New MAF Idea

[MNGSX]

Originally posted by QuickerDSM
FWIW, I personally know of two guys that are pushing OVER 650rwhp using the GM MAF's with absolutely NO driveability issues in the newer F-body cars.

I trully think the benefits of that other MAF system is nill IMHO.

Mike

The key point a little off my friend. A GM MAF in a GM F-body car ought to work well there as it is what it is designed for.

They have also been used in DSM's with great success. The issue at hand is if this sensor is $200 better as it will be designed and calibrated specifically for the application.

 

[MNGSX]

Originally posted by autronicDSM
Here's a link for you http://www.teamnabr.com/ubbpub/ultimatebb.php?ubb=get_topic;f=10;t=000162
Maybe tomorrow you will decide to get FAST or Motec.

I have heard of some of the glitches AEM EMS has had. I was going on information that they have been ironed out.

I know one thing.

I want a standalone engine management system. When I see a system that can do what I need it to do at a price which is competative with it's nearest competitor that will likely be the one I get. So maybe your right I could end up buying fast. I'll buy what ever works and wont be a pain in the ass later.


I'll need something that can be switched between two fuel and ignition maps easily. One for the E85 and E98. Most of the time I'll run the 85% as the mpg is alot closer to gas than on 98%. I also don't have to go too far out of my way to find the E85.

My brother has a 3.0 ranger that is FFV. He has run both gas and E85. He gets nearly the same MPG on either fuel.

Yes speed density still is an option and has been used by many. As you can probably tell I'm the type who likes to split from the group and blaze his own path from time to time.

From the car craft link

They are self-compensating for most reasonable upgrades, as well as extremely accurate under low-speed, part-throttle operation.

On a street driven car the extremely accurate low-speed part-throttle part is the big reason I justify spending the extra $ to go with a MAF specifically calibrated or the application.

There is more to it than just ET's but drivability when it is'nt just run wide open on a track 100% of the time you actually drive the car.

I don't know exactly what ET's I'll run. I am more looking to build something as streetable as it is fast. It may cost more to do something that combines drivability with performance. I know I'll be making use of the drivability far more often than the peak performance.

 

[MNGSX]

Originally posted by autronicDSM
MNGSX, you make absolutely no sense. All you do is brag about what you will buy and you change your mind 10 times a day.

Here you go a link for you.

http://www.dsmtuners.com/forums/showthread.php?s=&threadid=66114

Looks bigger than the 2g to me

I'm not going to buy something from someone with out looking to see if someone else has ran that part or bought something from that vendor. If new information comes to my attention involving a part I will change my mind. Like ECU glitches trashing motors or anything like that.

Originally posted by autronicDSM
You ask for advice and then start arguing. Why would you run MAF on a standalone that can use MAP? Because it says it will support 1500HP?

Because it is more accurate and better for street duty. Also I'm not going big enough with the sensor to support 1500hp (117mm) only match the TB diameter I put on a sheet metal intake. So around 75-80mm.

You can have a 75mm good to 600hp a 77mm to 700hp and an 80mm to 800hp.

If I go 80mm its because of a 80mm TB. Why bottleneck or go bigger just to reduce back down at the TB?

I posted up to 1500 to illustrate the wide range of what can be done MAF sensor wise these days.

Originally posted by autronicDSM
MNGSX, I don't have a timeslip yet but I don't day dream about having 1000whp car running on ethanol and write about it in the forums..

1. Where did you get 1000whp from?
2. Ethanol is easy to work with so it's not like telling people you can walk on water.
3. I am bouncing ideas about stuff in the forums off of people looking for usefull stuff. So far I liked the link about the EMS glitches. So believe it or not thanks for that link.

Originally posted by autronicDSM
I bet whatever you're trying to build won't even run like it supposed to..

You know that was pretty low. I could be every bit as pessimistic and bitter and say that when you get an ET slip it won't be as fast as you think it is. I wont... In fact I hope it hauls ass.

 

[QuickerDSM]

Originally posted by MNGSX


The key point a little off my friend. A GM MAF in a GM F-body car ought to work well there as it is what it is designed for.

They have also been used in DSM's with great success. The issue at hand is if this sensor is $200 better as it will be designed and calibrated specifically for the application.

Not off point at all. If you're going through the work to convert to a stand alone, the GM MAF will work perfectly well with a FAST system as it does any other stand alone fuel/timing management. It's a great MAF and will flow more than you will ever use on a 4G63...... The point I was trying to make was that it will deliver the goods (CFM requirments) and yet still be accurate enough to produce good drivability. You can talk all day long till your blue in the face a about how much CFM it will flow, but if it can't measure low speed CFM, then it's a pile scrap IMO....

At any rate, good luck with whatever you decide. I'm sure whatever you choose it will be viewed under a microscope.

Mike

 

[MNGSX]

Originally posted by QuickerDSM


Not off point at all. If you're going through the work to convert to a stand alone, the GM MAF will work perfectly well with a FAST system as it does any other stand alone fuel/timing management. It's a great MAF and will flow more than you will ever use on a 4G63......

My point is not that I'll overrun the max flow but that the voltage output for a given airflow is not maximized for the airflow of a 4g63 but that of a v8. I never once thought I'd overrun a GM MAS. I was actually more concerned with best utilizing the 0-5v range to represent what the engine is taking in for air. Almost worrying about under run if you will.

I wish a could make a footnote for this as it is a big block between points.

I found out that you cant compare v-out from this to a GM as the GM sensor is hot wire but converts output to a frequency to send to the ECU. Which is why it is a good choice for the translator. The circutry need only convert the gm frequency output to the same frequency format as the DSM stock sensor.

The GM sensor is calibrated in suck thru mode for a V8 which draws more air thru it at idle. The airflow curve for the two engines is different as is the thermal dynamic going on in that sensor when mounted in blow thru as opposed to the original configuration.

What pro-m will do is use pipes to connect the sensor to the calibration equipment exactly like it is in the car.

So if I have the sensor on the TB fed by a 7 degree included angle cone that is 80mm at one end and 2.5 at the other with a mandrel 90 at the end of it and then the rest of the plumbing to the compressor outlert.

They will use what they think is neccessary to match how the air will flow thru it on the car. Probably a match of the plumbing from what connects to the sensor thru the long pipe after the first elbow. It will not be necessary to replicate any of the other bends or straight sections leading all the way to the turbo. So the taper, the 90 and the first straight away to the bend.

GM does have a calibration standard for these meters but it is with done with the piping for that model car attached to recreate an accurate representation of the airflow as it will be when mounted on that car.

The standards are high and very specific, specific for that application.

Originally posted by QuickerDSM
The point I was trying to make was that it will deliver the goods (CFM requirments) and yet still be accurate enough to produce good drivability. You can talk all day long till your blue in the face a about how much CFM it will flow, but if it can't measure low speed CFM, then it's a pile scrap IMO....

At any rate, good luck with whatever you decide. I'm sure whatever you choose it will be viewed under a microscope.

Mike

The point I wanted to make is that I knew it could deliver the high end CFM requirements but can it read to a known accuracy on the low end. They can produce a custom calibrated GM based meter as well. But the ford meters are a bit streamlined as they give a direct voltage output.

Since the output signals are not compatable between GM and ford lets stick with a stock calibrated sensor, a mid sized one and a one so oversized it's stupid.

These are calibrating for injectors on a ford V8 but the max and min lb/hr of air are listed as est HP levels. That is what this app is concerned about. How to represent the airflow across the powerband as an accurate 0-5v signal. So just look at the voltage. lb/min and hp level columns.

Stock ford calibration

http://www.pro-flow.com/flow sheets/19flow.htm

Over run city

Mid sized.

http://www.pro-flow.com/flow sheets/50flow.htm

Not to bad with room to prevent ever running out of sensor capabilites as wickedly lean is very bad for engine parts.

One step up from that

http://www.pro-flow.com/flow sheets/62flow.htm

A bit larger than what is necessary but not outrageously when you consider leaving that headroom to prevent overun.

Overkill as f7cking hell

http://www.pro-flow.com/flow sheets/160flow.htm

The engine would only ever use three fiths of the voltage scale plus some change so the accuracy would be like half of the 50flow sheet. Not good.

These sheets are for a different application but the same type of data.
As the max hp of a meter diameter is different than the max hp of it's calibration.

What I they will probably end up doing is basing the maximum lb/min of airflow just far enough above the turbo compressor map to leave a overun protection margin using piping that represents my car. Pretty cool huh?

It is also all new parts and I get a calibration sheet specific to that meter used with an accurate representation of my plumbing. Also a lifetime warranty and tech support. I e-mailing back and forth with the guy I talked to on the phone. These guys are smart. So I get the waranty and custom matching voltage response across the powerband using my plumbing IMHO is worth the cost over a ebay gm sensor. Most factory mass produced factory sensors are +/- 6% from their design standards. This is +/- 1% to the calibration sheet for my specific setup. I actually think it is a alot for the dollar!

A new GM LS1 sensor with a warranty is what in the $200 to $250 range? A LT1 the same way is what $150-$200.

I'm measuring thrice, asking about it, measuring thrice again then cutting. I don't like kicking myself later.

 

[autronicDSM]

Originally posted by MNGSX

You know that was pretty low.

I guess I could've been nicer. Sorry.

 

[MNGSX]

When you look at the flow sheets keep in mind that they may have flowed them to 5.1 volts that the ECU's sensor input terminal only reads to 4.99 volts or so. The max voltage it can read (like 4.99) and the minimum it can discern from zero differs slightly by ECU design.


Were realy concerned with matching an airflow with a voltage level but alot of people here just talk in terms of HP.

The "19flow"

0.4V is enough air for 3.6hp
4.9V is enough for 292hp at the overrun point.

But again I'm matching airflow measurements to the comp map and calibrated around that so it would be closest to the mabe inbetween the "50 flow" and "62 flow".


"50flow"

0.4v 1.09lb/min air ~9.4hp
4.9V 89.42lb/min air ~770hp around overrun

It's all about calibrating it far enough above what the turbo can pump for air max so it has a safety margin.

Different engines can take in the same amount of air and have different power outputs due to mechanical efficiency and fuel type differences. So matching lb/hr is the right thing to do.

 

[MNGSX]

Originally posted by autronicDSM


I guess I could've been nicer. Sorry.

Appology accepted. Any zingers I made you want one for let me know.

Lets try to keep things technical not personal

 

[QuickerDSM]

The GM MAF's have proven to be very accurate/reliable with blow-through applications. Quite a few F-body guys have converted their supercharged cars to blow-through MAF's. They actually work better on blown cars in that configuation.

A moderately modified DSM will outflow the stock CFM of an LT1, so I'm not sure what your point was about CFM at low levels??? A stock LT1 only produces around 300hp.

I don't know where the heck you are getting those prices from on brand new GM MAF's, but you should do some shopping. If you did as much homework on the GM MAF as you have on that other, then you would know they sell for around 150.00 brand new, even from Ramchargers (re-seller)......

At any rate it sounds like you've made up your mind, so again, good luck to you. Let us know how it turns out.

Mike

 

[MNGSX]

A moderately modified DSM will outflow the stock CFM of an LT1, so I'm not sure what your point was about CFM at low levels??? A stock LT1 only produces around 300hp.

Not at idle. A big V8 with double the CI will draw alot more at idle even if it has no nuts. I don't know what CFM the output corresponds to at the low end.

so $150 vs $300

$150 still gets alot for the $. When I see a voltage output I know what airflow that means +/- one percent. The other way I know it's +/- 6% and can only guess the airflow.

The GM will be consistant and can be setup for it's levels in the ECU setup but will take more guess work. I hate guess work, I like to dig out micrometers and stuff. So having that 37 point calibration sheet to set the ECU up with is a boon.