JZS147 swap thread

[Kaiser]

What to consider when doing a swap on a first gen GS300. First thing is to make sure you have enough money to do this project. Expect to pay anywhere from $3000 to $6000 depending on how elaborate you are going to get with upgrades. Yes I know your buddy has a motor set for $1800 yada yada yada. There are some other parts that I would not start this project without. Before we get into parts lets talk about some things you should do before getting to deep. Once you get your motorset, check out those turbo compressors to see if there is any pools of oil in them. If so, consider them bad and be proactive. I recommend a compression leak down test but if all you have is a compression tester use it. Nothing sucks worse than installing a crappy motor. You will need to jump the starter to do this. There is a nut on the inside of the starter and a small harness that plugs into the starter right next to it. You will need to jumper both of these with 12v to get this to kick over. Do I need to remind you to ground the battery to the motorset? This is a dead cold engine and will have lower numbers than you will be expecting. It should be between 125–165. Now for the parts list. This is only if you are sticking with the twins.

1. Supra TT water pump is a must. The Aristo has a funky hydro fan that runs off the water pump. Can you re use the hydro pump? Sure, but if it breaks you are SOL. To put on a water pump you need to tear down the front of the motor past the timing belt so it’s best to do it out of the car. $ 130
2. Timing belt. You are already in there for the water pump so might as well. Line up the crank mark to 0 and there are two marks on the cams that will line up with two small indentation in the black metal surrounding the cams. If all that lines up you are at top dead center. $35
3. Supra throttle cable. A must have if you want to drive it. Put this in while the motor is out. $40
4. Valve cover gaskets. I did it because it’s easier out of the car. Don’t over torque those or you will crack one like I did. I was able to have my buddy tig it and it doesn’t leak. I got lucky. $20
5. Motor mounts. Lexus has fluid filled motor mounts that are almost always crap by the time you do a motor swap. Do yourself a favor and get them ahead of time or else you will have a show stopper without one. $100 a piece.
6. Upper intake manifold gasket. You need to drill and tap the intake manifold with a 3/8 hose barb for a vacuum line fitting for the brakes. The Aristo has hydro brakes and no you don’t want them. You have to remove the manifold to drill and tap obviously so make sure you wash it out good with parts cleaner to avoid shavings. $10
7. Wire and shrink wrap. You will need to at a minimum extend the wires for the cabin harness. About 75 wires 20 inches. About 125 ft of wire. $15 I did not extend the ECU harness as I was able to stretch it far enough to rest under the black cover on the floor, just not in it’s ‘home’ location. I suggest removing the brackets and attaching a ground cable to the ECU as the brackets were most likely the ground for the ECU. I did.
8. Oil filter and oil. I used NAPA brand for the first oil change. Made in the Valvoline factory and only about $1.30 a qt. I suggest changing the oil after a couple hundred miles as you don’t know what the last guy did with that motor.
9. If you don’t have an Aristo drive shaft you may need to swap the 3 pronged bracket off your GE trans to the GTE trans to use your GS driveshaft. If the rubber coupling between the trans and shaft is cracking, replace it. It will destroy itself under more torque if it’s already dry. Check the rear rubber coupling at the diff while you’re at it. $250 a piece.
10. I recommend the OEM fans. I have two electric 14" Zirgos on my car. I use them both as pullers with the additional A/C fan in the front. Still runs too hot for my liking and I will likely switch back to the clutch fan soon.
11. Trans cooler. GTE transmissions don’t like to overheat, then again what trans does. I picked up a small B&M trans cooler and placed it on the other side of my puller fan on the thermostat. $70
12. Spark plugs. Don’t rely on the plugs that came with the clip. I run NGK 6097 and I gap them down to about .026 ish. They will spread a little bit so I figure it’s better to start smaller gap. $12
13. Fuel pump. I made 325 rwhp on the stock fuel pump and no sign of running out. How long will it last like that I don't know.
14. Greddy BCC. If you plan on going over 11psi you will need a boost cut controller. This is a voltage clamp that goes inline with your map sensor. If you need a wiring pin out look up the directions for an APEXi AFC JZS147. $60
15. Supra radiator. Your current upper radiator hose is exactly where the pipe comes into the throttle body. Change radiators or try to find some funky hose that may fit but not look right.

Things you should know. The stock map sensor does not read absolute boost accurately. Once you get over 13psi the resolution is awful. I used my AFC to read pressure and it pegged at 14psi on a regular boost gauge but said 1.22 bar on the AFC. 1.22 bar is about 18psi. I got just under 400 rwhp with the stock map sensor before it’s to lean to go any further. You will need to do another work around if you want more than 400 rwhp. But then again the stock trans is only good to 450 rwhp realistically and the stock turbos will only do 350 efficiently. To put it bluntly, if you want more than 400 rear wheels it will cost you.

The only guage in the dash that will not work will be the tachometer. There is a work around for this on clubna-t.com but I havn’t had time to try it. Please add all other ideas, tip suggestions to this thread.