My car is running out of gas at 1/4 tank as well! I figured it was due to the return lines affecting the volume of gas available in the tank..

Whats the story on that?

UPDATE ON MY 2jzgte swapped GS300:

cars running leaner now (still, very rich to my standards though) at about 12.5-13.5 on highway with light cruising. Its better than before with the USDM maf, but still too rich.

Ive put in a ARisto OEM airbox as well, and thats helped lean out the mixture because I think the difference in size of maf tube was throwing off the maf calculations.

Cars running great now. Ran a 13.5@104 at dragstrip the other night.

This is with: 4.2 final drive differential thats making the car shift too early and with open gearing!

Im trying to find a Aristo differential now to get better longer gearing and better traction out of the hole. Figure it might help me drop .2 seconds maybe more at the dragstrip.

Oh, and Im running fulltime twin turbo now as Ive disabled the sequential operation and upped the boost to about 15 psi (hits fuel cut at 16 psi!).

Other than that, cars running great and Im LOVING it!

 

Sweet, keep an eye on that crank pulley make sure it doesnt fall apart on you and if it does get an ati pulley.

 

What are your 60ft times with the 4.2 rear diff? I would recommend a 3.73 or 3.91 rear ratio and the car will no longer shift into 4th gear prior to the traps at the track. The 3.91 rear gear out of the sc400 is easier to find then the supra tt/aristo rear diff.

I would strongly consider putting the car is sequential operation if you are running a stock 2200rpm stall. I put my car in true twin mode once and it was horrible from a stop. That might be what is hurting your times at the dragstrip. With a properly working sequential turbo system the 1st turbo will start making boost at low rpm's while also pre-spooling turbo number 2. With a 2100 rpm brake boost launch the car should pull 1.9-2.0 60ft's on the strip even with a street tire.

To get rid of the fuel cut issue you couild wire in a greddy bcc. Although if you are running the stock ceramic turbos then I would stay around 15-16 psi.

 

hmmm i have a different issue with my fuel leveling. it actually works perfectly fine 98% of the time, but that every blue moon my fuel level will drop all the way down to E. even though i know gas is in there. and then it will randomly pop back up to its correct level.

 

hey lexus dog.....how happy are you with your usdm twins? What boost are you running? Any times on the track or hp numbers? I need to plan my future.....thanks in advance!

 

Hey,

I am very happy with the us spec twin turbos. I do not have anything to compare to since I have never used the jdm twins. I run about 18-19 psi. If you are running or doing a jdm setup with us spec twins you will have to run 550cc injectors and the injector resistor pack so the car doesn't run to lean, or just run lower boost and monitor your A/F ratio with a wideband. My car has run numerous low 12 second runs. The us spec twins setup in sequential mode really work very well. Keep in mind the SC is a bit more aerodynamic compared to the GS.

I had a MKIV supra with a small single on it, and I really prefer the way the stock twins work. With an auto, a good working sequential twin setup will be quicker. Auto+single+stock stall=very slow low end.

 

Did you just install the parts and bang? Or did you need to run some kind of management? Sounds like a good plan besides the twins being a PAIN to change. How long did it take you? Where did you source them?

 

You can find a low mileage set on supraforums every now and then. They were installed while the motor was out of the car. I have changed a few sets on my previous Supra's while on the car and it is not that bad. Some spots are a bit tight but it is very doable. Give yourself 5-6 hours your first time. Replace the oil return hoses as well since they get very brittle. I am running a usdm Supra ecu and there is no extra tuning required. Just have to make sure you have enough fuel and are not running lean on the wideband.

 

Hmmm...how do the other things in the car work since your using the supra ecu? I wish the GS was able to just "run" the supra ecu with no other additions.