MartelJF

Let's get a little picky.

Looking at my current options for an SC400. I want as new as I can get within my price range. Few questions:

In 1998 the SC400 gained VVT-i officially, and a new 4 liter rig to replace the old V-8. Has anyone had experience with the 97- and 98+ engines to be able to tell me if there's much of a difference in power and performance from the engine change?

Additionally, are some mods limited to only the VVT-i or non-VVT-i versions?

Thanks much!

pcmw

Martel,

The mods for the V-8 SC400 are limited. More so for an OBD-II car 96+. If you are a looking for a power mod car, then most people prefer the SC300.

Hence frustrations: https://www.clublexus.com/forums/sho...threadid=69156

If you need years and VVti specs etc..

https://www.clublexus.com/forums/sho...threadid=72549

Question about ECU mods... try here.
https://www.clublexus.com/forums/sho...threadid=72112

MW

Phoenix88

I would try to get the 98, or newer if you could. 98 also got real wood center consol, 5spd gated auto shifter... as well as the engine that I know I would love to have. SC300 Turbos are great, but if I don't have to mod the engine I won't. (Also I am jelouse because in Canada we don't get either SC300 or any SC after 96)

lex400sc

If you're going to get an OBD-II car, might as well buy one with 290hp & 300tq from the factory.

Carpe Diem

Please, what is OBD-II?

MartelJF

I realize the mods are limited.

If I had more confidence that I could find an honest and qualified Toyota mechanic and/or shop in my city (Kansas City), I'd get an SC300 and turbo the hell out of it.

Realistically though, I plan on just keeping my mods simple. Intake, exhaust, suspension. Maybe a supercharger if those kits ever get worked out.

Hence the SC400 interest. Sound kosher?

MartelJF

Example of what I mean, after an hour of searching and whatnot:

The Weapon-R ECU upgrade is only good up to 1997 for the SC400. Apparently it's not compatible with the new engine/VVT-i. Same for the cold air intake.

Phoenix88

But if you think of it, if you have the 290 hp you are already 30 up from a 97... 97 is 260hp 270 torque if I am not mistaken. How much do you think those two will give you? The 5 speed tranny should help as well, and even if it doesn't, it looks cool lol, I guess I am all about gimmicks and cool stuff, hence why I bought the lexus in the first place, so many cool things on it. 99 had some sort of stereo update as well, I am unsure what it is. Maybe if you can test drive the two, if there isn't much of an improvement with the 30hp then get the 97. Or you chould be... whatever stumbles my way first I will take it... both are extremely nice.

MartelJF

It's a very valid point, and why I asked the question in the first place.

Electric fans: Relieve about 30 HP (though you might be able to do this on either model).

Racing Torque Converter: No required model year listed, so I'll assume you can do it to any automatic SC.

Weapon-R ECU gains (pre-98 only): "18-30HP and 16-35ft of
Torque"

LexusPros Computer Upgrade: This thing is actually for PRE-97. Gains seem to be higher than the Weapon-R ECU because it's a more complete replacement.

Cold Air Intake (pre-98 only): No specific gains, just, "By isolating the filter and allowing the engine to draw air from a cold source in the engine compartment, away from Horsepower Robbing Heat."

Having looked into exhaust, but I'm guessing that the model year doesn't matter.

I'm willing to bet that the supercharger and turbo kits are for pre-98.

pcmw

Great rundown of the mods Martel.

The exhaust with OBD-II is difficult because of the cats and the O2 sensors that need to be tricked if you are modifying anything forward of the 'resonators'.

MW

MartelJF

Which applies to any automatic SC, yes? So exhaust is an issue.

OBD being On-Board Diagnostic.

ChrisK

iTrader: (1)

Someone would think that 30hp and 30ftp difference is not that big, buy I have only one word to say: VVTi. VVTi makes a huge difference on how the car can be driven, power curve, etc. If you take both for the test spin you won't think twice which one is better.

808state

if you put on tex's headers, put in cats, then the o2 sensor, would it still give the dreaded check engine light?

if the aussie's supercharger kit comes to light, don't know if it would work on the 98-end models because of the different intake and vvti.

on the 96-97, i'm wondering if the supercharger would set off any sensors/check engine light. i'm "assuming" not since from what i read, putting nos, adding a larger flow fuel pump and injectors, hasn't caused these check engine lights to go on those models.

torque converters, i've read some people had problems with the check engine light going on (though i think it's more so of a problem with the gs400)...haven't heard of anyone with 97 or 98 get one. though, this is not a power upgrade but rather a traction/lockup upgrade.

quite honestly **in my opinion***, the only power mods worth doing for added power is the bfi and nos(doesn't matter what year you do it on)...everything else is window dressing meaning nice to do but *results may vary*... the holy grail would be the supercharger/turbo kit..but you know how that goes.

you also might be able to do an exhaust cam change out an tex's header on a 97 as pete did to get power output near the 98-end models...though this is speculative on the 96-97 since his car is older though *should* work. note, it's a lot of work and you'll have to do some shimming. again, power output may vary and may not be all that cost effective.

i think the electric fans gains/egr bypass only apply to sc300s and not the 400 models.

i'm reserving judgement on cpu enhancements on a 97 sc400 model plus i'm not exactly fond of raising the rev limiter (just my thoughts) though supposedly they are tuning the mixture accordingly. you can throw in the mine's ecu for the jdm models into the mix.

http://www.obdii.com/
http://planetsoarer.com/cats/cats.htm

lex400sc

Take those Weapon-R power gains with a large grain of salt. There was a dyno intake shoot-out between Injen, Weapon-R, and Swift on a stock GS400, and last I recall neither of the three produced the advertised numbers. I say take the '98+ model, that's what I'd do. The intake mods are a pretty lame reason to go with a slower, older car. The Dragon TC and 3.13 LSD will work on any year and will give you the biggest gains of any mod short of a blower. The electric fan is a good idea too, but Hermosa and I were examining the mounts between the SC300 and SC400 and it looks to be a bit different, so some discovery is in order to make that one work. Oh yeah the 5-speed tranny is the same as the GS4x0 tranny, and driving that car and mine, I can tell you that it is much more efficient.

MartelJF

Thanks for the insight 808state.

Here are some stock numbers I was musing over when looking at what year would be the best choice:

1995 Lexus SC400
Weight: 3506 lbs.
Horsepower: 250 hp
Max Horsepower: 5600 rpm
Torque: 260 ft-lbs.
Max Torque: 4400 rpm

1996 Lexus SC400
Weight: 3585 lbs.
Horsepower: 250 hp
Max Horsepower: 5600 rpm
Torque: 260 ft-lbs.
Max Torque: 4400 rpm

1997 Lexus SC400
Weight: 3605 lbs.
Horsepower: 260 hp
Max Horsepower: 5300 rpm
Torque: 270 ft-lbs.
Max Torque: 4500 rpm

1998 Lexus SC400
Weight: 3655 lbs.
Horsepower: 290 hp
Max Horsepower: 6000 rpm
Torque: 300 ft-lbs.
Max Torque: 4000 rpm

1996 seems to be the "worst" power:weight year with a gain of 80 lbs and no horsepower bump. 1998 is quite clearly the best, although seemingly the least mod-able.

One step forward, two steps back.