Carryfast:
It seems to me that there’s a lot of wasted potential out there which ‘could’ be provided by the idea of just derating the most powerful options like the 600-730 hp versions by having around a 1,200 rpm rev limit in the engine management which would remove all the issues of the thing being put in ‘the wrong hands’.
So, pay £140K for an all singing, all dancing 730 V8 Scania & restrict it to, say, 480bhp■■?
I’ve had a mad idea, why not just buy an R480■■
Radical eh■■?
Ross.
bigr250:
Carryfast:
It seems to me that there’s a lot of wasted potential out there which ‘could’ be provided by the idea of just derating the most powerful options like the 600-730 hp versions by having around a 1,200 rpm rev limit in the engine management which would remove all the issues of the thing being put in ‘the wrong hands’.So, pay £140K for an all singing, all dancing 730 V8 Scania & restrict it to, say, 480bhp■■?
I’ve had a mad idea, why not just buy an R480■■
Radical eh■■?
Ross.
Ross, I agree with you totally why spend £140k on a motor to downrate it (at more cost) when you can buy a 480 for about £60k? less.
Unless you have money to burn “literally” of course. regards Kevmac47.
Even if you had money to burn what benefit would you get downrating a 730 ? , better still to save the cost of downrating it just disconnect the wiring from two of the injectors and be the first to have a Scania V6 
philberg182:
Even if you had money to burn what benefit would you get downrating a 730 ? , better still to save the cost of downrating it just disconnect the wiring from two of the injectors and be the first to have a Scania V6
uprate,uprate,and uprate just to pee those tight gits with down hill clap trap shaking bags of ■■■ racers and owners of mean. and. nastys. “M.A.N” cos they jsut hate it when a proper motor goes by them and its just a whish on there lists coz they to mean to get one 
bigr250:
Carryfast:
It seems to me that there’s a lot of wasted potential out there which ‘could’ be provided by the idea of just derating the most powerful options like the 600-730 hp versions by having around a 1,200 rpm rev limit in the engine management which would remove all the issues of the thing being put in ‘the wrong hands’.So, pay £140K for an all singing, all dancing 730 V8 Scania & restrict it to, say, 480bhp■■?
I’ve had a mad idea, why not just buy an R480■■
Radical eh■■?
Ross.
The difference is that a 620 is putting out 425-480 hp between 1,000 rpm and around 1,150 rpm. 
philberg182:
Even if you had money to burn what benefit would you get downrating a 730 ? , better still to save the cost of downrating it just disconnect the wiring from two of the injectors and be the first to have a Scania V6
Which would be a great idea if you wanted it to go slower and use more fuel doing it than before. 
kevmac47:
bigr250:
Carryfast:
It seems to me that there’s a lot of wasted potential out there which ‘could’ be provided by the idea of just derating the most powerful options like the 600-730 hp versions by having around a 1,200 rpm rev limit in the engine management which would remove all the issues of the thing being put in ‘the wrong hands’.So, pay £140K for an all singing, all dancing 730 V8 Scania & restrict it to, say, 480bhp■■?
I’ve had a mad idea, why not just buy an R480■■
Radical eh■■?
Ross.
Ross, I agree with you totally why spend £140k on a motor to downrate it (at more cost) when you can buy a 480 for about £60k? less.
Unless you have money to burn “literally” of course. regards Kevmac47.
you’d be pushing it to get a R480 for 90k 
Carryfast:
dbt:
and as for mpg. put a v8 in wrong hands and it’l make your eyes water. BUT drive them right they are decent.
we have 2 164 580’s and they were doing 8.2 and 8.4, our man tgx 440’s on the same work wont touch 8! power pays,It seems to me that there’s a lot of wasted potential out there which ‘could’ be provided by the idea of just derating the most powerful options like the 600-730 hp versions by having around a 1,200 rpm rev limit in the engine management which would remove all the issues of the thing being put in ‘the wrong hands’.
It would need a lot of gear ratios to be able to keep it within such a restricted RPM range, unless it had one of those rubber band CVT gearboxes, as there’s no such thing available, it would never work in the ‘real’ world, which it seems, is the world that everyone but you inhabits
newmercman:
Carryfast:
dbt:
and as for mpg. put a v8 in wrong hands and it’l make your eyes water. BUT drive them right they are decent.
we have 2 164 580’s and they were doing 8.2 and 8.4, our man tgx 440’s on the same work wont touch 8! power pays,It seems to me that there’s a lot of wasted potential out there which ‘could’ be provided by the idea of just derating the most powerful options like the 600-730 hp versions by having around a 1,200 rpm rev limit in the engine management which would remove all the issues of the thing being put in ‘the wrong hands’.
It would need a lot of gear ratios to be able to keep it within such a restricted RPM range, unless it had one of those rubber band CVT gearboxes, as there’s no such thing available, it would never work in the ‘real’ world, which it seems, is the world that everyone but you inhabits
It would be interesting to see what the fuel consumption figures would be between a 480 six driven using it’s whole rev range from around max torque up to max power at 1,900 and a 620 V8 driven by short shifting it at around 1,200 rpm.However going through the gears in 200-300 rpm steps shouldn’t be a big deal for a decent box especially considering the actual road speeds that those rpm would relate to with over 500 hp being available at around 1,200 rpm.
1900rpm ? No one revs an engine that high in this day and age. 
Most powerful truck I have driven was a foden 4525 so I may be wrong but even with all the power of say a 730 scania it would need a bit more than 1200 revs to make decent progress.
kr79:
1900rpm ? No one revs an engine that high in this day and age.
Most powerful truck I have driven was a foden 4525 so I may be wrong but even with all the power of say a 730 scania it would need a bit more than 1200 revs to make decent progress.
In most modern trucks the torque starts in the region 950 - 1,000rpm & begins to ‘tail off’ at around 1450rpm, to all intents & purposes there’s no point in taking the engine beyond that point unless your within sight of the crest of a steep hill & changing up would halt your progress, so in most cases your best changing up during acceleration in that rev range.
On the 730 Scania, the engine delivers 3,500nm of torque between 1,000 & 1,350rpm at which point it starts drop off as the engine speed increases, this however ‘overlaps’ the point in the rev rang at which the power output really starts to rise. In fact, @ 1,250rpm the engine is producing about 630BHP going on to break the 700bhp line at about 1,650rpm reaching its max power of 730 @ 1,900rpm.
Other than that, the only time you need to take most modern engines above 1,500rpm is to get the best out of an engine brake.
Ross.
kr79:
1900rpm ? No one revs an engine that high in this day and age.
Most powerful truck I have driven was a foden 4525 so I may be wrong but even with all the power of say a 730 scania it would need a bit more than 1200 revs to make decent progress.
The fact is the 620 only needs around 1,000 rpm to get the benchmark of 10 bhp per tonne whereas you’d need to rev the 480 up to 1,400 rpm to get the same and up to 1,900 ‘if’ you want the same power output as the 620 can put out at less than 1,200 and in most conditions,at uk weights,there’d be no real need to take the 620 above,or even up to,that engine speed unlike the 480.It’s all about the difference in torque and that’s why it’s my bet that the 620 would be more economic on fuel than a 480 in a comparison at equivalent weight over an equivalent route at an equivalent average speed.
With that type of torque output the ‘decent progress’ is provided by using higher gears than would be the case with the 480.The extra fuel starts getting burned (resulting in the bad reputation of big powerful V8’s) when drivers try to use the extra power to get the job done faster than the less powerful wagon instead of just using the extra torque to provide the same,or at most a bit more,work for (a lot) less revolutions of the engine.
bigr250:
In most modern trucks the torque starts in the region 950 - 1,000rpm & begins to ‘tail off’ at around 1450rpm, to all intents & purposes there’s no point in taking the engine beyond that point unless your within sight of the crest of a steep hill & changing up would halt your progress, so in most cases your best changing up during acceleration in that rev range.On the 730 Scania, the engine delivers 3,500nm of torque between 1,000 & 1,350rpm at which point it starts drop off as the engine speed increases, this however ‘overlaps’ the point in the rev rang at which the power output really starts to rise. In fact, @ 1,250rpm the engine is producing about 630BHP going on to break the 700bhp line at about 1,650rpm reaching its max power of 730 @ 1,900rpm.
Other than that, the only time you need to take most modern engines above 1,500rpm is to get the best out of an engine brake.
Ross.
Using your figures of torque vs power got me thinking:
if you were going up a hill and which would be more useful the torque or the power if going at the same speed?
I would have thought that if you were in a high gear and revving at 1200 rpm would you use more fuel than being in a lower gear.
My theory being that at 1200 rpm your going to have your right foot to the metal to keep momentum fearing that if you let off you might slow down and then have to change down. If in a lower gear you might get up to 1650 rpm and then ease off the throttle knowing that if it slows you have the power to accelerate.
Foxstein:
bigr250:
In most modern trucks the torque starts in the region 950 - 1,000rpm & begins to ‘tail off’ at around 1450rpm, to all intents & purposes there’s no point in taking the engine beyond that point unless your within sight of the crest of a steep hill & changing up would halt your progress, so in most cases your best changing up during acceleration in that rev range.On the 730 Scania, the engine delivers 3,500nm of torque between 1,000 & 1,350rpm at which point it starts drop off as the engine speed increases, this however ‘overlaps’ the point in the rev rang at which the power output really starts to rise. In fact, @ 1,250rpm the engine is producing about 630BHP going on to break the 700bhp line at about 1,650rpm reaching its max power of 730 @ 1,900rpm.
Other than that, the only time you need to take most modern engines above 1,500rpm is to get the best out of an engine brake.
Ross.
Using your figures of torque vs power got me thinking:
if you were going up a hill and which would be more useful the torque or the power if going at the same speed?
I would have thought that if you were in a high gear and revving at 1200 rpm would you use more fuel than being in a lower gear.
My theory being that at 1200 rpm your going to have your right foot to the metal to keep momentum fearing that if you let off you might slow down and then have to change down. If in a lower gear you might get up to 1650 rpm and then ease off the throttle knowing that if it slows you have the power to accelerate.
That idea all changes in the type of different world provided by the type of torque output of something like a 620 V8 at uk type weights where it’s putting out more than 500 hp at 1,200 rpm.
Which is better for going up hill’s torque or power 
That’s a good question,i think it depend’s on the truck TBH. My previous Volvo did better if you let it lug on a hill revving the engine just seemed to be pointless there was no power/torque at the high end of the revband,Scania straight 6’s are the same. On my current V6 Actros it does best at high rpm you could end up 10kph faster at the top of a 1km hill by simply going up a half gear at the start of the incline instaed of letting it lug like a Volvo. The strange thing is it does’nt seem to affect the mpg adversely 
I must say though the inline engine is a more relaxed drive as you don’t need to read the road in front of you as much and of course auto box’s are designed to make engine’s lug on a hill,this is where vee engine’s really fall down as you will need to use manual mode alot more to get the best performance.
ellies dad:
Which is better for going up hill’s torque or power
Agree with ED over plenty of revs for the V engined Actros, they thrive on it. Mines a V8 Actros and its the same scenario, split the gear before a steep hill starts and nothing with the same HP can stay with it.
I keep reading where people have been told to make Mercs lug up hills, thats only relevent to the straight 6 Axor as they love to slug it out at low revs. Many years ago when I was shown how to get the best out of a V engined Actros, it was plenty of revs before the hills which means a change down, but things have changed. Reving the ■■■■ off a diesel is not the best for emissions, and as Merc are so super eco P.C.its probably why they have changed their advice, and also ditched the V’s and gone for all straight 6 low speed luggers in the new MP4 Actros.
A v6 v8 etc will always need revs to get the best from it whereas an in line will have better torque at low revs that’s on petrol diesel car or truck engines.
I don’t think it matters whether a straight or a v. It’s down to how the manufacturer designed it. A scania will lug from low, straight or 8, but as said the actros needs revs to get along. My mate reckons his new 500 volvo needs a down shift on hills, but the old 480 never needed one
Havent been on here for a while. Dont know too much techinical stuff about modern engines but there are plenty of streamline 143s earning money all day every day around here. Old motors but the V8s dont seem to die. P.S. they probably earn as much as the 60/70k newer stuff but were paid for years ago