This is my first datalog with my Cobb AP...please help!

[arkat3kt]

I hope that some of the experts on here may be able to interpret my datalogs and give me some indications as to how my car is running. I'm a little concerned because I have been getting quite a bit of hesitation/bucking in 2nd-4th gears when I am WOT. My mods are as follows:

Mazdaspeed CAI w/air straightener
PG turbo inlet pipe
PTP restrictor pill
TurboXS catless downpipe
TurboXS midpipe w/Vibrant 3" hi-flow resonator welded in
Denso ITV22 one-step colder spark plugs
Stage 2 + SF 93 octane map

After I flashed the ECU with the current map, I drove it lightly for 150 miles to let the ECU learn the new parameters. I have attached 4 datalogs, a 2nd gear WOT run, a 2nd-3rd gear WOT run, a 3rd gear WOT run, and a 4th ger WOT run.

Please take a look at these. I want to make sure I am not running dangerous in any parameter and if so, what I can do to make things right. Also, if I need to log different parameters or under different driving conditions, let me know and I can get those ASAP. Thanks!

 

[arkat3kt]

Nobody?? Am I doing something wrong? I'd like to learn more about tuning and I've searched and read a ton of threads, but I just need a little help...

 

[b e z]

Nope dont think your doing anything wrong and if i knew man id chime in, im waiting on responses as well, guys must be busy around here.

 

[the_caruch]

hard to tell from your data logs since it's only logging 2 times a second.

take out maf airflow, stft, speed. maybe that'll let the AP speed up the logging.

looks like you need to calibrate your maf since your LTFT's are off at WOT

how does your fuel psi look after a 3-4 WOT shift when you get back on the throttle? if it dips, then you'll need a fuel pump. but post up some more logs so we can see.

 

[arkat3kt]

new log

hard to tell from your data logs since it's only logging 2 times a second.

take out maf airflow, stft, speed. maybe that'll let the AP speed up the logging.

looks like you need to calibrate your maf since your LTFT's are off at WOT

how does your fuel psi look after a 3-4 WOT shift when you get back on the throttle? if it dips, then you'll need a fuel pump. but post up some more logs so we can see.

Thanks for the reply. I took out the three parameters you suggested and logged a 2nd-4th run at WOT. The fule pressure numbers look okay from what I can tell, but like you said, my LTFT's are off. I'm mostly concerned about the 14.66%. I think I read that anything under -10 is okay...but I could be wrong. What do you think?

 

[SallySpeed3]

Well unfortunately you are having some fuel pressure problems. In second gear your psi drops below 1600 a couple of times. Nothing drastic, but still, you should think about an upgrade. Having just upgraded my internals I can tell your car will perform sooo much better. And I wasn't even having bad pressure problems either. You are getting some knock in 4th gear. Try using a less agressive OTS map and see if that helps. Concering your ltft's, as said before, calibrate your MAF. It's not hard. Good luck

 

[the_caruch]

the knock you have is most likely related to running almost 13a/f ratio. That's very lean.

your pump is about on the verge of being maxed out. you can see it drop below 1600 right after a shift. it's always an easy spot to see if your pump can keep up. looks like yours is struggling.

i'll give you my opinion on pump upgrades. get the cp-e pump, it's a proven part. the price may be high but it is worth it on such a precision part.

for fuel trims at WOT, you want them to be locked at 0 (or you might see 0.8%). dont' worry about the 14% you see, looks like that's when you took your foot off the pedal and were decelerating.

 

[hugador]

Time to upgrade the fuel pump

 

[mazdaru]

you are on the wrong forum if you are looking for technical help. take to sign up on the other.

stop going WOT. your fuel pressure is dropped to 700. get a fuel pump. AWE makes a great up. then you have others like KMD, Auto-tech and APR/CPE

im going with the AWE pump

 

[arkat3kt]

Thanks for the replies. From what I've been reading, the stock fuel pump only provides 1600psi up to about 5,000rpm then starts to drop off. Do I need a new fuel pump or can I go with the PG PTP fuel pump internals kit? That seems to me a good solution to my problems...

 

[the_caruch]

Thanks for the replies. From what I've been reading, the stock fuel pump only provides 1600psi up to about 5,000rpm then starts to drop off. Do I need a new fuel pump or can I go with the PG PTP fuel pump internals kit? That seems to me a good solution to my problems...

The stock pump usually starts failing lower in the rpm band where the load is higher on the engine. Or right after a WOT shift where you get back on the throttle.

I already gave my opinion on pumps/internals. With such a precise and critical part, i would not trust myself with installing internals. If something gets in the pump while you are disassembling or reassembling it, that could spell disaster.

Also, don't buy anything from PTP.