AFR for Fd?
Thread Starter
Joined: May 2005
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From: Bay Area
AFR for Fd?
In my search into the depths of the forum for info on widebands, i came across a chart for recommended AFR's that supposedly was produced by Mazda? Can someone please show me where that is because i cant seem to find it anymore.
thanks
randy
thanks
randy
Joined: Mar 2001
Posts: 31,833
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From: https://www2.mazda.com/en/100th/
ive seen that pic in lots of places. its in english in the fd new model training book, and its in the cosmo book as well.
ive also seen it in the japanese rx7 magazine etc etc
ive also seen it in the japanese rx7 magazine etc etc
I thought 12.1 was perfect too, but I was told by a couple people that N/A applications should tune for 12.1 turbo applications should tune for 11.1. I ve seen a couple tuners tune for around 11.7 but havent seen any tune in the 12 for turbo.
Chris
Chris
Depends on your timing, gas in tank, boost pressure, air intake temps (and even fuel and water... a hot motor eats up some margin) too. If everything is perfect you can tune above 12:1, but from what I see most people with a reliable "street" car running high 10's to low 11's.
On the street, I run around 11:1 @ 13 psi on 91 octane with pretty safe timing. Regular abuse, hot and cold weather, and my motor still runs
On the track (road course) I ran 10-11 psi around 10.5:1.
It's all about how much margin you want for detonation...
On the street, I run around 11:1 @ 13 psi on 91 octane with pretty safe timing. Regular abuse, hot and cold weather, and my motor still runs
On the track (road course) I ran 10-11 psi around 10.5:1.It's all about how much margin you want for detonation...
Last edited by mdpalmer; Jun 19, 2008 at 02:21 PM.
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you can also taper it down.
the higher the boost level the richer you will want to be.
for instance in vacuum ranges i run close to 14.7 below 40- 45 MPH and close to 16 in vacuum above 40-45 mph.
then from 0 psi to about 5-6 psi i run right around 12. Above 6 psi i taper it from about 11.6 down to 11 at 15 psi.
above 16 psi is pig rich cause i dont plan to boost higher and want extra fuel in case it spikes.
the higher the boost level the richer you will want to be.
for instance in vacuum ranges i run close to 14.7 below 40- 45 MPH and close to 16 in vacuum above 40-45 mph.
then from 0 psi to about 5-6 psi i run right around 12. Above 6 psi i taper it from about 11.6 down to 11 at 15 psi.
above 16 psi is pig rich cause i dont plan to boost higher and want extra fuel in case it spikes.
Joined: Jul 2003
Posts: 4,678
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From: Bay Area, CA
Thread Starter
Joined: May 2005
Posts: 1,392
Likes: 8
From: Bay Area
It's looks a lot like the PFC base map, target lambda table (aka the INJ map) converted into AFR.
It is a 100% internet forum myth that FD's run exceptionally rich from the factory. They actually run leaner than many other turbo cars except at idle.
Take a look at these factory lambda tables from normal piston engines:
09 WRX
Z32 300zx twin turbo, disregard values in lower left because those are closed loop cells
Doritos on a toothpick
Joined: Oct 2002
Posts: 1,120
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From: west palm beach, FL
I run a mix with 1/3 C16 and 2/3 93....target AFR's with this gas are in the low 12's...12.2-12.4....18psi(precision 6776rsp)...car runs PERFECT.
...Idle is 12.5-12.8....cruise is 13.5-14.5....
...Idle is 12.5-12.8....cruise is 13.5-14.5....
^ I've run 12 AFR before as well @ 18 PSi and it made good power even verified on the dyno. Then I took it to Mosport and the motor popped on the 4th lap down the back stretch but boy did it make good power for what it had until that 4th lap. Curious what timing your running with that type of fuel, AFR, and boost.
thewird
thewird
Not necessarily From what I've seen I've tuned my car around 11.2 for ~10 psi, 11 for ~12, and ~10.8 for 14 psi. I have fluctuations about +/- 0.2 on those values... just started running 14.5 psi (1 bar) in the last couple months and the car is regularly beaten on the street /w stock turbos. Ambient temps anywhere from 40-80*F. No problems yet. My timing is pretty conservative and I use 91 pump gas and a good SMIC intercooler... May be rich and down on power, but at least my engine hasn't blown up
I got an email from someone a while ago... don't remember who. My email files are gone, so I can't dig it up, sorry 
Raymond, thanks for posting that. Very interesting to see those maps!!!! How are you able to read the map files, or are these screenshots of the maps? One thing I question though: those are "target" values, not actual measured values. It would make a lot more sense if someone had wideband data from a stock car to draw the conclusion that X car runs richer than a stock FD. Just saying...
From what I've seen I've tuned my car around 11.2 for ~10 psi, 11 for ~12, and ~10.8 for 14 psi. I have fluctuations about +/- 0.2 on those values... just started running 14.5 psi (1 bar) in the last couple months and the car is regularly beaten on the street /w stock turbos. Ambient temps anywhere from 40-80*F. No problems yet. My timing is pretty conservative and I use 91 pump gas and a good SMIC intercooler... May be rich and down on power, but at least my engine hasn't blown up Raymond, thanks for posting that. Very interesting to see those maps!!!! How are you able to read the map files, or are these screenshots of the maps? One thing I question though: those are "target" values, not actual measured values. It would make a lot more sense if someone had wideband data from a stock car to draw the conclusion that X car runs richer than a stock FD. Just saying...
