Facelift Standard Dyno Readout

[AudiNutta]

Hi Guys,

Just had my S3 on the dyno at Indigo GT, South Wales.

They didn't expect it to pull 300 because it has only done 2600 miles. It pulled 336hp, they were amazed.
I suspect the dyno is overestimating ever so slightly as the readout on my 120hp 1.4 was 131hp, but it won't be very far off at all.. very happy.

They Revo mapped a manual FL S3 yesterday and got over 380hp, they said they had to tone it down as well because the clutches in the manuals are so weak. They were trying to talk me into Revo for £720 and most likely 390-400hp.. but I have decided my warranty is worth more to me

Regards,

Matthew

 

[paulmc]

My Fl S3 is easy as quick as my RS3 8P was. I reckon 320 - 330bhp out of the box. Awesome wee car

 

[AudiNutta]

My Fl S3 is easy as quick as my RS3 8P was. I reckon 320 - 330bhp out of the box. Awesome wee car

I am shocked at the readout, it is a quick car.. very happy with it.

I do have a video, but photo bucket is an absolute waste of time!!!

 

[RGS3]

The FL S3 feels much quicker than the previous 8V, although the new one is S-Tronic which of course will make it quicker but it just feels stronger.

 

[Gordo77]

Hi Guys,

Just had my S3 on the dyno at Indigo GT, South Wales.

They didn't expect it to pull 300 because it has only done 2600 miles. It pulled 336hp, they were amazed.
I suspect the dyno is overestimating ever so slightly as the readout on my 120hp 1.4 was 131hp, but it won't be very far off at all.. very happy.

They Revo mapped a manual FL S3 yesterday and got over 380hp, they said they had to tone it down as well because the clutches in the manuals are so weak. They were trying to talk me into Revo for £720 and most likely 390-400hp.. but I have decided my warranty is worth more to me

Regards,

Matthew

Wow, that's impressive! I reckon you're right saying the dyno is probably overestimating, but still... can't complain!

 

[DrEskimo]

Aren't there different places to measure BHP? At the wheels and at the engine flywheel for example?

Perhaps this was at the flywheel, whereas the quoted figures are at the wheels, after some power has been lost through the transmission, differential, etc. ?

 

[paulmc]

You can only measure power at the wheels on a rolling road then the software calculates transmission losses and gives estimated power at the flywheel. So power at the flywheel is an educated guess.

Eveyone loves flywheel figures, for me I always like to see wheel power after all that's what's hitting the road not flywheel figures.

 

[lledwoc]

Aren't there different places to measure BHP? At the wheels and at the engine flywheel for example?

Perhaps this was at the flywheel, whereas the quoted figures are at the wheels, after some power has been lost through the transmission, differential, etc. ?

The manufacturers power/torque figures are generally at the crank not the wheels.

But they're often over/under estimated depending on where they want it to sit in the model line up/market.

 

[deanshaw24]

My Fl S3 is easy as quick as my RS3 8P was. I reckon 320 - 330bhp out of the box. Awesome wee car

Agreed, I think it's so much faster than the prefacelift felt

 

[DrEskimo]

The manufacturers power/torque figures are generally at the crank not the wheels.

But they're often over/under estimated depending on where they want it to sit in the model line up/market.

Ah OK.

I've seen a lot of cases where the actual BHP is higher than the claimed figure. Makes a change from all the other grossly underestimated figures, such as MPG and emissions

Presumably this transcends into slightly faster than claimed 0-60 times?

 

[AudiNutta]

The flywheel HP (quoted by Audi) is 336hp.

The wheel HP is 262hp, yes huge losses through the Quattro system.

 

[AudiNutta]

http://s867.photobucket.com/user/Ba...D-406F-BF29-A471B12D0691_zpsnil2pqsv.mp4.html

 

[GSB]

The flywheel HP (quoted by Audi) is 336hp.

The wheel HP is 262hp, yes huge losses through the Quattro system.

Audi only ever quote 310PS, or am I missing something? And losses through quattro of 72hp seem excessive. Those losses will generally emerge as heat, and 55kw is an awful lot of heat energy to dissipate without a dedicated cooling system. Also bear in mind that Quattro losses measured on a 2 wheel dyno are not representative of reality. Unless your transmission is knackered, you will never ever be pulling full wide open throttle with the rear axle disengaged.

You can only measure power at the wheels on a rolling road then the software calculates transmission losses and gives estimated power at the flywheel. So power at the flywheel is an educated guess.

Eveyone loves flywheel figures, for me I always like to see wheel power after all that's what's hitting the road not flywheel figures.

This is the American method, and I really don't like it. Measuring raw wheel horsepower is prone to induced errors, since the reading fails to take into account fundamentals like changing temperature and pressure in the tyres, changing viscosity of lubricants, and even the coefficient of friction between tyre and roller. You can induce a dramatic shift in power numbers simply by putting a fat bloke in the car. If you want to know what effect the changes you're making to your engine are really having, you need to eradicate as many sources of error as you can from the measurement chain.

 

[AudiNutta]

Audi only ever quote 310PS, or am I missing something? And losses through quattro of 72hp seem excessive. Those losses will generally emerge as heat, and 55kw is an awful lot of heat energy to dissipate without a dedicated cooling system. Also bear in mind that Quattro losses measured on a 2 wheel dyno are not representative of reality. Unless your transmission is knackered, you will never ever be pulling full wide open throttle with the rear axle disengaged.

Yes they quote 310PS, or 305.9HP. Mine achieved 336.2HP.

He told me at the wheels the figure was 262HP.

I think their dyno COULD be slightly out but not by much. My Dad's A6 Allroad 180hp 2.7TDi went on expecting 180hp, it got 196hp.

My Fiesta Ecoboost was expecting 123hp, it got 126hp.

My A3 was expecting 120hp and it got 131hp.



All on the same dyno, only the A6 and my S3 were 4wd.

 

[paulmc]

262 sounds about right. Losses will be around 18 - 22 % ish. I have not seen what audi quote as their tranny losses? its going to be somewhere between 18 & 22% at a guess.

Still great numbers for a more or less new engine.

 

[GSB]

Yes they quote 310PS, or 305.9HP. Mine achieved 336.2HP.

He told me at the wheels the figure was 262HP.

I think their dyno COULD be slightly out but not by much. My Dad's A6 Allroad 180hp 2.7TDi went on expecting 180hp, it got 196hp.

My Fiesta Ecoboost was expecting 123hp, it got 126hp.

My A3 was expecting 120hp and it got 131hp.



All on the same dyno, only the A6 and my S3 were 4wd.

262 sounds about right. Losses will be around 18 - 22 % ish. I have not seen what audi quote as their tranny losses? its going to be somewhere between 18 & 22% at a guess.

Still great numbers for a more or less new engine.

A couple of rules of thumb to consider (and trust me, I'm not trying to be a smartarse here).
When using a chassis dynometer, the number itself is meaningless. It has almost no direct correlation with actual flywheel power, so take the actual number with a very big pinch of salt.

The only way to measure flywheel power is at the flywheel, and that means taking the engine out of the car. Obviously this isn't really a practical consideration, so a chassis dyno is used instead. When using a chassis dyno you are using a rough but educated guess at flywheel power, made using a measurement of transmission system 'drag' that's measured at coast down. This is fraught with potential innaccuracy, and includes everything from the gearbox drag to the effect of the suspension alignment on the tyre to roller interface, and how much the tyres are deforming on the rollers. The key to success is to have a consistent dyno operator who can repeat tests with a minimum of variation between them. When using this sort of dyno it's more important to note what happens to the numbers when you make a change to the engine. The number could read 1000hp, but what matters is that when you change something it gets bigger. The coastdown offers an indication of what sort of losses are being incurred, since the same car can show very different power figures dependant upon so many factors, even down to how tight the retaining straps are and how much fuel is in the tank (A very quick way to increase your wheel horsepower on a dyno is to fit lighter wheels or change your suspension alignment to reduce camber and toe).

So, don't be fooled into thinking that the losses shown on a chassis dyno are the real losses, and your gearbox and diff are so inefficient that they are consuming 20% of the available power. The losses calculation is at best a dyno 'fudge factor' and not reflective of reality. A decent gearbox and transmission system will 'lose' 2-3% maximum. A transmission that's actually consuming 22% of your power will quickly be converted into a pile of very hot bits on the workshop floor.

 

[AudiNutta]

A couple of rules of thumb to consider (and trust me, I'm not trying to be a smartarse here).
When using a chassis dynometer, the number itself is meaningless. It has almost no direct correlation with actual flywheel power, so take the actual number with a very big pinch of salt.

The only way to measure flywheel power is at the flywheel, and that means taking the engine out of the car. Obviously this isn't really a practical consideration, so a chassis dyno is used instead. When using a chassis dyno you are using a rough but educated guess at flywheel power, made using a measurement of transmission system 'drag' that's measured at coast down. This is fraught with potential innaccuracy, and includes everything from the gearbox drag to the effect of the suspension alignment on the tyre to roller interface, and how much the tyres are deforming on the rollers. The key to success is to have a consistent dyno operator who. When using this sort of dyno it's more important to note what happens to the numbers when you make a change to the engine. The number could read 1000hp, but what matters is that when you change something it gets bigger. The coastdown offers an indication of what sort of losses are being incurred, since the same car can show very different power figures dependant upon so many factors, even down to how tight the retaining straps are and how much fuel is in the tank (A very quick way to increase your wheel horsepower on a dyno is to fit lighter wheels or change your suspension alignment to reduce camber and toe).

So, don't be fooled into thinking that the losses shown on a chassis dyno are the real losses, and your gearbox and diff are so inefficient that they are consuming 20% of the available power. The losses calculation is at best a dyno 'fudge factor' and not reflective of reality. A decent gearbox and transmission system will 'lose' 2-3% maximum. A transmission that's actually consuming 22% of your power will quickly be converted into a pile of very hot bits on the workshop floor.

I must say, I have never failed to be amazed by your knowledge on this forum.. well done sir

I knew it wasn't a totally accurate system with different external effects giving a different result and ultimately it also comes down to how and how often the dyno is calibrated. But I didn't expect things as little as how taught the straps are, or the camber of the wheel.. thinking about it now, it's obvious how it would all have a small effect.

I didn't put it on there expecting perfect figures, but it gives an approximate idea and I'd like to think that the system is within a tolerance of 10hp, but who knows. It all depends on the quality of the runs also, I were there before when somebody had a Focus RS mapped to 400hp by a tuning company, the car pulled 320hp after multiple attempts and the company just claimed that the car couldn't put power down on a dyno.. how they can conclude on that, I'm not so sure.

 

[GSB]

Thanks.
It's the result of bitter experience though. Being told an absolute load of conflicting BS by less than scrupulous 'tuners' meant I looked into it to avoid having my pants pulled down when getting cars tuned.

Theres so much variability in the measuring chain on a chassis dyno that it's hard to even make repeatable dyno runs on many machines, let alone come up with an accurate number, and many operators lack the detailed understanding required to get the best out of the machines they're using. What is certain is that you need a really good operator, and even then it isn't possible to compare dyno readings from one dyno to another, and the sorts of dyno used for mapping and tuning are actually really not that good at giving definitive numbers. They're brilliant (in the right hands) at detecting small changes in torque output from different engine calibrations, but can still be thrown off by something as simple as the weather. Hub mounted dyno's like the dynapack dispense with one of the biggest variables (the roller and tyre interface) but the only way to get a true and unmolested reading of engine power is to take the engine out of the car. Sod that...

 

[JunkStory]

i would like to see a FL side-by-side race a PFL at the track

 

[mike price]

Excellent figures fair play, nice to know you have a healthy engine if nothing else

 

[paulmc]

BMW quoted 18% losses through an auto box and rear diff, I did not just make up that numbers. Certainly from what I have seen power loss from flywheel to power hitting the road is anything from 18 to 22%. Although its quoted as tranny losses actually it encompasses a lot more. Brakes, tyre pressure, type of tyre, tyre drag, wheel bearings, manual boxes, auto boxes, dsg boxes, type of diff, fwd, rwd, 4wd, the list is endless so it can only ever be a guess.

As I said earlier flywheel figure is a pure guess I only ever like to see wheel HP but everyone likes to see flywheel numbers as they look better and you can compare again stock. I guess if manufacturers quote wheel hp we would prob move to quoting wheel hp instead of fly hp