AFR at Startup

Genuine question as I have never really paid mutch attention to it.

What AFRs on single turbos do people normally see when doing a cold start and for how long??

It depends on your cams a little I think, matey.

On my car at stock, I had high 13's I think - but with the 272s, it was happier at mid 12's.

When the coolant is around 70 degrees, it'll lean out a bit though - at least that's how I read it on the Syvecs.

I don't know if mine counts as its NA-T and has the single wire lambda sensors but mine also reads 13's untill it's warm

It depends on your cams a little I think, matey.

 

On my car at stock, I had high 13's I think - but with the 272s, it was happier at mid 12's.

 

When the coolant is around 70 degrees, it'll lean out a bit though - at least that's how I read it on the Syvecs.

Sweet, I have the same Cams as you, in which case I deffo need some fuel pulling as im sure mine used to be in the 12s before the fuel pump & line changed. What fuel pressure were you running?

Mike

i see about 13.0 -13.5 at idle parked

about 13.5-14.5 when driving away

creaps back to stoich after about 5 min i would say never really timed it though

these are abouts as sometimes i see more or less

i see about 13.0 -13.5 at idle parked

about 13.5-14.5 when driving away

creaps back to stoich after about 5 min i would say never really timed it though

 

these are abouts as sometimes i see more or less

are these warm or at cold start?

Sweet, I have the same Cams as you, in which case I deffo need some fuel pulling as im sure mine used to be in the 12s before the fuel pump & line changed. What fuel pressure were you running?

 

Mike

i have see 12's sometimes i wouldnt pull any fuel unless there was a issue whats the point

Sweet, I have the same Cams as you, in which case I deffo need some fuel pulling as im sure mine used to be in the 12s before the fuel pump & line changed. What fuel pressure were you running?

 

Mike

On the Syvecs setup, I had an 044, set at 4bar static with -6 dual fed stock rail. I did play with the fuelling on mine a little on idle, and it wouldn't idle at 1000rpm unless I was in the 13's. It needed 1200rpm to be happy in the 14's.

are these warm or at cold start?

cold start mate , sometimes goes into 12's though i was gonna put 12.5 first of all but it is normally around 13

On the Syvecs setup, I had an 044, set at 4bar static with -6 dual fed stock rail. I did play with the fuelling on mine a little on idle, and it wouldn't idle at 1000rpm unless I was in the 13's. It needed 1200rpm to be happy in the 14's.

4 bar static isnt that around 58 PSI ?? thought stock was more like 38??

4 bar static isnt that around 58 PSI ?? thought stock was more like 38??

Yes mate, that's right - I did it to get a bit more headroom out of the 800's I was running

Cold start AFRs will depend on the inputed cold start map on whatever stand alone ECU is being used, which will take its cue from the ECU water temp sensor, same as the std ECU if using a piggyback.