Formulaonehd
NWZ - The storm is here
HI all
Firstly Im no expert in tuning - lets be clear.
I had the unchip installed on a 2000 LX and not sure if it is the same in the US but in Aus the pre 2003 models came without post cat 02 sensors. Once i did the header/extractor and exhaust upgrade the economy went really bad as the AFR became even more rich than it was before. Lexus advised that these models are pre tuned to run at min 96 RON and if you don't (as i found out once before) it will knock and not run too well on anything less than 95 RON.
In any case I had the Unichip done to fix this and had a one program tuned on the dyno - Fuel saver mode, no wide band 02 sensor installed, and the results were great. With the mixture leaned out into much better values, the economy and delivery of power improved dramatically
Average HWY combo Urban pre tune was 20L/100 +/- or 12MPG
Post tune average was 15L/100 +/- 16MPG
Apologies for the screen grab quality pics from the dyno, we couldn't print out at the time. And NO the HP figures are not a true reflection of the engine power as many get confused by, plus the 4speed auto sucks a lot of the power from the results.
What i found out come winter which isn't even very cold where i live (the tropics) i couldn't fire it up first thing in the morning. Most times i would have to unplug the unchip and connect a loop and then start in the old "rich mode" . Once the car was warmed up and driven around it would start with the chip plugged back in for the rest of the day. Come the next morning if it was say below 25C/77F it wouldn't fire up and just cranked. Summertime no probs, every time it would start straight up as the temp doesn't drop below 28C/82F ever!
We are scratching our heads a bit after even adjusting the "start program" which im told is everything at start/idle but it had no effect unfortunately.
Bit of a novel i know but the context is important for anyone who might have some ideas.
Firstly Im no expert in tuning - lets be clear.
I had the unchip installed on a 2000 LX and not sure if it is the same in the US but in Aus the pre 2003 models came without post cat 02 sensors. Once i did the header/extractor and exhaust upgrade the economy went really bad as the AFR became even more rich than it was before. Lexus advised that these models are pre tuned to run at min 96 RON and if you don't (as i found out once before) it will knock and not run too well on anything less than 95 RON.
In any case I had the Unichip done to fix this and had a one program tuned on the dyno - Fuel saver mode, no wide band 02 sensor installed, and the results were great. With the mixture leaned out into much better values, the economy and delivery of power improved dramatically
Average HWY combo Urban pre tune was 20L/100 +/- or 12MPG
Post tune average was 15L/100 +/- 16MPG
Apologies for the screen grab quality pics from the dyno, we couldn't print out at the time. And NO the HP figures are not a true reflection of the engine power as many get confused by, plus the 4speed auto sucks a lot of the power from the results.
What i found out come winter which isn't even very cold where i live (the tropics) i couldn't fire it up first thing in the morning. Most times i would have to unplug the unchip and connect a loop and then start in the old "rich mode" . Once the car was warmed up and driven around it would start with the chip plugged back in for the rest of the day. Come the next morning if it was say below 25C/77F it wouldn't fire up and just cranked. Summertime no probs, every time it would start straight up as the temp doesn't drop below 28C/82F ever!
We are scratching our heads a bit after even adjusting the "start program" which im told is everything at start/idle but it had no effect unfortunately.
Bit of a novel i know but the context is important for anyone who might have some ideas.
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