What about the engine is different? I understand the emissions control would be different, but if it's only on the ECU side then what difference does it make?

Let's discuss.

 

The gas is different over there. The octanes are higher. This may be one reason.

 

woo hoo, finally someone who wants to talk some technical stuff!

Ok, that makes sense. what's the average octane rating? Also I would ask how dynamically programmed the ECU is and it's ability to adjust to external conditions such as octane rating. If it's aftermarket programming we're talking about, it should be conditioned for a wide octane range.

 

Japan,Europe etc, all rate their gas by the RON number. They don't bother posting the MON rating - though all gas is required in the European Union to meet the 85 MON minimum. What this all means is that UK 95 octane is 95 RON. 95 RON is about 90 (R+M)/2. The highest rated automotive gas in Japan
is unleaded 100 RON. That works out to about 95 (R+M)/2 -which is not available for the most part in the US (some of you lucky folks get 94 (R+M)/2 - though that may be with very insensitive gas and may still be a 96 RON 92 MON gas rather than a RON 99

So all in all Japans best pump gas is only 1 point higher then our best pump gas (around here anyway) of 93 octain..

This topic has been beat over, and over on many differant boards.

 

Wouldn't they speak different languages?

There was a post by someone a few months ago when the grounding kits first came out that raised a good point which is that ECU's for US cars come with a massive amount of poor-condition tolerances built in, which is why they don't come at top performance (why everyone is waiting for some good ECU reworks to come out)... For instance, Nissan built in a tolerance to allow some 89 octane to work in the engine with 91 (ca emissions)... Also theres another figure, 92 octane everywhere else, 91 octane in CA.

Anyways, I'm sure I'm not making very much sense, but I'd assume wait for an actual performance chip to come out, rather than blow my wad on a JDM spec chip that's certain to include complications.

 

It's not just the octane rating but also the blend of substances that go into what we call "pump gas." Dont quote me on this but one major issue is the amount of sulfur in US gasoline. This is one of the reasons that direct injection cannot work in the US but works just fine in Japan.

 

I believe you are correct. My question would be, wouldn't that then necissitate different hardware (ie - fuel filters, fuel dampeners etc) rather than software coding? When it comes to fuel the ECU is interested in burn rate and A/F mixture. Who codes the ECU for nissan anyway? Denso? I'm a nissan newbie.

 

If it was just octane, wouldn't they be able to program it so that if it "sensed" and lower octane it would use a different map for it. I am not sure how much storage the chip has so maybe that would be a limiting factor.

On another note, how large of a range will a new ECU be able to adapt to. I suppose limits are less restrictive than the stock one so that more HP can be gained from mods such as intakes, but at what level of mod will the ECU again become the bottleneck? If the new ECU can adapt to different mods, why not octane?

 

Most ECU's adjust for low octane by pulling out a few degrees of spark advance based on the input from a knock sensor which is an accelerometer tuned to "hear" the knock frequencies. Only the USA uses the stupid (R+M/)2 octane measurement because it is mandated by the EPA. The EPA could not decide between the Reasearch & Motor methods of octane rating so they decided to create a third totally unnecessary system.

Gasoline Direct Injection can not yet meet our current and future emmission requirements because of high NOX and the need for NOX storage catalists. This technology is advancing rather slowly.

The high sulfur content in US diesel fuel is keeping modern direct injection DIESELS out of the US market, totally different situation.

A JDM ECU is probably just like ours with a slightly different map in the EEPROM. It will tuned to meet Japanese emmission and fuel economy requirements but probably make very little if any more power than ours. It will be cheaper and more benificial to put an aftermarket chip in our standard ECU.

With the ECU controlling the variable valve timing, spark, fueling, throttle opening, rev limiter, etc. it should be possible to get this engine to make good power for an extra 500 rpm or so above stock with a chip change. For offroad use only! Ha Ha.

 

I'm not referring to a stock jdm ecu. I'm referring to the Mines ECU for instance. I live in NY where sunoco 94 is plentiful and if need be 100 octane is available. I have to believe that mines would map the ECU dynamically enough to support 94 - 100.

 

I discussed this in very long length with Tomei Racing about ECU's and gas. Japan gas is higher than the US. Running 100 octane BUT they did make a big deal about it. If you get a ECU and only have gas at 94 octane. Nothing but alittle 104+ won't fix.

 

Read my post above.. Japan rates their gas by the RON number.
100 octane in japan is equel to 94-95 octane HERE in the U.S
Which they do sell 94 octane here in the midwest( 66 )

 

damn the hippie government in california i want 100 at the pump, btw sport compact car ran the Z at 100 octane and it put down 5 or 10 extra hp at the dyno

 

Thanks Dr. Gallup for the clearification / information. It's always good to have people who know what they are talking about.

 

Update. I emailed mines asking if the current VX-Rom would work in the NA application. Here's what I got. (this is pasted btw)

ME - I have an american spec Nissan 350z Track. I would like to know if the VX-Rom currently offered would work in my car.

Thank you.

MINES - Dear Eric

Now I am developing VX-ROM of North America specification.
The release time is still undecided.

Tank you.

 

tank you

 

Eric. Did you get your new plates yet? Still BiTurbo?? lol
So how much is the ECU going to cost?

V

 

Haha, yeah I got the new plates BLKTRACK it is.

Looks like ECU's will be in the ball park of $1200 for a full ECU and $700 for just the EPROM. I hope that number goes down though. I miss the days of a $300 hypertech chip!

WRBLUEWAGON - no way we will see the kind of gains from an ECU that a turbo application would see, however, the gist I am getting is that the NA spec ECU is severly detuned. I say this because with the NISMO car making 340 with ECU exhaust and intake... figure 20 from exhaust, 5 from intake, where did the other ~35hp come from? ECU?? Let's hope so.