Long term fuel trim after cpe SRI and CS TIP install

[bigriver]

Originally Posted by E.Tinker

Use something like a zip tie or small worm-drive clamp to secure the vacuum line if the nipple seems a bit small.

As far as the ends of the TIP not being perfectly round, that might make the TIP prone to a leak if the silicone couplers can't make a tight seal when clamped down due to the irregular shape (I don't really know that this si the case, I'm sort of just grasping at straws and giving you ideas on what to check).

Try giving CorkSport a call if you're dissatisfied. Their products may not always be 100% perfect 100% of the time, but they will always do 100% to take care of you.

If the LFTFs are 0% at WOT (or even anywhere within +/-8%) then you're fine...in COBB's tuning notes, they deem anything within +/-8% @ WOT as safe.

Good luck!

Thanks! I'm using a 4mm vacuum line and the OEM clamps so this conneciton is tight.

So I put the stock TIP back and drove around for a little bit. LTFT dropped slightly to +6% at idle. AFR is still at 14.6 at idle. We'll see tomorrow after my commute to work to see if that holds. I'll try some WOT pulls tomorrow. With the corksport TIP on, my LTFT was +5% at WOT with AFR of 11.2.

Thanks for the info from COBB's tuning notes. that is very comforting.

[bigriver]

Originally Posted by ChaucneyM

This may be a stupid question...but will any scan tool be able to read the LTFT or do you need a tool geared more towards performance parameters?
I want to start pulling these numbers now that I have the SRI installed partly to make sure it's installed correctly and partly because I'm curious. And just to keep an eye on things in general to make sure everything is running correctly.

I have a scangaugeII which is a generic scan tool. The "X-gauge" feature allows you to program it to scan LTFT, STFT and Air/Fuel Ratio. I mounted in in the ashtray slot and since I lost the outlet, I ran an iSimple line for my iphone in the center console.

Here is my scangauge: The gap filler looks like foam, but it is black felt so it flushes better against the plastic.

[bigriver]

Installed HKS bov (full recirculate) and now my LTFT has dropped to +3%. Better LTFT now. I noticed the stock bpv has a small hole at the bottom so maybe that allows some unmetered air flow to get through, not sure. But dropping from +6% to +3% would seem to indicate that that is what's happening.

[warlord]

Originally Posted by bigriver

Installed HKS bov (full recirculate) and now my LTFT has dropped to +3%. Better LTFT now. I noticed the stock bpv has a small hole at the bottom so maybe that allows some unmetered air flow to get through, not sure. But dropping from +6% to +3% would seem to indicate that that is what's happening.

Just buying fuel from the gas station you always buy at but on a different day will change your LTFT's. Also abient temps will change them too. A BOV won't change your trims at all. The air has already measured by the maf. A BOV sends the air back to the turbo intercooler pipe so the MAF sensor never sees it again.

[bigriver]

Originally Posted by warlord

Just buying fuel from the gas station you always buy at but on a different day will change your LTFT's. Also abient temps will change them too. A BOV won't change your trims at all. The air has already measured by the maf. A BOV sends the air back to the turbo intercooler pipe so the MAF sensor never sees it again.

Thanks for the info! I'm a noob with these things. Just trying to isolate problems by changing one thing at a time. For the past week I've consistently had LTFT of +6% or +7% at idle right after installing my cpe nano intake. Prior to that it was -3% with the stock intake at idle. The change to +3% (tonight it was about +4%) was right after I switched out the stock bpv and reset the ecu. ambient temp has stayed the same before and after. So I'm thinking the stock bpv leaks a very very small amount of air on a consistent basis directly to the intercooler pipe which bypasses the maf as you stated. so maybe the 02 sensor reads more air and so the ecu compensates with positive fuel trim. the hks bov doesn't appear to leak any air (except for when venting) so there is less unmetered air going into the intake. I don't much about these things, just what I've read and discussed with Sander at cpe. He told me any vacuum leak or loose connection after the maf (and at the maf) are the primary causes for unusually high LTFT. This is just speculation on my part because I don't know how the stock bpv works.

[warlord]

Anywhere between -8/+8 is normal for a cp-e nano intake. Mine was -7.8 at idle till I bought a Cobb AP and calibrated the MAF sensor. The ecu can adjust fueling for trims that are below -25/+25. After that the car throws a cel. So your within the margin. There's a how-to for a home made boost leak checker over on MSF. Try it.

http://www.mazdaspeedforums.org/foru...er-15-a-81055/

[jmaister]

What's everyone's LTFT during acceleration? Just wondering if its + or -.

thx

[bigriver]

Originally Posted by warlord

Anywhere between -8/+8 is normal for a cp-e nano intake. Mine was -7.8 at idle till I bought a Cobb AP and calibrated the MAF sensor. The ecu can adjust fueling for trims that are below -25/+25. After that the car throws a cel. So your within the margin. There's a how-to for a home made boost leak checker over on MSF. Try it.

How-To NATOR A Boost Leak Tester for $15 - Mazdaspeed Forums

Thanks for your help! The Cobb AP is next on my list and I'll get it as soon as they release the 2012 tunes.

[bigriver]

Originally Posted by jmaister

What's everyone's LTFT during acceleration? Just wondering if its + or -.

thx

Mine go as high as +8 on acceleration.

[warlord]

I'm calibrated with my AP. My idle and just off idle is +/-2. My part throttle is 0. WOT is 0. AP is nice to have.
Before calibration I was -7.8 at idle and -3.1 at part throttle with my cp-e Nano. The car will always read 0 at WOT (open loop fueling) because it doesn't use the MAF sensor to measure airflow. The ecu uses rpm's to calculate fuel mixtures. Calibrating with an AP takes all the slop out of the AFR's so you have accurate fueling all the time. Especially when you want to push lean AFR's and higher boost for more power.