what is too lean for a safe DD tune for a turbo?

[Forge]

Right now, im using a 12.3 A/f at 7psi at 14 degrees of timing (hellion kit), is that too high?

Im ready to push it up to 9psi (after i figure out how to relocate the AIT), what A/F should i shoot for? is 12:1 to lean for a safe DD tune at 9psi?

 

[GIG4FUN]

Doesn't matter DD or not. A/F is A/F in my view. I think 12.1 is rich enough. I'd check the plugs a few times. I hope you know 12.3 is "more lean" than 12.1. Or do you have it mixed around?

Runnig rich has it's drawbacks. I have heard some running 11.8 and happy with it....! Did you keep the knock sensors in the tune?

 

[MikeVistaBlue06]

Corrected:

Mine runs 11.5:1 @ 6psi of boost (twin screw) from about 4K to 6K rpm.

HPP tuned it and they know both SCs and turbos.

Just ask Manny here:

http://www.ricekiller.com/forums/member.php?u=19067

Mike

 

[GIG4FUN]

Mine runs 11.5:1 @ 6psi of boost (twin screw) from about 2K to 6K rpm.

HPP tuned it and they know both SCs and turbos.

Just ask Manny here:

http://www.ricekiller.com/forums/member.php?u=19067

Mike

wow...

 

[don_w]

Mine runs 11.5:1 @ 6psi of boost (twin screw) from about 2K to 6K rpm.

My KB is in the mid 11s also.

 

[GIG4FUN]

Back in the day when I was building and racing and knew something, I made the most power with the A/F generally 12.1 to 12.4 but I suppose to keep the motor alive it's cooled a bit these days with more fuel. I suppose the combustion chambers are different and the spark etc. in these modern tmes. It sure seems rich to me.

 

[MikeVistaBlue06]

Good question and here are some possible answers:

Higher compression

More power per cubic inch

Unleaded fuel (no exhaust valve lube)

Lower octane fuel

Fuel injection (uses less fuel)

Now for N/A 12ish may be ok, but I trust them folks at HPP with my Saleen Tune and Doc does too.

Mike

 

[US-1]

Mine is 11.5:1 right now with 10 degrees timing. Typically, I would go no more than 12:1 with over 10 degrees timing. If you push into the 12:1 zone you better have some damn good fuel in there.

 

[Clay]

Above 12 is nearing dangerous. Mine is 11.5-ish, which is 'safe' rich. Higher 11's is a good place to start. I wouldn't go above 12