Racelogic tests the G-Tech with interesting results

[A80Avant]

AX doesnt have an air drag compensation that i know of.
rototest made 334whp and 520Nm when the car was boosting 1.9bar overboost and then 1.5bar after 5000rpm to the redline.
now these figures have gone to 1.9-2.0bar and 1.7up to the red line.

[EspenW]

@Espen... Further to this link you posted ---> http://www.csgnetwork.com/relhumhpcalc.html

Need some help understanding it better. Lets say I plug in some weather numbers for air temp, altitude, pressure etc relevant for a test run that gives me say 300whp (including aero losses) and it returns a result of 'Calculated Relative Horsepower To Rated' of 102% - does that mean the SAE number is 300*1.02 or 300/1.02 ?

Sorry if thats a dumb question - its just not obvious to me looking at the web page...

When conditions are more favourable than SAE standard, you will get a calculated relative horsepower to rated of more than 100%, for example 102%
It will give you the dynamometer correction factor in the line below. in this case, that would be 0.98.
Note: on WG controlled FI cars, correction for altitude and barometric pressure should be reduced by 50% due to the turbos ability to offer part compensation for lower ambient pressure. For example:
Testing on a day with lower than rated barometric pressure, say 29.00", you should enter (29.235+29.00)/2= 29.11
You will still get a favourable correction factor, but not as mucs as a NA car, because your turbo car won't suffer as much.
Of course, the 50% is an average. A turbo that is stretched to the limits of its efficiency chart will suffer more at lower ambient than a bigger turbo that is at the other end of the chart.
Same with altitude. If you are testing at 1000ft with a turbo car, enter 500ft in the calculator.
Some claim that turbo engines are more affected by heat than NA and some claim less. I have done some calculations on IC efficiency, and they get somewhat more efficient at lower temps, but not that much.

[EspenW]

AX doesnt have an air drag compensation that i know of.
rototest made 334whp and 520Nm when the car was boosting 1.9bar overboost and then 1.5bar after 5000rpm to the redline.
now these figures have gone to 1.9-2.0bar and 1.7up to the red line.

AX and MAHA measurements were both with 2.0 bar peak and 1.7 to redline?

[S2central.net]

Hehe, join the green revolution
Isn't Ireland the country with the second largest amount of E85 pumps or something?

That'll be Ireland as in Republic of... Up here in the North we get the shittiest piss poor fuel on the entire island. Never seen E85 anywhere. We can't even get 98RON here. The big rally series that runs here was making a big 'green' play for running all the cars on E85 cos its better for the environment.

E85 is one of those great marketing swizzes - its about as 'green' as toffee...

Just cos some of it grows in the earth doesn't make it green as its utterly unsustainable on a large scale...

However for die hard petrol heads like you its a great way to make more power than on pure gasoline... Thats why the rally boys are completely behind the moves for E85. It also gets less tax and stuff cos its allegedly green - enjoy it while you can sir !

Not holding my breath here.

[EspenW]

Hehe, yeah, I know your view on the enviro aspect of E85
if it goes away, I'll have to distill my own E100 that is

[A80Avant]

AX and MAHA measurements were both with 2.0 bar peak and 1.7 to redline?

yes pretty much...maybe slightly less with the overboost like 1.9 or something.Doesnt make a big difference

Also my 3d gear is more gradual than yours,which could account for the 3.8sec cause if you notice from my recent vids,my boost goes up more gradually to avoid surging

[EspenW]

yes pretty much...maybe slightly less with the overboost like 1.9 or something.Doesnt make a big difference

Also my 3d gear is more gradual than yours,which could account for the 3.8sec cause if you notice from my recent vids,my boost goes up more gradually to avoid surging

If the test on the Rototest was properly performed, and nothing else was changed on your car (except for higher boost..) then it proves that the MAHA test was flawed.
The Rototest is highy accurate, and if it said that you were producing 334hp at the hubs, then you were producing between 333 and 335hp for sure. That is pretty much what the B7 RS4 puts down. However, it only produced 367nm at the hubs. Weak 4.2L V8
You were producing a lot of torque compared to hp. Fueling problem at high rpm?

[A80Avant]

no no problem with fueling in my car.I have 044 pump and 440cc injectors.Just my tuner wanted safety first,only because of greece wrotten octane fuel,he did it too safe.Here in the UK with the wastegate screw a little screwed in and good quality fuel i get 1.7bar to the red line and still EGTs within the limits.
Im going to change the downpipe a bit and see if it frees up the backpressure a bit.Also water injection is always a big help when needed!