I want some advice on improving my horsepower on my GS400. Make it budgetable. . I want to start small and keep adding on. I keep getting advice to drop a Supra TT motor. anyone done this on a gs400 I know it's easier on a 300.

 

did that K&N filter give u a noticeable amount of power?

 

k&n filter wont give any power..

 

most people with the 8cyls start off with a SRT intake neo/srt ecu.

 

just basic bolt on mods like intake, headers, etc. piggyback if you want a tune.

 

start with K&N intake or SRT intake, S&S headers, colder plugs....then tuning, neo etc

 

Colder plugs why would he need that?

The most bang for your buck parts are headers and AFC, but they are some what expensive when you add install and/ or tune. The cheaper item you can go with is SRT, but there are some mix feeling with that intake system, so I'm not too sure about it and for the price tag it carries, you might as well go for one of the other upgrades.

 

Torque converter! Doesn't "add power", but makes it noticably faster off the line!!

 

Ditto. Colder plugs are to fight pre-ignition if your boosted. If your N/A you don't need them.

 

im assuming he will eventually desire to go forced induction once he realizes without doing some crazy NA build costing 10-20k+ (im slightly exaggerating but maybe not coawboy sells a NA stroker motor for like 16k i think it was) you'll never get any real power out of the gs400 so next step would be FI....so im thinking ahead

if u talk to rock-a-lex this is his mods and his HP. I THINK im not sure but i think he has highest NA v-8 on the boards
2000 Lexus GS400-
K&N FIPK-S&S Headers-Apexi Neo-Borla-PI TC-3.76 LSD-B&M SuperCooler-Supra TT shafts-Bilstein PSS-19" Ace Forged AMF030-Bridgestone RE0760 sports-X/S rotors-Akebono ProACT ceramics
Dyno: 2/2/08 - 267.1whp / 291wtq
Dyno: 4/11/09 - 281.8whp / 306wtq

 

You should tell him to get a FMIC too He'll be even closer then.

 

If you want the 2jzgte option you may do better starting with a 300.

Headers and tuning give actual real power. The rest of the exhaust has less potential and you can loose there. I am getting ready to build some exhaust parts for my 99 LS400 to compliment the S&S headers (that I have to modify for factory type fitment). If successful the secondary exhaust parts I create could be duplicated for the GS4xx. Headers are 15-25rwhp depending on whether the vehicle has tuning.

Torque converter is a definite performance improver even though it doesn't make more power in the engine it delivers more useable power to the tires.

Other engine internal options include properly ported heads (NOT big ports) and POSSIBLY cam upgrades. With VVTi the cam mods are still NOT documented for drivability.

These engines REALLY need more RPM range. The ECU is the problem PLUS the weak connecting rods. No clear options on the ECU for rev limit increasing.

Stroker options are appealing. Lextreme has a stroker crank, rods and piston combo.

Forced induction including turbo and superchargers are options.

If above 400hp is your goal you will need to change transmissions.

 

A little bit but not to much.

 

Well I was thinking of a supercharger on it or the turbo system on the exhaust ,but I'm also thinking maybe find a GS 300. if you know of anybody that has supercharded one let me know i would like to see how much it will cost to add this on.

 

As Sakataj mentioned with my mods list above as far as physical power my car at the time of the last dyno was putting out a hair under 282whp and around 306wtq; with the 20% drivtrain loss it equates to around 355hp and 385tq up from the stock 300hp and 315tq.

Now, this is JUST power. With this and the addition of a high stall torque converter and the steeper Supra TT rear gears the car "feels" like it has closer to 400hp (crank). WITH a HUGE box and amps in my trunk on 19's and 2 month old Bridgestone sports (275's) I STILL spin them off the line. The other day I slowed to around 10mph and punched it and went sideways a little all on bone dry surface.

All those mods would STILL cost you around $6K at least (with installs) when your all said and done. It makes a HUGE difference to the car but a supercharger or turbo application would be that much more impressive BUT it would probably be at least another $4-5K on top of the $6K for a legit setup (from what I've read).

My advice is to look at the ultimate goal of what you want the car to be. If you want a TON of power (but still keep in mind that the car is heavy so there will still be a lot of cars out there faster) go the FI route...even if it means NO modding for a year to save. If you want a fun; still quick sedan start your bolt-on modding now starting with my list.

Also, IF i would ever do anymore power mods...for my setup I would swap out my Borla exhaust and do a nice catback and perhaps delete a cat while I'm there. Also, there is a really cool meth injection kit out there by Snow Performance which puts an ICE COLD charge of air into the air intake; it can be setup to go at part or wide open throttle.

Both can be had together for around $1K. Just some ideas...GL!