Racelogic tests the G-Tech with interesting results

[A80Avant]

i kind of lost you somewhere...

You say: 318whp + 65(aero losses) = 383

How do you go about the drive/roll losses then to reach the 425 or 452 crank hp???

[EspenW]

318.5hp net + 65.5hp for aero drag should land you at 384whp.

I just talked to the designer of the MR Dyno meter that I have (he works at Mustang Dyno) and he said that a correctly performed MR dyno measurement will have a graph that overlays a correctly performed pull on a Mustang to within 1-2whp.
The G-Tech, when corrected for aero drag should be very close to the MR Dyno numbers, so in case the weight is entered correctly, the numbers should match the whp on a load type dyno.
Note: he also said that many dyno operators adjust the correction factors on their dyno in order to read higher (too high) in order to have happy customers...

However, I think that Vasilis has overstated the weight of his chariot. My RS2 (although lighter than stock) has a test weight of 1615kg with me (70kg) on board.

On E85, the highest I have seen is 401whp (uncorrected for temp) / 387whp (corrected for temp)

[EspenW]

Drivetrain loss completely depends on type of dyno.

Example:

A B7 RS4 will pull 335-350hp on a hub type dyno
It will pull 290-310hp on a Mustang
I have seen as low as 282whp on a Dyno Dynamics

Typically, Rototest/Dyno Dynamics rear high as they test at the hubs
Dynojet, Claytons and Dasteks read high
Mustangs read low
Dyno Dynamics read very low
Maha claims to estimate crank hp, but they read too pessimistic in my opinion. They put VAG turbo engines at claimed power and that has been proven wrong, power on most of these engines are grossly underrated.

[A80Avant]

Ill tell you this.

We measured the car the same day with a G-tech the older version which had a problem with its mount and was not mounted on the screen but was held on my mobile phone case near the gear lever.That measurement gave me on 4th gear 277whp.However the roads we did those tests in greece is rather bumpy on some areas.
Also the G-tech gave me this figure on around 5000rpm which on 4th gear is nowhere near 176Kms!!!


Then on the same day and the same conditions,we did the measurement with the AX-22 which gave me the 318,5whp @ 176Kms on 4th gear.

All measurements were made with 2 people on board and we had a truck lift to weight the car and mine was full,the way i use it everyday and was 1780Kg with me on board,which is why we entered that weight + 1 more person on the g-tech.

However i cannot be sure of the g-tech measurements because of the way it was mounted as well as the fact that it gave me as highest hp @ 5000rpm which cannot be true

[EspenW]

Ill tell you this.

We measured the car the same day with a G-tech the older version which had a problem with its mount and was not mounted on the screen but was held on my mobile phone case near the gear lever.That measurement gave me on 4th gear 277whp.However the roads we did those tests in greece is rather bumpy on some areas.
Also the G-tech gave me this figure on around 5000rpm which on 4th gear is nowhere near 176Kms!!!


Then on the same day and the same conditions,we did the measurement with the AX-22 which gave me the 318,5whp @ 176Kms on 4th gear.

All measurements were made with 2 people on board and we had a truck lift to weight the car and mine was full,the way i use it everyday and was 1780Kg with me on board,which is why we entered that weight + 1 more person on the g-tech.

However i cannot be sure of the g-tech measurements because of the way it was mounted as well as the fact that it gave me as highest hp @ 5000rpm which cannot be true

That makes more sense, then. I seemed to remember that your car was claimed to weigh 1900kgs with only you on board..
The G-tech measurement sounds sketchy, was that a mk1 G-tech?

[A80Avant]

i dont know,but definitelly not the pro RR version

It might have taken a better measurement if the windscreen mount worked that day.So thats why i take into account the AX-22 measurement more seriously,as its a kit that costs 1000+euros although old.

By the way Paul, my dyno results in a maha dyno were rediculus,they said i made 358hp crank and about 257whp !!!! so you see why i dont trust ANY dyno anymore...

[EspenW]

The whp from the MAHA must be ignored. An A4 1.8TQ (170hp US version, I think) was measured at 62hp at the wheels, corrected to 160hp at the crank...

358 on your setup sounds wrong by a mile, however, that 100-150kmh time of 3.8sec makes me wonder
Do you have a 3rd gear log off the AX22?

[S2central.net]

@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...

[A80Avant]

no,just a 4th in AX-22

why is 3.8sec much for 100-150? a 300hp rs2 does it in 5+sec

[EspenW]

no,just a 4th in AX-22

why is 3.8sec much for 100-150? a 300hp rs2 does it in 5+sec

It isn't that bad, but from my logs, I do it in 2.97 sec with approx the same whp. in addition, timing from the speedo usually gives a time that is lower than real life.
So stock RS2 is 5+sec?

For a fixed 3rd gear 100-150 run having a broad power band (ie lots of torque around 4000rpm) is crucial too. My midrange is nuts on E85, with 530nm at the wheels. That undoubtely helps the 100-150kmh time to the low 2.97s (60-90mph is 2.77s).

[S2central.net]

Espen - stop boasting about your E85 jungle juice - its making us all very jealous...

[A80Avant]

since i didnt have any gps readings as accurate as the PB i have now,i have no other way of making this logs.

Sorry,but your car with the E85 is about 60-80hp more than mine.No way i am anywhere near your hp.Not only i have a smaller turbo,but also i have 98octane gas too.

All the other tachos i have counted on a normal rs2 car is way more than 3.8sec.I will try and find the vids and post links of them.

My only torgue reading i might concider logical would be that of the hub dyno rototest when i made about 520Nm of torgue with 1.9bar of boost @ 3600rpm or so.
So basically if you are getting a second less than me with a 50-70hp difference,that is normal.

I believe my car should be around 400-420.No more.Im not sure about the air losses and ways of calculations.

[EspenW]

Espen - stop boasting about your E85 jungle juice - its making us all very jealous...

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

[EspenW]

since i didnt have any gps readings as accurate as the PB i have now,i have no other way of making this logs.

Sorry,but your car with the E85 is about 60-80hp more than mine.No way i am anywhere near your hp.Not only i have a smaller turbo,but also i have 98octane gas too.

All the other tachos i have counted on a normal rs2 car is way more than 3.8sec.I will try and find the vids and post links of them.

My only torgue reading i might concider logical would be that of the hub dyno rototest when i made about 520Nm of torgue with 1.9bar of boost @ 3600rpm or so.
So basically if you are getting a second less than me with a 50-70hp difference,that is normal.

I believe my car should be around 400-420.No more.Im not sure about the air losses and ways of calculations.

How much power did you make on the Rototest again?
Could the AX have some kind of aero loss compensation entered into it?

[EspenW]

2.04 is m2 or sf?

2.04 sqft would be sorta small