R32 Ecu Change

[Rolls]

An airflow meter adjust fuel requirements for differences in IAT.

Pretty sure the GTR ecu has IAT correction.

An airflow meter doesn't need intake temperature correction because the way it operates it measures exactly the right amount of air, doesn't matter what humidity, altitude, temperature or anything the method measures exactly the right amount of air. It is only MAP that needs IAT correction.

However I am talking temperature ignition/fuel trim, apparently the GTR is the only car that has the IAT sensor, what it does with the signal I am unaware of, Pete at nistune said they could almost certainly set it up to trim fuel/ignition but currently they haven't looked into it.

[Gts4RB30]

ok as i am still learning the abbreviations what is IAT?

[GTSBoy]

It's Inlet Air Temperature.

When you have a MAP sensor, you must measure temperature also, so that you can work out the mass of air entering the engine. Because you have to have the temp sensor, it makes it a no-brainer to make the ignition timing vary with air temp. Less benefit trimming the mixture, but also possible.

When I said earlier that the only Nissan ECU with IAT sensor is the RB26, I was talking about the RB engines only, because I'm pretty sure that SRs have it as well. Nissan absolutely must be using it to trim ignition timing, because there's little other reason to have it there.

FWIW, RB engines absolutely suck in this regard. My car actually seems faster in summer because it's closer to the detonation threshold, whereas in winter it could probably take another bajillion degrees of timing on those midnight hills runs.

[Gts4RB30]

hey GTS thats weird that you say that because i have seen NUMEROUS cars make more power in the cold then the heat, even the hi octane r32 when it went to japan it ran 150hp MORE in the cold air then our air here. And another thing japans "general" humidity is also higher, so in turn that would leave me to believe that it would also have an inherit benefit having more moisture in the air that the sensor would pick up on and compensate for?????

[GTSBoy]

hey GTS thats weird that you say that because i have seen NUMEROUS cars make more power in the cold then the heat, even the hi octane r32 when it went to japan it ran 150hp MORE in the cold air then our air here. And another thing japans "general" humidity is also higher, so in turn that would leave me to believe that it would also have an inherit benefit having more moisture in the air that the sensor would pick up on and compensate for?????

Yeah, well, the chance that the Hi Octane R32 was running factory management is pretty small, no? And isn't it an RB26.....which has an IAT anyway if it just happned to be using factory type management?

And no.....the whole thing about Japan's climate being different to Australia's and the whole effect that has on tuning is somewhat of a myth. In Australia we have a wide range of climates. From hot dry summer weather at 40+C, down to cold damp weather near freezing. And we have hot wet tropics too. The air in Japan is the same air we get here. 79.1% N2, 20.9% O2 as a simplification. The trace gases are the same, and the moisture levels might be a bit higher, but air can only hold a percent or so of water vapour, so we're not talking 5% or 10% differences in the "quality" of the air here, we're talking fractions of a percent.

The main difference is that winter in Japan can be a lot colder, and where the winters are really cold, the summers are not quite as hot as here. But that's regional in Japan, same as it is regional here.

Jap ECUs (like the infamous Mines ECUs) are just tuned with 100 octane juice in mind, coupled with a different approach to maintaining safe mixtures and timing. They lean on the margins fairly hard. That means that there's no margin left when the same ECU is used in Australia.

I also have seen numerous cars make a lot more power in the cold. Mine probably makes a little more too, because of the denser air, you get a little more charge into the engine. But the Nissan ECU can't take advantage of the cold air to wind in more timing, and so gives away a heap of power in the cold (if it is tuned not to ping in the heat). Simple bloody ECUs like Microtechs make more power in the cold on the same tune that won't ping in the heat. Just because they have an IAT and can use it.

Edited February 15, 2012 by GTSBoy

[Rolls]

You guys are forgetting the FMIC, the effect this has on air temperature on cool weather vs hot weather is massive. The larger the temperature differential the better it cools the air, this is almost solely the reason cars make more power in winter.

All of my completely stock skylines have been MASSIVELY faster in winter vs summer, I'm talking almost 100kw differences with a shitty pod and FMIC that gets heatsoak driving in traffic in a 35c day vs a 10c winter night in the hills.

[rob82]

Generally on a knock limited turbocharged engine using speed density style tuning you would actually reduce your ignition timing for lower intake air temps as your cylinder fill increases. This is due the fact that most ecu's dont have a load based ignition curve but rather just a manifold pressure based ignition curve. This is not the case on a maf based systems or some oem speed density ecu's.

Edited February 15, 2012 by rob82

[Gts4RB30]

Yeah, well, the chance that the Hi Octane R32 was running factory management is pretty small, no? And isn't it an RB26.....which has an IAT anyway if it just happned to be using factory type management?

And no.....the whole thing about Japan's climate being different to Australia's and the whole effect that has on tuning is somewhat of a myth. In Australia we have a wide range of climates. From hot dry summer weather at 40+C, down to cold damp weather near freezing. And we have hot wet tropics too. The air in Japan is the same air we get here. 79.1% N2, 20.9% O2 as a simplification. The trace gases are the same, and the moisture levels might be a bit higher, but air can only hold a percent or so of water vapour, so we're not talking 5% or 10% differences in the "quality" of the air here, we're talking fractions of a percent.

The main difference is that winter in Japan can be a lot colder, and where the winters are really cold, the summers are not quite as hot as here. But that's regional in Japan, same as it is regional here.

Jap ECUs (like the infamous Mines ECUs) are just tuned with 100 octane juice in mind, coupled with a different approach to maintaining safe mixtures and timing. They lean on the margins fairly hard. That means that there's no margin left when the same ECU is used in Australia.

I also have seen numerous cars make a lot more power in the cold. Mine probably makes a little more too, because of the denser air, you get a little more charge into the engine. But the Nissan ECU can't take advantage of the cold air to wind in more timing, and so gives away a heap of power in the cold (if it is tuned not to ping in the heat). Simple bloody ECUs like Microtechs make more power in the cold on the same tune that won't ping in the heat. Just because they have an IAT and can use it.

umm ok i know about weather as i was born in townsville and lived in mount isa for a few yrs and in melbourne. but the rest of what you just said i was like {:| huh

[Gts4RB30]

wow its quite interesting ready some of the old comments that you make at times and realising what a f u c k head that you can be to people. Really sorry everyone for being such a fu ck stain. wow cant believe that was me, so immature.