You can use the Cobb map just fine as far as I can tell. I started out with it also while I was waiting for MM to e-mail me my maps. It didn't change the idle or the MOP setting like MM's does, but it worked just fine.

 

Load up the Cobb stage 1. Use the AP to monitor your LTFT. It should be as close to 0 as possible. Don't worry about the STFT as that number will be constantly changing. If you do not have an A/F gauge, you can use the AP screen titled "eqiv ratio" to look at the AFRs. I would do a couple of WOT runs and make sure you're somewhere in the 12-13 range under WOT. Don't forget that the AP displays data about 1-2 seconds behind real time.

 

If you want to take the safe approach, load the Cobb stock map and take your car for a spin and watch the afr in the "Live" mode... if your in the 11's or low 12's at wide open throttle above 6k rpms, you might be fine with Cobb's Stage 1.

If not, I'd wait until you hear from Jeff.

 

I agree. Airfoils are completely different in terms of actual flows, but the principals are basically the same. Faster flowing air has less pressure at the same volume. That's why I brought it up, just to try to get people to relate the two together.

 

sure. Why not? Try it out. Watch the afrs and see if it works without going too lean.

 

Just wanted to let everyone know my latest findings...

When I first bought my car, I was able to get around 18 mpg during breakin process. After that I got around 16 mpg. When I went turbo, I got around 15 mpg. Basically each quarter tank of gas = 50 miles. So at 180-200 miles, I had to refill.

My last tank of gas was calculated to 16.3 mpg, which was pretty good, but didn't really count because I had the crappy maf housing and I couldn't accelerate for half of that tank of gas!

Today I was approaching 200 miles and decided to fill up, even though I had a quarter tank of gas left. I was worried maybe my fuel gauge was off and didn't want to be stranded without gas.. Sure enough, I filled up and I had 17.4 mpg! I've never had fuel mileage this good with the turbo installed. I am driving the same - lots of hard acceleration. Rarely ever driving for mileage.

The car previously had been premixing with 4 oz of FP+/FP60.

The changes since the fuel mileage increase are the accessport instead of the interceptor, the CAI, and a new premix blend. The premix now has 1 oz fp+, 1 oz mmo, and 4 oz idemitsu.

Given that I had premixed in the past with rp, and pettit's stuff without any change in mileage, I think the biggest factor to mileage is the accessport because the car is seeking better afr's as I cruise (where the car is most of the time).

 

Yeah. Seeking better AFRs was never something we could say to describe the INT-X.

 

Be careful with the stock Cobb Map.

I posted that it was way too lean on top end. 15.5 to 16.5 to 16.9

You have similar mods.

Stay away from 8k plus. You will see what I mean.

 

Air does not HAVE pressure, it EXERTS it. The air exerts less pressure(force) on a surface it flows parallel to than one it flows perpendicular to. Quit worrying about pressure. In this situation it is, for the most part, a non-entity.

the MAF is a MASS Air Flow sensor. This entire discussion has revolved around volume flow rate or density. But you need both to get mass. A hot wire MAF samples a portion of the volume flow, but the density is assumed to be constant.

Sorry, guys volume != density and density != volume.
density = mass/volume, or volume = mass/density.

We're talking about a SAMPLING of MASS.

crh is right, the biggest issue is misunderstanding of terms, by mulitple parties, due to both attempts at simplifying the problem and likely issues with vernacular being used when scientific definitions are required.

BTW, in an FI application, static pressures will ALWAYS be lower than ambient before the compressor. That's how it's drawing the air in.

 

OK, 10 drive cycles now on 1.3a for NA and my LTFT is 1. Pretty sweet if you ask me. Of course all things will change once I change my exhaust again...

This is with the REVi intake with bug sucker.

 

just to get a dig in against Dan- my dad's a very experienced technical diver using tri-mix etc for extended wreck dives in deep water and also cave dives. he hates re-breathers

 

Well at this point I just want to know why the larger pipe diameter would cause the MAF to show to much airflow(not just more airflow, but to much), unless of course that's incorrect. That's what got this whole thing started. Someone tell me that, that's what I've been trying to figure out.

Back OT I'm still at +1 LTFT and -1 STFT. I'm still waiting for my Mazsport midpipe and ignition. I wonder what those will do to my trims? My guess is a percent or two leaner.


Cel

 

Not sure, I'll try that and see what happens prior to going bonkers...

You and me both...

 

Yep, I know. I keep watchin your posts and responses in the Midpipe thread. I'm scared that they will finally get one or the other ready and send it to me forgetting about the other piece that I ordered.

It really sucks. Paying $1,100.00+ almost six weeks ago when they posted that the lead time was three weeks. They really shouldn't charge 100% for something untill it ships. If it's not ready this week, being they've said next week or so for about 4 of the almost six weeks, I'm canceling and waiting for BHR's ignition and getting my own midpipe made.

Cel

 

patience is a true virtue.

 

I don't mind waiting, I hate paying and then having to wait twice the time quoted. If they had said 6 weeks from the get go and only asked for 50% upfront, no problem. I waited 14 weeks and paid $1,200 up front for my wheels but that was the deal. This has been entirely different.

 

Thank You all for your advice. Here comes a stupid question what does LTFT and STFT stand for and what do they signify?

 

ft = fuel trim

lt = long term
st = short term

so short term fuel trim, long term fuel trim

it defines adjustments made to the fuel system to properly drive the car around. basically the car monitors how the car performs and adjusts it to meet the desired numbers it has in mind.

 

An explanation can be found here.
http://www.c5forum.com/diy/ltft.php

 

w0000000t!!!!!! UPS just showed up.

 

hey!! i have a sinus condition!!!

 

clutch pedal.


that was an easy game.

 

Thanks

 

Same here!!! Anyone?

 

HAHA, c'mon Ray...that was funny and you know it.