550cc injectors, wtf mpg?!

[JonnyDerv]

Had 550cc injectors fitted yesterday, no problems with them but my trip computer is claiming 42mpg even after so back road blasting and has now dropped to 38 with a very heavy foot on the dual carriageway. Does the injectors mess with the trip computer or something?

 

[ayfreetee]

I think it must do, I have 440 fitted to mine and it tells me I'm getting 42mpg as well.

 

[superkarl]

I take it these were properly mapped in?

And yeh I think the mappers have to do something with the trip computer and recalibrate it somehow in order for it to be accurate.

 

[Samuealle]

its all relative to the injector scaling essentially....as its gone 1 in the morning i really cant be ***** to go through it. You can run adaption with vagcom to sort it out

 

[sonique]

and you are setting up all paremeter the SW ?
need the KRKTE , TVUB , KVB ank fine tune FKKVS

 

[daz-20vt]

jonny i was under the impression your car was fairly standard?
like karl says you cant just go fitting these they need mapping
have you done this?

 

[<tuffty/>]

Fitting 550's without proper scaling in the map will result in incorrect MPG display (the ECU still thinks they are 386cc) and will cause the ECU to pull the extra fuel through adaption anyway...

Why have you fitted them and why were they not mapped in?

<tuffty/>

 

[JonnyDerv]

They have been calibrated. Standard injectors were at 93% duty cycle, making 276bhp, got some 550cc because I'm planning to go hybrid when BBT gets some back in stock. Fuelling is fine now, just the trip that's lost the plot

 

[<tuffty/>]

If they have been calibrated in the map for fuelling then I would imagine KVB has not been scaled correctly

<tuffty/>

 

[JonnyDerv]

I've done abit of quick reading and from what I can gather, you can alter it in vag com but not enough to make it read right, is that correct?

 

[<tuffty/>]

I've done abit of quick reading and from what I can gather, you can alter it in vag com but not enough to make it read right, is that correct?

No... not exaclty... there is a way of altering adaption channels in the instruments module to tweak MPG readings but there is a 1x1 table in the map that should have been changed to deal with this... 550cc is a fairly big leap from 386cc so should be changed in the map

<tuffty/>

 

[JonnyDerv]

Hmm interesting. Shame it's not 42mpg, that'd of been nice haha

 

[badger5]

kvb scaler

 

[badger5]

kvb scaler required