ewainwright

What Is Safe Cruising Air/Fuel ratio.

Yes, I am excessive compulsive, it’s my nature. I need to save every penny I got since this one particular vendor won’t take my ex-mother-in-law (with two broom sticks mind you - one for each hand) as trade for his system.

I am running in open loop. At cruising what is the lowest air fuel ratio that is safe long term for my head gasket. What are you running? Real world experience please. Thanks in advance

Tom M'Guinn

My o2 sensor keeps my near 14.7

schnellfahrer

Mine dithers all the time, but generally stays around 14.5:1 - 15:1.

hally

I'm interested in this too, how much leaner than 14.7 can we take our low load PT fuel maps.

ENGINEERMAN

They can give you the info you need. Ask for Dave.

I believe that up to 16:1 should not be bad at say 65 MPH steady state at or near sea level but I would confirm with DL.

Good luck!

RKD in OKC

Drove on a 400 mile trip with A/F at 15.7 cruising at 80 mph, sometimes slower sometimes faster, @%!! traffic. EGTs highest 1500°F when leanest.

NZ951

Talk to Vitesse, he has tuned more chips than all the others combined if you need help from a vendor, but this question does not need help from a vendor, each will have a different opinion, but really you want to run as safely lean as possible. For me, thats about 15-15.5:1. Any more lean and the car jerks, irrespective of the timing dialed in. I am hoping it will be leaner when the port water injection is finished. Got to combat fuel prices somehow!

ENGINEERMAN

Yes, ulimately the two factors to dial in are drivability and EGT since the cylinder temperature is what will burn valves and fry pistons.

I have 2 questions for you all:

1) What is a safe Max EGT? and
2) Since the turbo reduces the EGT so much after the turbo where is a reasonable place ot measure the temperature?

Please advise.

Thanks!

RKD in OKC

My understanding is that you don't want to see EGT's over 1650°F for any length of time.

My EGT sensor is about 3 inches off the #3 exhaust port on the exhaust manifold.

Mike1982

I am interested in this as well because I have the SMT-6 from Vitesse and want to get my low loads to be on the lean side to get good milage on the highway. I will e-mail him after I get my car back from the shop, hopefully next tuesday!!

ewainwright

Good Afternoon,

I just heard from Chris White. He stated that at 15 to 1 will work in off boost levels. However, at stock boost or higher engine damage will occur. Its just a matter of time. Thanks Chris I know that you are a busy man and I do appreciate your help

Hey Mike 1982
When you hear from Fast951 please post his feed back.

for lunch time I am dealing with cells 330 and 430 along with McDonald's drive through. ed