My AFR's

[Squeak]

Do I need to worry or am I being too fussy and wanton it perfect? Also what would be the perfect AFR about 13.6?

Just a quick one this is my graph from Surrey rolling road 31st August. Are my afr's anything to worry about its a bit lean but I'm wondering whether I should be addressing this or not? Any help would be appreciated.


Spec of the car:.


Engine
2.1 over bored Bottom End
Lapel 11:5 High Compression Pistons Standard Rods with ARP bolts
APD Stage 2 Headwork (Port and Polished)
Cat Cam 213 Cam Shafts with Cat Cam Vernier Pulleys (Work Performed @ 519 Automotive)
Jenvey ITB’s (Work Performed @ 519 Automotive)
Chadil Manifold (Work Performed @ 519 Automotive)
Custom Loom (Work Performed @ 519 Automotive)
Canems Standalone Management (Work Performed @ 519 Automotive)
Full Mongoose Exhaust (Work Performed @ 519 Automotive)
K-Tec Racing Mild Steel Supersprint Manifold (Work Performed @ 519 Automotive)
Custom Live Map Peformed by Andy Cutler @ K-Tec Racing Producing Producing 211.9BHP and 180ft/lb


BHP and AFR’s:

 

[Ph1 Tom]

It's not dangerous. And it'll make a little more power as it is.

 

[Squeak]

I thought it would make a little botore power if it was running richer? It's lean ATM?

 

[Dan@SJM]

You want it to be around 12.8 at WOT.

Lean gets a hotter burn and therefore makes more power but goes through piston rings etc. 12.8 is perfectly safe with a loss of a few bhp.

 

[Martin.]

Cor that must fly

 

[Chip-mk1]

That's too lean. Would make more power and be safer if it was high 12s or low 13s.

Peak power is anywhere from mid 12s to low 13s on these engines. Peak economy but as dan mentions (i assume he meant loss of a few mpg but type bhp, lol) also peak heat is high 14s and you are very near that.

Get it fixed and there is another 10ish bhp in it.

 

[Cub.]

What chip said. Mine was running similar peak AFRs, and its now eating oil like a trooper. Read into that what you will.

 

[Chip-mk1]

I thought it would make a little botore power if it was running richer? It's lean ATM?

You are correct. It's too lean currently. Put more fuel in and it will get faster from that starting point.

 

[Dan@SJM]

That's too lean. Would make more power and be safer if it was high 12s or low 13s.

Peak power is anywhere from mid 12s to low 13s on these engines. Peak economy but as dan mentions (i assume he meant loss of a few mpg but type bhp, lol) also peak heat is high 14s and you are very near that.

Get it fixed and there is another 10ish bhp in it.

I did. Too early for me.

 

[Chip-mk1]

What chip said. Mine was running similar peak AFRs, and its now eating oil like a trooper. Read into that what you will.

If he had standard pistons he'd have problems too but on forged ones that aren't so liable to break up on the ring lands its less of an issue. Still would be safer and faster if it was a bit richer though.

 

[Chip-mk1]

I did. Too early for me.

Mapping for economy of full throttle looks like it was too early for whoever mapped it too. Lol.

 

[Dave..]

Chip, didn't you melt a piston on the turbo from running it too lean?

 

[Chip-mk1]

Chip, didn't you melt a piston on the turbo from running it too lean?

Yes mate, I had an injector fail and leaned out on one cylinder, which finished it off nicely.

Its a lot easier to melt a piston on a turbo motor in the first place with a lean condition as you have a lot more gas in there to begin with, so the same EGT translates to higher crown temperatures, so I doubt that the OP here will have that issue, but its still costing him power and over a long period of time could even soften the head.

 

[Squeak]

Thanks for your input guys. The car will be going to Danny@519 to get sorted as its far beyond my knowledge. I thought if it was the possibility of just a sensor then I could try and replace to see if it corrects it.

Also chip I think the car was given to the mapper under the instruction it would need to be back the next day. They done what they could in the time frame.

 

[Chip-mk1]

Also chip I think the car was given to the mapper under the instruction it would need to be back the next day. They done what they could in the time frame.

Never a good idea to rush a mapping job, but Ive had to do it myself in the past, thats just life, sometimes you have to take risks or not have your car ready.

How long ago was it mapped out of interest?

The weather has changed a lot recently, and Canems temperature correction is relatively crude at best, and even with the best ECU in the world without a climactic chamber it is actually impossible to map a car on one temperature of day and be 100% confident it will fuel exactly the same on another day, so half the difference between where it is and where it should be could even be down to that (when my engine failed at bedford my first thought was that when I initially mapped it, it had been mapped in freezing temperatures and yet had just melted in hot ones which Id not had a chance to do anything with and so it was possible it was out as a result, it was only once I pulled it apart that it became apparent the problem with leaness was localised to one specific cylinder/injector)

 

[Squeak]

Never a good idea to rush a mapping job, but Ive had to do it myself in the past, thats just life, sometimes you have to take risks or not have your car ready.

How long ago was it mapped out of interest?

The weather has changed a lot recently, and Canems temperature correction is relatively crude at best, and even with the best ECU in the world without a climactic chamber it is actually impossible to map a car on one temperature of day and be 100% confident it will fuel exactly the same on another day, so half the difference between where it is and where it should be could even be down to that (when my engine failed at bedford my first thought was that when I initially mapped it, it had been mapped in freezing temperatures and yet had just melted in hot ones which Id not had a chance to do anything with and so it was possible it was out as a result, it was only once I pulled it apart that it became apparent the problem with leaness was localised to one specific cylinder/injector)

Well that was the previous owner I don't know the ins and outs.

Also was mapped around Feb/March last year I think not to sure tbh.

Ill take it to Danny and go from there though.

Thanks

 

[Chip-mk1]

Sadly if mapping a car in very cold conditions its always worth getting it checked in the summer and adjusted if required, and its just not something most people think about!