APynckel

pull your head out of the clouds. You're not a "bearer of bad news" you don't understand that I don't want to tune the car for power, I want to tune the car for drivability. I understand that the ECU is intelligent, but it's obviously not so intelligent to know that when my foot is off the gas, I want to coast, and not decel in gear (to conserve gasoline).

I still own my DSM. And I didn't have a shop build / tune it either.

DaveGS4

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Guys please keep this thread polite and mature.

my95tsi

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Good luck man! Wish you the best

Jeff Lange

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Unfortunately doing any sort of tuning will require either replacing the ECU with some sort of standalone ECU, or reverse-engineering the stock ECU to come up with a new program to flash it with. Both of these suggestions will be somewhat difficult due to the complexity of the system.

The factory ECU controls a lot of systems in the car, and can't just be replaced with another ECU. There aren't a lot of ECU's on the market that also control the transmission and the IS also uses a D4/D4S direct port injection system. On the IS350 you'd need to control 2 injectors per cylinder (1 direct port, one manifold port), on the IS250 just the direct port injector. The ECU also controls the cruise control and the throttle body based on the pedal signal. It also controls the immobilizer system, etc. and is in constant communication with the other body ECU's in the car.

Basically, you'll need to run a standalone while leaving the stock ECU in place. A lot of IS300 guys do this, but it does present a few problems regarding what the stock ECU can see and what it can't. It also means that the ECU either thinks the car is not running, or is running but it can't control anything, which typically leads to a light show happening on the dashboard.

If you have the capability to figure out what's going on in the stock ECU to come up with a new program for it, that would of course solve a lot of those issues, but Toyota/Lexus is very tight-fisted with information about how their electronics work, and flashing procedures. You'd probably be able to get the hardware to reprogram the ECU somewhat easily, but there is no way to actually pull any information out of the ECU (with what is on the market now) as far as I know. So that would be something you'd need to develop. Perhaps contacting the companies out there that have done something similar with the Scion tC and Tundra may yield some results.

I'd love to see you do some things with the 2IS, as not a lot exists out there right now, but my hopes are not that high. The 2IS is not a tuner car, and as such, not much is available even to just change driveability.

Jeff

Stylnhonda

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At least you have the Lexus for when the DSM is broke! hehe just kidding.

Sounds like you need a Hybrid!

APynckel

That's why I bought the Lexus. The DSM does not get adequate fuel economy for my 2x a day 45 mile commute to and from work. It's A/C also sucks (only works intermittently on the freeway). So it is now the dedicated toy, until I buy the real toy.

And hell no, I will never own an Hybrid or an electric drive vehicle until nuclear power becomes more than 20% of the american electric grid. Costs WAY too much in materials to produce those vehicles (and the battery packs are hella expensive to replace).

Stylnhonda

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Well the Lexus already gets better gas mileage than your GSX! Why mess with it any further? I'd say the guys at Toyota know a thing or two about tunning the cars!

I see you have Mechanical Engineer in your sig. Are you fresh out of school?

Kurtz

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You might be surprised. AFAIK the car runs fairly lean already (thanks to direct injection).

It's one of the reasons the couple guys who have run AFCs at the track to lean it out only picked up single-digit hp too.

Might benefit you to put a scanner on the car and see what it's doing. Not to say there's no room to improve anything but I think it's less than you suspect.

The MAPECU3 might be one way to go- AFAIK PEPOS is only using it on open-loop mode though so that won't help any for normal driveability. IIRC you need additional hardware to try it in closed loop, which I don't think anyone has done yet on the 2IS.

APynckel

Yes, it gets better gas mileage, but my brain demands it get better (and I like to have control of my vehicles).

I graduated this summer, yes.

Stylnhonda

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I see, well congrats! I would just do some small mods to the IS to have some fun with it. It makes for a good sporty daily!

APynckel

Yea, as far as the engine will go is an intake pipe / drop in K&N filter, and then aesthetic mods (replacing interior bulbs / exterior). MAYBE an exhaust if I get bored with the car, but it's not likely. I like having the car quiet under cruise.

Eventually, I'd like to take it to do some road course racing and learn how to drive. The DSM has too much power to learn with (though AWD sure is a hell of a lot of fun).

06isDriver

I dont understand why you want to mess with the ecu below 60% throttle anyway. What did you hope to accomplish that the oem ecu doesnt do already?

I mean, I purchased the mapecu to eek out what I could at WOT and I'll let the oem ecu handle the rest of the day to day issues. For what it's worth, my afr's were reading only 11.1 at WOT near redline. I should have plenty of room to safely squeeze out 20 more ponies I think.

APynckel

Your AFR's need to be closer to 13:1 for a "good" tune in an N/A car, but you get more power from a good timing curve than air/fuel ratios.

GilIS250

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He said it for me , if I wanted to go fast I would just get me a civic...

hydralisk

Good luck APynckel,

This forum is very pessimistic and just because someone on the internet said it cannot be done, 99% of them believe this and quit. I get the same slack from the ISF section and already have proved a few "facts" as wrong. The world is still flat.

Dont think buying an ISF will solve the problems either, we have a smaller aftermarket.

Stay positive and do what you do. HKS350 should have some answers you seek. I love his ambition.