RE: Skoda Octavia vRS Revo Technik: Driven
Discussion
I think what irritates AER is that nobody is even acknowledging two things: (1) the power output is highly suspect, especially at the claimed revs because the maths just don't work to extract enough torque from that engine and (2) the top speed is hard to reconcile with the claimed power output (which it very definitely is given that I cannot find a slower car with 400bhp and long enough gears to be comparable).
I drive a car with a bit shy of 400bhp, and it is faster than the supposed 400bhp Octavia despite being normally aspirated and so having much less torque across the revs (and so a smaller area under the curve for a given peak power). The tradition advantage of a 911 is maybe worth a second or so, but no more than that to 100mph.
Would anyone actually bet their house on the car making a legitimate 400bhp?
I drive a car with a bit shy of 400bhp, and it is faster than the supposed 400bhp Octavia despite being normally aspirated and so having much less torque across the revs (and so a smaller area under the curve for a given peak power). The tradition advantage of a 911 is maybe worth a second or so, but no more than that to 100mph.
Would anyone actually bet their house on the car making a legitimate 400bhp?
Would anyone dare bet their house on it not making 400BHP? Seems a little extreme either way to me. The applied maths is interesting to read if a little hard to understand but there seems to have been as many arguments for as there have been against so it obviously isn't black and white. It would have saved around 10 pages of this thread if it was though!
I don't doubt AER for a second with the maths he has put to it (I don't know anything about it so I can't say otherwise, that would be silly). I simply said it must be somewhere near its 'claimed' bhp figure to be accelerating like it is.
I'm not arguing with anyone or ignoring someone who clearly is very, very knowledgeable in this, I was simply asking.
I'm not arguing with anyone or ignoring someone who clearly is very, very knowledgeable in this, I was simply asking.
Just out of interest. If the Revo car is doing 170ish flat out in 5th what would the standard car be doing flat out in the same gear? Would it be significantly lower than the quoted 150-154 top speed or is the 6th gear for economy only and has little effect on the overall top speed? Would it effect any of the maths that have been applied if for example the standard car only manages to hit 140mph in 5th?
Edited by gigglebug on Wednesday 24th February 22:05
gigglebug said:
Just out of interest. If the Revo car is doing 170ish flat out in 5th what would the standard car be doing flat out in the same gear? Would it be significantly lower than the quoted 150-154 top speed or is the 6th gear for economy only and has little effect on the overall top speed? Would it effect any of the maths that have been applied if for example the standard car only manages to hit 140mph in 5th?
6000rpm in 5th is the same speed regardless of power. More power just allows you to get there quicker. Edited by gigglebug on Wednesday 24th February 22:05
A standard car may never have had the power to achieve that rpm in that gear though.
gigglebug said:
Ah right OK. It can't change as that is what the car is geared to?
No. Sometimes a car can go faster in a gear if the rev limit has been raised (and there is enough power at that point to make it worth while not changing up) but gearing is fixed so mph-rpm are the same regardless of power. Gtom said:
No. Sometimes a car can go faster in a gear if the rev limit has been raised (and there is enough power at that point to make it worth while not changing up) but gearing is fixed so mph-rpm are the same regardless of power.
Yes it's OK that was how I was reading what you had said, you had used 6000rpm in your post so I was working on that fixed figure. These things are obvious when they are pointed out, good learningGtom said:
6000rpm in 5th is the same speed regardless of power. More power just allows you to get there quicker.
A standard car may never have had the power to achieve that rpm in that gear though.
That must be right. 6th must be an overdrive and the standard car doesn't have the power to get to the limiter in 5th. A standard car may never have had the power to achieve that rpm in that gear though.
So if the top speed in any particular gear is determined by the permissible rev limit and gearing rather than the specific output of the engine does that answer ORD's question as to why the top speed for the Revo (in 5th gear at least) is only 170mph? Is it just that the gearing used won't allow the car to go any any faster at the rev limit set regardless of bhp? Would we need to know the top speed for the car in 6th to make a fair comparison to other vehicles?
AER has worked out that the car would roughly only need 300-320bhp to be able to reach the 170mph indicated by using the standard cars 220bhp/150-154mph as the basis of his calculation, but again that is not necessarily an indication of the cars overall output as a car with a higher output would merely get to the same point quicker?
So the only questionable part of the cars performance goes back to the claimed 410bhp at 5400rpm which AER has pointed out is unrealistic?
Sorry if this is going around in circles but it's good to be clear!
AER has worked out that the car would roughly only need 300-320bhp to be able to reach the 170mph indicated by using the standard cars 220bhp/150-154mph as the basis of his calculation, but again that is not necessarily an indication of the cars overall output as a car with a higher output would merely get to the same point quicker?
So the only questionable part of the cars performance goes back to the claimed 410bhp at 5400rpm which AER has pointed out is unrealistic?
Sorry if this is going around in circles but it's good to be clear!
AER said:
BTW, if you dropped it into sixth at 160, and it really did have 410hp, revs would drop to the claimed peak power speed of 5400 and the remaining 100hp or so would rocket you off to about 190mph at 5700-ish...
Really...?
I noticed that there's this new technology available that allows me to repeat myself at the click of a button...Really...?
ORD said:
I think what irritates AER is that nobody is even acknowledging two things: (1) the power output is highly suspect, especially at the claimed revs because the maths just don't work to extract enough torque from that engine and (2) the top speed is hard to reconcile with the claimed power output (which it very definitely is given that I cannot find a slower car with 400bhp and long enough gears to be comparable).
I drive a car with a bit shy of 400bhp, and it is faster than the supposed 400bhp Octavia despite being normally aspirated and so having much less torque across the revs (and so a smaller area under the curve for a given peak power). The tradition advantage of a 911 is maybe worth a second or so, but no more than that to 100mph.
Would anyone actually bet their house on the car making a legitimate 400bhp?
I am still awaiting the mathematical calculations to show power and torque figures of this car... can you provide those please?I drive a car with a bit shy of 400bhp, and it is faster than the supposed 400bhp Octavia despite being normally aspirated and so having much less torque across the revs (and so a smaller area under the curve for a given peak power). The tradition advantage of a 911 is maybe worth a second or so, but no more than that to 100mph.
Would anyone actually bet their house on the car making a legitimate 400bhp?
As I said previously if you look at the 0-100 times it's very much in keeping with a car with 400+ BHP.
xjay, you have personally demonstrated in a recent post that your ability to understand anything remotely technical is close to zero. That and your attitude will pretty much guarantee no one is going to take the time to explain to you how engine power can be calculated. You'll have to do your own research on this now if you want to know
AER said:
Standard car does 150-154 claimed at 220hp according to the brochure. Same car at 170 is only consuming 220*(170/150)^3 = 320hp max, or 295 if you take the 154mph top speed as your baseline.
Still doesn't mean it's not ~400bhp.Is Vmax achieved in the standard car at peak power rpm?
Is Vmax achieved in the modified car at peak power rpm?
the video also appears to show the revs continuing to rise after the speedos are pegged at 170mph.
amstrange1 said:
Still doesn't mean it's not ~400bhp.
Is Vmax achieved in the standard car at peak power rpm?
Is Vmax achieved in the modified car at peak power rpm?
the video also appears to show the revs continuing to rise after the speedos are pegged at 170mph.
A bit weird, that. Hard to see why the digital speedo would cap out at 170, but it does seem to do so.Is Vmax achieved in the standard car at peak power rpm?
Is Vmax achieved in the modified car at peak power rpm?
the video also appears to show the revs continuing to rise after the speedos are pegged at 170mph.
Perhaps AER's calculation does not take into account that peak power is quite low down the rev range so that the car would accelerate on past its peak power and then, in effect, bog down at higher revs and reach max speed. I suppose that might explain why 400bhp would not give you say 185mph (as would be expected).
My car will do 170 indicated... its got 320bhp... its a golf.
I believe that there will be some interesting footage coming from revo soon..... hopefully it will shut up the doubters of it being 400bhp.
Just to add.... This is basically a golf mk7 R engine (with the IS38 turbo) Stage 1 brings the Golf R to 370bhp without any hardware. ergo... this skoda will have at least that and obviously more.
I believe that there will be some interesting footage coming from revo soon..... hopefully it will shut up the doubters of it being 400bhp.
Just to add.... This is basically a golf mk7 R engine (with the IS38 turbo) Stage 1 brings the Golf R to 370bhp without any hardware. ergo... this skoda will have at least that and obviously more.
Edited by thebraketester on Thursday 25th February 10:55
thebraketester said:
My car will do 170 indicated... its got 320bhp... its a golf.
I believe that there will be some interesting footage coming from revo soon..... hopefully it will shut up the doubters of it being 400bhp.
Just to add.... This is basically a golf mk7 R engine (with the IS38 turbo) Stage 1 brings the Golf R to 370bhp without any hardware. ergo... this skoda will have at least that and obviously more.
Playing Devil's advocate here but does it still make 370bhp after 15 dyno pulls on a 28 deg summer's day? VAG's component protection maps are pretty aggressive when IATs hit 50+ C and / or EGTs soar past 850 C. That chunky catalyst ~4" downstream of the turbine wheel is not EGT friendly, so that would need to be binned for starters. And VAG aren't one for over-engineering their intercoolers either, so that will heat soak quite nicely.I believe that there will be some interesting footage coming from revo soon..... hopefully it will shut up the doubters of it being 400bhp.
Just to add.... This is basically a golf mk7 R engine (with the IS38 turbo) Stage 1 brings the Golf R to 370bhp without any hardware. ergo... this skoda will have at least that and obviously more.
Edited by thebraketester on Thursday 25th February 10:55
That's why I threw the AMG A45 engine into the mix because it's two tuning companies attempting the same thing - 200hp / litre.
I'm not saying either Revo or AER are 100% correct, but something just doesn't add up here. With AMG's expertise and (massive) financial backing from Mercedes, how did they 'only' arrive at 381bhp from 1.8 bar and Revo achieved 410bhp from 1.7 bar? As AER was suggesting from his calcs, the VAG engine cannot, in theory, produce that much power from the air it's fed.
AER said:
xjay, you have personally demonstrated in a recent post that your ability to understand anything remotely technical is close to zero. That and your attitude will pretty much guarantee no one is going to take the time to explain to you how engine power can be calculated. You'll have to do your own research on this now if you want to know
Yeah yeah yeah.Anyway can you actually provide your mathematical calculations?
Or not?
Because I'm quite happy to use dyno figures to get an engines power figure. You know. By actually measuring it.
Accepting dyno variances within ~10 bhp or so either way.
I do not claim to be able to calculate the engine power without seeing or measuring the engine at all. And I don't go into every thread with an otherwise boring car (usually old, diesel or front wheel drive) and claim the power figure is BS just to stroke my own ego.
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