LexCiting

Keep us up to date. I would particularly like to know when you are finished. I am planning on getting to FL sometime this summer, and since you are in FL, we could do a "real" world shootout between a SRT TT (stage 2) vs your single.

JZS14SEVEN

V8 gonna go single turbo??? how are you going to fit the piping in the engine bay?
opposite exaust manifold sides of a V8 feeding a single turbo?
are you keeping acessories(AC, power steering, etc etc.)
a 4.0L V8 could spool a T78 easily...
but 750rwhp from a T78.. tax the turbo already to hit that Hp

question???
where are you gonna fit the proper(huge) intercooler & piping you are going to need to hit that kinda power with that turbo

LexCiting

JZS14SEVEN - great point! I was going to say something about that, but didn't want to sound like a "hater", particularly on someone else's project. I don't think people realize just how little room you have to work with in the engine bay of a GS4. From experience, there is not much room. As JZS14SEVEN said, with a single turbo, you have to worry about not only both exhaust mainfold pipes feeding one turbo, and the heat problems with that (because it is a V-8), that turbo size itself taking room, and the intercooler piping. Now if you eliminate some of the accessories, such as the AC unit, resposition the battery to the trunk, reposition the CPU housing, re-route the power steering unit, maybe, but you probably will be losing some of the luxury. The BIG problem is going to be on the drivers side of the engine bay. Not to get into any details, but Lexus designed the frame, driveshaft, and the steering unit in a unique way! (Hint - Reason why there is so much piping in my design, but that is about to change SOON! ) Also when you think about getting that much rwhp, taking into consideration that your HAVE to get forged piston/rods/custom fuel management unit/rebuilt tranny), you have to worry about the driveshaft from twisting/breaking, custom engine mounts (you will tear away those stock rubber mounts as soon as you gun it) to hold the rwhp, and all types of fluid coolers.

Check out my engine bay in the attached pic.

But not to say it can't be done. Tuners can become VERY creative when challenged! (the good ones at least!) I hope his project gets off the ground, I didn't think the TT setup could not happen, but it did!

Good Luck!

LexCiting

Pic

Richie

LOL, you're not kidding about the lack of room!

leogsx97

Should be doable, easier than twin turbo.

You will need to remove front fans and place slim fan on the other side of the radiator,
You will need a custom manifold in shape of

||-----engine------||
||-----engine------||
||-----engine------||
||---------------------||
=====turbo=====

double line is shape of the header (exhaust manifold), make sure the turbo is supported
in the front or the manifold will crack.

T78 looks like a good choice for a 4.0 V8 (my Starion with T78: inline 4 2.6L (some log, start spool at 4K))
by the time I hit full boost (6.5K) the car would loose traction in third gear, very hard to drive.)

Problems you will have
lots of money to setup engine and tranny for such a large turbo
messing with fuel and aftermarket fuel controller is another big problem will never run as factory turbo car
will not be reliable
will still be slow compared to other sports cars unless you will run slicks on the street (12.5s 1/4mile)

Rear wheel drive, heavy cars with lots of power are very hard to drive on the street,
and they will always be slow on the street, unless you want an all time drag car (GS400 is bad choice)

If you want a fast car for cheap, it easier to buy an AWD turbo 1G (1990-1992) eclipse for 2-3K
spend 2-3K and run 12s, want to go faster spend another 3K and run mid to high 11s, want to
go even faster? To run 10s will be very hard, but very doable. The good thing about AWD
is that you can run as fast on the street as on the track. If you don't like 2-door cars
you can always buy Galant VR4 or Lancer Evolutio VIII.

Good luck with you project
Leo

2JZGTTE

Leogsx97, Why does it have to be unreliable? What part or feature will make this car unreliable? Also with aftermarket fuel controllers and EMS units it all comes down to who is setting the programs up. With hours on the dyno and a good tunner who knows what hes doing. You can make that car more efficient than the factory set up. I know this first hand from daily driving an AEM EMS car. I have logged over 12,000 miles with not a single problem with it.

leogsx97

Part and features that will make the car unreliable,

forged pistons can be considered unreliable, used JE forged pistons in one of my cars
they made a lot of noise before the car warmed but they held 27psi of boost.

Used Haltek E6K and I cosider its a hack and not reliable, AEM EMS could be better,
but I have not used one of those, is there one for GS400?

another part, is lots of money that it will it eat up, will you alsways want to dump so much
money into the car? Seen many people who stop in the middle of the project and loose
all (most of the money), not very reliabel

I consider that lexus is reliable from the factory, and it will not be as reliable when it makes
over 700HP it can be made some what reliable, but I would not drive it everyday.

Overall I have not seen the car that runs mid 11 and is reliable (daily driven), not saying that you can not
build one (everything is possible with enough cash) Will you drive you car everyday?

Anyway I wish you lots of luck

Leo

Bling

I will definitely tell you all about any problems when I have them. I know I am spending enough on the car, that if its possible not to have problems, we shouldn't be having any.

Personally, I think the problems that will be the ones the tuner is least prepared for are heat in the engine bay, and rearend blowing up. The highest level trd I am getting is supposed to be able to handle over 800 rwhp daily. We'll see. It is my guess that the car will have quite a few bugs for the first 2 months, just because I don't know of anyone else in the world with a big single on a gs400.

The only question I really have right now is whether I should spray it too. Its only like 5% more money to add another 250hp. Maybe we'd only do a 175 shot.

Oh, the other big problem I can see is traction. We basedlined the car on 20's at moroso yesterday. 14.76 1/4 with a .818 reaction time. on lownehart ld1's. (Air filter pulled out.)

The car is supposed to pull 14.3's stock, so I read. If I had a perfect reaction time (.50) It would have been a 14.442 Pretty good considering completely stock on 20's.

JZS14SEVEN

since when is reaction time factored into 1/4mi E.T.?

"Big Single" is a relative term is it not? whats big to another motor.. maybe kinda small for yours
with that much exaust gas to move..

Bling

Good call. I think I am a dumbass. The thing doens't know to start counting until the second laser is broken. Thus reaction time has nothing to do with the time I run, only the finish line against the other car. I was doing dial in, and ran against the worst possible. Dial in at 12.0 ran 12.011. wow. I did beat her reaction time though.

2JZGTTE

Bling- Both heat and traction are not going to be a big problem. 1. The heat is easy. either a heat shield or header raps is all you need. I have two turbos and still have no heat problems(simple heat shield by the turbos). 2. traction- there are many upgrades that can be done to a TRD LSD. Mine was a build up and I do just over 600 RWH. My tuner says he could build it up more for me if needed, just is a money factor. Now I will say one thing GET SOME SLICKS! If the trans is built to take the beating then go for it. Also you cant forget the drive shaft. Please build this item up too. I cant tell you how many hours it took me to walk back to the shop from the local drag spot. Either get the stock one beefed up or go with supra/racing style drive shaft. Good luck and dont let one or two haters get you down. I have a daily driven sc300 with now just over 600rwh and it starts everyday to get me to work which is about 19 miles one way. I have well over 12,000 miles on the install and the motor had over 50K on it. I have only returned to the tuners for minnor BS with the A/C belt. The damn thing wasnt tight and was screaming like a B*#CH. Have a good one and keep the faith.

Bling

Right on! We are using a custom drive shaft, highest level trd rearend, color for the drive shaft just if it breaks free...Stainless steel fuel line all the way up, I am big on saftey. If you can think of any other reliability upgrades, now's the time!

Thanks.

ChrisFL

Ok, I have a few insights/questions about this. I realize this is about the GS400 mainly, but there may be some similiarities

First, I have the Turbo magazine with the IS300's running automatics and 415 and 600+ RWHP, so the engine for the GS300 won't have a problem, but the transmission is a concern

Is the transmission on the IS and GS300 basically the same, besides the manual shifting?

They did have to strengthen the transmission on both cars listed, a "valve body upgrade" and a few other things.

Does anyone know if it would be necessary to upgrade the transmission if I was only running about 350 crank hp?