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Discussion Starter · #1 ·
Just picked up a 99 GS400 for $4200. Going to start pulling the engine tonight, maintenancing it in prep for installing it into my IS. I wanted the whole car because there's always parts you're missing during the swap and I can cannibalize them off the GS.

Going to put the GE back into the GS and re-sell it for nothing ($3000 maybe) to help cover the cost of the swap.
 

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Discussion Starter · #3 ·
Naw, A GS400 has a 1UZ 4 liter aluminum V8. Twin cam. 300 hp 315 ft/lbs torque.

GS300 has the 2J

Weights between 50 and 100 lbs less than the 2J too.
 

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No way! The 1uz is lighter??
 

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^ if I remember correctly isn't the 1uz 45bs lighter?

One thing I was always curious about, if a gs400 and gs300 should have a interchangeable crossmember/engine mounts for there chassis, does that mean a gs400 crossmember/engine mounts fit into a is300? While unlikely, it would be cool if they were.

I hope to do this swap one day, with a 3uz, and put the SRT stage 2 charger on it, hopefully by then I could get one second hand since I would never deal with SRT directly.

Good luck on your swap, and take lots of pictures and notes, to document it well here on the site, I for one am extremely interested.
 

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Discussion Starter · #6 ·
I was thinking 3UZ too but, all the ones in my year range were nearly twice as much money for only another 15 ft/lbs of torque. The 99GS has VVTI on both intake cams. The 1UZ got VVTI in '98. I pretty much lucked into this car. It just came up on CL for 5K. The CEL had been on for 2 years and they were within a month of needing an emissions inspection. The engine leaks oil from the valve covers too. The combination of the CEL and the oil helped me get it pretty cheap. I actually fixed the CEL on the way home. Someone had left one of the evap lines disconnected in the engine compartment.

I'm not pioneering this. It's already been done and documented.

IS300 V8 Swap

He started with an 02 IS and some of the wiring is different. I'm hoping the 01 IS with 99 GS will be pretty close wiring wise.

I'm looking forward to taking apart the GS and comparing parts to the IS.

The GTE's are 100 lbs heavier than the GE's so, it depends on what model of the 2J you're comparing too. 45lbs sounds about right for the vanilla GE. The difference is that the 1UZ and 3UZ are all aluminum blocks with cast in cylinder liners whereas the 2J has a full cast iron block.
 

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Discussion Starter · #7 ·
Suspension on the GS is exactly the same design as the IS. I'm sure the parts aren't identical but, it's the same design down to the front #2 bushing and the under-brace. Think I might have the drivetrain out tomorrow or sunday. The front upper control arm and rear upper control arm are both aluminum on the GS. The rear looks to be the same dimensions as the IS arms but, I won't know for sure till I remove one of each and compare.


The GS diff is significantly bigger and stronger than the one in the IS. I won't be drag racing or drifting so, I'm, not sure that matters.
 

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Correction here, quad cam. V8 has 2 cams on each head. 1UZ VVT-i are beast and highly reliable in stock form, but boost is kind of out of the question since they have smaller rods also (much like GE vvti vs. non-vvti). However, the torque band is simply amazing. 200+ lb ft at around 1600 rpm is awesome. I test drove a nice 1998 SC400 (in the rare purple color, not to mention very well kept inside and out) and that block pulled that luxbarge pretty hard. I still regret not buying it to this day, but I got the IS300 I have now instead.

Once my turbo GE dies out, I'll probably try to find a 1UZ VVT-i to swap in.
 

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Discussion Starter · #9 ·
Yeah. you're right. You know it's a funny design, they have one pulley on each head and the exhaust cam is driven off the intake cam.

Got the front suspension off. I've decided to drop the motor out the bottom and drag it out on a sled with a come-along. Means I won't have to remove the radiator or AC condenser but, does mean I'll have to re-install the diff cradle and suspension to push the carcass out of my shed. It's a hell of alot of car for $4000.

The front upper control arm is cast iron. It uses spherical bearings on the body side. I'm going to take pics and measure it and see if it's the same as the IS one. In general several of the GS suspension bolts are one size bigger than the IS bolts and the knuckle seems to have more cast iron in it than the IS one. #2 bushing is bad on both sides. Not really surprising. Some hammer head torqued the shit out of the suspension. Had to break out the long breaker to get some loose. The under brace is in 2 pieces so, you can take the brace part off without removing the #2 bushing nut.

Taking the exhaust off now. It's pretty new. I think it would make a good base for an IS exhaust. I'm just worried about the exhaust clearing the rack. The GS rack is in the same position as the IS so, I hope it's a non-problem.
 

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I'm sure you can manage something using the stock headers and just have a shop custom-make the rest of the piping. You'll probably have to merge into a Y and go single exit, unless you're really cool and go custom duals lol
 

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Discussion Starter · #11 ·
The stock GS exhaust has 3 cats like the IS. 1 on each side of the head. Those are the main cats and the ones monitored by ODB2. Then it merges down into single 3" and a third cat that seems to be more noise damper than anything else. Then it splits again into 2 resonators and 2 mufflers. It's heavy as hell. What I'd like is to remove the 3rd cat and use 3" pipe back to a single 3" exhaust in the stock position.

GS has lightweight heat shields on everything. Even between the driveshaft and the exhaust.

The driveshaft is a wierdy. Has a "guebo" on both ends (if you're a BMW guy you know what that is) basically a rubber coupler on both ends. I guess it's used to dampen the drivetrain.

I've got everything done underneath. Only sheared off one exhaust bolt on one cat. Need to disconnect the steering wheel to rack coupler. Then drain everything and start unbolting. Disconnecting the engine wiring from the body is pretty simple. I'm basically taking it back out the same way it was put in from the factory.
 

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I like the sound of this build :300 HP NA IS300 the way it should of came from factory or GTE . I fixed the title :)....Best of luck ill be watching !!!
 

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interesting, goodluck with your build
 

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Discussion Starter · #14 ·
Got the engine and tranny out. The method I chose, out the bottom works pretty well with subaru's but, not with 1UZ lexi. I won't do it this way again.

I have to decide whether I want to use 1UZ or 2J motor mounts. The swap I'm referencing used 2J mounts. Motor needs valve cover gaskets, timing belt and idlers and probably the water pump. New plugs too. That's the next part of this project, getting the engine ready for transplant. Going to re-loom some of the wiring. The rubber protective cover on some of the harness wires is falling off.

Quick and dirty measurements suggest the frame to frame width of the engine compartment is very close between the IS and the GS. Just for grins, I'm going to be measuring the engine cradle to see if it can bolt into the IS.
 

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Good stuff there EK.. Do you have pictures of your progress? I wanna see this stuff
 

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Discussion Starter · #16 ·
Been taking pics. To document how things go together and sizes and such. I'll look into posting them.
 

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Cool swap.. it will make a nice "factory" IS400 :)

I'd be interested to see pics too..
 

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Discussion Starter · #18 ·
The guy I'm modeling the swap on swapped the tailshaft and output shaft on the 1UZ transmission to make it compatible with the IS300 drive shaft. I really don't want to take apart the OEM transmission so, I think I'm just going to order a custom one piece driveshaft that converts the 1UZ "guibo" end using an aluminum plate into a conventional. u-joint. Then have a conventional joint on the diff end. Another reason I don't want to use my '01 tranny is that it doesn't have a speedometer gear built in since the 01's get speed from the ABS. Lexus wants $400 for a tailshaft with the speedometer gear. I can buy a complete used transmission for less that that. So, all that points to the idea that in the long run it'll be cheaper and easier to buy a custom driveshaft and just use the transmission unmolested.

The Driveshaft Shop | TOYOTA 93-98 Supra Turbo 6-Speed 1-Piece Pro-Series Heavy-Duty 3.5'' Chromoly Driveshaft with Aluminum Conversion Plates - Toyota - Import Driveshafts

Something like this.
 

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Brad Bedell also did this swap in a Sportcross- he then supercharged it....... he is insane if you have never heard of him. he actually won a spocom shoot out with his 3vz MR2.

check him out- he will have a ton of the help and diagrams and parts and tricks you need to do this easy and successfully

BEDELLRACING.COM

my buddy Andrew actually went and helped him on this swap- said it Brad drove him like a slave but it was worth it lol (no offense intended)
 

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Discussion Starter · #20 ·
Yeah thanks, been to his site. That's what started the ball rolling. It was his experience building 3 transmissions to get one working one that decided me on a custom driveshaft.

I was taking the engine apart tonight. To replace the valve cover gaskets, you pretty much have to pull the harness off it. Got the timing covers off too. Think it needs a PS pump. Not sure if I want to paint or powder coat the aluminum covers.
 
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