Lexus CT200h Forums banner
41 - 48 of 48 Posts

·
Registered
Joined
·
19 Posts
Rather than supercharging, is it possible to change the valve timing to resemble Otto cycle? Could that be done "on the fly", i.e. engaged in Sport mode to kick up HP but then return to Atkinson-style valve timings in Normal/Eco mode, or does valve timing require a more physical change?
 

·
Registered
Joined
·
19 Posts
Hi,

First off, I personally have no interest in upping the HP on my own car, or modding it in any way post-market, I like my car the way it is! :)

That being said, I'm not sure if this qualifies as ECU remapping, I was more thinking along the lines of electronically controlled variable valve timing, but I didn't know if that could even be approached on the current engine (even if somewhat inefficiently) or would require a total powerplant redesign.

Since Atkinson cycle engines and Otto cycle engines differ in the inlet valve timing, I was wondering if changing that "on-the-fly" could increase torque, for example in Sport mode, but then switch back to the more standard mode.

Anyway, I'm waaaay out of my element, but was just curious. Thanks for the response!
 

·
Registered
Joined
·
199 Posts
Yes, this could be done. Subarus have a sytem on STI's called "SI-Drive" which has 3 settings, ECU programers have been changing the mapping on each setting with that car for awhile now. It shouldn't be much different with the CT.
 

·
Registered
Joined
·
21 Posts
"EV mode" with cold engine



Have checked this subject and it appears we are both right!
There are some design differences between the US version and the European/Japanese version, among them:
In the Euro/Japan model you can engage EV mode during the time frame from pressing START to engine firing (about 10-12 seconds) provided that the hybrid system temperature is not lower than 0 C (32 F). In the US model the lowest temperature to do this is 20 C (68 F)!

So, it's nothing to do with safety.

I wonder what version our friends in Canada get, can you engage EV mode in the morning when temp is between 0-20 C?

Giora.
Down here in New Zealand, I guess we get the European version as I can go straight to EV on start up always.
 

·
Registered
Joined
·
85 Posts
Hybrids are notoriously difficult to modify for extra horsepower. I have a few thoughts and comments, though:

- Given that CT 200h uses a variant of the 3rd-gen Toyota Prius' powertrain, visit PriusChat or some similar forum and see if anyone there has done anything noteworthy.

- Wait and see if the fact that Lexus has registered CT 300h and CT 400h trademarks translates into those more powerful from the factory models later on.

- Bear in mind that the CT 200h's powertrain is NOT 100% identical to the Prius', since the Lexus' full-on Sport mode that seemingly works like virtual boost isn't on the Prius.
Prius and CT shares the same horse power output
And same time 0-60.
Therfor both are same same,
especially the
Powertrain.
 
41 - 48 of 48 Posts
Top