Rmis350

Hey Folks, long time admirer of the Lexus platform, especially the 3.5 v6.
I Love to tinker and tune vehicles, I built my itb mx5 and self tuned through speeduino so I am familiar with the electronics on that car. The Lexus is confusing though.

Plenty of searching has turned up nothing apart from RR racing as the only flash tuning method.

What I am looking to do is have the factory denso ecu control everything except for the fuel and ignition. I would wire in my own ecu to control those.

Problems I can think of so far is noisy signals from tps, clt sensors. The other issues might be the transmission. Does anyone know if the car can force the transmission to go in to a limp mode of sorts if it detects a fault with fuelling or ignition?

Not concerned if I have a dash that looks like an Xmas tree.

Note, I have not purchased this car yet. I will be getting a new daily driver and want to tinker with it and diy a rear mount turbo install once I sort the ecu. Is350, G37 are the main options at this stage.

Ultra4

I'd try looking into VFTuner before running a piggyback. I'm under the impression that the port injectors can be upgraded, and your additional fueling needs can be handled through the factory ECU's control of them.

2013FSport

iTrader: (2)

My street bike has Bazzaz piggyback tuner on it that reads the inputs, and builds its own fuel MAP using the stock injector timing compared to the AFR, then you pick your desired AFR and the difference between the two drives the injector duty cycle to achieve the fueling desired.

It's not all that complicated but I'd definitely keep it simple and use the OEM ecu until it can't do any more.

Look up WinOLS, it's a tool to read and edit maps.