i have the ap with the stage 1 map form cobb and it runs so bad with a aem/ms cai it bogs and doesnt have the power it did wile running the oem maps

 

I saw those ones, but there was no FI maps there, and I'm sure he'll get back to me fast so I can wait

 

I'll get back to you tomorrow afternoon.
I didn't think anyone was going to get them before the weekend!
I was at the dyno all day today and I'll be there much of tomorrow, but I'll get everyone their calibrations then.

 

i know, that was SUPERFAST! thanks!!!

 

that shouldn't be the case. The AP lets you tune your PCM. If it worked with the pcm before, it should work after. The only thing I can think of is that maybe the MAF sensor was scaled and now the readings are off.

Even with my crappy intake, and 2 5/8" maf tube (see video above), my car idles and drives fine. It only has issues when I accelerate because of it being unable to track the air properly.

 

Your killing me bro!

Can't you just plug it in and see if it will comunicate with your PCM?

 

mysql - don't you have the Greddy MAF tube still? Why not put that on your car and see how it works?

 

Ditto

 

I have it, and I was going to say that I doubt it would help since it reduces immediately after the intake filter, but I always forget that the greddy maf housing works in reverse - it has a small 3"(?) opening, then opens up to 3.5" around the MAF. So while it doesn't reduce behind the MAF, I doubt the airflow would be smooth ...

I can try it out, but Jeff would once again have to give me new maps since the stuff he sent me was scaled for 3" and then later 2 5/8" maf housings.

The scaling techniques he uses seem to be spot on. Injectors on my car are larger but the car idles and cruses at low speeds at the exact afr's you'd expect.

 

Can you take a picture of the Greddy MAF tube? I would like to see how it makes the transition from 3 to 3.5 and how long it is. I am still working on my MAF tube and any information is valuable. Thanks!

 

Sure.

The large opening has an ID of exactly 3.5"

The smaller side isn't perfectly round, but it's just under 3" wide.

It's almost 5" long.

 

Yeah, I that seems like it would mess up the MAF readings quite a bit. The transition is too close to the MAF and the 3.5" id is larger than the 3 3/8" ID of the OEM tube. It's probably a good idea to wait on the replacement that Jeff is making for you.

 

my new intake has a long alumn tube with supposedly a 3.5" ID. If that's true, then whenever Jeff has time to make a 3.5" maf housing map for me, I can test out the greddy intake just to see if it works even a little bit. The intake I have now does not work even slightly - it will not read properly and I cannot go into boost because the car goes spastic rich.

 

Yeah, I saw that from your video. Doesn't Jeff have a 3 3/8" ID MAF tube? I thought he was using 3.5" OD polished tubing with a 1/16" wall thickness. If so, that matches the ID of the OEM MAF tube pretty closely.

I will post a picture of my MAF tube when I get it. Should be any day now. It was shipped early last week.

 

I'm not using Jeff's maf tubing - I bought mine from TeamRX8... but now that I think about it, he was running with the AP on a custom map, so chances are he would have wanted to replicate the stock intake's ID closely.

 

3.5" OD with a 1/16" wall thickness is pretty common and easy to get. My MAF tube is supposed to be made from this and its supposed to be 8" long. I will need to cut it down a little but I'm hoping to keep it at least 6". 3"-3.5" before and after the MAF. Hopefully, that gives a good reading because thats about the best I can do in the space I have.

 

A mole is nothing more than a number, so by saying moles of air, it's saying you have x number of air particles. So I'm guessing you're just talking about air, being mostly molecules of dinitrogen and dioxygen, are just particles flowing by, colliding with this detector and carrying the heat energy away, so staticlag's description is quite accurate except he left out heat exchange. I don't think the sensor actually measures moles of air. I'm pretty sure the detector doesn't count the number of collisions of these particles, but what do I know.

 

all this talk of different maf tubes and all i want is a tune for a aem/ms cai on 93 octane and im willing to pay

 

No, it is not 'counting collisions'.

The 'hot wire' style of mass air flow measurement simply heats a filament (of platinum or some other wire metal) to a prescribed temperature above ambient.

A certain voltage is required to maintain this temperature, as referenced by a thermistor circuit.

Resistance of this wire increases as its temperature increases.

As airflow, (i.e. molecules of the various gases that comprise 'air' of which the thermal conductivity properties [affected by temp, density and humidity, so allows for good mass calculation] are known and assumed) moves over this heated wire, the wire is cooled.... so now, the resistance of the wire is.....you guessed it, lowered.....and therefore, the circuit has to decrease its electrical drive to the wire to maintain that 'prescribed' temperature.

This constant analog swinging of electrical drive to this wire (again, based on the resistance of the wire to maintain a set temperature) is what provides your root mass air flow values, which are then converted to something that your ECU can use in it's fuel calculations, many times a second.

The volume and dimensions of the tube are known, so yes, the whole process in fact does accurately calculate true mass air flow (i.e. Standard Liters Per Minute, moles/hour, kg/s whatever you like).

This is why you want as close to the nicest, smoothest, laminar air flow in the region of your hotwire sensor....for nice and smooth analog sensor behavior.

-C

 

Thanks, that certainly makes more sense. I confused this sensor with a simple thermometer.

 

I will do that within the next few hours, and try loading Cobb's tune if I don't get an email soon, and report back.

 

Awesome!

I will be waiting!

 

I'm still at the dyno.
I'll try to get some-mails out soon.

 

Dynojet I hope!

 

No. Dynapack.
More precise, better software and it does load cell hold.
I"m not looking for impressive numbers, just useful ones.
Besides, a properly calibrated Dynojet and Dynapack will produce the same numbers.