I have a 2016 GS 200t base trim with about 80k miles.


Currently, I have a K&N performance drop in filter and a stage 1 ECU tune via D3 performance out of Houston.

The tune is great. Most noticeably in sport mode, the throttle response and gear shifts are more aggressive. Even though the max boost is 17 psi from the factory, it would rarely peek at anything over 15.2 psi approximately. With the stage 1 tune, the turbo achieves a full 17 psi much more willingly.

My post today regarding advice for next steps. I called D3 performance and spoke with them a few separate times. They were very helpful in answering my questions. But I also learned some thing that sort of confuses my anticipated build trajectory for the car.

They sell a charge pipe and resonator for the turbo, which allows them to provide a stage 2 ECU tune, increasing max boost up to 20 psi. So I’ll be getting that and having my local shop install it.

In addition, I’m someone who really likes the low-key sleepy nature of Lexus, but it would be nice to open up the taps more on the turbo-4 and hear it scream sometimes. So the other thing I’m considering having my shop do is throw on an electronic cut out valve, so I can switch between stock exhaust, and essentially straight pipe.

Now there is some confusion out there about electronic cut outs, and to be fair I’m sure there are wildly different results people achieve, but from what I understand it’s pretty clear that unique circumstances notwithstanding, and especially for boosted engines, they cut out, essentially making it a straight piped engine, can often very noticeably increase horsepower… To the tune of 20-30+ hp depending on all things.

This is where a piece of confusion comes in. The guys at D3 told me that they’re stage 2 tune would achieve 280 hp at the wheel, and that no matter what I did, straight piping or otherwise, would increase the horsepower anymore, as there is a limiter within this engine/software that closes the throttle to prevent anything over 280 hp.

This is where some of my questions arise. So let’s say I assume that’s completely correct, as I have no reason to take D3 add anything other than their word. It seems like they are some of the folks that have the most experienced tuning these particular engines, so I am inclined to just trust what he’s telling me.

So if that’s the case and the engine will never allow over 280, and let’s say I have both the stage 2 tune and I am running the cut out in straight pipe mode, can I reasonably expect performance increase to have a greater envelope? As in, even if it can’t make more than 280, will running both of those mods assure that I am at a higher power setting more of the time? As opposed to if I only had the stage 2 tune, and at times would still make 280, but maybe not at lower RPM or other settings then if I had to cut out going as well….

This is just something I don’t really understand, and although I’m fairly committed to both those mods regardless, as I’d like the ability to raise the decibels when appropriate regardless of performance advantages, I’d still like to know what kind of expectations I should have.

Outside of that the next thing is brakes for some better heat dissipation, I just got dash cams and a sub, and she’s going in for paint correction and a ceramic coat and a couple of weeks. Starting to come together. I’ll post some good pics after she’s looking fresh.

I greatly appreciate any and all advice y’all can give. Especially those of you who are more familiar with motors, and can speak to that supposed limitation that Lexus imposes at 280 hp. Much thanks.

 

@BMGS come back!

 

The saying is you can spend thousands of dollars trying to eke out 20 more HP/Torque at the wheel to go 0.2 seconds faster in the 1/4 mile, or you can just buy a vehicle that goes faster at the 1/4 mile. But if you want more exhaust noise on demand, go for it. Just don’t expect to race any Tesla’s at the track.

 

It really depends on if you are looking for a loud exhaust noise car or hp, or both? You are correct that D3 has more experience in Tuning that engine and other Lexus/Toyota engines than anyone else. The Dyno Tuner at one point was solely focused of development of a very nice increase tune for that Turbo motor. I talked to him a few times about some custom changes to my own GS350 tune and spent a good part of the conversation talking about the progress he was making on that 8AR-DTS tune gain.

For prospective, the 200T Tune is at about 280+ rwhp, and the responsiveness and drivability as you probably already know is so much better. If was me I would get that charge pipe/downpipe and resonator they sell. It works well. Back to prospective.... the GS350 stock does not Dyno out rwhp anymore than about 255 rwhp. So the D3 GS 200t Tune + pipe and resonator would have your 200T walk all over a GS350 not tuned and stock. lol! Personally I would not want any Exhaust cut out as that is going to be Civic 4 banger obnoxious Loud, and will likely kill the mid range power some. D3 is correct about the Lexus Limiter that closes the TB percentage and limits power. What I would do is something in a Axel back exhaust mod of the mufflers. Also you could do a more free intake like the Full cone Injen or AEM Tube set up. There are Full cone Intake dyno's that showed gains in the 12 -15 plus hp increased that were Dyno'd verified on the 8AR-DTS . If I remember correctly D3 does have a Full Intake and Axel back exhaust Tune selection option for the 200T engine. A Axel back + Cone Intake plus Boost tune increase is going to give you a nice much more aggressive noticeable engine sound increase especially on Boost.

The last thing those seem to be interested here in the 4th Gen GS forum and/or have knowledge about is performance mods. It's just not something they do or have experience with. One former owner for a 2018 GS200T was on his way to some nice gains with his 200T including Meth/water injection, but he got rid of the GS and traded it in. In the conversation I had with the D3 Dyno tuner some months ago I think he actually was able to break the Lexus program Map that limited the TB opening and peak hp restrictions. I think likely the problem was he wanted to stay in a universal very safe Tune that no one blew their 200T motor with a hotter Tune. For that Lexus limiter override, you would want things like the Meth kit, to be sure you were running high octane 93+ premium fuel all the time, some added in tank Octane booster. For even higher boost things that other high boost T cars do are lower compression head gaskets, retarded timing and so on. All to keep from engine detonation. Below are a few threads on your Turbo Lexus, with guys in the IS forum who have shared some post about the D3 and JB4 Tune. I run the D3 Pro Tuners on my modded GS350 and also run the JB4 Tune on our Kia K5 GT 2.5T. I really like them both, but the D3 Tune is confirmed better for the Lexus 200T engine. Keep us updated on your progress and outcome.

https://www.clublexus.com/forums/per...ance-tune.html

https://www.clublexus.com/forums/per...200t-tune.html

 

Is D3 just throwing boost at it to make a high HP number? I've seen tons of 200t owners claiming they make more power than the 350s, yet not a single one can keep up in a straight line despite supposedly having a better power to weight ratio. I would hope D3 understands that the power under the curve is just as important if not more than redline power.

I don't understand why you would even want that... HP bragging rights just to get smoked by a stock 350 in the quarter mile.

OP have you tried a dragy or dragstrip to see what the car runs?

 

TreyGS460, I think you should call D3 one day and ask the questions you are commenting on. I did and it's much more he worked on than just boost for that tune. I'll leave that at that until you talk with them to get the info if you want. Just to point out one change was them overcoming the TB limit opening restrictions, not just boost.

Can you link us to any of the tons of runs you speak of Tuned 200T vs 350 runs? I have never seen one. Thanks.

 

I would take a look at the IS and RC forums to see what's the deal with the 280whp limit that you mentioned. I doubt the stock turbo can get there but with an upgraded turbo, hitting that level of about 330bhp would be a respectable gain from stock levels.

There was at least one IS200t that did a turbo upgrade at D3 if you search around on those threads. There's not too much activity here or support for the GS200t but it was fun modding it and seeing what it can do. I am dealing with the same thing on the Porsche forums now with my 2.0t Macan.

I installed a water/meth injection kit on my 2016 GS200t to combat the heat and higher boost from the D3 tune. There's some videos at the end that show the difference of how it helped to hold the boost better in the higher rpms. It was definitely a fun car to work on!

https://www.clublexus.com/forums/gs-...ispreloading=1

 

Sounds good.

I haven't seen any either, I'm going off the real world times from the Dragy leaderboard. Street races don't always tell the whole story anyways, but the times on the leaderboard can.

 

Ok, so to the 1st post comment about D3 and boost increase. Just think about what Turbo car Tune would not increase Boost? All BWM M, MB AMG, Hell Cats, Porsches, all boosted FI cars Tunes, all tune in higher boost don't they? lol! To run higher boost without detonation and problems, you are going to have to tune the added Fuel a/f ratio, timing, MAF map and other. That's just a must. So to say D3 just increases boost just don't make sense. I know for a fact that they also do a Trans tune, with the TQ lock up also and shift points, along with the TB throttle response delay increased.

My 1st post comments was directly related to the op's 1st post. He mentioned the charge pipe and resonator, plus tune also. I talked to Dennis at D3, and as I stated he can get over the 280hp limit and has already on some 200T cars on his own shops in house Dyno already. The Draggy is nice but looking at the Draggy and not comparing runs with, air temp, humidity, incline, traction, was the 200T ECU tuned with charge pipe and resonator and many other factors is just computer racing is all. My Daughter had a 2015 Kia Optima,SLX 2.0T rated at 274hp. With weld in Tanabe mufflers, and drop in K&N filter it walked on my then Stock GS350 from 40mph to 70mph. It also walked from a 5mph run to 60mph on my 13 GS350 when it was stock. My 13 GS was claimed 306 hp stock. Turbo cars just do things sometimes.

All real GS350 Dynos, below. I'll also tell you there are G4th Gen GS350 owners here who had the 6th Gen ES350 beat them. Why I say a D3 Tuned 200T with charge pipe and resonator, and a Intake cone would have my money on the 200T winning.

https://www.clublexus.com/forums/gs-...-my-350-a.html
The 3rd Gen GS350 stock does 259 hp & 228 tq! give or take +/- 5hp.

You Tube

13 GS350 F Sport about 245hp , 263tq

13 GS350 AWD 259.7 HP

You Tube

 

Well I didn't say they were... it was posed as a question. Those times on dragy were from the IS200t, with the mods you mentioned, and nothing about them was impressive to be honest. That's why I doubt the GS200t would be any faster, but I'll wait and see.

And I imagine that Kia is around 400lbs lighter than your GS right? My quick math says the power to weight is pretty much the same so gearing comes into play, but like I said before, street races don't mean much, reaction time and road conditions/ traction can easily nullify a faster car.

I'll keep an eye out for them dropping better times with the updated tunes.