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[quote author=CosmicBlueMS3 link=topic=71369.msg1255278#msg1255278 date=1173317522]
dang af of 15:1 it seems
you think thats due to the intercooler?
id be a tad nervous that you are running so lean in warm weather. I really wonder if thats somehow a function of the larger diameter cai or the maf sensor getting some bugged readings.
hopefully someone dyno's the mazdaspeed cai to get some comparisons becuase I dont see how the intercooler could make it so lean, but i dont know volumes about intercooler physics to rule it out either.
[/quote]

I'm not sure why everyone seems to think he's running "so lean". Must be a Mazda thing where we get comfortable at 10 and 11:1.

He's *crossing* 15:1 for a nanosecond at a given rpm on the way to 13:1. By 4000rpms, he's solidly at 12:1. From the programmable ECU tuning I've done, this seems nearly optimal. Granted, not much room for error, but his #s support that things are working very well. And considering the tempermental nature of the Mazda ECU, I've got think it'll prevent itself from hurting the hardware. Just dicing it up for conversation and exploration but it looks pretty good to me. At least we don't have rotor seals to worry over....
 

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Can someone explain how different intercooler would cauze the a/f ratio to lean out.
I'm cornfused. :?
 

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[quote author=dread link=topic=71369.msg1255358#msg1255358 date=1173319339]
I have no idea what optimal is, it would be interesting to ask some of the tuners on this forum what they think.
[/quote]

GT1 posted a link to a turbo manufacturer awhile back where they state that 12:1 is borderline lean in a turbo application vs. 14:1 for N/A. But I don't know if they mean across all rpms or just at higher rpms.
 

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[quote author=Kawwikid link=topic=71369.msg1254953#msg1254953 date=1173308156]
Ok, while my wife trys to get the scanner working again for me..Heres what the dyno graph says, correction fact..is un-corrected..Im at sea level, it was 73degrees this morning and 33% humidity and the smoothing is 5....
[/quote]

I came up with a dyno correction factor of 1.009.

By the data you gave, I assume you dyno'd around 4pm today. From that I took MCO's reported weather at that time to fill in the remaining required data

Temperature: 73F
Dew Point: 43F
Relative Humidity: 33%
Absolute Pressure: 29.18in/hg (MCO reported altimeter of 3014 - elevation 96ft = 29.18)
Vapor Pressure: 0.28in/hg

So with the correction applied to your peak numbers, you made 271.5whp and 293.1ft/lbs. Obviously the correction is pretty mute in this case.
 

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[quote author=tuckaloe link=topic=71369.msg1255348#msg1255348 date=1173319079]
[quote author=CosmicBlueMS3 link=topic=71369.msg1255278#msg1255278 date=1173317522]
dang af of 15:1 it seems
you think thats due to the intercooler?
id be a tad nervous that you are running so lean in warm weather. I really wonder if thats somehow a function of the larger diameter cai or the maf sensor getting some bugged readings.
hopefully someone dyno's the mazdaspeed cai to get some comparisons becuase I dont see how the intercooler could make it so lean, but i dont know volumes about intercooler physics to rule it out either.
[/quote]

I'm not sure why everyone seems to think he's running "so lean". Must be a Mazda thing where we get comfortable at 10 and 11:1.

He's *crossing* 15:1 for a nanosecond at a given rpm on the way to 13:1. By 4000rpms, he's solidly at 12:1. From the programmable ECU tuning I've done, this seems nearly optimal. Granted, not much room for error, but his #s support that things are working very well. And considering the tempermental nature of the Mazda ECU, I've got think it'll prevent itself from hurting the hardware. Just dicing it up for conversation and exploration but it looks pretty good to me. At least we don't have rotor seals to worry over....
[/quote]

after my previous comment I wanted to do a bit of research on whats up because I found it very hard to believe that the intercooler was causing the leaner af's right before boost kicks in and I think I found the cause. GDI engines are unique and function differently than regular non GDI turbo engines. If you didnt know, our 2.3 DISI is a GDI :p ok, so you prolly knew that. anyway, I found a passage that sums things up better than I could in twice as many words.

Existing turbocharged multi-port injection engines suffer from turbo-lag, or the delay in boost response. This stems from the delay in acceleration of turbine speed when the throttle is opened, and is due to the slow turbine speed at low loads when there is only a small exhaust gas flow. The GDI Turbo engine, however, operates in a lean-burn mode at low loads, thereby producing almost twice the exhaust gas flow as an engine operating under stoichiometric conditions. The turbine is therefore already spinning at a higher speed when the driver opens the throttle to start accelerating, and so turbo-lag is significantly reduced.

I took the above paragraph from a Mitsu press release, it was extremely good reading (the bottom half) http://media.mitsubishi-motors.com/pressrelease/e/products/detail446.html

In closing, the leaner a/f is 100% cool, its on purpose and its ideal. Keep it rockin! :D
 

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Discussion Starter · #28 ·
Cosmic,
thanks for looking that info up about A/F and GDI motor. It makes me feel a little better about the A/F ratio that im getting right now..The only reason that I could think of that the TMIC might lean out the mixture a bit was that the increased air flow after the MAF senor, but im not sure about that. I had heard that the opt. A/F for a turbo car was 11.5 to 1, but that might have been with a normal fuel injection set-up..But for now she pulls hard, and spind the tire like no tommorw even with the DSC on, so it a fun place to be until more parts can be found. Im thinking Turbo XS down pipe and high-flow cat and the Cobb or CP-E programmer..Not to mention the Turbo Smart BOV.....Thanks everyone for you responses...
 

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Discussion Starter · #30 ·
I think thats the right name. Streetunit has a kit comming for the Speed 3 and Spped 6..Supposed to be a really nice BOV, that is very tunable and works in a neat Rec. and VTA mode...
 

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[quote author=Kawwikid link=topic=71369.msg1255468#msg1255468 date=1173322751]
Cosmic,
thanks for looking that info up about A/F and GDI motor. It makes me feel a little better about the A/F ratio that im getting right now..... I had heard that the opt. A/F for a turbo car was 11.5 to 1[/quote]


no problem looking up the info, I enjoy sharing as much as I do learning about the cars we love. 11.5:1 is the a/f that many tuners use as a baseline, however stiochometric a/f for gasoline is 14.7:1 to achieve a complete burn (100% efficiency) which in a nutshell, is impossible since the fuel we get is not necessarily pure and when you toss ethanol and mtbe into the mix..... forget about it.
 

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So combining this with the Mazdaspeed CAI discussion about running the car too lean, this all seems to be a mute point. Since both CAI are running the car alot leaner than what we expected. But the way the car handles it - it is good thing.
 

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[quote author=CosmicBlueMS3 link=topic=71369.msg1255531#msg1255531 date=1173324928]
[quote author=Kawwikid link=topic=71369.msg1255468#msg1255468 date=1173322751]
Cosmic,
thanks for looking that info up about A/F and GDI motor. It makes me feel a little better about the A/F ratio that im getting right now..... I had heard that the opt. A/F for a turbo car was 11.5 to 1[/quote]


no problem looking up the info, I enjoy sharing as much as I do learning about the cars we love. 11.5:1 is the a/f that many tuners use as a baseline, however stiochometric a/f for gasoline is 14.7:1 to achieve a complete burn (100% efficiency) which in a nutshell, is impossible since the fuel we get is not necessarily pure and when you toss ethanol and mtbe into the mix..... forget about it.
[/quote]Well actually the a/f's can be much much more varied now since we are running direct injection. Alot of DI engines run as rich as 6:1 and as lean as 32:1. Thats the beauty of DI
 

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[quote author=TruboPower link=topic=71369.msg1255881#msg1255881 date=1173339446]
[quote author=CosmicBlueMS3 link=topic=71369.msg1255531#msg1255531 date=1173324928]
[quote author=Kawwikid link=topic=71369.msg1255468#msg1255468 date=1173322751]
Cosmic,
thanks for looking that info up about A/F and GDI motor. It makes me feel a little better about the A/F ratio that im getting right now..... I had heard that the opt. A/F for a turbo car was 11.5 to 1[/quote]


no problem looking up the info, I enjoy sharing as much as I do learning about the cars we love. 11.5:1 is the a/f that many tuners use as a baseline, however stiochometric a/f for gasoline is 14.7:1 to achieve a complete burn (100% efficiency) which in a nutshell, is impossible since the fuel we get is not necessarily pure and when you toss ethanol and mtbe into the mix..... forget about it.
[/quote]Well actually the a/f's can be much much more varied now since we are running direct injection. Alot of DI engines run as rich as 6:1 and as lean as 32:1. Thats the beauty of DI
[/quote]

By 'alot of DI engines', which are you referring to? Any links to further read up on the latest on DI engines?? Thanks :)
 

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[quote author=desperado callado link=topic=71369.msg1255383#msg1255383 date=1173320298]
[quote author=dread link=topic=71369.msg1255358#msg1255358 date=1173319339]
I have no idea what optimal is, it would be interesting to ask some of the tuners on this forum what they think.
[/quote]

GT1 posted a link to a turbo manufacturer awhile back where they state that 12:1 is borderline lean in a turbo application vs. 14:1 for N/A. But I don't know if they mean across all rpms or just at higher rpms.
[/quote]

That was from the Garrett sight IIRC. I'm in no position to argue with a company as big and successful and full of engineers as Garrett, but.....in the world of aftermarket programmable ecu's like SDS, Motec, Haltec, MegaSquirt, etc, most turbo guys are tuning for 12:1 AFRs to be safe, not on the ragged edge. 12:5:1 AFRs for max effort and hope an injector doesn't hiccup. And it works well very well. Normally aspirated engines are usually tuned to 13.6 or 13.7:1 AFR for max output and 14.7 and leaner for cleanliness. I offer this only as a point of reference. I think Garrett is being very conservative in that statement.

Now the lean burn angle of direct injection is interesting. Now that it's mentioned, I recall that as well. Stratified charges and all that, although it's being used alot more in Europe than over here from what I recall.....
 

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If the motor was having fuel issues it would get leaner 4-5.5k..Its getting richer so is likely part of the program to be a little lean apon spool up. Vs a base run it is definitly leaner so this might be to lean. Will a datalogger moniter knock? if so, then it might be a good thing to watch. It looks like its holding richer than 12/1 from 4k on. This is where max Hp and Tq is on the dyno. Should be safe for now. Also the super rich after 6k is likely as the boost falls off and the fuel is the same to its gonna go way rich. Course the Ecu should see this and taper fuel accordingly. Likely a safty factor to..
 
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