Soarer209

So I was wondering I’ve had my 99 sc300 for a while now and I’ve put on currently 211k miles still runs and drives very good. Would it be stupid do put a little turbo kit on it? Would I ruin the engine or possibly blow it up lol it’s pretty much all stock besides the exhaust. Sorry for such a nooby question I guess and it’s also an automatic. Which goes into would it be worth swapping for a manual tranny? Should I just stay stock?

KahnBB6

iTrader: (5)

First off, beautiful '99 you have there!

211k is normally still okay to consider going turbo but it's always recommended that you do a compression test first or even a compression leak down test to be sure how healthy your engine is. NA that engine has been proven to go at least 500k+ miles while sticking to all the maintenance.

But since you have a 2JZ-GE VVT-i engine your rods and piston rings are of a weaker design than those found in stock 92-97 2JZ-GE Non-VVT-i engines. That's very easy to cure with either a 92-97 short block swap (and an adapter for retaining the VVT-i function on your cylinder head) or a bottom end rebuild with stronger rods, pistons and rings.

There are documented very low boost setups that IS300 owners have used for years but generally the stronger 92-97 internals (or better) are where you will make the real power most associate with these engines.

There will be the problem of smog since you're in CA and have a '99-- no NA-T or GTE will fly there in the legal sense without getting G&K Auto to make it pass emissions for an extremely high fee for their services and modifications. The only people who have used them to date are exotic and imported JDM car owners.

But... that has nothing to do with whether or not your car is actually a mechanical candidate for going turbo. It likely is but the weaker 98-00 bottom end is what gives me pause on the technical side.

A 5-speed manual swap, whether you are going turbo or not, is a great idea! It does not matter if your car has 211k miles for that at all. However as with going turbo in you '99 in CA there is also the issue of there being no 2JZ-GE engine produced by Toyota from 1998-2001 until the 2002-2005 IS300 5-speed M/T was sold here.

So if you were to do a totally straightforward (mechanically) W58 5-speed manual swap in your '99 SC300 you would want to look into getting a 2002-2005 IS300 5-speed M/T ECU which will work with your very, very similar slightly older 2JZ-GE VVT-i engine and figure out how it needs to be wired up to your car electrically so that no CELs from missing airbag sensors or other bits that the SC didn't come with aren't triggered. Theoretically it can be done with some work and your '99 SC300 would be CA BAR'd as an "IS300 5-speed M/T".

Technically you can easily get a 1998-2000 SC300 2JZ-GE VVT-i to run on its stock ECU without doing all of that work. You'd want to follow threads by Cartmill where he detailed how he got rid of his CELs in his W58 manual swapped '99 SC300. But... I don't think he was in California where even with a 1999 OBD2 you're still required to take your car onto a roller dyno for testing. Only 2001 and up vehicles get the non-dyno smog tests in CA as you know.

Forgetting all the CA-specific aspects you totally can go either or both of these routes in your SC technically. It's just the stock VVT-i bottom end that is really the consideration for an upgrade for turbo duty. And with a manual swap it's still better to go with a beefier transmission than a W58 if you are also going turbo. An SC300 W58 or MKIV Supra W58 are totally fine to use without a turbo and should be cheaper theoretically.

An R154, CD009, converted AR5 or pricey T56 Magnum are the common choices for big turbo power. And the V160 of course but at this point they're hard to rebuild from lack of parts and they are mega expensive.

Soarer209

Wow what a great reply thanks for all the info! A lot more technical then I was thinking.. if I did the manual swap with the bmw or the cd009 how much would you say would be a fair price to install the swap?

KahnBB6

iTrader: (5)

Welcome, and I cannot say what a fair price to install the swap would be. I'm also aware of but not very familiar with the ins and outs of the BMW Getrag/ZF manual swaps. I've never had a shop do a big project like that for me so I cannot say. A W58 swap from a 92-97 SC300 or 93-97 MKIV Supra will be the most bolt-in of all however.

First thing would be to start reviewing the big manual swap sticky thread and start making a list of all the parts you will need.

For you with a 1999 SC300 and being in CA the biggest aspect will be how, if possible, you can follow pinout diagrams and any available guides to possibly make a 2002-2005 IS300 5-speed M/T ECU work in your SC without any check engine codes. To do it by the book anyway with a compatible 5-speed M/T ECU for the 2JZ-GE VVT-i engine that is the same year or newer than 1999. To do it using your original A/T ECU, follow Cartmill's '99 SC300 W58 swap threads:

One has to do with backup lights and another has to do with how to deal with the lack of A650E auto transmission shift solenoids that the ECU will be looking for-- you actually remove them from the auto transmission and bolt them up somewhere under the car plugged in. Alternatively there is or was a shift solenoid custom simulator logic board available from some electronics maker in Russia that is linked in one of those threads. Not sure of the continued availability on that. The way CA would prefer you to do it to have the least trouble passing smog once it's signed off on is figuring out how to perfectly wire in a 2002-2005 IS300 5-speed M/T ECU.

So far I can't recall anyone who has posted here about doing that but that doesn't mean it isn't technically possible with some research along the lines of engine harness functions. 1st gen IS's have been gone over tremendously for all manner of NA-T builds, GTE swaps, use of JDM ECUs and aftermarket ECUs so I think the understanding of how the electrical systems in those cars and by extension their ECUs is as well known by now as the 92-00 SC chassis and ECU electrical.

The easier aspects will be gathering your parts and getting those fitted into the car. Nothing needs to be mechanically custom fitted if you go the W58 route and can acquire all the factory parts.