do supras need premium gas???

WhtMa71

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EGR doesnt work under boost though, only regular driving with minimal load.
As already stated..the EGR system helps deter knock under min. load, above idle to 4k rpm. Even if the engine is not under boost, there still needs to be something to control knock. Thats where the EGR system comes into play. Since I do not have an EGR system I need all the help I can get, when not in boost, so my engine doesn't knock itself to pieces. Hence my decision to run 93 octane. Georgia roads are not flat by a long shot..And duh..who drives a supra turbo the same as grandma drives her corolla on a county road on her way to church?
 

bsupra

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I ran both 91 octane and 87 octane since I owned my 91 turbo R154. My car is stock. I ran 91 when I first 2 years (2009-2011 I think) owning the car, then switched to 87 eversince....

I found the car to have a better response on 87... And again, this is my car. I am just sharing opinion... Also, switched to 87 because of smog issues. (See attachments)

87 Octane - lower HC (MEAS 18)

91 Octane - higher HC (MEAS 103)

Other pic shows Owners Manual fuel recommendation.
I live in Riverside County California

Its not being cheap on gas (not sure why some people always say that). It was based on whats better for my car.
 

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JDMMA70

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on a stock turbo car with no mods, as long as there is no pinging you can run 87. Start modding it, increase timing, and cylinder temps, you'll need to run 91 or higher.
 
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figgie

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@bsupra

HC is only a good inidicator of the fuel combustion process but the REAL number is to look at NOx. that tell us cylinder temperature.

Also, point blank, with the TCCS having been full reversed engineered in this very forum. As my post in SF and now here say, you are one dead or disconnected battery away from a another 7M casualty.
 
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debrucer

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@bsupra

HC is only a good inidicator of the fuel combustion process but the REAL number is to look at NOx. that tell us cylinder temperature.

Also, point blank, with the TCCS having been full reversed engineered in this very forum. As my post in SF and now here say, you are one dead or disconnected battery away from a another 7M casualty.
I've read 3p's 12 year long thread but I don't think I've seen your TCCS reverse engineering posts. Where are they?
 
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bsupra

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@bsupra

HC is only a good inidicator of the fuel combustion process but the REAL number is to look at NOx. that tell us cylinder temperature.

Also, point blank, with the TCCS having been full reversed engineered in this very forum. As my post in SF and now here say, you are one dead or disconnected battery away from a another 7M casualty.
Attached is the complete smog reading. I guess its a bad thing when car is producing less emissions. Thank you for the kind words.

Again, I am not advising people to run 87. I was just sharing how my car runs with 87.
 

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I've read 3p's 12 year long thread but I don't think I've seen your TCCS reverse engineering posts. Where are they?
Agreed, is the TCCS about to eat it if it randomly loses 12v power? Makes me glad I've been thinking about standalones.

Man, I'm happy I've never had to deal with emissions testing. Not that the car wouldn't have passed, just another hurdle to worry about.
 
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figgie

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I've read 3p's 12 year long thread but I don't think I've seen your TCCS reverse engineering posts. Where are they?
It is strewn together in that thread in bits and pieces. He has all the code. That how he was developing the daughter board for the control ala "techtom".

That thread has the bits for ignition timing, along with some dependancies and learned knock value. Fuel and ign ve based tables. It does not have any of the trim tables. For whatever reason, people have a hard time trying to decipher VE to pulsewidth. It is just some math to covert.

Point blank, doing the "techtom" way of piggy backing the CPU is just not cost effective today (back 2010 it was already teetering at the edge of cost effective) which is what 3p was trying to do.

Edit: at one point there was a github or github like code repository for the machine code, I THINK.
 
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figgie

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Agreed, is the TCCS about to eat it if it randomly loses 12v power? Makes me glad I've been thinking about standalones.

Man, I'm happy I've never had to deal with emissions testing. Not that the car wouldn't have passed, just another hurdle to worry about.
Of course not. It just goes to the most aggressive ignition setting the TCCS had and it has to relearn the knock threshold.

It was one of the OG tricks during the alphabet soup era. Disconnect battery or remove EFI Fuse, Reconnect. Fill tank with highest octane fuel possible, dyno.
 
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