So i've been driving around for a year on my 07 Base with only Injen long tube intakes and stillen catback (stock CATs).

I have been working with Vince @ RT tuning the past 2 weeks doing some Uprev Etuning with data logs.

I simply cannot suggest them enough for tuning of the Z. My car has woken up, major pickup in throttle response and low-midrange torque. No dyno plots yet, will have in the next week or so.

Anyways.....

I don't have a log of the base ROM but here you can see the difference in AFRs between the first ball park tune he sent and the final. I'm willing to bet my AFRs were in the 15s on the OEM tune, NOT GOOD!

Goes to show if your modifying your Z, even basic bolt-ons need a tune.

I havn't made a plot comparison yet but there is a major jump in ignition timing. Version 1 held at 25 degrees the majority of the time, while Version 4 ran at 30 to 35 degrees.

 

your AFR problem is from the Injen intakes, the intake tube diameter is not "tuned" causing incorrect reading of the amount of air entering the engine, if you didn't know it is the same air flow meter in a 1.5L versa all the way to 5.6L titan, intake tube diamter changes to compensate for additional air flow

all that is being done here is re "calibrating" your mass air flow amount for of additonal air going in the engine

 

your car is WAYYY too rich. NA cars make highest and most efficient power in the high 13s.

I barely drive that rich on my built motor, big turbo car. Does Vince know you are running FI AFR on a stock NA motor?

 

^^^N/A VQ's like to be at 12.8-13.2ish. This is where were have found to make the most power. anything over 13.5 they shows signs of detonation and you cant be as agressive on the timing. Usually on E tunes I try to get them around 12.6-12.8ish. Also the factory widebands tend to read a couple tenths richer then actual aifuels.


Ian, thanks for the good words and recomendation...

 

detonation? use premium... or your timing is waaaaaaaaaay too advanced

 

^^^ yes running air fuels in the high 13's and trying to run over stock timing shows signs of detonation, even with premium..

 

I only run 93 octane. As far as intake diameter and the maf goes I specifically went with the injens bc they are the same diameter as stock. Stillen intakes have a larger diam to lean the motor out.

 

Johnwigs,

Not trying to start an argument but wanted to clarify why i believe the MAF is not out of calibration due to the Injen intakes.

OEM Airbox are a smaller diameter that opens up to the rubber elbow.



Injen VQ35HR Long tube intake, see the tubing diameter neck down at the MAF housing and then open back up like the OEM airbox. I have not put calipers to the ID's but I looked specifically at this when installing. My calibrated eye ball says they are very close.



Stillen Generation 3 Long Tubes, NOTE the lack of a tubing size reduction @ the MAF sensor. I have not held a stillen intake in-hand so i cannot verify the ID at the MAF housing but i know people have reported running pretty lean with just the stillen intakes.

 

my rebuttle without an arguement:
This intake is the same one for a 3.7, stock intake maf assmebly size is different between the two...

 

how much timing are you running out of curiosity? surprising you run out of octane before you hit MBT

 

I was running 30 to 35 degrees on the last pull. I'll post a graph tonight.

 

Well Vince just sent me a new ROM with cruise control enabled!

I've got a DIY thread going for this as well.