3.0L TT dyno graph?
Discussion
But if you don't trust flywheel figures then why would you trust wheel figures?
Wheel figures are an even more inaccurate way to measure power. You have tyre pressures and gearbox oil temperature in the equation for a start that can make a huge difference in power.
I would recommend that the ‘someone’ you are trying to convince gets along and drives the Noble, as no power graph can even come close to illustrating quite what the Noble does!
Wheel figures are an even more inaccurate way to measure power. You have tyre pressures and gearbox oil temperature in the equation for a start that can make a huge difference in power.
I would recommend that the ‘someone’ you are trying to convince gets along and drives the Noble, as no power graph can even come close to illustrating quite what the Noble does!
Well, flywheel figures are sometimes exagerated by the manufacturer. Like the US version Mazda RX8 for example, they claimed 250bhp or something like that, then had to lower that claim when it became obvious the cars weren't making anywhere near that much power. Dyno figures and 1/4 mile trap speeds clearly indicated a much less powerfull car than 250bhp.
In my experience oil temps only change things by a few hp. I'm sure wheel alignment and tires pressure can change things too. Besides, its the power put down at the wheels that actually moves the car!
If anyone does have a chassis dyno graph, please state what brand of dyno it was.
In my experience oil temps only change things by a few hp. I'm sure wheel alignment and tires pressure can change things too. Besides, its the power put down at the wheels that actually moves the car!
If anyone does have a chassis dyno graph, please state what brand of dyno it was.
I have dyno plots of pre and post upgrade 2.5l setup by a very respected and talented engineer, and I can assure you that the figures quoted are absolutly spot on for production cars.
However - what's the point - just get into a car and see what you think. Power is a bit like comparing just the length-of-dicks* when you are trying to assess how good a shag will be.
J
* Old Jewish proverb about length and width springs to mind. Trust me
www.pumaracing.co.uk and look under Power, Torque And Vehicle Dynamics
>> Edited by joust on Monday 22 March 18:10
However - what's the point - just get into a car and see what you think. Power is a bit like comparing just the length-of-dicks* when you are trying to assess how good a shag will be.
J
* Old Jewish proverb about length and width springs to mind. Trust me
www.pumaracing.co.uk and look under Power, Torque And Vehicle Dynamics
>> Edited by joust on Monday 22 March 18:10
BTW, I don't know about the UK, but in the US we have several cars that are underrated from the factory. The 2003 Ford Cobras are rated at 380bhp, but can put down 370 at the wheels. The MK4 Toyota Supra and Dodge SRT4 Neon are others.
Power is certainly only one factor in the overall car, but it is an important one and possibly the easiest to measure over the internet. I have witnessed inconsistancies between measured HP on a chassis dyno, the weight of the car, and the car's actual performance before. I know there are many things that can throw the measurement off, but for the most part (especially for stock cars) the chassis dyno should be accurate.
I'm already familar with the points brought up on the Puma Racing page (its also got a link to another good site, the SDS tech page). I was just hoping someone had a dyno plot online somewhere...
>> Edited by GrantB on Monday 22 March 20:29
joust said:
I have dyno plots of pre and post upgrade 2.5l setup by a very respected and talented engineer, and I can assure you that the figures quoted are absolutly spot on for production cars.
However - what's the point - just get into a car and see what you think. Power is a bit like comparing just the length-of-dicks* when you are trying to assess how good a shag will be.
J
* Old Jewish proverb about length and width springs to mind. Trust me
<a href="http://www.pumaracing.co.uk">www.pumaracing.co.uk</a> and look under Power, Torque And Vehicle Dynamics
>> Edited by joust on Monday 22 March 18:10
Power is certainly only one factor in the overall car, but it is an important one and possibly the easiest to measure over the internet. I have witnessed inconsistancies between measured HP on a chassis dyno, the weight of the car, and the car's actual performance before. I know there are many things that can throw the measurement off, but for the most part (especially for stock cars) the chassis dyno should be accurate.
I'm already familar with the points brought up on the Puma Racing page (its also got a link to another good site, the SDS tech page). I was just hoping someone had a dyno plot online somewhere...
>> Edited by GrantB on Monday 22 March 20:29
Whilst I agree that the figures are important, I have yet to find a way of reliably discovering if said figures are based in reality. Engine dynos are about the only valid way, but even then its no longer mounted in the car which buggers things up again, especially as people often run without the real exhaust & induction.
Big broohaha in VTEC engine circles at the moment as one of the main US tuners claims that he can get 250bhp out of an NA 2.0 litre K20a with only an ECU map and 'tuned' manifold. He has dynapack figures to prove it... All I'm equipped with is my deep scepticism for them achieving 250bhp (dunno if thats wheel or crank) in that way.
DanH said:
Whilst I agree that the figures are important, I have yet to find a way of reliably discovering if said figures are based in reality.
Right, I agree. In the US we have too many drag racers for our own good, so the standard has become the trap speed of the car at the end of a 1/4 mile. This speed is mostly idenpendant of poor driving, and usually consistant. I don't think it gets any more real than the acceleration of a car over a known distance. Of course if anyone has drag raced their Noble's I would be interested in hearing the results, but I didn't think that was very likely.
We also have a "standard" dyno of sorts in the US, called a Dynojet. Its a inertia chassis dyno that more or less produces consistant results, but does have some drawbacks. It automatically corrects for atmospheric conditions, but the numbers can still be fudged by changing those conditions. Also, since its an inertia dyno the load is set and changes with gearing, not the best thing for dynoing a turbo car. There are other issues with inertia dynos, but you guys probably don't want to hear me ramble...
250bhp for a stockish K20A would be a crank figure. It actually doesn't sound too far-fetched, as I know people with the basic bolt-ons are making 195 or so to the wheels.
>> Edited by GrantB on Monday 22 March 22:27
GrantB said:Don't know about US law, but that would be highly illegal in the EU under many and varied laws.
BTW, I don't know about the UK, but in the US we have several cars that are underrated from the factory. The 2003 Ford Cobras are rated at 380bhp, but can put down 370 at the wheels. The MK4 Toyota Supra and Dodge SRT4 Neon are others.
GrantB said:Is it, and what are you trying to "measure" over the Internet.
Power is certainly only one factor in the overall car, but it is an important one and possibly the easiest to measure over the internet.
Sorry, but I've never heard so much tosh. Power without weight means nothing, and without gearing ratios will tell you absolutly sod all about how the car performs.
Would you buy a TV from just seeing a JPEG of the TV screen showing Dallas to judge picture quality???? If you would - then go ahead - just look at power figures. You'll get the same results.
J
GrantB said:
Whilst I agree that the figures are important, I have yet to find a way of reliably discovering if said figures are based in reality.
Right, I agree. In the US we have too many drag racers for our own good, so the standard has become the trap speed of the car at the end of a 1/4 mile. This speed is mostly idenpendant of poor driving, and usually consistant. I don't think it gets any more real than the acceleration of a car over a known distance. Of course if anyone has drag raced their Noble's I would be interested in hearing the results, but I didn't think that was very likely.
We also have a "standard" dyno of sorts in the US, called a Dynojet. Its a inertia chassis dyno that more or less produces consistant results, but does have some drawbacks. It automatically corrects for atmospheric conditions, but the numbers can still be fudged by changing those conditions. Also, since its an inertia dyno the load is set and changes with gearing, not the best thing for dynoing a turbo car. There are other issues with inertia dynos, but you guys probably don't want to hear me ramble...
250bhp for a stockish K20A would be a crank figure. It actually doesn't sound too far-fetched, as I know people with the basic bolt-ons are making 195 or so to the wheels.
>> Edited by GrantB on Monday 22 March 22:27
I don't like quarter mile times to be honest. To get a real idea you need cascade curves otherwise there are just too many factors.
As to 195 at the wheels from a standardish k20a that also seems unlikely given they start with 215 or whatever at the crank if you have the JDM spec one. Guess it depends what drive train losses are though. Anyway how they could then boost that to 250 with an ECU program and a 'magic' manifold I'd love to know
joust said:
Don't know about US law, but that would be highly illegal in the EU under many and varied laws.
Really? Its not very uncommon on this side of the pond.
joust said:
Sorry, but I've never heard so much tosh. Power without weight means nothing, and without gearing ratios will tell you absolutly sod all about how the car performs.
Would you buy a TV from just seeing a JPEG of the TV screen showing Dallas to judge picture quality???? If you would - then go ahead - just look at power figures. You'll get the same results.
Good lord, all I asked for were some dyno results! I never said that a dyno graph would somehow tell me how the car performs, or even how it accelerates. Is it so hard to post a link to a graph, if you know of one? If not, just say so. I know how much the car weighs, and I know what its gear ratios are. If all we cared about was power, do you honestly think I would be asking about a Noble? I'd still own a single-turbo MK4 Toyota Supra if that were the case, sheesh.....
DanH, I don't like 1/4 mile times either. Thats why I said I judge by trap speeds
The times are mostly dependant on launch, while the trap speeds are not (until you get into much faster cars) Its a "real world" measurement that takes into account gearing, aerodynamics, weight, etc. BTW, have seen dynos of K20As making around 200 at the wheels, but its a very peaky graph, so they don't quite accelerate as well as their HP would lead you to believe. Thats with full exhaust, intake, header setup and tuning. Did a quick search and came up with this: http://images.cardomain.com/member_images/9/web/417000-417999/417645_23_full.jpg
It produced a 103mph trap speed, which is about right (as the car is light for a production model).
m12_nathan, thanks. 115 is about what I would have expected.
>> Edited by GrantB on Tuesday 23 March 00:30
GrantB said:??? So the quote "Power is certainly only one factor in the overall car, but it is an important one and possibly the easiest to measure over the internet. I have witnessed inconsistancies between measured HP on a chassis dyno, the weight of the car, and the car's actual performance before." wasn't you then?
Good lord, all I asked for were some dyno results! I never said that a dyno graph would somehow tell me how the car performs, or even how it accelerates.
Interesting view on the English language that you seem to say that you want the power graphs to veryify the performance, but you don't think that performance relates to how the car performs.
As for a "simple" URL link to a dyno graph, I'm not aware there is a graph available on the Internet.
J
joust said:
Good lord, all I asked for were some dyno results! I never said that a dyno graph would somehow tell me how the car performs, or even how it accelerates.
??? So the quote "Power is certainly only one factor in the overall car, but it is an important one and possibly the easiest to measure over the internet. I have witnessed inconsistancies between measured HP on a chassis dyno, the weight of the car, and the car's actual performance before." wasn't you then?
Interesting view on the English language that you seem to say that you want the power graphs to veryify the performance, but you don't think that performance relates to how the car performs.
As for a "simple" URL link to a dyno graph, I'm not aware there is a graph available on the Internet.
J
The only reason I said I wanted to see a graph was to try and help convince someone to buy a Noble. You replied with power alone means nothing to performance, which I agreed with. But given that I have the published gearing and weight of the Noble right here in front of me, it stands to reason that a dyno graph will give us a reasonable idea of how the Noble accelerates.
The cars I've seen that don't accelerate as well as their dyno graphs show were highly modified, running a lot more boost than the Noble does, and had less of a problem with detonation in a short dyno pull than in the real-world.
OK Grant, but given the official independant tested figures from Autocar (a very respected weekly UK car magazine) of 0-60 @ 3.9 and 0-100 @ 9.8 for the 2.5l is there much more that you need?
The full Autocar report is at www.autocarmagazine.co.uk/RoadTest_FullData.asp?RT=204574 and gives
0-30mph 1.7 sec
0-60mph 3.9 sec
0-100mph 9 sec
0-150mph 28.2 sec
0-200mph no data
30-70mph 3.4 sec
0-400m 12.3/115 sec/mph
0-1000m 22.8/142 sec/mph
30-50mph in 3rd/4th 2/2.9 sec
40-60mph in 4th/5th 2.4/3.8 sec
50-70mph in 5th 3.3 sec
60-0mph 2.9 sec
Much more telling than any dyno graph.
J
The full Autocar report is at www.autocarmagazine.co.uk/RoadTest_FullData.asp?RT=204574 and gives
0-30mph 1.7 sec
0-60mph 3.9 sec
0-100mph 9 sec
0-150mph 28.2 sec
0-200mph no data
30-70mph 3.4 sec
0-400m 12.3/115 sec/mph
0-1000m 22.8/142 sec/mph
30-50mph in 3rd/4th 2/2.9 sec
40-60mph in 4th/5th 2.4/3.8 sec
50-70mph in 5th 3.3 sec
60-0mph 2.9 sec
Much more telling than any dyno graph.
J
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