Air Fuel Ratio

[scam75]

I have recently fitted a wideband AFR kit. I am seeing high 11's on full throttle and idle when warm is around 13.4. The car is mildly tuned (see below). Are these values ok? I have set the FQS to +3% fuel as it was mid to high 12's under full load previously when it was dyno'd.

Thoughts?

Cheers

Stuart

 

[TTM]

At idle and on the cruise with little to no load it shouldn't get much lower (richer) than 14.7.

What is your peak boost set at?

 

[robwright]

11.5 - 11.9 is good for full boost if you are running a DPW. Mine is running lower than that at the minute and I can't think of what to do other than another map. On idle 14.2 is the equivalent of 0.6% CO, which is the emissions setting from the manual. Whilst cruising you should really be reading perfect stoich of 14.7. The idle mixture can be adjusted at the AFM.

 

[scam75]

ORIGINAL: TTM

At idle and on the cruise with little to no load it shouldn't get much lower (richer) than 14.7.

What is your peak boost set at?

18 psi peak boost. It sits round about mid 14's when cruising.

 

[TTM]

Then I agree with Rob, 11.8 at full throttle and 18psi seems healthy enough to me, at least with all standard mechanicals in good condition.

 

[GPF]

ORIGINAL: robwright

11.5 - 11.9 is good for full boost if you are running a DPW.  Mine is running lower than that at the minute and I can't think of what to do other than another map.

Turn the boost up higher.....[]

 

[robwright]

ORIGINAL: GPF

ORIGINAL: robwright

11.5 - 11.9 is good for full boost if you are running a DPW. Mine is running lower than that at the minute and I can't think of what to do other than another map.

Turn the boost up higher.....[]

Graham I wish it was that simple. I am already pusing 18 psi out of the K26. The only reason I think I am achieveing that is because essentially it is brand new and only has about 4k on it. It was a remanufactured unit. I have thought about fitting a K&N panel filter to try increase the air volume into the engine but I am doubtful that it would be effective. The map was off the shelf and should be suitable for 15-18 psi cars so I am concerned that another off the shelf map from Promax may only be the same. Perhaps a trip to the dyno and a custom remap is the only option. What are your thoughts mate?

 

[sulzeruk]

Why not slot a 26/8 in Rob if you can get one. Easy enough to get the parts to convert.
Alasdair

 

[robwright]

The budget just isn't there for anymore serious modifications at the minute mate. Bigger turbo would also mean 55lb injectors also just for starters.

 

[GPF]

What are your AFR's like off WOT?

 

[sulzeruk]

Don't need bigger injectors matey, standard ones are good for over 300 bhp although they wil be open for a fair bit of time at that!
Al

 

[robwright]

At cruising speed 40 mph spot on at 14.7 and around 14.2 cruising at around 80 or 85 mph. Off WOT but powering I would say in the low 12s. When I bury the foot and start reaching highers revs they are dipping to the high 10s - 10.5 to 10.9.