Hello,

Does anyone know what differences there are between the JDM engine and the USDM engine in terms of specifications? What is the factor that allows the JDM engine to produce 215 hp vs the 204 hp that the USDM engine produces?

Thanks.

 

I think the only difference is the quality (Octane) of the fuel that is used in N. America vs. Japan for the Hp/Tq ratings and or testing. The ECU might be set a little differently as well based on the minimum recommend octane fuel for each country. But that is just a guess. Otherwise the engine design/performance is the same.

 

i cant seem to find a previous thread, but i recall reading a thread about a 220d where the guy wanted to know why a certain european model had like 10 more hp and it ending being some kind of relay or harness that cut the certain IS model down by a few hp. it was a simple mod but resulted in the car gaining 10hp or so... maybe this could be something similar. does anyone recall this thread im talking about?

 

^^ Yeah, i've read that thread , just couldnt recall where i read it from .

 

usually it's an emissions thing. most car makers have higher outputs with the same engines in their home countries but detune it a bit with mods to the engine, ecu or what have you so to meet US emission standards. it's a pretty common thing because there are such things as global cars but not global emission laws

 

If that's the case, has anyone experimented with an JDM ECU swap? It sounds to me like this should be a valuable upgrade since it gains 11 hp by simply "un-restricting" the true potential of this engine.

 

interesting thought but you'd need to check the specs and see what the actual difference is between the USDM and JDM cars is

 

True. Maybe this is why so many people are waiting for TRD to come up with a chip program or ECU mod. The jdm ECU must be difficult to swap in.

 

https://www.clublexus.com/forums/sho...ighlight=relay

found that thread on accident about the 220d deal...

 

So has anyone found this in an IS250 yet? If that's the case, we can remove this so-called "regulator", and instantly gain 10-15hp? Oh my...

 

Nope,

The IS250 is a naturally aspirated V6 whereas the IS220d is an in-line turbo diesel.

There is no such electronic limiter attached to the MAF sensor on the IS250. Again, the difference is fuel related only. Mechanical limiters such as the CATs etc… are the best options for more power but these types of modifications also have drawbacks as well.

Regards,