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Discussion Starter #1
What type of gas does the car use? Regular or Hi-Test

If you use regular instead of high octane in error will the cars computer know to adjust for it or will it affect driveability?

I heard that California uses different gas and that the engines need to be adjusted according on most cars. Will all cars have the same factory settings or are they adjusted by where they are being sent to?

This could be a problem if you order the car in one state and plan on driving it in another.

If I am at sea level and go to the Colorado Rockies, doenst there car need to be adjusted for higher altitiudes, or has modern day programming made all of the adjustments a thing of the past?
 

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If they want to be able to lap at the pump in California, the highest available here is a lowly 91 octane.

I'd be curious to know more about the Lotus-designed ECU too. Will it support CANbus or just the basic OBD-II data? If Lotus can download performance history, do they do it through the J1962 connector, or did they add something more?


The normal thing for high-compression cars to do is detect knock and back off the timing accordingly, so it adjusts to bad fuel and punishes you with low performance.

Airflow metering usually takes altitude/temperature/density into account and measures the air in grams-per-second or something similar. The computer does the math to keep the fuel metering correct.
 

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I very much doubt that they use different programming per state. California isn't the only state with 91, and even if you have 93 at home, you'll want to be able to fill up when you drive somewhere.

Modern ECU's can adjust to some degree. My car was tuned with 93 octane, but it runs fine with 92. I had to use some 87 in an emergency, but then only drove on low throttle until I could fill it up with good gas.

The same is true for altitude. If it's programmed right, a stock ECU should be able to handle all conditions you find in this country.
 

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Very good questions up there.

You know that we have 100 Octane fuel over here in Europe an some mountains, too. ?

You should ask your questions in the European Elise Forums and perhaps to Nick Adams, too.

He tried to explain in his forum the difficulties Lotus had with the ECUs they used so far. Hope for you that they have learned their lessons in the meantime. May have taken longer than expected.
 

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Ruediger said:
You know that we have 100 Octane fuel over here in Europe an some mountains, too. ?
But the European and the US method for measuring Octane differ. The European octane specification uses one method, and the US octane specification uses the same European method and a second method (that provides lower numbers) - then the two are averaged.

It is quite possible that 100 Octane European is equivalent to our 91 Octane rating...

Tim Mullen
 

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atyclb said:
98 over there is roughly equivalent to 93 here, I believe
I stand (sit actually) humbly corrected...:bow: ;)

Tim Mullen
 

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This price explains your SVUs and also the foreign policy of the actual US government.
But image that in China and India car population is growing very fast, too.
 

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There's always the local airport... the one around here has 100+ octane fuel.
 

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Not an expert, but since this is a modern Toyota engine I would think that it has all the usual sensors like Idle Air Temp, Air Density, Knock Sensors, A/F monitoring etc and the tuning adjusts based on those and that factors out any different tuning based on location anymore.

My understanding is that most modern systems understand heavy acceleration and normal driving and have differing engine management for those scenarios. Even though Lotus tweaked the ECU, I would assume this means they optimized the fuel curves and such that are used under "heavy acceleration" but left normal driving parameters alone.

So I agree with GroundLoop that you "could" use anything safely. The ECU will penalize you if knock occurs, at higher altitudes, and in high air temps (or if your car is Chrome Orange).

I personally always use best standard gas (91 here), but do not think there is any gain from any octane boost on a standard compression engine.

-Todd

And Colin said,
"Let there be Light"
and there was Light..... And it was Good.
 

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Still remains the open question:
The 2ZZ-GE engine in the Elise designed by Yamaha for Toyota and used by Lotus in the 111R Elise does it have a knock sensor now ?

As far as I know Honda`s KA 20 A does not have it therefore I doubt that the ECU, (made by ??? ) Toyota installs for controlling the 2ZZ-GE have such detectors.

Please correct me in case I am wrong.

But for boosting that engine knock sensors should be used anyhow and even my tuned but still NA Rover engine would be safer in some countries where you are not sure about the quality of the of the expensive stuff you are getting at the gas stations.

Somebody can tell us what is used for boosted Honda and Celica engines ? There must be some alternatives to MOTEC.

BTW : Is it good to have launch control for autocrossing ?
 

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Ruediger said:
BTW : Is it good to have launch control for autocrossing ?
On most (well set up) autocross courses, a hard launch doesn't pay off. There's mostly a tight turn shortly after the start line. There are exceptions, like the North course at Nationals last year. At local events, you see all kinds of setups.

In ProSolo, which is a different form of autocross, you have a drag race start. I know that some people use launch control in classes where that much engine management is legal. I doubt that they gain a whole lot. It can't be much faster than using your feet to launch the car really hard.
 

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As installed in the Celica, the 2ZZ-GE has a knock sensor. I have a hard time believing any modern engine doesn't have one.

As for turbo conversion ECUs, I believe the APEX'i Power FC is the most popular, since it uses all the stock sensors and wiring. But it might not work so easily with an Elise.
 

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As Ian said, K20A has a knock sensor.

if the *knock* exceeds it's pre-set level then it dumps 10 degrees off the ignition timing, and then every ~10 sec's increases it again by 1 degree until it ether get's back to the map setting or encounters *knock* again
 
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