designo

iTrader: (6)

Okay boys, I dynoed the car last night on a dynojet. I must admit, it wasn't as tricky as I had feared it to be.

So here it goes, got the car on the rollers, got her all set up and strapped in place.

Power button on simply because I really wanted the car to delay shifts, give me a more accurate and sensitive throttle indication and finally... hold gears!!!

Traction control fully switched off by depressing the traction button for 5 seconds.

We don't have snow mode here, all we have are the ECT power button. Kindly observe below picture.



Now the secret to getting the car to hold gears is to linearly apply throttle, shift at just below 4000rpm and once you get up to the desired gear ( in this case 5th gear )... let off slowly so it falls by about 500rpm and apply a relatively aggressive throttle punch all the way down to the kick down button. The car did not downshift and stayed in gear!

Now before I show you the dyno chart, I want you guys to pay attention to my A/F ratio! Lexus Middle East have detuned our GS460's from 342hp to 322hp simply because they were forced to detune the LS460's due to Direct Fuel Injection not coping too well with our pump fuel. So basically, detuning the GS460 was a straight out marketing nonesense!

Our cars are running so rich due to this detune, it is literally choking our cars and depriving us of 20hp if not more! There must be some way I can get my ECU retuned again... there must be!

Here's the dyno chart



And here's the video of the dyno run! Enjoy!

http://www.youtube.com/watch?v=QaXKEZB7jvE

Rider

Great find and numbers ! I think that our cars are detuned because even in US, the 460 is equipped with a DI engine ! I always thought that the GS460s were all N/A ....

Rider

Can you elaborate more about the A/F ratio, I dont get it. Should it be linear?

KevGS460ML

That's a 21% loss due to the drive tran? I'd thought Lexus is more efficient than that.

Are you planning to do another dyno after the exhaust swap? If there's no loss from that, I may do the same on mine.

passnu2

iTrader: (33)

I think mine showed a 20% loss also. I still think the car did not dyno properly. We tried all modes to get it to hold gear and this along with all the electronics are the issue IMO. I have to dig for that PDF on my car. If we didnt use snow mode I think it showed ~ 170 hp. If we used snow mode then I was around ~ 220. I dont think you want to run the dyno in power mode but I could be wrong. I had mine in normal or snow with our tries.

I will dig for my dyno runs to see how they compare.

designo

iTrader: (6)

Air to fuel ratio should be around 12 or 13. As you can see from the chart, it was actually 10 and below at some point. This means more fuel is being injected mixed with air which is choking the combustion.

A stock E60 M5 pumps out 390 to 400 at the wheel. That's a 25% loss due mainly due to the transmission.

However, keep in mind that drivetrain loss is a fixed figure, not a percentage. So if you modify your car and pump out more at the wheel, just add he initial loss to it to see how much you are pumping out at the crank.

YES, I am going to dyno again once the exhaust and air filter are installed. I might run even richer which is bad news for me. It is vital we get our car tuned accordingly.