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Author Topic: New ProEFI user turboing a 2001 IS300  (Read 468 times)

Offline FluxCapacitor

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New ProEFI user turboing a 2001 IS300
« on: June 11, 2018, 08:05:58 PM »
Hello, I'm new here but not new to turbo cars or car forums.  I learned turbo cars and tuning on DSMs and have finally decided to turbo my IS300 after much consideration.  I researched like crazy to find out which ecu would work best and I am vehemently against the idea of piggy back ecu's.

My requirements for my car were the following:
* Do not sacrifice creature comforts
* Stock systems must still work (Cruise Control/Traction Control)
* No check engine lights
* Must be able to pull a trailer "well" (2000lb. towing cap. in IS300)

I realize most peoples' goals consist of "I want to make x horsepower".... but my goals are low here because I have other cars that are more ridiculous and I'd like to keep this one driving without breaking it a lot.

The ProEFI is not installed in my car yet although I have run the wiring for most of it already.  I think I'm going to be able to make mine fit by the brake booster rather than where the stock airbox went.  Everything has gone pretty smoothly so far and the goal is to take the upgrades towards a turbo car in steps that don't take the car down for any long period of time.

I will show some pictures when I'm done and satisfied that everything is to my liking.... but not yet.

The first very large snag I ran into is that once I removed the 2-bank stock exhaust system (1/2/3 front, 4/5/6 rear), the 2 front o2 sensors, and the 1 "middle" o2 sensor (between two cats).  I had a 3" exhaust fabricated and installed the 2 front sensors in the exhaust upstream and extended one harness to install 2 downstream sensors.  This "should" work like stock but it doesn't.  Another big hurdle with these cars and keeping the stock ecu happy is keeping the stock maf happy.  I did this by cutting it's pipe (calibrated I.D. for MAF) out of the stock air box and fitting it with couplers and a filter pre-compressor inlet.

What I've been seeing on the OBD2 gauge is the long term trim for bank 1 goes mega rich (30+) and the bank 2 goes mega lean (-18) after about 30 miles of driving.  Open loop the car runs fine, reset the ecu's trims by pulling the negative terminal, car runs great for about 30 miles or so.

I have checked for vacuum leaks and exhaust leaks and everything seems to be pretty sealed up.  My goal is to get the car to run w/o any CEL with the wastegate actuator removed from the turbo so it cannot build boost.  This **should allow the car to believe it just has a large intake/exhaust on it but the o2 sensors should be happy.  They are not.

I talked w/ Larry from Sound Performance on the phone a bit about it and explained the situation and he brought up the idea that the stock setup with 2-banks has the stock ecu seeing 2 different AFR's and expecting them to be that way; being that one bank is going to be richer or leaner on average than the other.  He said that putting both upstream sensors in the exhaust stream of all 6-cylinders might be causing the ecu to really be unhappy given that it's seeing identical AFR's on both sensors.

The "easy" thing is to not care about any of this and swap to a 5-speed.  I must maintain my path though as this is not a race car and I have an upgraded A650E (stock 5-speed auto) in my car and enjoy the automatic.  This leads me to my next contention with this car in general.  The A650E apparently uses PWM on some of it's solenoids which is, as I hear, not a normal thing because most transmissions do not use PWM.  If the stock IS300 ecu had been decrypted then the maps for how to control the trans in exact stock form would be available and there'd likely be an aftermarket solution to running this transmission.  At time of writing there are very few/slim options for controlling this transmission with anything other than the OEM ecu.

I'm sure I'm beating this subject to death on my first post for some people but I really wanted to just post here and see if pepole are active on here.

My next step for tomorrow morning is to complete the sensor wiring necessary to start the car w/ the patch harness plugged in and the ProEFI 128.  I am doing this with the intent that I can just tune the motor to not trip out like it is w/ the stock ecu applying trims to it.

If anyone has any thoughts or questions about my setup please let me know.  By the way, I'm a linux/cloud engineer by profession so technical things aren't foreign to me.  Of course, I guess if you're on this forum they probably aren't for you either!  Thank you.