Data logging

[Kor]

Re: Data logging

Yes and no.

Changing the N75 is purely a mechanical change, that is you are changing how quickly it responds to requests from the ECU (some have also argued that the interior volume is slightly different). There is no communication between the N75 and the ECU, the ECU does not know how the N75 behaves. The ECU simply issues requests to open or close the valve. Although it may over time notice that it needs to request slightly more open-time or slightly more closed-time to aproximate the boost curve in memory, you do not need to wait before the mechanical characteristics of the new valve are observable. If the different valve is going to boost higher (delayed response) it will do so immediately. If it is going to spike less (increased response), it will likewise do so immediately. This will be regardless of the N75 adaptation parameter of the ECU.

The ECU adjusts requested boost based on a number of runtime factors including temerature, air pressure, air density, and all kinds of of other things that I probably don't know about. Also take these things into consideration when comparing your boost levels from day to day.

[1.8Trip]

Re: Data logging

...it may over time notice that it needs to request slightly more open-time or slightly more closed-time to aproximate the boost curve in memory, you do not need to wait before the mechanical characteristics of the new valve are observable. If the different valve is going to boost higher (delayed response) it will do so immediately. If it is going to spike less (increased response), it will likewise do so immediately. This will be regardless of the N75 adaptation parameter of the ECU...

I think we are thinking the same thing here. I noticed that the characteristic is immediately different, but the level (or amplitude?) is still not matching what the ECU is requesting (according to what we logged i.e. 18 psi)

[Khyron]

Re: Data logging





Well I have to practice logging I guess - I didn't do the coast down after the 120 run so can't calculate HP. Not sure exactly how the AF metric works either.

Khyron

[R_Ethug]

Re: Data logging

geoff 120 should have tq/hp on it.. get the sample files from ross-tech's site

[1.8Trip]

Re: Data logging

Geoff, take your block 120 values and convert them to ft lbs. Then calculate Hp by:

HP = rpm x torque (in foot pounds) / 5252

You can then plot the torque and hp.

[Khyron]

Re: Data logging

Geoff, take your block 120 values and convert them to ft lbs. Then calculate Hp by:

HP = rpm x torque (in foot pounds) / 5252

You can then plot the torque and hp.

Hrm - I will try that when I get home. How do you go from those 120 values to ft pounds? What is the unit anyway ( I just called it load, since it can't be straight TQ).

From reading the Ross-tech section, the coast down is important to calculate the how much load is generated from the acceleration and how much is generated just from wind resistance. You subtract the energy logged in the coasting from the energy used in acceleration and the net is the engine power (at least that's how I read it).

I will try Andy's pre-filled spread sheet and see if I can run the logging in turbo mode. Need to find a longer stretch of road to coast down though.

Khyron

[1.8Trip]

Re: Data logging

Hrm - I will try that when I get home. How do you go from those 120 values to ft pounds? What is the unit anyway ( I just called it load, since it can't be straight TQ).

From reading the Ross-tech section, the coast down is important to calculate the how much load is generated from the acceleration and how much is generated just from wind resistance. You subtract the energy logged in the coasting from the energy used in acceleration and the net is the engine power (at least that's how I read it).

I will try Andy's pre-filled spread sheet and see if I can run the logging in turbo mode. Need to find a longer stretch of road to coast down though.

Khyron

ftlbs = 1.35581794833 Nm

That coast down thing is interesting. I didn't do that. I'll have to look into that.

[milesmcewing]

Re: Data logging

Hey Bart,
Give me a call, I will lend you our Data Logger, it is GPS based and monitors a pile of different settings. I can lend you the vag-com too if you wish.
Miles

[bart]

Re: Data logging

hi miles, its not that important, i have vag-com too, but i guess the tdi's dont have the same blocks as the 1.8t, and i already have real dyno plots of my car, its just something i wanted to try when i was bored. thanks though!

but i wouldnt mind borrowing that nice red shiny 800hp monster you have!

[milesmcewing]

Re: Data logging

hi miles, its not that important, i have vag-com too, but i guess the tdi's dont have the same blocks as the 1.8t, and i already have real dyno plots of my car, its just something i wanted to try when i was bored. thanks though!

but i wouldnt mind borrowing that nice red shiny 800hp monster you have!

The red car doesn't even get on the cam until about 10,000 rpm!! We are getting everything out tonight for startup, give me a call!
Miles

[bart]

Re: Data logging

ahah. at race city? i'm sure there would be a few people interested in watching...

[Stonewall]

Re: Data logging

ahah. at race city? i'm sure there would be a few people interested in watching...

I am interested, do tell.