On road tuning will commence soon. Dyno tune of course done couple of months ago, but this is just fine tuning - and also learning for interest’s sake.
For those who have knowledge, what AFR range should I aim for? In cruising (0 load), light to moderate accel (10-50% load), WOT and so forth.
It currently seems to sit on low to mid 13s on City speeds (40 – 80) and gets richer to mid 12’as when loaded.
There is a peculiar spot at 1900 RPM, where mixture leans suddenly and engine seems to surge a bit. This indicates to me that it likes AFR on the 13 side rather than 12.
Does that RPM sound (literally) familiar? Yep, it’s where all Magnas have the resonating rumble. I’m assuming it’s simply intake piping resonance and flow (power) improves “greatly” at 2000 RPM which then causes this leaner AFR. Interesting.
The SF plenum doesn’t have this feature, the design is better for low RPM as we know.
I have only driven it yesterday, alone, so my observations are limited. Need to watch the traffic too hehe. XMas hols will provide more time and playing!

Should be showing 14.5-15 most of the time when cruising. 10-12.5 when wot. Do you have some major mods ?

You're suggesting quite lean crusing figures and very rich load figures. Where does your figures originate from (ie tested, dynoed etc)?
NA, basic breathing mods.


Should be showing 14.5-15 most of the time when cruising. 10-12.5 when wot. Do you have some major mods ?

I got the same gauge ,installed. By the sound of it ,its running open loop when cruising ,which is not good for economy. Could be wiring issue or if you still have the original O2 sensor running to the ECU then the sensor might be faulty.

I too have the same gauge. On WOT I'm at 12.5, Light to moderate acceleration About 13.5-14 and cruising 15-16.0

Cool, you do sound like you know stuff....
Those AFR numbers are after the dyno tune I did few months ago.
Std O2 is working ok (tested the volts), tho it is original (220'000km). How long do they last?
Consumption figures are quite good - ~8/100 on HWY with plenty of luggage, S'burbs ~10/100.
Is it recommended to run the engine without std O2 connected? I thought not.
Haven't yet done proper tuning driving, just monitoring during shopping trips etc. Noticed more, that the below 2000 RPM AFR seems richer (mid 12s) until the engine (or 'box?) warms after some 10 min drive and then it decides to lean to mid 13s. Strange IMO!
I'll organise a proper tuning day shortly and take in to my consideration the advise given. Somewhat similar what I've been thinking anyway, but extra intel is always welcome.

And thanks to TUFFTR recommending this device to me.


I got the same gauge ,installed. By the sound of it ,its running open loop when cruising ,which is not good for economy. Could be wiring issue or if you still have the original O2 sensor running to the ECU then the sensor might be faulty.

It's odd but if your economy is good then who cares.
Mine sits on 12.5 when cold but it only takes about 20 sec to go into closed loop then it sits there until WOT. But I am running the wideband in place of the original and have it set to P4 (emulation) mode, so that might explain the difference in readings.

It's odd but if your economy is good then who cares.
Mine sits on 12.5 when cold but it only takes about 20 sec to go into closed loop then it sits there until WOT. But I am running the wideband in place of the original and have it set to P4 (emulation) mode, so that might explain the difference in readings.

Interesting....Mine sits on 10.0 when cold for a good minute before it starts to marginally lean out. I think my cold start map defiantly needs some fine tuning.

What ECU are you running?

;1176587']Interesting....Mine sits on 10.0 when cold for a good minute before it starts to marginally lean out. I think my cold start map defiantly needs some fine tuning.

What ECU are you running?

Just stock TH ecu. I do have piggyback installed as well (SMT6) ,but gave up fiddling with it once I heard about editing the roms on H8 ecu's.
10.0 sounds a bit rich for cold.

Just stock TH ecu. I do have piggyback installed as well (SMT6) ,but gave up fiddling with it once I heard about editing the roms on H8 ecu's.
10.0 sounds a bit rich for cold.

Without trying to hijack the thread or anything, Yeah, The cold map needs alot of improvement.

how does the standard ECU handle a wideband?

Funnily enough, mine isn't too rich at all at start.
Went out for lunch, 20 km one way trip, and on the way back home, the mid 12s were there again and then suddenly settled to mid 13s. And it's not just a certain RPM or load, it's on 4. gear (Auto) at 1300-2000 RPM ruffly. Inconsistent....
Still haven't driven on HWY speeds to monitor higher RPM etc. Will soon.
Cops every where!!! RRT? Revenue Raising Time?

;1176777']Without trying to hijack the thread or anything, Yeah, The cold map needs alot of improvement.

how does the standard ECU handle a wideband?

The emulation seems to work just fine , I'd expect it go into safe mode or open loop if there was something off. But it made no noticeable effect on the engine. My guess the magna ecu isn't too picky.:happy:


Funnily enough, mine isn't too rich at all at start.
Went out for lunch, 20 km one way trip, and on the way back home, the mid 12s were there again and then suddenly settled to mid 13s. And it's not just a certain RPM or load, it's on 4. gear (Auto) at 1300-2000 RPM ruffly. Inconsistent....
Still haven't driven on HWY speeds to monitor higher RPM etc. Will soon.
Cops every where!!! RRT? Revenue Raising Time?

Just curious , do you see the leds oscillating up and down like it was running in closed loop?

Reading and leds are quite steady, just 0.1 - 0.2 variations on steady load.
Today tuned from mid 13s to mid 14s on crusing speeds and loads. And then after a while it dropped back to mid 12s and stayed there for a while. Not tuning S/W related cos didn't close it and the initial change took place immediately. Can't understand.

How long does OEM O2 last? Cost?


Just curious , do you see the leds oscillating up and down like it was running in closed loop?

Good timing of this project - just got my knock sensor hooked up and working, got a wide band sniffer setup arriving any day now, a laptop lined up and I'm off Thursday :D

Always wondered whether to remove/electrically disconnect the oem o2 sensor, the car will go into limp mode and then tune it. Only 1 map to tune that way. Go lean at cruise even 15-16:1 is probably possible with these heads. Get a steady afr for all your load points that way. What are the downsides? Auto box may not upchange, wont effect manuals. :think:

Brilliant to hear, 'ol chap.
I was also considering to disconnect the OEM oxy - but, as the AEM manual states, one should not run the engine without the oxy sensor being powered. Hence, do a plug (cos I believe you have the machines) M18 x 1.5 and pull out the std oxy (disconnect wire to avoid major twisting). I had to buy a bolt, cost 25 bux... mmhhh....

I'm in process of eliminating this odd issue of mine. Starting with simple checks of coolant temp sensors etc. Then unplug MT Interceptor (D-connectors, 5 min job) and run the OEM ECU and see if same issue repeats.

Yep, gonna tune light load to high 14s to 15s and mid load to 13s and full noise to 12.8 However, my tuner did the high RPM full loads to ~11. Quuuuite rich, eh? He did say that he did a safe tune though. Yours, after the tune months ago?


Good timing of this project - just got my knock sensor hooked up and working, got a wide band sniffer setup arriving any day now, a laptop lined up and I'm off Thursday :D

Always wondered whether to remove/electrically disconnect the oem o2 sensor, the car will go into limp mode and then tune it. Only 1 map to tune that way. Go lean at cruise even 15-16:1 is probably possible with these heads. Get a steady afr for all your load points that way. What are the downsides? Auto box may not upchange, wont effect manuals. :think:

Hmm....11? I guess diff tuners have diff opinions, Mine has been tuned for 12.5 at full load.

Too right my man!
Unfortunately I've been hit with a snot disease and cannot do much now for this stuff. Especially, cos allegedly, there is some big thingyparty happening in cuppla days, says The Mrs K. And if I veer near the garage/car/tuning/AFR I'll be sleeping there too, she adds. Well, I ain't too big or tall, so I guess the back seat is ok for sleeping, eh?
Bugger!


;1178091']Hmm....11? I guess diff tuners have diff opinions, Mine has been tuned for 12.5 at full load.

13.7 is stoich

*cough* 14.7:1

Tune 14-15:1 upto 30% load
12.5-13:1 upto 70%
11.5 upto 100%

Safe tuning, will keep exhaust valves cool.

im just sayin 13.7 is stoich not sayin tune to there

im just sayin 13.7 is stoich not sayin tune to there

No....14.7:1 is stoich. Anything BELOW is rich, anything ABOVE is lean. (er)

it is too my mistake ignore me

with a healthy exhaust size, full noise (WOT) you should be able to punch around 13.5:1 out no real dramas. Obviously this leave little to no room for error or even bad fuel, when tuning above 13:1 you basically have to pick a fuel and stick with it otherwise performance or engine longevity may suffer.

As important as AFRs are, does/have anyone also used a temp probe to also monitor each cylinders performance? Temp is a good way to find out if the AFR you are chasing is right or wrong for your engine.

13.7 *maybe* stoich if you have ethanol blended.

Ooookkkk. Finally got some testing (of various sensors) done. Seems my OEM Oxy is d-e-d. When cold, gives correct 0.7V but when warm it drops even below 0.1 V - and when driving (hot), it causes significant fluctuations in AFR. So, disabled it and went for a drive! Firstly, no ECU errs, no limp modes, all cool. Tuned the previously mad AFRs to ~14.7 just on local driving, to see. And it all went fine. Will see how weather affects this fixed tune now, cos there is no OEM oxy to fine tune the mixture.
Obviously I now need to do HWY testing and tuning as well. Obv on-road fullnoise tuning is quite difficult to do, but...

Ezy, got your toy yet?

Thanks for the AFR suggestions ppl, pretty much what I've been thinking about.

Yep, been fiddling heaps today. Blanked off one of my dual exhaust pipes and the AFR readings with the LM2 are now perfectly consistent. Idle is excellent, had to add 5deg and remove some fuel but everywhere else needed a dash - so it was easier to adjust the idle baseline for fueling (I have the 470cc injectors to scale back) and build the rest of the map from there. I presume you're tuning TPS vs RPM. I'm tuning in MAP vs RPM so my natmo mapping is in the vacuum regions, boosted SC mapping in the boost region (obviously). Interesting to note that when monitoring psi/vac from 2000-5000 there is zero vacuum and zero boost! You can log it with the datalogger very simply (as you'd know).

Aiming to get the SC head unit back on tomorrow and get some more tuning done later in the week. I wont get the water to air system finished before I have to send the wideband back but I'll richen it up a touch to compensate for the cooler/denser inlet charge when it's running. The good ol' knock sensor can help keep an eye on things.

Your hardware is so different to mine!

I'm using just TP, Load and RPM, well actually, the TP does nothing, just indicates. With FI you'd need MAP, I guess. Do I understand correctly - you have surrounding air pressure at that RPM range? Shouldn't you have more....?

Nah, I'm doing live tuning, not logging it - I just find it better that way.

Why did you blank the exhaust? To reduce flow?

Does the knocker help with too lean AFR? Or just with diff octane gasoline?

Have you (yet) noticed if ign timing changes affect AFR and how much? I haven't tried as yet - only today got this thing running.

BTW, we're lucky to have our Moristechs working ok - that guy just doesn't provide after-sale assistance. I really don't appreciate it and wouldn't recommend, if that's the way he runs his business!


Yep, been fiddling heaps today. Blanked off one of my dual exhaust pipes and the AFR readings with the LM2 are now perfectly consistent. Idle is excellent, had to add 5deg and remove some fuel but everywhere else needed a dash - so it was easier to adjust the idle baseline for fueling (I have the 470cc injectors to scale back) and build the rest of the map from there. I presume you're tuning TPS vs RPM. I'm tuning in MAP vs RPM so my natmo mapping is in the vacuum regions, boosted SC mapping in the boost region (obviously). Interesting to note that when monitoring psi/vac from 2000-5000 there is zero vacuum and zero boost! You can log it with the datalogger very simply (as you'd know).

Aiming to get the SC head unit back on tomorrow and get some more tuning done later in the week. I wont get the water to air system finished before I have to send the wideband back but I'll richen it up a touch to compensate for the cooler/denser inlet charge when it's running. The good ol' knock sensor can help keep an eye on things.

The MAP sensor (inbuilt into the MT PS) uses atmo pressure as the zero baseline, while I know what you're trying to say, the display will tell you deviations from std atmo pressure.

I'm live tuning AND logging, as the logging shows me which cells on the map are/were being used.

I have dual pipes and the LM2 sensor was all over the shop trying to give me a reading when only stuck up 1x pipe. Dyno's had this drama too in the past. Because it's dual 2.25" it wasn't a real problem closing one pipe down to do some tuning without killing anything. Goes well atm, so should fair fly with the banana taken out of the pipe ;)

The knock detection setup should alert me to any pinging; if the cylinders get too hot, due to lean mixtures. Or there's too much spark advance AND/OR too lean a mixture. Too much advance may not show up as knock but as power loss which very unlikely to ever be detected on-road. The mixture is expanding and the rising piston is fighting against it instead of being pushed away from it. So atm I'm being very tame with timing changes. Also mindful of fuel octane lowering if the fuel/car sits for a while too.

Sadly for MT it's not his fulltime job, I know what it's like trying to pay the bills with 3 jobs but it'd still be nice to get more than 5words back after you email an essay! I find tuning very interesting so it's a touch frustrating. That asside I was impressed that D.P. took the time to drive 2.5hrs to check my install when it was first done and do some on-road tuning to verify the install. Can't remember if he charged me or not but I would've paid for the service I got that day.

Time you guys got an adaptronic ;) :P

Yep, keep the bananas in the fruit bowl along with mangos.

Yeah, lot of ppl think they can feel the difference between few kWs. Nope. We can see it on drag time slip (when tried different tune options) though. To feel a power loss, it has to be quite significant, like 10% perhaps. I'm just aiming for a good AFR graph.
Do you use the suggested Telnet stuff for your datalogging?

Yeah, tuning and AFR readings are very interesting. Puts a lot of dots to many assumptions :happy:
He drove to your place? He only lives cuppla suburbs away from me. Heh, I didn't even send an essay, just asked for a new basic Map and related stuff. Remember when you saved me from strife by sending your map, when I somehow managed to kill the basic settings/map on my MT. Do you know if the 3 and 3.5 L basic tune is the same, cos ign timing is bit different. Would it matter?

Nice day, might go to Bondi.


The MAP sensor (inbuilt into the MT PS) uses atmo pressure as the zero baseline, while I know what you're trying to say, the display will tell you deviations from std atmo pressure.

I'm live tuning AND logging, as the logging shows me which cells on the map are/were being used.

I have dual pipes and the LM2 sensor was all over the shop trying to give me a reading when only stuck up 1x pipe. Dyno's had this drama too in the past. Because it's dual 2.25" it wasn't a real problem closing one pipe down to do some tuning without killing anything. Goes well atm, so should fair fly with the banana taken out of the pipe ;)

The knock detection setup should alert me to any pinging; if the cylinders get too hot, due to lean mixtures. Or there's too much spark advance AND/OR too lean a mixture. Too much advance may not show up as knock but as power loss which probably can't be detected on-road. The mixture is expanding and the rising piston is fighting against it instead of being pushed away from it. So atm I'm being very tame with timing changes. Also mindful of fuel octane lowering if the fuel/car sits for a while too.

Sadly for MT it's not his fulltime job, I know what it's like trying to pay the bills with 3 jobs but it'd still be nice to get more than 5words back after you email an essay! I find tuning very interesting so it's a touch frustrating. That asside I was impressed that D.P. took the time to drive 2.5hrs to check my install when it was first done and do some on-road tuning to verify the install. Can't remember if he charged me or not but I would've paid for the service I got that day.

If you have the map *zero'd* then there is no difference between 3L and 3.5L MT config. Tuning will be different - rather significantly I'd suspect given reduced displacement but large bore inlet and exhaust. If you're tuning for 95 or 98 you can no doubt add 1-2deg timing across the board as long as you keen AFRs from 70-100% tps around 11.5-12. Important to keep the heat at bay - given the poor track record of hot magna pistons.

The 3L probably wants a little bit less spark advance as the bore is smaller so the flame front doesn't have to travel as far as the 3.5 and 3.8. Then again the 3.8 has higher compression so the 3.5 is likely to require more total spark advance than either the '72 or '75. Then throw the Ralliart into the mix with the additional 0.4 comp. Just make sure you tune for 95 minimum, I only run 98 even when I'm natmo - the extra $3 a tank or whatever it is hasn't put me to the wall yet! ;)

Hope you're allowed out to play this weekend. Looking forward to seeing some maps.

Basic idle ign advance in 3L is greater than 3.5L. But if you reckon MT basic tune comes with same tune, then ok.
Tested it with my old strobo and it was bit too much - around 20, cos had the total advance turned bit too much. So retarded it 4 deg to keep things to norm.
The adv is anywhere from 1 to 3 deg added, as per Dyno tune.

Did some tuning on Sun and noticed that AFR at 30 deg temp vs 20 deg is ruffly 5% different. Which we all kinda know but it's good to put some figures in to this. Would that directly correlate to power - perhaps.
Note, I'm still driving without OEM oxy, so tune is fixed - like we used to do with carburettor jet changing long time ago. Will get new oxy soon though, but it's ok to experiment, eh.

Got new Oxy Sensor last week, NGK, actually same as I had in there until now. Cost 125bux at Burson in LPool, Syd. Direct fit, no wiring harness issues. So far all good. Since I was at it, did some experiments with OEM ECU Fuel Map and discoverd it to be quite decent, surprisingly lean on light load and low RPM, mid 15s to 16s. High loads went "down" to 12s, not 11s.
Anyway, plugged the new oxy in and - AFRs all over the place and no tune seemed to change the display. Leaned it by -35 % and it almost killed the uphill drive (funny that!) but AFR Gauge was still showing 14-15 and just pumping up and down.
WTF, says me! Only idle AFR was able stay steady at high 16 and changing Fuel % altered it accordinly. Also when driving at high loads, it was displaying somewhat ok, 13s and 12s etc. Did some further testing and concluded that the new oxy is causing truble. Grrhhh - oh why. Will call Burson back tomorrow and see what we can do.

So where's your map at atm, I guess you're still waiting for consistent feedback before you get into the tuning?

Well, can't really say cos it just pongs all around. But once oxy disconnected, it's decent (but fixed). Would like it bit leaner on low loads for economy. Sigh.


So where's your map at atm, I guess you're still waiting for consistent feedback before you get into the tuning?

Did you end up installing your meter into a bung before the car or up the tailpipe? Almost better off pulling a sensor off a wreck?

The new AFR sensor is installed near std oxy, on the opposite side of pipe.
Been driving around without std oxy and using Fuel Trim function to compensate situation variations, which can sometimes be surprisingly great.
Have to fix this issue for sure, but have no idea any more. Double tested all other related sensors again the other week and all work fine. Same when running OEM ECU, no issues - so it's not MT ECU issue either. But the moment I plug the std oxy in, all goes mad. And it's now a second sensor I tried, in case the first one was faulty, but still.... grrrhh.

Forgot to add that the std oxy bung is now blocked with a M18 bolt.


Did you end up installing your meter into a bung before the car or up the tailpipe? Almost better off pulling a sensor off a wreck?