Hello my name is Rob, and I am considering buying and IS250 with a manual trans. So here are 3 questions that I have that are stopping me from buying this car, and I would greatly appreciate if someone could help me out. 1. The 250 has a 2.5L V6 while the 350 has the 3.5L is that the only difference between the engines? If i were the bore the 2.5L out to a 3.5 would it make the same power output or is it more complicated then that? 2. If i couldnt do that to the engine would a swap be possible? Either the 3.5 L or the new V-8 that will be in the Ls460? 3. Will there be as many mods made for this car as there are for the Is300? Well If anyone can help me out i would greatly appreciate it. Thank you for your time and assistance.

 

1) The 350 has bigger brakes and a cabin smog sensor.

2) Probably not. The V8 is bigger, and there is hardly any more room under the hood. If they plan to make the IS460, there definately has to be a redesign in the whole car's structure.

3) For now, there aren't a lot of options, but I see more options in the future. You can mod anything. Check out some of the new IS pics from recent car shows: people can definately do anything with cars nowadays...

 

1) won't be that easy. if you want the same power output, you need to change the ecu, etc.... definitely a lotm ore involved than just boring it out
2) on the is300 you can throw in the v8 relatively easy, coz' the i6 was actually longer than v8. but now with the v6 it looks pretty tight in there already, i am not sure if you can swap in the v8 easily at all. not to mention you need to change all the harness, intake, and who knows what's going to be in the way
3) i am pretty it will ramp up quick within the next yr

 

It would be much easier to either turbo/supercharge the IS250 or swap a manual into a IS350. No way you can increase the displacement of the 2.5 to 3.5. There is room for a V8 but I seriously doubt the IS250 trans will mate of handle the torque. The cost of any of the above is extreme. Could easily reach 50% of the cars cost and go much higher depending on your choices. If you have the desire and very deep pockets I am sure there are people here that can point you in the right direction.

 

Ok thank you all for the help. Now back to a previous comment. What kind of transmission would be needed to make a IS350 a manual? Also wouldnt the ecu need to be changed if that was done to or no? Thanks

 

not sure about the tranny, i guess the engine is still too new for anyone to say anything

but yes, you will need to change the ecu, or at lesat full it to think the auto tranny is still there. if you do it, i say just change to a stand alone ecu and throw out the stock one

 

You're better off just buying a 350 instead of buying a 250 then doing all that work. With all the time and money you'll put into modifying the 250 it'll probably cost you just as much if not more and it probably won't be as reliable.

 

I agree - probably less work with the 350 converted to MT.

OR even better - LEXUS JUST BUILD A 350 with the 6 speed manual tran!!!

I might wait until 2007 model year anyway if they might build the 350 with manual.