mspnp + maf?

[sumoashe]

Have a couple questions about using the mspnp system with a maf sensor. This is not a maf vs. map debate. Just specific questions when it comes to using a maf.

1. Firstly, I'm not absolutely sure your can use a maf with the mspnp setup. The info on their site says yes, but in the detailed info list under load inputs it doesn't list maf. Just an, map, ect.. I do believe it should be able to cause it's based on ms2 extra with a microsquirt. Which has been used with maf's.

2. Given it does work. Is there a maf that works better than others with the ms setup. Seen a couple guys use a q45 unit. Or instead of a unit from a oem, what about aftermarket units? Such as Pro-m, figure this might me a better choice based that when you purchase a unit they provide a full transfer/flow data sheet (all the info you need). Also the fact that the unit will be calibrated for the exact injector size being used. This should mean less tuning of the transfer map.

Any info would be great.

[Jaxx_]

1. You can, but you will have to tune for mass air instead of speed density.

2. Why do you want a mass air system?

[nando]

there's no real reason to use a MAF if you have an MSPNP.

but yes, it can.

[sumoashe]

Thanks for the replies, anyone here used this setup before? And as for why, if you've never tuned with amaf the reasons will be lost on you unfortunately. Simple answer is this will be a dd car. So my concerns are drivability, not peak power. Theres a reason pretty much every oem uses maf, and almost every race car uses speed density.

[nando]

emissions?

[sumoashe]

Emissions to a lesser effect. A good speed density car will pass smog in most states. As a hint, kinda, maf is actually easier to tune for a certain reason.

[Ginsterman98]

Have a couple questions about using the mspnp system with a maf sensor. This is not a maf vs. map debate. Just specific questions when it comes to using a maf.

1. Firstly, I'm not absolutely sure your can use a maf with the mspnp setup. The info on their site says yes, but in the detailed info list under load inputs it doesn't list maf. Just an, map, ect.. I do believe it should be able to cause it's based on ms2 extra with a microsquirt. Which has been used with maf's.

2. Given it does work. Is there a maf that works better than others with the ms setup. Seen a couple guys use a q45 unit. Or instead of a unit from a oem, what about aftermarket units? Such as Pro-m, figure this might me a better choice based that when you purchase a unit they provide a full transfer/flow data sheet (all the info you need). Also the fact that the unit will be calibrated for the exact injector size being used. This should mean less tuning of the transfer map.

Any info would be great.

The Pro MAF is way better than any OEM MAF for sure. All OEM MAF sensors send realtime data to the ecu. The Pro MAF sends a average of several samples to the ECU which will give a much more stable signal for the ECU to use. The Pro MAF comes calibrated for the injector size you intend to use. Main issue I have had with MAF based tuning is un even airflow over the MAF element at load egine load. Been there, done that with my VW's and will never look back.

Are you planning on running the MS as a piggyback? To keep your OBD2 functions intact? If so I know some guys who have done this to pass emissions but they were using VEMS.

[whodwho]

Looks like I missed this thread when posted...

OP looks like you are not following up on this thread but I have a MSPNP with Q45 MAF running MSExtra, the code was a bit green but there have been recent updates and the documentation lacking but it does work.

If you come back let me know if I can help.

[sumoashe]

whodwho, been following but havent had time to post. Between a odd work schedule and the lack of responses I've just been checking in here and there. As for all the questions as to why I want maf, simple. I car more about having a really nice drivable car. To me this is more important than the 1 or 2 hp that going to SD (speed density) gains. By drivable I mean a car that doesn't stumble, have erratic hiccups, pops, dead spots, ect. Basically a car that drives like stock.

When going to SD you lose some of this just because of the nature of SD. What alot of people don't understand about SD is that what you are doing is in fact trying to recreate a mass air curve (i.e. your ve table) via math. The one major downside to this is that your trying to solve this math problem without one major measurement. The amount of air entering the engine. This is fine for track cars that are being retuned at the track for the days current enviromental conditions. For a street car tho, this is a little hard to do. A SD tune is only good for as long as the conditions don't change. After that the quality of the tune is going to fluctuate. Thats why the car will run better and worse from day to day.

Yes you can use lots of comp. tables to help with this. And have a pretty good driving car. But its more or less a bandaid fix. Hell, I barely see anyone using ms's real time baro adjustment. And this would go a long ways to getting the car to drive more consistent from day to day.

Now for the maf stuff. When you purchase a maf (lets say a pro-m 80mm) they provide you with a flow sheet/map that is scaled to the injector size of your choosing. This is the first important thing, you should not use a maf that is scaled to a different injector size. I.E. using 19lb inj. with a maf scaled for 30lb inj.. This will cause the fueling to be way off from the get go. The flow sheet provided is also your transfer data, the info that says at this cfm the sensor puts out x volts. Guess what? That right there is your ve table.

[whodwho]

I am not pro or con with either, there are pros and cons to running them both.

SD is very forgiving, it is not sensitive to vacuum leaks, it is not sensitive to using a BOV and not having to recirc, is not sensitive like MAF placement and air turbulence and there is no additional expense. A MAF can be more accurate and can compensate dynamically for barometric changes without adding an additional sensor. A MAF's element can be delicate and can foul easily.

There were issues with tune stability with MS like you describe but was from sensor signal stability and no fault of SD, they have address that in recent firmware releases and has help with getting a stable tune with SD.

I have been mainly running SD and have a stock like running experience. but I do have a mild motor and live in a fairly mild weather state and don't have major elevation changes during a normal daily drive. MS does utilize barometric input without adding an additional sensor by taking a snapshot reading from the MAP sensor before startup.

I definitely think you can get SD to work more acceptable then it is if you are not running a big cam or ITBs but see no reason not to go with a MAF if so desired :)

With all that said I have been wanting to pop my MAF back in and see how the recent code changes related to MAF and sensor signal stability and see how it goes!

[sumoashe]

Yeah I'm not really pro or con for a particular one either. Just really would like to try it, havent seen it done much. I guess its the challenge aspect of it. I come from dealing with high power ford drag stuff. So I've become used to working on, tuning, and building big power cars that use a properly done maf system. This ranges from 400+whp 9k rpm 331 n/a strokers to Ysi blown 347 setups seeing 20+ lbs of boost and making around 800hp. All these cars were maf'ed and street cars that would see occasional strip duty. And they all drove like butter. Including a particular Ysi blown car that was street driven almost daily. It would be driven from central Ill to Kentucky towing a small trailer with race gas, slicks and what not. Then raced all weekend, and driven back. All while making 750 to the wheels on pump gas. Never a hiccup or drivability issue. So when I see guys saying it cant be done or a waste of time, I really wanna prove them wrong.

[nando]

whodwho, been following but havent had time to post. Between a odd work schedule and the lack of responses I've just been checking in here and there. As for all the questions as to why I want maf, simple. I car more about having a really nice drivable car. To me this is more important than the 1 or 2 hp that going to SD (speed density) gains. By drivable I mean a car that doesn't stumble, have erratic hiccups, pops, dead spots, ect. Basically a car that drives like stock.

When going to SD you lose some of this just because of the nature of SD. What alot of people don't understand about SD is that what you are doing is in fact trying to recreate a mass air curve (i.e. your ve table) via math. The one major downside to this is that your trying to solve this math problem without one major measurement. The amount of air entering the engine. This is fine for track cars that are being retuned at the track for the days current enviromental conditions. For a street car tho, this is a little hard to do. A SD tune is only good for as long as the conditions don't change. After that the quality of the tune is going to fluctuate. Thats why the car will run better and worse from day to day.

Yes you can use lots of comp. tables to help with this. And have a pretty good driving car. But its more or less a bandaid fix. Hell, I barely see anyone using ms's real time baro adjustment. And this would go a long ways to getting the car to drive more consistent from day to day.

Now for the maf stuff. When you purchase a maf (lets say a pro-m 80mm) they provide you with a flow sheet/map that is scaled to the injector size of your choosing. This is the first important thing, you should not use a maf that is scaled to a different injector size. I.E. using 19lb inj. with a maf scaled for 30lb inj.. This will cause the fueling to be way off from the get go. The flow sheet provided is also your transfer data, the info that says at this cfm the sensor puts out x volts. Guess what? That right there is your ve table.

I'm sorry but this is all nonsense. if you get stumbling, popping and flat spots in an SD tune, and it changes with the weather, then you suck at tuning.

MS's real time baro is cool but it's not neccesary at all, which is why few use it. I've had it on and off and can't tell any difference. also, it still reads the ambient pressure when you turn on the car.

the ideal gas law isn't exactly black magic either.

[sumoashe]

Nando, it's not really bs. It's the nature of a SD car. Like I said, you can get a good drivable SD car. No argument. But a SD car will never be as consistant over as wide a range as a maf car. Thats why the oem's went to maf. For consistancy. Yes SD is cheaper, yes it is easier to setup. If it was better then maf tho then the oem's would have it on all their cars. This isn't a argument for or against SD, this is a discussion about maf setups and megasquirt, and how well they work together.

[sumoashe]

As for the real time baro thing, were you using a secondary map sensor? And you wouldn't notice a change in normal driving around town, say in a 100 mile radius. Where you would notice this is on greater drives, ie going from sea level to say 5000ft elevation. Or going from 80 deg weather to 50 deg within the same drive. Yes ms takes a baro snap shot at start up, but this is a static measurement of a ever changing variable. The baro reading at sea level is not the reading at elevation, but because ms is still using the first reading your tune is off. Unless you stop and restart the car every thousand feet or so to take a new reading.

[nando]

I drive my car year round, its pretty damn consistent. I havent touched the tune in 2 years.

If you prefer maf thats fine, but your argument about the tunes is completely bogus. I've driven in the mountains and on days where its 95f and 15f with the same tune I use at sea level. If you want baro you can do it but its not a noticeable change.