Alright I installed my LC-1 WB, but I'm having trouble actually understanding it. I idle at 11-12 ish which I understand is really rich (with air pump plug disconnected). While cruising I see 12-13ish. Also my WB seems to lag behind about half a second (probably because of the distance from the turbo). When I get on a little bit of boost though (1-2psi?) the afrs creep to 14 ish. I got scared so I let off. Oh and also for context, I was tuned by Steve a while ago with stock injectors and stock cat. I dropped in some 1300cc secondaries, cleaned primaries, a HF cat and I'm waiting for a tune.

What are ideal AFRs? I remember 10-11 was recommended for WOT, but what about low throttle with and without boost? I'm also afraid to get on the throttle in order to find out what the AFRs are, so is there a safer way to do this?

 

any ideas?

 

i tune for 11.4 at WOT.

for really light throttle applications/cruising i go for something close to 15. regular acceleration around 13.

should dip down into the 10s-11s at more than 50% throttle.

 

Don't worry about the AFR's being too lean under cruise conditions. You won't blow the engine if you aren't in boost. For AFR's in cruise you can run as lean as the engine will let you. I usually aim for 15.5 at anything over 40 mph, i have run as lean as 16.5 under cruise but under certain conditions the engine hiccuped. Idle i try to get around 13.5. Low speed cruise is around 14.

Boost: I aim for about 11.2-11.5 for anything under 15 psi. and run 10.8-11 at 23 psi. (this is with water injection) When tuning boost just start extra rich and work your way down with the fuel. Start at lower boost levels and work your way up until you reach the target boost. I also like to add an extra rich section at boost levels beyond my peak target. That used to be around 17 psi and is now above 25 psi.

 

Idle works out for me to be no leaner than 13:1 with any kind of stability.

I think I'm still at 15:1 at atmospheric at anything below 3k. It takes very little throttle to get to that point though.


As far as the AFR the engine "likes"... how long is a piece of string?

 

In cruise, I tune for 15-16 A/F. I have seen it go up to 17 many times though.

On my new motor with 550cc Water injection. I tune for 10.8 @ 23psi and 11.5 @ 15psi.

 

i get mine to like 14.7 and 15 and it starts hiccuping on me. doesnt seem too lean but my engine doesnt seem to like leaner.
unless my timing is the culprit?

 

Is that highway cruise? At low speeds the engine usually likes more fuel then going down the highway

 

well 40-50 mph maybe? my haltech is setup to go into closed loop around 14.7 afr

 

IDK sounds like the engine just likes more fuel. You could try different timing but I doubt it will help much unless you're pretty far off. I'm running close to stock PFC timing in my cruise area so you could look at a PFC base map and try those timing values just in vacuum to see if it helps. I have a large street port.

Are you bridge-ported?

 

na street port

 

the haltech closed loop can cause that, the closer the map is to 14.7 in that area, the better it'll run.

or to put it another way, if the map with the closed loop off is rich or inconsistent, the ecu will cycle from rich to lean (or vice versa). the stock ecu will do this too sometimes, if you have a really free flow exhaust

if you clean up the map, so its closer to the 14.7 the surge/stumble will go away

 

thanx for the heads up. i noticed sometimes it would be at 14.7 then radomly deep below 12.5

sometimes itll removed 5-10% fuel to get it to 14.7