Master pinout/16236757

[ericjon262]

no I haven't tried it, I'm only going to be running one o2 on my setup, I just thought I would help with ideas.

[TGP37]

Well, you definitely helped with the pinout locations for the second O2. Seeming I can change the setting in HPT (which isn't a common setting found in 97 pcm through HPT as far as I can tell)

It may not be perfect due to the turbo, but still.


Getting the PCM to log the 2nd O2 is an interesting idea if the fuel adjustments can be prevented on bank 2 (keep it single bank) but use the 2nd O2 feed for data logging a wideband.

[ericjon262]

you might be able to do that, I don't know. I am more interested in dual knock sensors then the dual 02's though. if I were to go that route, I might try to log EGT's through the second 02 port, but I'd be concerned with the PCM trying to adjust something through some hidden code somewhere...

[TGP37]

you might be able to do that, I don't know. I am more interested in dual knock sensors then the dual 02's though. if I were to go that route, I might try to log EGT's through the second 02 port, but I'd be concerned with the PCM trying to adjust something through some hidden code somewhere...

I agree about the hidden code possiblity. Seems logging wideband via EGR position data signal line has some issues as well.

A/C Pressure signal line works too. If your tune is good, you should be fine with just 1 KR sensor. You can actually make them more or less sensitive and change how fast they rebound from knock detection against RPM. With TT you can do that and also tune burst knock variables.

Ultimately, you should not want your KR sensor to ever be needed. Only on a rare occasion, really hot day or bad gas should you need it.

Spark advance can only go as far as the most KR offending piston, imho. Flow testing injectors to balance piston kr will really help. I read some piston AFR can be as far off as 0.5 AFR. That's a lot for a turbo, holds back safer power.

Have you considered balancing the injectors?

[ericjon262]

I bought a set of flow matched injectors for my build, the balance problem could be in part caused by a poorly designed intake. you can actually skew the injector pulse width to compensate for poor distribution or an over/under performing injector.

[ericjon262]

also, it could be argued that with a perfect tune, you wouldn't need o2 sensors either...

[robertisaar]

with a perfect tune, no closed loop correction of any kind would ever be needed. fueling, spark, idle, line pressure, any of it.

the entire end-goal of tuning is to eliminate the need for any correction, preferably without sacrificing anything along the way.

[unchained01]

BUT that's in a perfect world perfect fuel ,perfect temps etc as the story goes....................perfect would be ECT on all Cylinders on a dyno

[ericjon262]

I wasn't saying perfect tunes existed, merely that saying you don't need a knock sensor if your tune is right, isn't right.

[robertisaar]

fuel has to be assumed, temps are all accounted for in the calibration with good sensors...

it's why tuning is part art, part science.

[ericjon262]

fuel has to be assumed, temps are all accounted for in the calibration with good sensors...

it's why tuning is part art, part science.

depending on who you ask, science=art.

[unchained01]

Tunes have to be changed for temp changes IE+seasons or tuned wide enough for deffeerence

[robertisaar]

1 tune should account for whatever temperature variation you might see in a day to day, season to season, even continent to continent difference.... if it doesn't, you have issues somewhere in the calibration.

[ericjon262]

1 tune should account for whatever temperature variation you might see in a day to day, season to season, even continent to continent difference.... if it doesn't, you have issues somewhere in the calibration.

I was thinking the same thing.

[robertisaar]

once you start changing assumed variables(like octane or alcohol content of the fuel, for example), then you would benefit from multiple tunes, but if it's something that can be measured, it can be accounted for.