AF rich at Vtec crossover

[Hoggy]

Hi,

Vtec set between 5200 t0 5800rpm. AF at low cam about 13.0 and when cross over to high cam, it drops to 11.5 and starts to climb to 13.2 at about 6500 rpm.

Is this normal and can we lean out at the crossover?

Thanks.

[ridewhencan]

Hi,

Vtec set between 5200 t0 5800rpm. AF at low cam about 13.0 and when cross over to high cam, it drops to 11.5 and starts to climb to 13.2 at about 6500 rpm.

Is this normal and can we lean out at the crossover?

Thanks.

I have the same problem (see me earlier post with dyno graph.) Sure hope the answer gets posted up here though it would seem it's just a question of taking fuel out at the xover.

[Hoggy]

I'm trying to lean out the hi cam fuel map at the cross over, slowly to see the effect. I just wanted to know if it is normal to get rich AF due to the transition or the ecu actually pumping in more fuel than specified. If it is, then I wouldn't bother to match the fueling between the low and hi cam maps.

[Hoggy]

Hi,

Vtec set between 5200 t0 5800rpm. AF at low cam about 13.0 and when cross over to high cam, it drops to 11.5 and starts to climb to 13.2 at about 6500 rpm.

Is this normal and can we lean out at the crossover?

Thanks.

I have the same problem (see me earlier post with dyno graph.) Sure hope the answer gets posted up here though it would seem it's just a question of taking fuel out at the xover.

Managed to even out the AF at cross over. I used the lamda overlay and that really helps. I get even AF pretty consistent ....about 13.2. However, I get one knock at cross over so i intentional rich that range to below 13.

Btw, thanks Hondata for shipping the USB cable. It works and resolved the disconnection during dataloggin. It improved the tuning process.

[Hondata]

A single knock at VTEC is often mechanical noise, not knock, and you can ignore it.

[Hoggy]

A single knock at VTEC is often mechanical noise, not knock, and you can ignore it.

Thanks again!

[ridewhencan]

Thank you as well. I'll ask my tuner about the lamda overlay. When I asked him what the numbers were on the grid (I had been expecting a/f and they weren't) he said he wasn't sure

[Hoggy]

Thank you as well. I'll ask my tuner about the lamda overlay. When I asked him what the numbers were on the grid (I had been expecting a/f and they weren't) he said he wasn't sure

There's a good guide at clubrsx on how to use the overlay. In short, you set the AF you want to run, do a datalog and load the same datalog for analysis. Switch to the lamda overlay on fuel and as you move along the datalog graph, it shows how much fuel to add or lower at a specific point on the AF graph. It is a good help to get even AF, will get better after a few runs but try to do it within the same day/temp conditions.