GS400 N/A 450rwhp

[checkm1ego]

My goals are allot more HP and long term reliability during aggressive driving. I'm looking for an N/A engine build that can produce close to 400 rwhp, I was told 375 was possible at the flywheel.. The car will be on the interstate often, with occasional trips to the drag strip when im feeling up to it. My budget is $5k+ But im willing to spend up to $10k if reasonable high power gains can be made.. think 500hp - Please let me know costs and what is required, and what options I have that "Make Sense". I'm in Georgia, and dont mind bringing my car to your shop if that is more convenient for your team to provide a full install and service and do the job right the first time. I was told that you could ship a fully built engine as well. Let me know the advantages either way.

- I thank you in advance for any and all info you may provide in helping me make a wise purchasing decision..

 

[stevechumo]

500 rwhp is like more than double the hp from stock. I haven't heard of anyone who could achieve that in NA, even from different engines. I'd think FI is needed to achieve that.

 

[XR8tt]

Yep !! 480 at the fly with a hell let spent on valve gear etc...
9500 rpm... To do that...
Cheaper to fit up a 60 to 66mm turbo with good tune..
Much more drivable at low rpm..

 

[JBrady]

My goals are allot more HP and long term reliability during aggressive driving.

Welcome to Lextreme.

I don't know your background or experience but obviously you are enthusiastic about your Lexus and HOPE to make a powerful car out of it.

I HATE to let you down but your goals are not obtainable for your budget.
Lexus did not design the needed strength in the engine or transmission and MOST importantly it is NOT easily tuned. Many cars can have their ECU recalibrated to accept modifications. The Lexus ECU is "locked" and integrated between the engine and transmission. You will have to go to a stand alone control system WITH a VERY capable person to FULLY tune it and even then it will be LESS drivable on a day to day basis than it is now. Just this portion of the "goal" eats up your $5k.

Making big power on engine alone is MORE expensive and LESS flexible than doing it with turbo/supercharging. The stock engine and transmission can TOLERATE with so/so reliability around 400rwhp. Even then EXPECT to replace BOTH at some point at least once. A turbo/supercharger system can be custom built for this goal for around your $5k budget.

To build a NA engine that can make 400rwhp would take at the minimum pistons/rings, rods, cams, professional head porting and valve work with springs, custom headers and exhaust AND most importantly the previously mentioned TUNING ability. The transmission would need at least a torque converter to allow the engine to get going because the low to mid RPM torque would be less than stock. Without the TUNING you would be looking at at least $5k and you would need to turn more RPM than the stock ECU allows to make the power goal.

I HIGHLY recommend taking this in steps. READ, READ and READ some more and then install a good torque converter, headers, and possibly 100hp nitrous system and ENJOY that while you continue to learn about WHAT it takes to turn your car into a BIG power car. Hint: BIG money.

If you ignor my advice you will spend your $5k and will have more headaches than you can imagine and probably want to dump the whole thing. My suggestions above will allow you to do some car crafting and have FUN within your budget while you decide and SAVE for more.

Good luck... have fun... be safe!

 

[stevechumo]

It's interesting that you brought up the tranny cost. A rebuilt tranny with a torque converter to handle more than 400 rwhp will cost around $3K and more.

Another option to gain big power is stroking the engine. But it still wouldn't get near 500 rwhp. 400 rwhp may be possible with stroking the engine, head works, valves, aggresive cams, raising compression, headers, exhaust, intake, EMS, and tuning.

The other things come to mind is the suspension components of the GS are fairly soft/weak. You'll need to spend several more grands to beefen them up to handle the +400 rwhp.

And now you finally need a good braking system to stop the power. This costs several grands as well.

 

[mshawari1]

I would vote for a single - mid size- turbo with rods and pistons (lower compression) along with good ECU and tune.

if you get 375 - 400 RWHP out of that ... it will be a good power - considering the durability - for that car.

 

[spf_lexus]

I second the single turbo idea. Gotta remember the VVt has the equivelent to a fully ported early UZ head in stock form and has the dual stage manifold. I would think 400wheel should be easy to attain.

 

[phillipfym]

Forum is pretty old, but I want to say something to implement options coming from 2023 that people might like.

XAT Racing offers a lot of aftermarket support for these engines and will definitely help you out in long run. I've been running numbers for my own build which is a 1uz vvti with a built A650e trans.
There's a lot of info on the a650e trans builds on youtube that if someone wants links to, i do not mind sharing.

But, post is for 1uz vvti, so here is my part to share. You can do the link ecu g4x extreme for $2800. Cams, springs and retainers, head studs, Around $2700 for parts. Estimated 50+ ish hp. Haven't seen many people only build heads for better air traffic and throwing a bigger fuel system.

Don't worry about building block or snapping rod, crank, etc., Since you won't be pushing more than 400hp. But it is enough of a boost than what you have.

If you want more, you can go about building the block which is around 7-8k and throw a ford blower on it for 10k w adapter plate, throw a jaguar xj supercharger for 4k w adapter plate, even a TRD blower from the old tundra's for like 9k before adapter would be pretty cool, but you would be smarter to just throw a high ram intake and a fatter cam at the same time and keep it NA like you said.

I could be wrong about some stuff where as there is limited info, but from what I've seen, there is a limitless amount of stuff you can do, but no one has done it publically. Prices are weird for these car's because you could start building the heads and need a valve job on your car or who knows what's wrong. Then your 5k budget turns into an 11k budget yk. It's all "yea i threw 30k into the motor and its a 1100 hp beast" and it's some random on the internet that can never send pictures. Hope this post helped someone

 

[Zuffen]

If you search this Forum you will find a build I did where I threw the equivalent of US$30,000 at a supercharged 1UZ and certainly didn't get anywhere near 1,000HP, flywheel or wheels.

Further searching will find a Doctor in Sydney Australia who built a super high revving N/A engine with the best of everything, then a little more and he didn't get anywhere near the 400hp.

N/A it just won't happen.

 

[gloverman]

If you search this Forum you will find a build I did where I threw the equivalent of US$30,000 at a supercharged 1UZ and certainly didn't get anywhere near 1,000HP, flywheel or wheels.

Further searching will find a Doctor in Sydney Australia who built a super high revving N/A engine with the best of everything, then a little more and he didn't get anywhere near the 400hp.

N/A it just won't happen.

And then there are the kiwi guys making 500+ with VVti engines with the vvti removed, 10:1 compression and a carb. This is engine horsepower. Best I have seen is around 575Hp. The supercharged drift car I work on is around 750rwhp, the drag car I went to the track with recently was 830rwhp but turbo through an auto too.

 

[ivan129]

And then there are the kiwi guys making 500+ with VVti engines with the vvti removed, 10:1 compression and a carb. This is engine horsepower. Best I have seen is around 575Hp. The supercharged drift car I work on is around 750rwhp, the drag car I went to the track with recently was 830rwhp but turbo through an auto too.

Must be good fuel and clean air over there.

 

[gloverman]

Must be good fuel and clean air over there.

We have 20 years of engine development on the 1uz platform for a specific racing class. Experience helps. Once upon a time they were $100000nzd engines, these days its possible to buy one race ready for around $40000nzd. and some guys have them on the shelf.

 

[super_red_sc]

My goals are allot more HP and long term reliability during aggressive driving. I'm looking for an N/A engine build that can produce close to 400 rwhp, I was told 375 was possible at the flywheel.. The car will be on the interstate often, with occasional trips to the drag strip when im feeling up to it. My budget is $5k+ But im willing to spend up to $10k if reasonable high power gains can be made.. think 500hp - Please let me know costs and what is required, and what options I have that "Make Sense". I'm in Georgia, and dont mind bringing my car to your shop if that is more convenient for your team to provide a full install and service and do the job right the first time. I was told that you could ship a fully built engine as well. Let me know the advantages either way.

- I thank you in advance for any and all info you may provide in helping me make a wise purchasing decision..

Well, your budget puts you out of the game right off the bat. Also consider you lose 150hp thru the transmission. So if you make 600 you get 450 to the rear wheel. go check 1uztech website and browse their performance packages. You'll get an idea of cost.