Sunder

1) In physics, no there isn't. Your capability to turn X weight, Y Quickly on a dyno is completely irrelevant whether the power was done through two wheels or four wheels.

If you have A torque put down to the road, and B weight, then physics does not allow for anything but F=MA. Your force (torque) and mass (weight of car) are known, your acceleration is not affected by the means this power is transmitted

2) No, for several reasons.

Firstly, some loss is due to the dyno, not the car. Yes, there might be additional losses by reading through a second set of drums, but they connect back to the same sensor, which also has loss, but which will not be increased, since it's just aggregating the power from the two spinning drums instead of one.

Dyno losses ARE NOT LINEAR. a dyno might lose 25% when measuring between 2000 to 3000rpm, but lose 29% when measuring between 7000-9000rpm. This is known to happen, as parts expand as they get hot, causing more friction.

The reverse can also be true. It is also possible that it has a loss that starts fading, as power goes up - just say there was a fixed frictional loss in the dyno which was not accounted for in the software.

Let's just say it's 10Nm no matter how much power is put through the dyno. If you were measuring a car with 100Nm, then that's a 10% unaccounted loss. If you were measuring a car with 1000Nm, it's a 1% unaccounted loss.

Secondly, there are plenty of common parts in a drive train, which have loss, such as the gearbox and clutch. So the loss from the diffs would be doubled, but the loss from the other components would not increase whatsoever. It would be safer to say that an AWD, in absolute worse case scenario, would have less than twice the loss of a FWD. In reality, I doubt it's anywhere near as high. I've heard 25 for FWD and 35 for AWD.

In short, the only fair comparison, is to say, that you gained x% on your car, using Y dyno. People can then make a judgement on whether the kit is worth getting or not. You can't compare with any other car, same drive train or not.

Unrelated to either topic, I have an anecdote too. A mate of mine bought a V6 2.0L Mivec engine from you. He is indeed very pleased with it. Why wouldn't he be, he's putting out 150Kw at the front wheels, after shaving the head, port and polish, new intake and exhaust manifold and computer! (And his success alone puts a lot of faith in me, regarding your work)

In my Evo Lancer, I'm putting out 150Kw through all four wheels. The lancer weighs 300 kilos more than the mirage, yet, I know even from a rolling start (to negate traction issues), I cane him hard.

The difference? We measured on different dynos. (well, actually, there are two differences - The EVO has a greater area under the curve, even though it has the same peak - in other words, he has a sharper rise, where I have a nice flat rise)

Mitsiman

Dyno printout of the magna at 8 psi boost on the link below.

http://www.fastmagna.com/feature/rpw/

Foudn the problem to be a broken intercooler pipe so we have rectified, driven and now takign the car back to the dyno for more tunign and greate horsepower levels.

Sunder

Any chance of a wheel power graph instead?

I use that particular dyno, so I can search my databases for a car that has similar power, just to get an idea.

Thanks.

Mitsiman

That was at the wheels using a Dynapack Dyno which bolts onto the hubs of the wheels. This is not an engine dyno.

At this stage no chance of using the more traditional chassis dyno no as the upcming dyno shootout event is using the same dyno as what I am using which is becomign the preferred means of tuning in WA as it is more accurate.

Sunder

I know... I use that dyno. You take off the wheels and bolt directly to the wheel studs.

But the dyno operator actually chose to display Flywheel numbers which are calculated, rather than the real numbers that the Dyno read off the sensors.

Nevermind. Thanks anyway.

Mitsiman

For those who have teh sharp eye it has just been pointed out to me to my dismay that the horsepower reading on teh dyno is the figures at the flywheel not the front wheels.

The confusion has come because the first dyno we used was a chassis dyno which read at the wheels and I did not realise that the dyna pack dyno was set to read corrected at the flywheel. I will get the next dyno sheets to show at the wheels so it is consistent with what most people would like to know.

Sorry if I have mislead anyone here - it has certanily burst my bubble but on the other hand is now consistent with the mods and low boost setting weare running. We are still running out of fuel but explains the relationship between fuel pump and hp rate.

So now I am looking at running the external fuel pump system as a second system for the higher boost settings for racing purposes only. I want that higher horsepower at the wheels.

I just realised what you mean't when someone else in another forum stated that.

YEs I will be getting front wheel figures at the next dyno. Sorry about that

Mitsiman

I just came back from the dyno and have the breakdown fo teh dyno sheet.

For those interested we do have 360hp at the front wheels. If you look at it you will see that the HP reading at the wheels and the flywheel are the same. The correction factor for the flywheel hp reading is set to zero.

So I am happy to say that we do have 360hp at the front wheels and with todays tunign on normal pump gas we should finish up at around 430hp.

So I can absoloutly confirm this vehicle has 360hp at the wheels and after todays dyno tuning we should have around 430hp at the front wheels.

Mitsiman

Well we went down and a great success. Did some mods to the O2 sensor set-up and the Greddy came up very nicely for the tuning. We placed some larger 450cc injectors in the car just for insurance and took it down for tuning. With immediate results we proceeded with it nicely and at 9 psi boost we were up to 386hp at the wheels immediately. Injectors up to 77% duty cycle (Glad we changed them), fuel pump looking good - time to raise boost. Slowly we raised it up to 11 psi and bang - (Not bang as in blown) 407hp at the front wheels on BP Ultimate 98 fuel.. Nice flat torque curve, no detonation on a very safe tune. We started to go further - but you guess it we now need to do more modifications.
It seems our 3" mandrel bent straight through exhaust is too small and we need to go larger on our dump pipe to a complete 3 1/2" system all the way through. The back pressure on the turbo's has become a limiting factor as well as our intercooler is starting to get higher in air temperatures telling us we need more air flow / possibly larger intercooler. This is our next project over the next month and then back for more work - after we sell the exhaust on our car as it is which already sounds great.
Most amazing is that we have over 500 ft/pd of torque at the wheels - this is more than a 600hp EVO IV lancer had at the wheels and is in the realms of Group A Touring Car time. Did someone say auto trans - I think I saw it in pieces down the road. The Manuel box is handling it nicely, the special clutch is a dream. For the first time I went as a passenger as Andrew Jordon from Speed Works who tuned the car drove, and I was literally scared at how fast the thing accelerated. Very different being a passenger let me tell you.
So that is the latest news - new Dyno sheets here soon and once the new exhaust is done we estimate around 450hp at the front wheels on BP Ultimate 98 at around 14 psi boost. Those considering this form of conversion - don't hesitate do it as it is just too amazing for words - if you are in Perth, drop by for a mind blowing drive with David from RPW.

Redav

Don't mean to steel your thunder, Dave, but I thought I'd keep the lads informed.

Mitsiman

Thanks Redav - always appreciated

rexhunta

iTrader: (1)

Could this be Aussie's quickest ATM ? then again, when youve got the traction sorted, can it be the worlds? or is there a Diamonte out there that someones boosted and dragged ?

Pete

Mitsiman

I don't know about outside of australia but this is certainly the quickest in Australia at this time and for sometime to come I beleive

Mitsiman

http://www.rpw.com.au/Downloads/Downloadindex.htm

Video of some runs included

Raptor

Dave

I was wondering if you could please post up your latest times using the slicks etc. The movies are a big large for us dial up people (that is not a complaint).

We're all keen to see the progress

Thanks

Redav

Latest time is a 12.8