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Its not so much about how much flow there is. Its more about the volume that is allowed to pass the sensor at that time and how it flows (straight vs roly poly vs around a bend, etc). Faster air movement = more maf voltage = more power = leaner AFR (leaner until you or the ECU accounts for it). But the MAF Scaling tables will tell the ECU how much volume there is at that MAF Voltage.

Basically, as long as the sensor is scaled properly for the volume, you can have more or less restriction before it without having to change anything in the tune. It will account for it.

A sensor that is set up for a 2" pipe will not know about the extra inch in a 3" pipe. But if you tell the sensor that there is more volume, it will compensate, with everything else being equal.

Compare the ID of your stock maf housing to your intake and if they are close, it will probably work. But you dont want to do it until you are ready to tune. The MAF Scaling tables in the tune will take care of the fact that the pipe ID isnt the same. If its really far off, it may not work...

Just make sure the tuner knows this upfront and if it ends up being a problem, you may need get the correct one. But there probably wont be any harm in trying.
 

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Discussion Starter #22
Good info. In the long run yeah...I will try and find a tune (or try myself) with the ability to recalibrate for any non-stock MAF housing difference. I just wondered what the computer's ability to adapt for (closed loop?) with STFT or LTFT. If it was "close enough for now," I could cheat and install the narrow one now. Maybe it would pull fuel. Then I could data log some intake temps for comparison to OEM and just let the computer handle it. I'm a horribly impatient person.

I think I'd always want to go bigger, assuming not too much tumble is introduced when it has to narrow down to the throttle body. Even if I can compensate for the narrower ID with those MAF calibrations, too small is just a bottle neck right?

I tweaked my Scanguage at lunch to show bank 1 short and long term trims. The short term seems to fluctuate around -1 and -4, the long term is at -4. I've never managed to get any of the main bank AFRs to show...but commanded A-F and Alt A-F show up. Commanded is almost always 14.5 until you get close to WOT or heavy load and it goes to 12.5. If you go WOT in 6th up a hill, with a full trunk, on a hot day, in a headwind it'll dip to 11.5. Alt A-F is always just behind commanded by about a 1/2 second/~2 refresh periods.

Is the tactrix/mazdaedit user friendly?
 

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Is the tactrix/mazdaedit user friendly?
Not really, unfortunately. If you are familiar with tuning, its not that bad on the surface. But once you start digging in and finding out that some of the maps are improperly labeled and sometimes completely backwards, it can get frustrating. My high det timing map is actually open loop timing. My low det timing map is closed loop. High det fuel is open loop fuel. there are several instances like that and its different for each ROM ID.

Do keep in mind that the purchase of the software and cable is part of the e-tune from most tuners. Some have an option to rent the stuff, but if you ever have the desire to do it yourself or just monitor it, get the package. You can also go straight to Epifan to get it.

I wouldnt go with a smaller intake pipe ID. If its not the same physical sensor, it may not even fit. Im fairly certain that my MS CAI is the same ID as stock. The gains are from the non ribbed intake tube, cone filter, and better flow characteristics after the filter.

Note: My experience below applies to the 1st gen, but Im sure its the same on 2nd gen. Hell most of the concepts are exactly the same as how my Evo ecu was done.
There are several groups of long term fuel trims. You said you saw -4. That is likely only for the maf flow that you were measuring at that time. For example, 0-35hz may be the 1st "zone" that has its own stored LTFT. Then 35-60hz would be the next. And so on. That way its not applying the same correction across the board.

Commanded AFR doesnt tell you a whole lot more than what the map is calling for. LTFT, MAF Scaling and other stuff impact Actual AFR. My Actual AFR was below 10.0 AFR on the stock tune.

I use a bluetooth adapter and Dash Command to monitor stuff on the fly without my laptop in the car. They have a Mazda PID patch that opens up knock retard and some different ways to log afr and other stuff. Im suprised that scangauge doesnt have an actual afr loggable item. But now that I think about it, I may be using the custom Actual AFR PID. You may have to log Lambda instead. Lambda of 1=14.65ish AFR for gasoline.
 

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Discussion Starter #24
I agree, the commanded is useless. The "main" AFR item for CANSF has never worked, however the "alt" AFR item does return. That is what I usually use to "log" AFR. The Scangauge is a display and has no logging capability, I just peek at it visually.

The alt AFR is "real time" but usually 1-2 reporting cycles old. I don't think I've ever seen it go into the 10s, but it certainly richents to 11-12 under the heavy load/WOT conditions I mentioned. It's usually in the 14s, 15-16 on liftoff or 29 when coasting.

I will start researching the Epifan and logger you mentioned. This sounds like a great chance to educate myself.
 

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Discussion Starter #26
Planning to swap out the HPS soon. Was comparing 5.0 vs EBC Yellowstuff. Going to give the 5.0 a shot...never had any issues with my HPSs, and I've read the 5.0s are supposed to be the closer to the performance of HP+ while still maintaining the HPSs' mild manners.

I need to measure the rotors while I'm down there. Anyone know the minimum thickness off the top of their head? I'm assuming there's something stamped on there to compare to, but I haven't looked yet.
 

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Planning to swap out the HPS soon. Was comparing 5.0 vs EBC Yellowstuff. Going to give the 5.0 a shot...never had any issues with my HPSs, and I've read the 5.0s are supposed to be the closer to the performance of HP+ while still maintaining the HPSs' mild manners.

I need to measure the rotors while I'm down there. Anyone know the minimum thickness off the top of their head? I'm assuming there's something stamped on there to compare to, but I haven't looked yet.
Minimum thickness for the front rotors is 23mm and rear rotors it is 9mm.
 

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Discussion Starter #28
Thanks, Adam. Hope things are drying out and the pairings are good.
 

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Discussion Starter #29
Put in new brake pads on the fourth. Bedded them per instructions.
They are fine going forward. One of the fronts tends to clank when braking on initial pressure in reverse though. Retaining springs and clips are all snug...don't know what's up with that.

Street 5.0s have slightly more bite than the HPS they replace but not as much bite as I remember OEM having. HPS and 5.0s are both easier than OEM when it comes in to dialing in and releasing pressure. I don't know if it's linear, but a very predictable easy pedal to braking proportion.

The streets seem to have slightly more stopping power than the 75,000 mile 2/3 worn HPS they replaced. They dust a bite more. They did not fade as much.

I preferred them over the HPS at the last track night in america. Can't wait to try them during evo school and the next autocross.

https://www.youtube.com/watch?v=cRUT0Qlw8gw

Last session. I let too much air out after session 2...and then the sun went down and it dropped like 12 degrees. I was rolling them over something wicked.
 

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Discussion Starter #32
I'm not really worried. It's just something I'm noting that was new.

The OEM/HPS never did that on my 1st gen and the OEM/HPS never did that on my 2nd gen. The 5.0s do seem to have tweaked the thin steel backing plate behind the pad material thick plate. Ever manufacturer probably does that part differently and that might just cause something I hadn't encountered before. I was mainly chalking it up to them not having been abused yet, still having factory-fresh chamfer, etc.

The noisy guy is on the driver's side, and I did have to tweak one of the spring clips on the driver's inside pad...so there's some correlation there.
 

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Discussion Starter #34
yellow stuff and hoosierstones seems to be a new formula.

Did Evo school today, Phase 1. It was warm but everything held together. No brake fade for me, though another guy had them disappear on him. We weren't allowed to touch tire pressures, to reduce the variables...so I set them to 38 in the morning and assume they were low 40s hot all day.

Wish I had had 1 more run. I strung some stuff together and tried a diff line that ended up letting me go flat out for 2 elements on my final run, but I missed a second missing 2nd right out of the start. wouldashouldacoulda.

I was going to skip the 7/19 event to spend a weekend in Maine driving/hiking/NEFR, but I'm going to drive back Saturday night. Need more seat time.
 
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