Anyone using a JET ecu upgrade?

[GSMnow]

While trying to find some performance parts for the 1UZ enigne, I came across the Jet Performance web site. They don't list any 1UZ aplications, but they can do customs and have done Supras. All I really want is the rev limit and shift points raised a few hundred rpm. I figure 6500 should be no sweat on these motors. If it is anything like the 2AZFE in my 04 Camry, (it pulls hard right until the rev limiter cuts the fun at just 6200 rpm) then a few more rpm will be very welcome. On their web page, Jet lists increased rev limit and shift points as some of their primary "fixes". They also adjust mixture and ignition timing to optimise the engine. The 1UZ is coming from a 93 LS-400 and is going into my 83 Celica GT-S, complete with the stock ECU and auto trans due to the California smog laws which require all stock emissions controls to be in place AND WORKING. My Celica is about 1000 pounds lighter than the LS AND it has a 3.727 rear end (LS has a 3.62) and I race on 22.5 inch tall tires (LS tires are about 26 inches). This will make it run out of rpm very quickly. I am also planning on some mild cams and maybe some porting to help it breath up at 6500. My previous engine was a very built 2.4L 22RE with a turbo setup and I revved that to 7200 rpm regularely. Trying to shift it before 6200 was near impossible as it ripped to 60 mph in under 5 seconds. Of course the W58 second gear is a bit shorter than the A341E second gear but it should still be a short trip to redline.

I plan to send Jet an e-mail to ask if they can do a 1UZ ECU with just the raised RPM numbers as Toyota did a very good job in the first place, I doubt there is much to be had with just a chip. With other mods, the stock ECU may start to show more merit, but the learning ability of the ECU can "un tune" any changes to the fuel map and ingition timing. I will run the motor stock for a while, but some mild cams and porting is probably in my future as well. My turbo beast was close to 300 crank HP (Probably 250 at the wheels) and I want to come close to that with the 1UZ.

Gary M.

 

[SCV8]

I don't trust those guys to do any good to a Lexus ECU; too much $ for an unknown.
The Self-Learning feature will likely get in the way of any gains they claim to have made.

 

[GSMnow]

I am only hoping that they can do a rev range increase. Any change in mixture can be learned out like you said, and timing advance will only hold if you run good high octane fuel, something rare here in CA. At least it can't learn to lower the rev limit. Firmer shifts should also be possible if it increases line pressures. There is some adaptation to compensate for clutch wear, but if they change the target rate, it should learn to the new "desired" shift time. I do agree they are a bit pricey for a higher rev limit alone, but it should be CA legal since they have Toyota CARB EO numbers.

 

[SCV8]

I was told my Unichip thing was supposed "alter" the shift points, when all that changed was the vacum signal from the adding timing, the shifts became firmer because of an increase in power basically, nothing really changed in the trans/ecu.

 

[GSMnow]

Hmm. If I knew the code, it does not seem too hard to just change rpm values in the tables. I programmed my TEC II on my turbo 22RE and I have written microcontroller code. The problem is I don't know the assembly code of the Lexus ECU or the location of the tables, so I have no place to start. I was hoping someone like JET, Unichip, Superchip, etc would have the tables and be able to up the rev limiter and shift points to make use of some mild porting and maybe cams. Only revving to 6,000 is not really making use of those nice 4 valve heads.

 

[highlander]

Code shouldn't be that hard.. It shouldn't be that difficult to find them. If they have been found on GM PCMs...

The problem is .. REFLASHING The damn thing... any thoughts?

 

[GSMnow]

TECHTOM has come up with a daughter board that they install inside the ECU in place of the CPU chip with a reprogrammable memory (I would guess a flash type) but it is quite pricey. They list it for the SC400 and have not tested it in an LS400 yet but say it should work fine. The only real difference is the hydraulic fan stuff.

Gary M.