Mazda Rotary Club

General => General Technical => Topic started by: Jono FD3 on February 23, 2010, 10:22:36 PM

Title: Air Fuel Ratio??
Post by: Jono FD3 on February 23, 2010, 10:22:36 PM
Guys, just checking to see what the AFR should be on the FD?? is it around the 12 mark??

Jono
Title: Air Fuel Ratio??
Post by: philiwily on February 23, 2010, 10:36:20 PM
Think most folk have it at about 11 at 1 bar. 13-15 on cruise, you can lean it out a bit in the vacuum areas ie 15 for economy.
I can send you some different target maps if you like.
Phil
Title: Air Fuel Ratio??
Post by: m1tch on February 24, 2010, 06:49:46 PM
12.5 is probably the leanest you want to go on boost, slightly richer nearer 11 would probably be best as a safety margin, My FC is running UBER rich on boost and drops to about 9:1 lol on cruise if your O2 sensor is working correctly and the mapping is good should be 14.7 - stoich, which on my chipped ECU is bang on.
Title: Air Fuel Ratio??
Post by: DR SCHNITZEL on February 25, 2010, 11:26:25 AM
I tuned for 10.8 at 1 bar, and 14 on cruise/ idle.
 
I put a touch extra fuel in for the cells in the 2000rpm leading up to peak power just to be safe
Title: Air Fuel Ratio??
Post by: BlitzBoy on February 25, 2010, 11:32:26 AM
Quote from: m1tch;674825My FC is running UBER rich on boost and drops to about 9:1  

wow you are probably getting carbon build up on ya rotors from running that rich
Title: Air Fuel Ratio??
Post by: Tintin on February 27, 2010, 05:00:43 AM
I run 16:1 in all cruise areas, no problems and I actually get half decent fuel economy doing a steady 80 on the motorway
Title: Air Fuel Ratio??
Post by: exige on February 27, 2010, 09:49:50 AM
I\'m surprised there\'s not a sticky somewhere for this type of info
Title: Air Fuel Ratio??
Post by: clive on February 27, 2010, 10:20:34 AM
Quote from: exige;675490I\'m surprised there\'s not a sticky somewhere for this type of info

You right so this thread is now a sticky :3gears-lh
Title: Air Fuel Ratio??
Post by: m1tch on March 02, 2010, 10:06:43 PM
Quote from: BlitzBoy;674960wow you are probably getting carbon build up on ya rotors from running that rich

Indeed, which is why I need to get my e-manage and water injection in! lol its mainly caused by the uprated fuel pump, the upside to it though is that there are flames :D
Title: Air Fuel Ratio??
Post by: paul3944 on April 24, 2010, 07:33:03 PM
Hi,

I found this Excel spreadsheet on RX7club some time ago.

You copy and paste in you wideband results into the sheet on the first tab.

There is a selection of maps on the maps tab for cruise, boost, Variable Lean and Power.

Not tried these myself yet but looks like a useful tool.

Regards,
Paul
Title: Air Fuel Ratio??
Post by: a.tapos on July 01, 2010, 11:13:17 AM
I found a thread about this ages ago when i was experimenting and it appears alot of mappers especially americans prefer using lambda rather then afr though your probably better off sticking with what makes it easier for you lambda always confuses me because the measurement is the opposite to what im used to on a 0.1 to 1.0v narrowband sensor,though that in mind we dont use them to tune and ive only ever used narrowband readings on a standard car.Think i went off topic a bit oh well.
Title: Air Fuel Ratio??
Post by: kompactor on July 15, 2010, 07:37:45 PM
I never tune richer then mid 10\'s. At 24 psi I\'m around 10.8:1, at 15 psi i run 11.3:1. I never tune leaner then 12:1 anywhere in boost. By 10 psi i\'m in the 11\'s. Idle I run 13:1 speeds under 50mph i run 14.7 and highway cruise I run 16:1, or as lean as it will let me without missing.
Title: Air Fuel Ratio??
Post by: PGiljevic on February 21, 2011, 09:35:37 AM
12.4:1 idle

15.0:1 all cruise regions

13.5:1 up to 5psi boost

12.2:1 @ 20psi boost


Water Injected, and pump petrol ;)
Title: Air Fuel Ratio??
Post by: FD Dave on June 20, 2011, 10:31:57 AM
can you check your afr via the apexi or will i need to get a wideband sensor and gauge?
Title: Air Fuel Ratio??
Post by: Aubec on June 20, 2011, 12:02:48 PM
Quote from: FD Dave;770326can you check your afr via the apexi or will i need to get a wideband sensor and gauge?

Wideband is required.  Ideally you want to pair it with a datalogit for the Apexi if you want to tune yourself as there are settings on the PFC you can\'t get at via the Commander unit.
RX7Club PFC sub forum is well worth a read, work through their stickies.
Title: Air Fuel Ratio??
Post by: Prof on June 20, 2011, 02:17:44 PM
Quote from: a.tapos;702220I found a thread about this ages ago when i was experimenting and it appears alot of mappers especially americans prefer using lambda rather then afr though your probably better off sticking with what makes it easier for you lambda always confuses me because the measurement is the opposite to what im used to on a 0.1 to 1.0v narrowband sensor,though that in mind we dont use them to tune and ive only ever used narrowband readings on a standard car.Think i went off topic a bit oh well.

lambda and afr are functionally related lambda = afr / afr at stoich - so if you tune for one or the other the results would be the same - with one possible exception - and that\'s differing fuel types.  Since most people don\'t change the fuel type during running of the engine (I say most, because there are meth heads and people who have tanks of other stuff that get injected on boost), afr is fine - provided you tune for the fuel type.
 
Wiki says this :  http://en.wikipedia.org/wiki/Air-fuel_ratio
 
Petrol / Gasoline is 14.7 to 1 afr for stoich burn, but for a turbo\'d car you want to be a lot richer in the boost part of the map - high 11\'s seems to be the favoured numbers - but it can be dependant on whether you run WI or meth on boost, as this can allow leaner afr with no knock.
 
I\'ve been running close on 13.5 on warm idle, can\'t get it higher without the idle becoming unstable, and 14.7-15 in cruise - which is great for fuel economy :):)
 
I run about 11-11.5 on full boost which is too rich and the engine drops power, but it\'s staying that way till more mapping is done.  I\'d rather bog than have to rebuild. :cheers
Title: Air Fuel Ratio??
Post by: FD Dave on June 21, 2011, 01:40:53 PM
i dont plan to do any mapping myself, i just wanted to check my afr as when idlin i can taste the petrol in my mouth lol.
Title: Air Fuel Ratio??
Post by: woolley bully on February 25, 2013, 06:32:43 PM
I know this post is a tad old now but can I adjust my fuel maps on my pfc 16bit without a datalogit just using the commander ? As in just adjust the fuel according to afr ? Cuz my cars über rich on tick over to the point where people\'s eyes start watering if I leave running to long :-/ lol
Title: Air Fuel Ratio??
Post by: Grant Monkhouse on February 25, 2013, 06:48:54 PM
I\'m prety sure you can but your commander may have been locked out if you have had it mapped previously. Your going to need an AFR meter
Title: Air Fuel Ratio??
Post by: woolley bully on February 25, 2013, 07:17:31 PM
Quote from: Grant Monkhouse;851721I\'m prety sure you can but your commander may have been locked out if you have had it mapped previously. Your going to need an AFR meter

It\'s still on base map running twins parallel @7psi with decat system but runs very rich from what I can tell  ,, I\'m going to fit a single turbo set up the weekend , I\'m only looking to run 10ish psi as I\'m on stock fuel system , got afr meter on the way ,,but was wondering is the stock fuel system up to the task for running to4s @ 10pai ? an wanted to know if I could adjust the map until I get it mapped
Title: Air Fuel Ratio??
Post by: Grant Monkhouse on February 25, 2013, 07:24:40 PM
I would say you are most definately goin to need either 850 primaries or 1680cc secondaries, and an Aeromotive fuel pressure regulator
Title: Air Fuel Ratio??
Post by: woolley bully on February 25, 2013, 07:48:40 PM
Quote from: Grant Monkhouse;851727I would say you are most definately goin to need either 850 primaries or 1680cc secondaries, and an Aeromotive fuel pressure regulator

In that case then I will mod the primary rail to take the 850 secondary\'s an just get a new secondary rail an run 1680s then with upgrade fpr , someone told me the standard fpr is 3 bar ? Any truth in that ? An also will the fuel lines cope with more than standard fuel pressure ? (Sorry if all this has been coverd before)
Title: Air Fuel Ratio??
Post by: Grant Monkhouse on February 25, 2013, 07:59:16 PM
Fuel lines will be fine. Just keep the 550 primaries and get the 1680 secondaries with rail, and you defo need the FPR.
Title: Air Fuel Ratio??
Post by: woolley bully on February 25, 2013, 08:04:22 PM
Ok will do ,, that\'s cleared that up ,, had loads of people saying that 10psi on a to4 would be fine on stock setup because the twins run 10psi standard
Title: Air Fuel Ratio??
Post by: Grant Monkhouse on February 25, 2013, 08:11:52 PM
You are going to need to change settings on the ecu too, the injector sizes will need changing to 1680.

I suppose you could run it at 10psi without changing anything, providing you monitor the AFR gauge, BUT you won\'t be happy at 10psi for very long. On a single turbo 1 bar should be minimum.

If you have the cash to do the fuel system now then do it.
Title: Air Fuel Ratio??
Post by: woolley bully on February 25, 2013, 08:21:26 PM
Hmmmm might have a re think on what I\'m going to do as I\'m planing to pull the engine out this summer so I think I\'m going to buy all the parts an fit everything in one hit wile the engines out ,, was hoping to put the single on an run low boost until I upgrade the rest of the parts but if there\'s a good chance it\'s going to run lean I will leave it until summer when I pull the engine an just stick with the twins for now
Title: Air Fuel Ratio??
Post by: Grant Monkhouse on February 25, 2013, 08:26:10 PM
Best bet is to ring up one of the specialists. And ask your questions.

I personally would do the fuel upgrade before turbo or at the same time.
Title: Air Fuel Ratio??
Post by: woolley bully on February 25, 2013, 09:11:53 PM
Ok mate , cheers for the info
Title: Air Fuel Ratio??
Post by: BlitzBoy on February 26, 2013, 11:39:33 AM
10 psi on a T04S and 10 psi on twins is different, the TO4S will be pusing more VOLUME of air, it will be very lean on the stock base map of the APexi