AFR Range.

MrMcQuacker

New member
Hello guys. I just wanted to ask you 3sgte gurus or what is considered a good zone for our cars. I was asking my brother and cousin and they said usually you don't want to go any higher than 12.5. Just wanted to know where I can be. If needed this is where I am at with motor wise. I have a st205 swapped into a st165. Full 3" exhaust, upgraded inter cooler core/pump and On its way are ARP head studs.Thank You.
 

warracer

New member
12.5-13.5 for cold engine idle and load
14.5-15.5 for idle, which ever is smoother on your set up(and more rich is a waste of gas)
14.5-15.5 cruise, any leaner and your heating up the engine and will be lacking torque
>10.5 in boost, up to 11.5 - 12 max to be safe.
 

MrMcQuacker

New member
With max boost 10.5 to 12 is safe? So if I hit 12.3 or 12.6 for a split sec or so and then It drops back to 11.9-12.2 ish is that ok? At WOT I'm around 11.9-12.5 is that ok?
 

MrMcQuacker

New member
I guess I'll leave it where it stands like I hear from a lot of people. St205 17psi is good and that's it. Of course with some supporting mods.
 

klue

New member
MrMcQuacker":2cz3g8w1 said:
I guess I'll leave it where it stands like I hear from a lot of people. St205 17psi is good and that's it. Of course with some supporting mods.


if you hear something rattling in your exhaust, and the turbo doesn't make pressure anymore; that's your turbine wheel :p
 

MrMcQuacker

New member
Good thing my turbo is upgraded with a steel wheel! Woot woot thx for the heads up! Also soon I'll have arp head studs. Once that done I guess I'll try and pump it up maybe 1-2 psi more :) as long as I don't pass 12.5 afr's right?
 

klue

New member
MrMcQuacker":4t5jer9e said:
Good thing my turbo is upgraded with a steel wheel! Woot woot thx for the heads up! Also soon I'll have arp head studs. Once that done I guess I'll try and pump it up maybe 1-2 psi more :) as long as I don't pass 12.5 afr's right?


Realistically, you'll blow a ring land, or melt a piston before the turbine lets go

keep it cool keep it fueled, stock pistons like 11s or less
 
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