What's the difference in 1UZ engines (apart from vvti)?

[Westy]

Hey,

I have myself a 1995 1UZ in my 1995 Lexus LS400 and have now picked up a wrecked 1999 Lexus LS400.

What is the difference between the 2 engines apart from vvti? I have been told that the vvti version has a weaker bottom end and it seems people don't have (or don't make) superchargers for them.

Ideally, I want to start with the best base possible. I know the 1995 has about 195kw and the 1999 has about 220kw, so obviously this would be better to start with as I have to chase less power in the future. I am definitely going to be doing an exhaust upgrade which I think either engine will appreciate but after that, I don't know. Have been told for the supercharger, the vvti has to go.

Any help will be greatly appreciated.

Thanks,
Aaron

[George]

your '95 1uz has weak rods as well. vvti ECU is more complicated, so whatever you choose (piggyback or standalone) to support supercharger will be more expensive. I've heard vvti heads flow more though.

[4th surf]

Effectively the bottom end is much the same so the engine itself will be a direct bolt in. Yes the heads on the VVTi version flow way better than ported early 1UZ heads. All the electrics are different between the two engines with the VVTi being "Fly by wire" and non VVTI cable throttle, VVTi has coil on plug ignition and they can be supercharged it's just horrifically expensive. To give you an idea you might like to search for costs on supercharging the late 2UZs which are similar.

So VVTi has to go for forced induction? Yeah right.. Doesn't on most other engines that have it, but it's the making it all work part that makes it hard. Given the costs involved however you might be best to part out the '99 to recover costs and make some profit to put towards what you already have. Sad to say with the UZs in the pursuit of more power it's "All or nothing"

[JustenGT8]

I can offer you a built VVTi bottom end to solve that issue

[mullett]

If you're committed to going SC, it'll be a lot cheaper to use the non-vvti motor. If you're not keen to put the $$$ in (5-8k for SC), then use the VVT motor! They're a much better engine in so many regards. Plus, you can build an SC non vvt motor on the side and put it in when you're feeling like some skids

End of the day, I consider the LS400 a cruiser, i wouldn't spend mega dollars trying to give something that heavy more power...might as well start with a lighter base!

All of that said, i wouldn't bother swapping the motors out at all...it's a lot of hassle unless you really love the car, I'd put the motor in something a bit more exciting