Whats the difference between GS400 and LS400 engines and Ecu?

[msmile]

Hi guys!
Tried searching the forum, but couldnt find exactly what Im looking for. If theres a thread already, please give me a link.

The question is:
As I know GS400 produces 10hp and 15Nm more than LS400 (1997-2002).
They both use 1UZ-FE VVTi engines.
Is this the ECU mapping that makes the difference or is there something different on the engines?
Are GS and LS ECUs and Looms interchangeable or not?
Will I be able to use GS Ecu on LS loom?

Thanks alot!!!

 

[msmile]

Still interested. Any ideas guys?

 

[gloverman]

Ive run GS400 ecus on the same test bed as the LS400 ECUs and they both function. When I have swapped them into vehicles there have been no noticable differences in the vehicle but this is just a subjective test for a very short time. I haven't done dyno runs to check power output. If the main engine componants are the same then I have been able to mix and match looms so far or in some cases I've swapped engine componants too between different 1uz and 3uz VVti engines.

 

[George_R]

msmile
I bet there's very simple thing involved in that extra 10hp / 15nm like maybe timing being advanced a tad, and allowed maximum throttle opening angle increased, too (drive-by-wire system easily offers that level of tweaking). I think these performance figures are not that impressive , they're not worth the price difference between UCF21 and GS400 ECU's

 

[Yotarip]

Gloverman,
I have a 98 GS400 1uz vvti motor/ ECU and I have a 98 LS400 harness that I plan to use in my swap because it will located the ecu behind my glovebox. The GS harness locares the ecu in the engine compartment.

Do you know if the 1998 GS400 ecu will work with the 1998 LS400 harness without repinning the plugs?

Thanks in advance.

 

[gloverman]

So far they have all been the same on the early ECU's. I always check the pin out with my test bench before fitting to a vehicle.

There is a pin out change in the VVti later on.

 

[EyesofThunder]

According to my friend at Lexus, he said he is pretty sure the LS400 and GS400 engines (VVTi) are identical PN, the only diff is the air cleaner, ECU tune and exhaust. He feels it is the silent exhaust in the LS that lost the 10 hp.