Chillinit

Whats up all....i've been doing some research and came across this. Now having learnt that us honda's don't have a MAF sensor(still new at this)...and MAF sensors come stock with most Factory Turbo rides(reads boosts)....has anyone thought of incorporating this into our setups?? Just a thought....don't know if it would work ...pros.cons.?!!?.
check it....

http://www.splitsec.com/index.html

Chillinit

go to PRODUCTS

MAF KITS

MAF 3.0 KIT

HXMan

Our cars have map sensors which read boost.

Chillinit

i know that the map sensor is tricked to read boost. However..our air/fuel is not a direct result of the amount of air going into our motors. I believe hondata has set values for what our air/fuel should be(there is some sort equation involved)....If we had a map sensor...the air fuel can be calibrated according to the air going into the motor.

underpressure02

Just some food for thought. How many times do maf sensors blow or go bad vs map sensors? I know in VW and Audi's like my S4 and VR6 that we have a lot of problems with MAF sensors. My friend anthony made a ram air for his s4 using the headlight and was blowing mafs everyday b/c it was seeing to much pressure. At a few hundred bucks a MAF this got costly.

BROOD

You would have no need for a MAF sensor in a speed denswity (MAP based) engine system.
Personally I like speed density better than MAF systems.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chillinit &raquo;</TD></TR><TR><TD CLASS="quote">However..our air/fuel is not a direct result of the amount of air going into our motors. I believe hondata has set values for what our air/fuel should be(there is some sort equation involved)....If we had a map sensor...the air fuel can be calibrated according to the air going into the motor. </TD></TR></TABLE>

You meant to say MAF sensor not MAP, we already have map sensors. And yes Hondata or oem are both based on fuel tables measuring engine load (map) against rpm. This is why WB tuning is important.

Do you really think MAF equipped systems are better? What are your reasonings, I'm curious? I don't think I would like to buy calibrated MAF sensors each time I change my injector sizes.

0xenocron

MAF systems are more accurate than MAP sensors because they actually measure flow instead of calculating it.

But Honda's speed density technology comes very close with a MAP sensor and ECU.

I dont believe you could incorporate a MAF sensor in a honda with a honda ECU...maybe some of the standalones out there use MAF sensors, probably some of the systems that are popular with the DSM/VW/Audi crowd...check it out.

Chillinit

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BROOD &raquo;</TD></TR><TR><TD CLASS="quote">
You meant to say MAF sensor not MAP, we already have map sensors. And yes Hondata or oem are both based on fuel tables measuring engine load (map) against rpm. This is why WB tuning is important..</TD></TR></TABLE>

yes...my bad...i meant to say maf sensor

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BROOD &raquo;</TD></TR><TR><TD CLASS="quote">
Do you really think MAF equipped systems are better? What are your reasonings, I'm curious? I don't think I would like to buy calibrated MAF sensors each time I change my injector sizes.</TD></TR></TABLE>

I pretty new at this **** so my reasoning is strictly theoretical. I was thinking that Maf equipped systems would be benefial because you are constantly optimizing air/fuel while driving....(ie...1/4 throttle/1/2 throttle..etc)...I haven't gotten my ride tuned yet so I'm a little uncertain of the our side of the spectrum. Can we tuning for different throttle settings...or are we restricted to WOT tuning?
As for buying a calibrated MAF sensor each time you change injector size..I don't think that is the case...wouldn't changing the piping diameter be sufficent??

raene

You tune for all throttle settings by setting the vacuum areas of the map.



The fueling values are on the left, the RPM is on the bottom, and the lines are for a given amount of vacuum (measured in inches of mercury) in the manifold. The MAP sensor reads this value of vacuum and compares that with RPM to determine fueling and ignition (which is set very similarly). In the above picture, it shows you how I added fuel in the upper rev range (low vacuum) by raising the fueling values. The greyed-out lines are the prior readings (I photoshopped this pic for clarity).

I highly dislike MAF sensors. Always breaking.

omahaturbocivic

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chillinit &raquo;</TD></TR><TR><TD CLASS="quote">

I pretty new at this **** so my reasoning is strictly theoretical. I was thinking that Maf equipped systems would be benefial because you are constantly optimizing air/fuel while driving....(ie...1/4 throttle/1/2 throttle..etc)...I haven't gotten my ride tuned yet so I'm a little uncertain of the our side of the spectrum. Can we tuning for different throttle settings...or are we restricted to WOT tuning?
As for buying a calibrated MAF sensor each time you change injector size..I don't think that is the case...wouldn't changing the piping diameter be sufficent?? </TD></TR></TABLE>

With map sensors the ecu can adjust for partial throttle just as well, watch a vaccuum/boost guage as you move the throttle, the vacuum level changes with it and thats exactly what the map sensor is seeing. The engine will flow the same amount of air at a certain pressure/vacuum and rpm everytime its at that pressure/vacuum level and rpm so if the ecu knows the pressure level and rpm it can reference its fuel table for the proper level of fuel to deliver at that instance

kpt4321

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by underpressure02 &raquo;</TD></TR><TR><TD CLASS="quote">Just some food for thought. How many times do maf sensors blow or go bad vs map sensors? I know in VW and Audi's like my S4 and VR6 that we have a lot of problems with MAF sensors. My friend anthony made a ram air for his s4 using the headlight and was blowing mafs everyday b/c it was seeing to much pressure. At a few hundred bucks a MAF this got costly. </TD></TR></TABLE>


Most MAF-equipped cars don't suck, and the MAF's will last longer than the car.

BROOD

Maybe so in most cases but if the MAF does fail or it needs to be replaced with a larger diameter MAF for changes in engine configuration.....it is an expensive sensor...period. On the flipside I have rarely had a MAP sensor fail either, it could also last the lifetime of the car.

Chillinit, I was just curious of why the question was asked. I figured you may have known about something new to me. I'm not a MAF fan but that does not mean I can't learn something new also.
And yes I tune for multiple throttle conditions, it is pretty well described above.
Still, IMO I would rather work on a (hondata, Uberdata, etc) equipped MAP system than a MAF ssytem anyday.

blueturboteg

just some food for though but maf's are actually quite restrictive and many high power cars convert to map style systems. I believe that is the purpose of an hks vpc.

Joseph Davis

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by xenocron &raquo;</TD></TR><TR><TD CLASS="quote">MAF systems are more accurate than MAP sensors because they actually measure flow instead of calculating it.</TD></TR></TABLE>

Whoa up there, buddy. Until you get a better grasp of EFI theory, don't make comments like that. All technical arguments aside, if MAF were all that and a bowl of grits, why wouldn't every single last 1.9 million dollar standalone make you convert to it? They don't because it is a bullshit plumbing hassle, and offers no gains over a MAP/speed density system.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by xenocron &raquo;</TD></TR><TR><TD CLASS="quote">I dont believe you could incorporate a MAF sensor in a honda with a honda ECU...maybe some of the standalones out there use MAF sensors, probably some of the systems that are popular with the DSM/VW/Audi crowd...check it out.</TD></TR></TABLE>

Most MAF operate in a 0-12v range, usually a freq based setup as opposed to a voltage based one. Some early MAF output 0-5v linear signal, which could be adapted. Why, I don't know.

0xenocron

I wasnt try to say that J. - I realize the issues with plumbing and restriction when it comes to a MAF sensor...

But wasnt my statement correct that MAF sensors measure actual flow while a speed density system calculates is based on MAP and VSS and a few other key sensors.

BTW, I got this from reading the Tech2Tech articles...thought they were pretty factual.

kpt4321

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BROOD &raquo;</TD></TR><TR><TD CLASS="quote">Maybe so in most cases but if the MAF does fail or it needs to be replaced with a larger diameter MAF for changes in engine configuration.....it is an expensive sensor...period.</TD></TR></TABLE>

And if you want to run a MAP sensor on a Honda, you have to buy a $75-100 3-BAR MAP sensor. A brand new GM MAF, like one I'm running in my *coughtDSMcough* is 100 bucks new.

I'm not trying to argue that MAF is a better system, although I do feel that in a lot of cases it is. I'm just trying to point out that using price to justify either is absurd.

J. Davis knows what's up. Speed-density is used for other reasons besides cost, and that is what you need to focus on.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Still, IMO I would rather work on a (hondata, Uberdata, etc) equipped MAP system than a MAF ssytem anyday.</TD></TR></TABLE>

But why?

kpt4321

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blueturboteg &raquo;</TD></TR><TR><TD CLASS="quote">I believe that is the purpose of an hks vpc. </TD></TR></TABLE>

The VPC is a TERRIBLE design of a good idea. As a matter of fact, its systems like the VPC that make speed-density look bad. VPC's have the great side effect of getting rid of the MAF, and enough bad side effects that I'm not going to talk about them.

Speed-density is great, but it's dependant on quality of programming and setup a lot more than MAF is. When we're talking about the "best" of the two, speed density wins. For example, if I were to run an AEM EMS, I would run it in sped density. However, if I have the choice between something like a VPC or a high flow MAF (for non-speed-density cars, like the Supra, DSM, etc) I would take the MAF.

kpt4321

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">
All technical arguments aside, if MAF were all that and a bowl of grits, why wouldn't every single last 1.9 million dollar standalone make you convert to it? They don't because it is a bullshit plumbing hassle, and offers no gains over a MAP/speed density system.</TD></TR></TABLE>

Bingo!

There are certain cases where MAF has advantages (insert comments about FD3's blowing up here), but the vast majority of the time it's just another stupid thing to put in the intake pipe.

danl

THe good think about MAP is that is has less intake restriction.

THe good things about MAF is that it actually physically reads the incoming air DENSITY instead of taking values, calculating them, comparing them to a fuel table, and then adding a fudge factor.

THe bad things about MAP is that when you change your injector size, you change the relationship that the ecu uses to add fuel when the temperature changes, the atmospheric pressure changes, and humidity changes (if it even calculates for it in the first place). A classic example is my friends honda. It was tuned 12:1 this summer on the dyno. Now in the winter he is adding 10% more fuel everywhere with the afc because the honda computer is not able to properly compensate for the 450cc injectors. If we increase the VE of the engine with an exhaust cutout or simillar, he is in really big trouble unless he retunes.

With a MAF car everything is calculated since the MAF actually reads the DENSITY of the air. It also automatically calculates (in most cases) for the air humidity. THeirfore I can tune my DSM to a certian A/F ratio with the stock exhaust. When I open my electric cutout, the added airflow at the SAME boost levels is automatically compensated for.

FOr the street I preffer MAF on a turbo car. I think people like mazda realized this when they implimented MAP into the turbo RX7's

FOr all out performance, MAP is where its at. A race car is tuned for a specific and a lot of variables are more controlled. Also, a MAP system is usually less restrictive.

dasher

Here is a brief comparison of the advantages and disadvantages in load sensors:

MAF - airflow meter
- allows for greater accuracy in tuning
- favoured in many newer cars because allows manufacturers tighter control in
emisions tuning.
- More tunning flexibilty because it measures actual airflow
- ECU doesn't have to compute as much as a speed-density system and can have less brainpower.

Their are three different types of airflow meters:
1)) Vane-type airflow meter - used in older efi systems - a pivoting flap opens as airflow increases. flow is determined from the combined calculations of flap angle and a seperate intake air sensor. They provide greater transitional smoothness then Hot wire meters.

2)) Hot Wire airflow meter - most common meter in newer cars - uses a thin platinum wire which calculates airflow by computing the amount of current required to heat the wire up to a pre-configured temperature. They provide superior transient response then vane meters.

3)) Karman Vortex - used in many mitsubishi engines - internal vortices are measured via an untrasonic tranducer to calculate airflow.

MAP - Pressure sensor
A pressure sensor which measures vacuum , or vacuum and boost and outputs this information to the ecu where it is referenced with Intake Air temperature and revs to calculate flow.

- MAP sensor based systems offer greater transient response than MAF airflow meter systems.
- Compact size
- More reliable then MAF
- No required maintenance
- The MAP sensor doesn't pose a restriction on the incoming air unlike airflow meters and thus have the capacity for greater power to be generated.
- In high power turbo applications MAP sensors make it easier to tune idle and low speed situations because they don't suffer from intake turbulence issues like air flow meters do.
- No susceptible to engine backfire damage , unlike MAF sensors thus are more reliable.

In summary both systems have their place in modern cars depending on the application.

kpt4321

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">MAF - airflow meter
- allows for greater accuracy in tuning </TD></TR></TABLE>

How is it more accuarate? A properly designed S-D system can be just as accurate.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">MAP - Pressure sensor
- MAP sensor based systems offer greater transient response than MAF airflow meter systems.
- Compact size
- More reliable then MAF
- No required maintenance
- The MAP sensor doesn't pose a restriction on the incoming air unlike airflow meters and thus have the capacity for greater power to be generated.
- In high power turbo applications MAP sensors make it easier to tune idle and low speed situations because they don't suffer from intake turbulence issues like air flow meters do.
- No susceptible to engine backfire damage , unlike MAF sensors thus are more reliable.</TD></TR></TABLE>


How do the offer more transient response?

I've never had to do any maintenance to a MAF.

Engine backfires killing MAF's are just as uncomming as overboosting ripping MAP's, so I wouldn't agree with you there.

Otherwise, I agree with all of your points. Want to discuss the ones I don't agree with?

BROOD

Seeming that I already have a MAP sensor from the factory which is sufficient for lower boost operation, the extra cost is null.
I only paid $60 for my 3bar MAP, which is still lower in cost to a MAF sensor.

And why would I rather work with a speed density system? Only a few reasons..
~I'm more comfortable tuning it, more familar.
~I do not have time to screw around with anything other than a speed density system.
~I can only think of a slight few of my friends cars that even have MAF systems in them anyways.
~Every aftermarket standalone system I would ever want to deal with is based around a speed density MAP system.
~and why change what is already working for me??

Cost, better operation...blah, blah. We all could go back and forth for days with random facts and stuff. Also I find that people forget that factory systems are not always the best or even ideal to performance. And just in that we have fell off the original topic.....

Don't get me wrong, I would like to get more familar with MAF systems. I have a Focus and a Mazda Protege to turbocharge yet...and both of those are MAF systems.

Joseph Davis

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by xenocron &raquo;</TD></TR><TR><TD CLASS="quote">But wasnt my statement correct that MAF sensors measure actual flow while a speed density system calculates is based on MAP and VSS and a few other key sensors.</TD></TR></TABLE>

Actual flow - which an ECU is completely unaware of - can be calculated by engine speed and air density, too.

I think everyone is getting too caught up in the mechanics of the process and not looking how it fits into the big picture. Porting a head on a MAF car can make it go a touch lean just as it can on a MAP equipped car, because while the MAF detects the exra flow it's VE tables are now thrown off as the engine is more efficient.

At no time does the ECU think, or calculate flow. It takes arbitrarily assigned sensor values and compares them to fixed data tables, follows unvarying algorythms that tell it how to behave under certain circumstances, and tunes for stoich when you are cruising.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kpt4321 &raquo;</TD></TR><TR><TD CLASS="quote">

And if you want to run a MAP sensor on a Honda, you have to buy a $75-100 3-BAR MAP sensor. A brand new GM MAF, like one I'm running in my *coughtDSMcough* is 100 bucks new.</TD></TR></TABLE>

Whatever dealer you went to, don't ever go back there. http://www.gmpartsdirect.com, gets it shipped to you for under $50.

BROOD

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">
I think everyone is getting too caught up in the mechanics of the process and not looking how it fits into the big picture. Porting a head on a MAF car can make it go a touch lean just as it can on a MAP equipped car, because while the MAF detects the exra flow it's VE tables are now thrown off as the engine is more efficient.

At no time does the ECU think, or calculate flow. It takes arbitrarily assigned sensor values and compares them to fixed data tables, follows unvarying algorythms that tell it how to behave under certain circumstances, and tunes for stoich when you are cruising.
</TD></TR></TABLE>

excellent point

kpt4321

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">Porting a head on a MAF car can make it go a touch lean just as it can on a MAP equipped car, because while the MAF detects the exra flow it's VE tables are now thrown off as the engine is more efficient.</TD></TR></TABLE>

What MAF-equipped cars use VE tables?

In all of the cases I am familiar with, there is no need for them.

Speed-density applications need VE tables, because it's one of the pieces necessary to calculate the mass of a gas. However, a MAF car measures the mass directly, and therefore does not need VE tables whatsoever.

The DSM ECU, which I am most familiar with, does not have any VE tables.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">At no time does the ECU think, or calculate flow. It takes arbitrarily assigned sensor values and compares them to fixed data tables, follows unvarying algorythms that tell it how to behave under certain circumstances, and tunes for stoich when you are cruising.</TD></TR></TABLE>


Not necessarily. Some ECU's, at least MAF ones, will take in the MAF sensor reading, and then apply some multiplication (factoring in temp if necessary, etc) then then come out with a desired injector flow or pulsewidth. Now, not all cars will do this, but some do.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Whatever dealer you went to, don't ever go back there. http://www.gmpartsdirect.com, gets it shipped to you for under $50.</TD></TR></TABLE>

HAHAHA!

Ok! If GMPD is really that cheap, then a MAP sensor does have an advantage over a MAF.

My point simply was that it's not a better system because it's 50 bucks cheaper, it's better for other reasons.


Thanks for the discussion!