gt500 MAF/blow thru setup

[1lowtoy]

No i dont think the mafia can do anything for the hpx as it has the larger voltage range already, the hpx would still be limited by maf pipe size just as the stock maf with a mafia would be.

The stock 05-up sensors do not output all the way to 12v like the older sensors did. This is why the factory slot meters can not be used with a Mafia as far (it is not that they can not be used). I think 05stroker will find that once he turns his car up the meter will peg. He is olny on setting 3, he then trys to turn is to setting 4 only to find out that the voltage will seem to peg earlier yielding no more headroom. The HPX sensors are made to output all the way to 12 volts, BTW. An HPX in the right size tube is the right choice, bar none. If the tube is a bit to small, then the Mafia can be used to increase the headroom a bit. Any good tuner should be able to tell you this.

 

[JeremyH]

So when/if the mafia does peg the stock maf you just need a bigger maf pipe just like the hpx states to make more power.

It looks like since you already have a mafia u spent money on, see where it pegs the stock maf at, for some real word testing since everyone is convinced u r gonna peg it lol, and if it cant get you to the hp numbers u want, get a bigger maf pipe, or get a hpx maf and bigger maf tube.

But until then why waste the money. My 2 cents.

 

[1lowtoy]

This isn't something that we are "guessing" about. The "real world testing" has already been done. You don't want to have this problem on a 800 horsepower car. I'm just trying to help here and Lito has backed up the facts.

 

[JeremyH]

This isn't something that we are "guessing" about. The "real world testing" has already been done. You don't want to have this problem on a 800 horsepower car. I'm just trying to help here and Lito has backed up the facts.

I didnt say you guys were guessing, and when i say real world testing im am specificly talkin about his setup. He may have to step up to a 90mm maf after 800 if he goes that far. Just like u would have to increase maf size with a hpx. He may not. So i think it is very sound advice to save money and use what he has because it will work, If he maxes it out, then upgrade.

 

[JeremyH]

And looks like the mafia actually reducing voltage will allow more power than the hpx would normaly make, so you wouldnt have to get a bigger maf pipe if you used a mafia on the hpx, although i would reccomend a 90mm at least for those numbers.

 

[JeremyH]

Interesting stuff, the mafia actually reduces maf output voltage to prevent it from pegging and in turn reduces the pcm fuel and load calculations . So everytime the sotck maf reaches 5v, changing the mafia setting reduces voltage signal again and so on allowing you to make more and more power on the stock(5V) sensor.

So effectively the hpx maf(12v max) allows for over twice the adjustability with the mafia over the stock 5v maf.

If the 5v maf with mafia pegs around 800-900hp

The 12v hpx (2.4 times max voltage than stock) would be able to make 2.4 (12V / 5V = 2.4) times the power with the mafia for around 1900-2000 hp, (800 X 2.4 = 1920), makes sense to me now.

 

[JeremyH]

Stroker, keep using that stocker and mafia, im very interested to see what u can make!

 

[05stroker]

Stroker, keep using that stocker and mafia, im very interested to see what u can make!

I will , but I will make sure there is a HPX there ready to spaw as well . I should be arount 25 psi .

 

[JeremyH]

Cool, sounds like a good plan, keep us posted.

 

[lito]

Interesting stuff, the mafia actually reduces maf output voltage to prevent it from pegging and in turn reduces the pcm fuel and load calculations . So everytime the sotck maf reaches 5v, changing the mafia setting reduces voltage signal again and so on allowing you to make more and more power on the stock(5V) sensor.

So effectively the hpx maf(12v max) allows for over twice the adjustability with the mafia over the stock 5v maf.

If the 5v maf with mafia pegs around 800-900hp

The 12v hpx (2.4 times max voltage than stock) would be able to make 2.4 (12V / 5V = 2.4) times the power with the mafia for around 1900-2000 hp, (800 X 2.4 = 1920), makes sense to me now.

Read all the posts again so you can think again on your "recommendations".

I'll give you the facts so you can redo your math.

There are two limiting factors:

1) The PCM won't allow a MAF input signal greater than 5V, that is when the MAFia comes to the rescue, it translates the actual bigger voltage output of a MAF signal into a 0-5V range the PCM will then read complete.

2) The stock sensor won't work well over 5.5V, some will go to 6V, so you should not use them with MAFia settings bigger than "2", "3" on some.

Given the previous facts, you just cannot keep switching the MAFia, because it just won't work.

Other facts:

1) The HPX has close to double the range of the stock sensor, it is not that it will only allow more voltage output, so you will achieve the same range with half of the pipe section.

2) Bigger pipes generate more turbulence and the pipe you will need with a MAFia and a stock sensor to hold 800+rwhp (without doing some calc I guess it would be 4" at least -maybe more-with MAFia@ 3) is just almost impossible to have a worth signal inside on a blow thru config.

3) You can make 800+ on a 3.5 HPX without any MAFia (BTDT), the problem is how to accomodate a long and straight enough section of 3.5 pipe under the hood.

So, realistically, it is too hard to make over 800 on a blow thru config with the stock sensor.

One other thing, there is no need to adjust injector slopes or displacement (per MAFia's manual), just need to see the MAF as a new thing with a completely new transfer function and everything will still makes sense automatically, load will be right.

 

[JeremyH]

Read all the posts again so you can think again on your "recommendations".

I'll give you the facts so you can redo your math.

There are two limiting factors:

1) The PCM won't allow a MAF input signal greater than 5V, that is when the MAFia comes to the rescue, it translates the actual bigger voltage output of a MAF signal into a 0-5V range the PCM will then read complete.

2) The stock sensor won't work well over 5.5V, some will go to 6V, so you should not use them with MAFia settings bigger than "2", "3" on some.

Given the previous facts, you just cannot keep switching the MAFia, because it just won't work.

Other facts:

1) The HPX has close to double the range of the stock sensor, it is not that it will only allow more voltage output, so you will achieve the same range with half of the pipe section.

2) Bigger pipes generate more turbulence and the pipe you will need with a MAFia and a stock sensor to hold 800+rwhp (without doing some calc I guess it would be 4" at least -maybe more-with MAFia@ 3) is just almost impossible to have a worth signal inside on a blow thru config.

3) You can make 800+ on a 3.5 HPX without any MAFia (BTDT), the problem is how to accomodate a long and straight enough section of 3.5 pipe under the hood.

So, realistically, it is too hard to make over 800 on a blow thru config with the stock sensor.

One other thing, there is no need to adjust injector slopes or displacement (per MAFia's manual), just need to see the MAF as a new thing with a completely new transfer function and everything will still makes sense automatically, load will be right.

I agree with all this completely, good info, looks like hes gonna see how far he can get on the stocker with the mafia and have the hpx ready to switch to if need be. Only math i did was what a mafia can do for an hpx which came out to 2000hp which u also mentioned.

Im gonna stick with the mafia as this is my daily driver and wont see over 600hp.

 

[lito]

One more thing, there is a new (some months old actually) sensor, is the ProM unit.

http://www.promracing.com/mass-air-meters-c-2/proslot-style-mass-air-sensor-p-28

I already installed one but it was in a config I've never tuned before (a F1R with the huge intercooler) and that thing had a range so huge it was kind of stupid. It made over 700+rwhp and it just barely got over the 3V range.

Now, the intercooler is way bigger than the D1/F1A uses so I couldn't make a direct comparison of ranges, I think I may get to tune other one soon on a known config so may report then how they compare.

Maybe they are the same unit (ProM & HPX) after all.

 

[1lowtoy]

Well written Lito.

 

[JeremyH]

So if the hpx can output up to 12v and the pcm will only read up to 5v. How does the hpx correct this?

 

[1lowtoy]

So if the hpx can output up to 12v and the pcm will only read up to 5v. How does the hpx correct this?

It doesn't. The transfer function is different than the stock meter from 0-5 volts. It will continue to output all the way until 12 volts unlike the stock meter.

 

[JeremyH]

Ok right so it will ouput up to 12v depending on airflow, so then what happens to the signal to get it back under 5 for the pcm?
Or does the hpx software allow the pcm to see over 5v?

 

[1lowtoy]

Ok right so it will ouput up to 12v depending on airflow, so then what happens to the signal to get it back under 5 for the pcm?
Or does the hpx software allow the pcm to see over 5v?

It is hard for me to put into typed words. The PCM with never see anything over 5 volts. I'll see if I can post something up for you to best understand how it works in the morning. Its late and it will take to long to type it all out tonight.

 

[JeremyH]

Okay cool, iim really wanting to understand the different ways these setups work, thanks.

 

[lito]

A stock MAF sensor on a 3.5 pipe (about 83mm of ID) will need about 50Kg/hr of air to reach 5V, an HPX sensor on the same config will need to over 120Kg/hr of air to reach that same voltage. THIS IS THE MAIN ADVANTAGE OF THE HPX, THE RANGE.

Now, the stock unit, if you keep adding airflow it will stop metering around 5.5-6V when the HPX will continue to measure (something I have not tested myself, I always try to plan the piping mods so we won't peg the sensor or need an extender)

Hope this helps you understand the differences between the meters.

 

[Dex]

idk if the stock maf and a mafia will be enough for 700hp

i hit over 700rwhp and 800tq. I ran out of turbo