Proper AF range for turbo \ stock application
#1
Proper AF range for turbo \ stock application
Here are some questions for the group, I’m just trying to educate myself on the entire AF deal, do you mind explaining the A/F ratio for our cars
(GTM stage II kit G37)
Questions might seem a little redundant but without fully understanding it I am not sure what to ask.
What should be the minimum AF range for turbo or non-turbo applications?
1. At WOT?
2. At idle?
3. Normal driving without going into boost?
What should be the max AF range for turbo or non-turbo?
1. At WOT?
2. At idle?
3. Normal driving without going into boost?
What is the BEST AF range to have for a turbo application?
1. At WOT?
2. At idle?
3. Normal driving without going into boost?
(GTM stage II kit G37)
Questions might seem a little redundant but without fully understanding it I am not sure what to ask.
What should be the minimum AF range for turbo or non-turbo applications?
1. At WOT?
2. At idle?
3. Normal driving without going into boost?
What should be the max AF range for turbo or non-turbo?
1. At WOT?
2. At idle?
3. Normal driving without going into boost?
What is the BEST AF range to have for a turbo application?
1. At WOT?
2. At idle?
3. Normal driving without going into boost?
#2
Registered Member
iTrader: (13)
normal driving you will not be able to monitor it cause the air intake charge and metered air will change all the time and you will not see KR or have issue with normal driving, Part throttle and hard accell is what you need to worry about,, WOT turbo should be in the 11-12's range anything in the 10's is pig rich and high 12's 13's are a little lean( IMO).. If you get a tune shot for high 11's mid 12's you should be fine,, I was running my MS3 in the 12's at WOT..
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#10
Registered User
iTrader: (1)
Here are some questions for the group, I’m just trying to educate myself on the entire AF deal, do you mind explaining the A/F ratio for our cars
(GTM stage II kit G37)
Questions might seem a little redundant but without fully understanding it I am not sure what to ask.
What should be the minimum AF range for turbo or non-turbo applications?
1. At WOT?
2. At idle?
3. Normal driving without going into boost?
What should be the max AF range for turbo or non-turbo?
1. At WOT?
2. At idle?
3. Normal driving without going into boost?
What is the BEST AF range to have for a turbo application?
1. At WOT?
2. At idle?
3. Normal driving without going into boost?
(GTM stage II kit G37)
Questions might seem a little redundant but without fully understanding it I am not sure what to ask.
What should be the minimum AF range for turbo or non-turbo applications?
1. At WOT?
2. At idle?
3. Normal driving without going into boost?
What should be the max AF range for turbo or non-turbo?
1. At WOT?
2. At idle?
3. Normal driving without going into boost?
What is the BEST AF range to have for a turbo application?
1. At WOT?
2. At idle?
3. Normal driving without going into boost?
2. Idle: 14.7; stoichiometric, always. If you have very aggressive cams, this may be difficult, but that doesn't apply to the VQ37
3. under light acceleration: slightly richer than stoichometric, or stoichiometric. As you apply more throttle, it should get richer to whatever your target is. It's easy to tune for WOT. Partial throttle tuning takes MUCH more work. Most tuners only tune for WOT, and 'derive' from that.
Best? There is no best. It depends on your application. It is generally better to run cooler, rather than hotter, in the interest of not overheating, and longevitiy.
#12
Registered User
iTrader: (1)
The only really essential gauges, IMO, are oil temp, coolant temp (or recalibrate stock gauge), EGT, and oil pressure.
If you don't have boost, you'll know. If your AFR is out of range, you should notice it when you're driving. You're not gonna be looking at those gauges as your driving.
If you don't have boost, you'll know. If your AFR is out of range, you should notice it when you're driving. You're not gonna be looking at those gauges as your driving.
#13
Registered User
iTrader: (10)
The only really essential gauges, IMO, are oil temp, coolant temp (or recalibrate stock gauge), EGT, and oil pressure.
If you don't have boost, you'll know. If your AFR is out of range, you should notice it when you're driving. You're not gonna be looking at those gauges as your driving.
If you don't have boost, you'll know. If your AFR is out of range, you should notice it when you're driving. You're not gonna be looking at those gauges as your driving.
#14
Registered User
iTrader: (9)
normal driving you will not be able to monitor it cause the air intake charge and metered air will change all the time and you will not see KR or have issue with normal driving, Part throttle and hard accell is what you need to worry about,, WOT turbo should be in the 11-12's range anything in the 10's is pig rich and high 12's 13's are a little lean( IMO).. If you get a tune shot for high 11's mid 12's you should be fine,, I was running my MS3 in the 12's at WOT..
As for your Mazdaspeed 3, I had one too that was tuned mid 11s, 12s would cause detonation and eventually bend / snap a rod which was well known especially when the car first came out since no one actually knew the limits on the block - 12 is way too lean especially since the internals were weak from the get-go.
#15
Good post and good info. I had a 1992 Honda Prelude with a stock 2.2 SOHC motor that I turboed and kept in the low 11's (AFR). I ran that thing hard, and it was very reliable. I would say mid to low 11's on our cars sounds about right.