "Haters", really ? this isn't an American Teenagers Xbox forum, next someone will drop a "Butthurt" in for good measure, nobody hates this car, it is fantastic, it is just some of the figures seem a bit out of the ordinary.
Need a diesel dyno day organising, bring your own respirator
Minor scepticism aside, I love this, OP, have you taken any performance measurements, 1/4 mile etc ?
Regarding the dyno figures : if it is a hub dyno, power at the hub should be reasonably close to flywheel power. Most losses on a chassis dyno are at the tyre-roller interface.
The dyno measures torque and rpm at the hubs - if the tacho setup is wrong, it should still show the correct power, but at the wrong engine speed.
Assuming the dyno is correctly calibrated, and not applying ridiculous atmospheric compensation, the most common cause of error is fast acceleration without proper compensation for drivetrain inertia. With a fast sweep, a lot of energy goes into speeding up the spinning bits : to compensate for that you need to tell the dyno what that driveline inertia is. How you do that varies wth dyno.
For a properly accurate test, power should be measured at steady state.
As an example, we were playing with a postie bike (Honda super cub) today, all of 50 cc and 5 hp.
The effective driveline inertia in 2nd gear is twice that in 4th!
And the CVT scooter - forget it.
Edit : Just noticed stevesingo beat me to it on the flywheel power figure
The dyno measures torque and rpm at the hubs - if the tacho setup is wrong, it should still show the correct power, but at the wrong engine speed.
Assuming the dyno is correctly calibrated, and not applying ridiculous atmospheric compensation, the most common cause of error is fast acceleration without proper compensation for drivetrain inertia. With a fast sweep, a lot of energy goes into speeding up the spinning bits : to compensate for that you need to tell the dyno what that driveline inertia is. How you do that varies wth dyno.
For a properly accurate test, power should be measured at steady state.
As an example, we were playing with a postie bike (Honda super cub) today, all of 50 cc and 5 hp.
The effective driveline inertia in 2nd gear is twice that in 4th!
And the CVT scooter - forget it.
Edit : Just noticed stevesingo beat me to it on the flywheel power figure
Edited by AW111 on Monday 8th February 12:02
egomeister said:
There is huge amounts of BS in the aftermarket though. I'm all for this being filtered out, and the best way for this to be done is through better educated customers with more knowledge to appraise claims being made
There can be.I am happy to agree some dynos can be optimistic. A variety of dynos is a good idea to get a solid baseline.
Although based on my knowledge using a modern common rail 3.0 V6 with a smaller s200v turbo can manage 420bhp with relative smoke-free then I see no reason why an older injection pump engine with a larger turbo, pushing the boundaries of the hardware couldn't be at 550+.
But ultimately we have someone who has a dyno with a value of say 550bhp. Then we have people saying "no more than 400". Well, sorry, we have a value at 550bhp, the fact that you/i/dave disagrees with the reading is nothing more than conjecture.
xjay1337 said:
There can be.
I am happy to agree some dynos can be optimistic. A variety of dynos is a good idea to get a solid baseline.
Although based on my knowledge using a modern common rail 3.0 V6 with a smaller s200v turbo can manage 420bhp with relative smoke-free then I see no reason why an older injection pump engine with a larger turbo, pushing the boundaries of the hardware couldn't be at 550+.
But ultimately we have someone who has a dyno with a value of say 550bhp. Then we have people saying "no more than 400". Well, sorry, we have a value at 550bhp, the fact that you/i/dave disagrees with the reading is nothing more than conjecture.
I think you are contradicting yourself there. You say that you agree dynos can be optimistic but then say it is conjecture that the 550bhp is not correct. Add in the experience from Max Torque with very reasoned engineering input and it certainly is a contradiction.I am happy to agree some dynos can be optimistic. A variety of dynos is a good idea to get a solid baseline.
Although based on my knowledge using a modern common rail 3.0 V6 with a smaller s200v turbo can manage 420bhp with relative smoke-free then I see no reason why an older injection pump engine with a larger turbo, pushing the boundaries of the hardware couldn't be at 550+.
But ultimately we have someone who has a dyno with a value of say 550bhp. Then we have people saying "no more than 400". Well, sorry, we have a value at 550bhp, the fact that you/i/dave disagrees with the reading is nothing more than conjecture.
And definitely no hate for the little guys from me, I know they can be the ones who come up with the breakthroughs in many areas. But they can't change basic rules of physics which have been adequately explained here.
currybum said:
When you have significant experience and expertise on a subject you have a pretty good barometer of what is possible. In this case based on underlying physics and thermodynamics. So when an expert says that something looks wrong it is more than just conjecture.
For me, I have more confidence in my expertise, and experience than I do in a photo of a graph on the internet.
Just as you judged a technical claim in this thread as implausible based on what you know of the world http://www.pistonheads.com/gassing/topic.asp?h=0&a...
People who know stuff are doing the same here.
Based on what other engines can do there is enough fuel and boost and engine capacity to make that power that the poster claimed. (certainly the 550bhp figure, the 650+ hmm not sure but many American cars often suffer 80-100bhp drivetrain loses on a variety of dynos, again calculated with best efforts in mind). For me, I have more confidence in my expertise, and experience than I do in a photo of a graph on the internet.
Just as you judged a technical claim in this thread as implausible based on what you know of the world http://www.pistonheads.com/gassing/topic.asp?h=0&a...
People who know stuff are doing the same here.
Diesel tuning is of great interest to me having spunked a good proportion of my life's wages on doing so. (for not much result
) I see a lot of what can be done that I thought was previously impossible, etc.
Tuning an Audi V10 TDI race engine is different to a back street tuner on an old Merc engines. For the back street tuner there's no economy to worry about, smoke output is not a concern, component life of things like pistons, rods is not a concern.
I fail to see what the other thread you have linked to has any relevance.
currybum said:
Several people discounted the power/rpm numbers here based on what they know, in the thread I listed you discounted a "snake oil" fuel economy modification because presumably it sounded like BS based on your knowledge.
Based on what I know the power/rpm numbers on this thread sound implausible, I would love them to be true but I would require a greater level of evidence and explanation as to how/why before I reassessed me baseline knowledge.
I discounted?Based on what I know the power/rpm numbers on this thread sound implausible, I would love them to be true but I would require a greater level of evidence and explanation as to how/why before I reassessed me baseline knowledge.
I made one post which was hardly serious. I didn't even read the OP links.
Some people have very empty lives to go back through posters history lol.
xjay1337 said:
Based on what other engines can do there is enough fuel and boost and engine capacity to make that power that the poster claimed.
IF you have time to burn it. Otherwise it comes out the back as black smoke........xjay1337 said:
but many American cars often suffer 80-100bhp drivetrain loses on a variety of dynos, again calculated with best efforts in mind
On a roller type rolling road yes depending on the vehicle etc etc. But this was a hub driven dyno, so the losses are only drive train. There's no frictional loss between the tyres and the rollers.The builders claim roller type losses on a hub driven machine. This is either intentionally done to inflate the crank bhp or innocently done because they don't understand what they are talking about. Either way it leads me to be highly suspicious of their claims...
Edited by Mikeeb on Monday 8th February 12:42
Edited by Mikeeb on Monday 8th February 12:43
Just like every other poster in this thread, I'm a big fan of the car 
Have learnt a lot from MT's posts (as usual), so thank you for taking the considerable time to post it all. I was unaware of the physics behind diesel's rpm limitations, didn't know it had a slower burn time. It's frustrating when something you hadn't thought about is so obvious once it's been pointed out to you
This thread has also made me, at 29, feel old
Have learnt a lot from MT's posts (as usual), so thank you for taking the considerable time to post it all. I was unaware of the physics behind diesel's rpm limitations, didn't know it had a slower burn time. It's frustrating when something you hadn't thought about is so obvious once it's been pointed out to you
This thread has also made me, at 29, feel old
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