Gs400 to gs430 assistance
12-01-15, 07:41 PM
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Gs400 to gs430 assistance
My GS400 started to blow a lil smoke and then ultimately, slight rod knock. I purchased a 02 SC430 engine and many have said run the Gs400 ECU. AFR and timing will be affected, but what safeguards should be followed. What options do I explore APEXi SAFC and dyno?
Seems a few on here are very knowledgable and hopefully you will be willing to share.
I DO NOT PLAN ON PULLING THIS ENGINE APART. SWAPPING THE THROTTLE BODY, THE ONE DAMAGED VALVE COVER, THE WATER PUMP AND THE WATER NECK IS ALL I HAVE PLANNED.
THANKS IN ADVANCE
Seems a few on here are very knowledgable and hopefully you will be willing to share.
I DO NOT PLAN ON PULLING THIS ENGINE APART. SWAPPING THE THROTTLE BODY, THE ONE DAMAGED VALVE COVER, THE WATER PUMP AND THE WATER NECK IS ALL I HAVE PLANNED.
THANKS IN ADVANCE
Can't you simply drop the GS400 throttle body on and call it done? Isn't the rest the same?
Now, be VERY aware, the cams are different in the GS430 than the GS400, and the timing curve will not be ideal, and it could cause drivability issues that can't be solved.
Now, if you drop in the 4.3L engine and the 4.0L Cams, that would be a better choice. The ECU will be off with the displacement change, but it ~should~ be in the realm of being able to handle it.
Displacement change will only affect AFR, which is already screwed up thanks to our politicians who play chemist and mandate we run E10 fuel (aka, 10% ethanol) which Lexus NEVER designed it to run. It CAN handle 10%, but it was TUNED in Japan for 100% gas, not 90% gas/10% ethanol.
Think of it this way. 4.3L as is, computer will have timing maps messed up (peak torque on a GS430 is significantly different than the GS400), the cams will dictate that. Displacement change on the ECU will only affect AFR.
If you need to use a 4.3L, fine, use the 4.0L cams and 4.0L Throttle body and if you have to, intake and GS400 wiring harness and ECU. That would be less invasive. Can't say it will be 100% check engine light free, but likely it will handle it better.
Now, be VERY aware, the cams are different in the GS430 than the GS400, and the timing curve will not be ideal, and it could cause drivability issues that can't be solved.
Now, if you drop in the 4.3L engine and the 4.0L Cams, that would be a better choice. The ECU will be off with the displacement change, but it ~should~ be in the realm of being able to handle it.
Displacement change will only affect AFR, which is already screwed up thanks to our politicians who play chemist and mandate we run E10 fuel (aka, 10% ethanol) which Lexus NEVER designed it to run. It CAN handle 10%, but it was TUNED in Japan for 100% gas, not 90% gas/10% ethanol.
Think of it this way. 4.3L as is, computer will have timing maps messed up (peak torque on a GS430 is significantly different than the GS400), the cams will dictate that. Displacement change on the ECU will only affect AFR.
If you need to use a 4.3L, fine, use the 4.0L cams and 4.0L Throttle body and if you have to, intake and GS400 wiring harness and ECU. That would be less invasive. Can't say it will be 100% check engine light free, but likely it will handle it better.
Last edited by NVR2EARLEY; 12-02-15 at 07:06 AM.
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03-12-14 01:04 PM