What a/f ratio to tune for with S2+big turbo???

[wfosrt]

It seems that people with big turbos are running about a 12:1 AFR. Is that to lean for pump gas??? I will have a 3147 turbo, boost controller,wide band o2 and S2. With this setup the afr will start to lean out up top right (when the boost level starts to get to high )?

[Glacius]

Honestly, for safetys sake, I'd stay 11.5:1 up top. I'd rather be a few horsepower shy of max and have a motor that lasts then try and squeeze every last bit out of it. You also need to be watching your egt's and have something hooked up reading the knock sensor

[wfosrt]

Yeah. I plan on getting an egt probe drilled into the manifold. Where can I get a knock guage.

[wfosrt]

Another question. Is it ok to be lean in the lower midrange? In all the dynos that I see the car is ~13 afr untill about 3-3750 rpms.

[Glacius]

you can go a bit leaner down low because you're not making as much boost, but the majority of the times it's showing that 13+ afr cuz they're only partial throttle, hitting the activator on the dyno and then going full throttle. basically, if you're full throttle, you want to be no more then 12.0:1 imho. Do 12.0:1 until about 3700 and then from there u want to bring it down to 11.5:1 for a safe and happy motor

[NoLongerStock]

I'd say look at both EGTs and AFRs as long as the reading within limits and there is no knock I'd say it is tuned

[PVO SRT]

I have mine set up for 11.4-11.6 and i'm into the 470 range. I'd rather be safe and a bit low on hp.

[Orange Blast OC]

Quote: Originally Posted by PVO SRT

I have mine set up for 11.4-11.6 and i'm into the 470 range. I'd rather be safe and a bit low on hp.

I agree....that's where I have my Focus tuned. It's better to be safe than sorry.

[NIVO88T]

11.8:1 or below. no lower than 10.8:1