In the discussions of Bernoulli's Principle, I mistakenly claimed that air behaves like a fluid. This is not entirely true. It has some of the properties of a fluid, but WILL compress (a fluid won't). Also, fluid wants to move in circular motions (see "wave action"). Air does too (see "tornadoes") in response to pressur differences, but fluid doesn't compress and air does. Air on the long side of a curved tube will accelerate faster than the air on the short side, but because of the difference in pressure from one side to the other, it will tend to continue to swirl afterwards (see "inertia" i.e. an object in motion... etc).

As you increase the size of a tube, with volume of flow remaining constant, velocity decreases. As velocity decreases, the character of the flow (swirls, eddies, pressure) all changes. As Kane points out, he has to DOUBLE the pressure applied to 1/4" hose to deliver the SAME amount of air to a diver as he would with 3/8ths inch hose. 1/4" to 3/8ths" is a very small difference, but over a 300 ft distance is quite remarkable.

All of this thinking makes my head hurt...

Bernoulli's Principle works because each molecule of fluid pulls the next right along with it, each seeking the path of least resistance, i.e. low pressure (see "venturi effect". Weber carbs owes their entire existence to this principle.

What does it all mean? I haven't the foggest clue!

 

You are hired! I need a PR guy.

I am swamped. However, I consider every person that has purchased an AccessPORT from me to be to be part of a sort of personal tuning "Wiki".
Each change or update ultimately helps everyone, including myself.

Its kind of like the "open source" tuning that Lola was trying to do only without the "me giving him everything so that I only have the work and he gets the money" part.

I only need to sell another 50 of these things and I get the pink Lincoln Continental!

 

Is there a Cobb AP out for that too?

 

^^ if you sell 100, does it comes it come with a Pettit SC?

 

A quick note on STFT and LTFT:

I get this comment/question a lot, so let me address it here in brief.

Short Term Fuel Trim is an "instantaneous" value. It is all over the place and can be a value from +24 to - 24. The way I use it in helping you decide which flash to start with is NOT what it was intended for.
It is just an effective shortcut.
So, your idle STFT may be +/-2, but the value may go all over the map when you are driving. Some will see it jump up 10 - 12 when they hit the pedal or see it go to -12 when cruising at low speeds.

Ultimately, what matters is the Long Term Fuel Trim.

When I ask for the STFT to determine the flash "family", it is only the initial, instantaneous value - right after the first start up - at idle I am interested in. After driving the car a bit, the LTFT will start to "absorb" some of the STFT offset, making the STFT number smaller. You should watch for that and be aware that the sum of the two numbers will now affect your choice if you have waited too long to make your decision between "X_1b" and "X_2b".

A lot of factors go into the STFT and it is constantly changing. The LTFT is much more stable, but there are only a few values for it at different fixed load settings and it takes a while for it to establish.
If, after driving around for a bit, you find that your LTFT are big numbers in certain places, than you need to make adjustments and the best way to do that is to start over.

I sure hope not. Where would I put it? My storage area is already full and I don't think it will make a very good flower pot.

[[I am not anti-supercharger. It just sounds that way because it is such an easy target. Sorry to all the Pettit owners for the cheap joke. Void where prohibited.]]

 

btw Jeff, 2 days ago I flashed down to the stock 3 map (no a or b modification).

LTFT and STFT were 0 almost all the time during idle.

I'm still on the lean side and haven't been able to data log information for you, but I'm ok waiting till whenever you have time. The car runs flawlessly otherwise.


BTW, I too think the AP should be sold as you originally stated. Buying the AP from you gives the buyer the base maps for FI and NA.

Any custom tuning should cost extra. Also you haven't told me what I owe you for the intake. If this is how you're trying to run a business (giving crap away for free), you're doing a poor job my friend! lol

 

Did you notice my LTFT was zero? LOL - you nailed it spot on perfect.

 

I think you are interchanging fluid with liquid. Air is a fluid which happens to be compressible because it's a gas, not a liquid which is not compressible but also a fluid. A fluid is a substance that has a tendency to flow and will take the shape of it's container. Hope that helps.

 

Wait until everyone gets my bill!

 

there needs to be a new thread made specifically for "MAF Discussion" it seems...haha.

 

There is:

https://www.rx8club.com/series-i-engine-tuning-forum-63/fi-maf-sensor-130428/

 

Man, I should have kept up on my reading in this thread.. One day it was just 10 or so pages, now its bout to push 60! I work two jobs.. I CANT KEEP UP!. haha

 

How do you think I feel? I took three days off to do my taxes and other non-car-related stuff and look what I come back to!

 

stop giving Jeff ideas!!!

 

Hey Jeff, I just got you're email but you sent me maps for 2004 model.

I have a 2005.

 

Jeff is uber busy I have been trying to get a hold of him for a week now and all I wanted to do was place an order

 

why didn't you just place the order through his website like most of us?

 

Clicky!

 

speaking of orders: Jeff, you should be getting something in the mail today. Thanks.

I haven't checked my email in a few days; did you send anything to me? If not, it's cool... I won't mess with the AP till this weekend and I know you've been busy

 

Thanks!

Send an e-mail to ap@mazdamaniac with your year/model/mods (mention that you are in Cali).
That is the only way I can keep track of everything.
I'm closing in on the triple digits over here...

 

:o I know how to order off of the Website... but I had asked him some important questions via PM and until those questions are answered I don't want to get the AP then later I found out it won't work for my application.

 

Please send your needs to ap@mazdamaniac. I can't keep track of the PMs.

 

 

I did that on Sunday night

I'll send you another one, I'm sure your poor inbox has seen better days. No huge rush. Thanks.

 

Kind of off topic, but I did not plot my intake temps on the graphs, but they went from 63 F standing still, down to 57 F once I came up to speed in 4th gear. Must be due to the REVi bug sucker duct mounted in the grill.