Im sorry but where are you guys getting your figures?

208 fwkw = 150 rwkw???

That's a drive train loss of 58kw which is about 28%

Since when has 28% been used to calculate power loss through the drive train?

I was under the belief its around 15% depending on the vehicle.

flash, 15% sounds very very generous, and probably a manual.

considering its expected a stock ef-au to do abt 105 rwkw on a dyno, theres a "loss" of around 50kw from the quoted engine power. say age accounts for 10 of those kw, and its a loss of around 40kw, which at 157, 40 represents 25%.

its only an estimate unless you get the engine out and put it on an engine dyno.

pete, two engines both with this 208kw mark can feel entirely different depending on the bore/stroke ratio, induction method and power curve. a turbo supra with 208kw will have more power under the curve than a NA 4lt i6. That said, fix the gearing in a falcon and it definately helps keep things in account.

The only place it will matter is down the strip, and at the pub and both are for fun. But dont expect to beat a turbo supra in the falc, unless you have a lot of work done, not just engine wise but drivetrain wise as well.

A stock xr6 makes 164fwkw. depending on the dyno and the operator they will do about 110-115rwkw

by your 15% an XR6 should show about 140rwkw. thats just not going to happen

Auto's chew more power than a manual, don't they????

Well i did state depending on the vehicle, but from what ive read and the operators ive talked to the average is 15%, Some people say 25% some say 10% but as Grimketel said without checking rwkw on the dyno then pulling the motor and comparing fwkw how would you know? I just think 28% drive train loss is extremely unlikely.

A few people said i was being generous with the 15%, i was actually thinking the other way. As i believe giving the car a 28% power train loss is generous. So by my reckoning for the stated car to produce 208 fwkw it would need to be generating around 170 rwkw.

I mean think about it, thats over 1/4 of the engines power lost through the drive train!!! so when your doing say 160kmh and include aerodynamic drag, how much power are you producing then? We would be talking almost 50% of the engine power being lost, which would leave us 82kw.

I would like to see the so called xr6 that produces 115rwkw have its engine pulled out and put on a dyno and see if it is still generating the claimed 164fwkw? Are we talking a 10+ year old car that is being put on the dyno now, or are these results from 1992-1998. Sorry tickford_6 but im actually saying the xr6 that is producing 115rwkw is only putting out 140fwkw, not the other way round.

you can dyno race all you like, and talk about what ever dyno number you like. at the end of that it's only number.

run the car at the strip and work out the power needed to run MPH and you soon realise how s**t dynos are

Mate i agree 100% that dynos are full of b/s. There are so many variables (like what i said above) and there inconsistencies, what mode there in blah blah blah....

The only real way to measure h/p is with a g-tech. It takes into account ALL the variables and also aero drag and measures actual Road hp.

For example a 600hp cat in a flat nose truck will be producing LESS "road" hp than a 600hp cat in a bonneted truck, as the flat nose has to work harder to move the air. So the "bonneted" truck will pull 40t up a hill at 100km/h easier than the flat nose.

G-tech's get a bad wrap because people are never happy with the results
Ive had people say to me...
"my car put out 250rwkw on the dyno but only 210rwkw with the g-tech there s**t!"
Some people have no idea.

Oh and btw, at what stage did i say dyno's are the be all and end all???

Your talking like i did.

OH DEER.

Great response there.

Tell me im wrong?

Dynos = for tuning

G-force = for telling real word h/p

G-force meters have been used since the 60's and probably earlier to measure h/p.
Read the book turbocharges by Hugh Mcinnes (spelling?) he explains why and how to do it.

your wrong. 15% is wrong, if both the truck are using 1st low range and identical drivelines they will both put the same power to the ground and both drive the hill the same. wrong again. G-force doesn't tell you how much power the engine is making, it tell you how much of it is moving the car. wrong again.

The "real world power" argument has been done to death and doesn't need reviving.

It's not what the thread was about and not were this thread needs to be taken

IF 15% was right, new BF falcons would be showing about 165rwkw. THEY DON'T. so wrong again

one last point befor hopfuly this thread goes back on topic or dies a dismal death.
how you stop reading books and start building engines?

yeah ive had this arguement with engineers, they say 15% is drivetrain loss, but engineers live in a world of numbers and words, not reality.

real world its around 25% loss from engine quoted power to power at rear wheels on an average dyno.

sometimes more sometimes less, as its only a tuning tool, but it does give a rough indication.

so you can loosley get an idea of a ballpark engine figure by adding around 40-50kw to the rw figure with a NA ef-au motor (depending on the state of the engine) if its an auto, around 30-40 rwkw if its manual.

its by no means accurate down to the letter, and actually quite ussless, as its the power at the wheels that moves you.

take my au when she was stock, did a 16.5 on the 1/4 which is rather s**t imho. 89mph trap speed is rather good. 2.6 60 foot is bad.

this tells me i might be loosing a bit of power through a dodgey torque converter, as the power is there to get good trap speed, but crap time and 60 ft.

the track is a great indicator to check your car out.

Why aren't we comparing apples and apples here? How many RWKW do we expect from a supra? Forget talking about Flywheel power for a minute and you might get somewhere.

Sorry but if your going to quote me how about you quote what i said and not make up b/s to support your own feeble argument.

I said if both trucks where doing 100 km/h for a start. so your wrong.
see this is the same as the dyno argument, you need to test at speed, not in first gear on the road, or on a set of rollers.

Yes they will put the same power to the ground in first gear, but how about 18th at 100? the flat nose will need more power to do the same speed yes? = so your wrong again.

And this is my point, its all about usable power.

Put two identical Falcons on a dyno, one a waggon and one a sedan. They may very well put out the same power on the dyno. Then hook them up in a race, the sedan will win.
Its lighter.
Its more aerodynamic.
It can utilise its power more effectively.

The g-tech would tell you that!!!

You need to learn mathematics. By you reckoning bassed on a 25 % loss a 240 fwkw bf will be putting out
240 / 100 x 25 = 60
240 - 60 = 180 rwkw.

my calculations bassed on a 15% drivetrain loss is
240 / 100 x 15 = 36
240 - 36 = 204 rwkw.

Which sounds closer to the mark, mine or yours

And btw i started building engines about 17 years ago, and how about you look at the turbo car in my gallery. Yep thats all built by myself.
All i see against your name is a gq patrol?

Where's your proof expert?

i wasn't talking about a an xr6 turbo when i mentioned the BF. was talking about the base model engine.

yeah so i own a GQ so what. what does that prove? the only thing it proves is one of my cars is a GQ patrol.

it's over. let it go.