I have a 98 GS400, it is around 105k in mileage now.

I have come to a crossroads on what to do with the motor, this is my daily driver, with occasional hard tracking days, so reliability and performance is still a factor.

Later on I will be building another project for my full on track car.

as of right now:

option 1: Swap in a new shortblock from lextreme with the stronger bottom end, stock compression ratio, sleeve it to a 4.3L, and do some basic headwork. Basically to refresh the car with a "new" motor and some, while keeping it N/A.

option 2: Swap in the 2jzgte VVTi (I want the 5 speed still with e-shift, + I need OBD2 for emissions), then obviously it is a great platform for adding more power if needed later. However i've heard that this option is harder for GS4s, what would I need (besides the obvious motor, tranny, ecu, etc.)

Either way i'm looking at doing a swap, now i know I could do the v8 swap and then turbo, but i'm trying to compare similar costs, and that route will obviously put me way over in cost, since i'd be spending another 5-9k on the turbo set up alone for the v8.

So what should I do? keeping in mind cost, reliability, fun, potential, etc.

hope that all made sense. I did do a search for the 2jz swap but found mostly opinions and information on the gs3 to 2jzgte


Oh and where can I find a good complete swap/clip for the VVTi 2jzgte

 

being that you have a GS4...i would choose option 1. again just me tho.

 

Stay w/the V8 then boost it.

 

Supercharge your current at 105K it's just getting started

 

or maybe I should just sell and buy an STI or supra

 

^^^ That would be my choice.. Leave the motor alone and supercharge it, that is if you are keeping the car

 

I'd go with option 1. It'll give you DD reliability (though I'd imagine the current 4.0 should be good for a long time) with some good punch. Later on down the line you could always go the S/C or turbo route, but until then you'll have a nice performer with some *****.

 

I would just lower the compression and boost it. Once the car was set to the way I wanted it then I would buy a refresh the bottom end with a lextreme one and finish tweek it. Just a note be very careful because lextreme is not getting a lot of props in other lexus forums. There is not many turbo boosted gs400 anywhere maybe supercharged but not boosted.



Supercharged= 389 rwhp with a lot of belt slippage
turbocharged= 400+ rwhp easily (8psi) with room for much more

 

I do not have belt slippage at 389 rwhp. Depends on your setup and how much tinkering you've done, not sure whose you are referring to.

AKY, what kind of 'occasional track days' do you mean? Will this car still be your daily driver?

Anything boosted over 400hp is going to be borderline unreliable IMO and other parts of your car (most notably your drivetrain) will also need upgrades.

On Option 1 I think you may be the guinea pig somewhat for built NA VVT-I motors in a Lexus. I don't recall reading of any, but if Lextreme is selling them I guess somebody has. If it's proven that is the option I would take.

 

Clarify what you mean by "track days".

Are you saying you will take your porkly, nose heavy GS and hurl it around a race track?

I personally see that as a waste of time, but that's just me. If I wanted to track a car, I would buy a lighter car with better dynamic balance - like an M3 for instance.

Oh BTW, the engine in your car is not even broken in yet at that mileage.

 

it'd be track days as in some fun lapping days. like I said the gs will never be my full on race car, but my fun dd with some track use.

 

I have a GS3 in WA, we can trade!

 

Swap in a stroker, a REAL 5.65L stroker with a 2uz iron block. Raise your CR up to 11:1, upgrade your cams, and have a VERY tough V8 GS. You'll be pushing the limits of your stock Lexus transmission at that point, but it'll be a serious blast to drive on the street.

Agreed 100%.. The stock V8 internals are weak as water.

Eric

 

yup that's one reason why I don't want to boost on stock internals. i've already done my FI projects on my past car and was always at the edge of reliability. so I try not to boost motors not boosted from the factory, at least for daily drivers.

however I miss boost a lot and so that is why I am questioning the 2jz or just getting another boosted car.

 

i would just get low compression pistons and rods, throw twin garret gt28rs turbos on there and call it a day

can the valve bodies in the gs4xx transmission be upgraded?