Virtual Dyno Room

[prj]

Did another run today with a bit more boost from 1.8 and rising to 2 bar after 6000 RPM. A made it just to see how rich it gets up there (with 0.76-0.77 lambda from 4500 till 6500) it is WAY TOO RICH and maxing out the Siemens 630 on the ADU FPR.

RON 98

You are probably maxing them out because your fuel pressure is tapering, not because your injectors are too small.

And why would you ramp boost instead of tapering to redline?

[Billman]

You mean because of the fuel supply? maybe...I run 044 pump on the stock fuel lines system on ADU FPR (3.8?).

The boost ramp was due to N75 DC, I was testing settings out. The VDR graph was a byproduct.

[Rocco]

You mean because of the fuel supply? maybe...I run 044 pump on the stock fuel lines system on ADU FPR (3.8?).

The boost ramp was due to N75 DC, I was testing settings out. The VDR graph was a byproduct.

i am with the same injectors as you,also same 044 pump and stock fuel lines...but 4Bar FPR
are you running near to 630Hp?

[prj]

Tomas had exactly the same problem until I relayed his fuel pump.
Are you running a relay Billman? Because if not, I am pretty sure your fuel pressure is tapering.

[Billman]

I think I am far from it but I don't think I can get there with "98 RON" (or whatever it is that they call 98 RON).

and as I said the map is not near ready yet because it run too rich to make max power. This run was only to 6500 RPM what also means far from top.

Car is an RS2 and I don't run a relay. Should I use one? That means the + from the fuel pump to the relay and a + from the battery though the relay to the pump?

[prj]

There is pretty much no way you are going to max those injectors at 6500 rpm with 2 bar of boost, unless you have some sort of uber flowing engine...
So my bet is that the voltage is actually dropping at the 044 pump. Relay it directly from the battery and it should run way richer up top with the same VE map.

[Rocco]

There is pretty much no way you are going to max those injectors at 6500 rpm with 2 bar of boost, unless you have some sort of uber flowing engine...
So my bet is that the voltage is actually dropping at the 044 pump. Relay it directly from the battery and it should run way richer up top with the same VE map.

yes ,like we did in Jorge´s garage


Jose Luis also did it in the past in the coupe.... to can use it with RS2 fuel pump and RS2 turbo... what an old days

[Billman]

Nice....thanks for the comments...really helps!!!

At 6545 I have exactly MAP 300 KPA (2 bar) and there is 0.76 lambda, 96.8 InjDC.
At 6580 I have MAP 302 KPA lambda 0.74 and 97.2 InjDC.

Engine is a stroker with reclocked 7A cams and Super 40 turbo.

[andy10v]

Do you run the relay wiring right to the pump? Or is the connector to the fuel tank sufficient?

[Billman]

Do you run the relay wiring right to the pump? Or is the connector to the fuel tank sufficient?

[prj]

Usually the wiring in the tank is okay, so I just make the connection under the upper lid, and hide the relay between the upper lid and the tank

[Billman]

Usually the wiring in the tank is okay, so I just make the connection under the upper lid, and hide the relay between the upper lid and the tank

I will do it next week (hopefully) and I will post....surely even 0.3V difference is worth it!

[prj]

I have seen difference as much as 2V and more on some cars.
Depends how bad the existing wiring is.

The 044 draws a lot of current.

I relay every car that is over 440hp.

[andy10v]

Usually the wiring in the tank is okay, so I just make the connection under the upper lid, and hide the relay between the upper lid and the tank

Thank you

[EspenW]

I haven't fiddled with testing or the Virtual Dyno / VDR program in a long while, but recently pulled up the program again to analyze some old data.
I loaded the time stamp vs. rpm data from both the VAG Com log and the 100hz accelerometer log for the same run. The logging rate of vag Com is a pathetic 2Hz (on average), so it is missing the peak values, but still gives decent results. The accelerometer calculates rpm from the ratio between engine speed and road speed in that specific gear, just like is done on dynos when an inductive pickup is not available. This is the first time that I ran accelerometer power/torque data vs vagcom power/torque data in the same chart, and it gave a very good correlation.

A £5 vagcom type cable and the free VCDS Lite program is all that is needed (in addition to the free VDR program) to generate power/torque curves, so good stuff.
Power/Torque at the wheels.

This run was at baby boost (MOT time boost setting) of 1.1bar peak vs the normal 2.2-2.3 bar peak that I run.