mrseannath

Hey Guys,

Picking up my new 2018 IS300 AWD FSport 2 this week and wanted to know is it possible to 'tune' my engine to give the same output at the IS350 model? To my knowledge, the engine is the same but it's probably tuned differently. Found it difficult to find my answer but really just want to know what makes the IS350 spit 300+ HP when the IS300 only pushes 260HP

jmull3r

iTrader: (1)

Answer

Gains are from the tune, the headers only helps achieve the numbers.

gthal

Hope nothing goes wrong and there is a warranty claim issue... then it would have made more sense to just buy the 350 in the first place and keep it stock

I'm sure it's a pretty low risk and most would not worry at all. Personally, I'd be too concerned and it would bug me and not worth it.

Jeff Lange

iTrader: (1)

The difference is completely in the tune.

Jeff

RKSTRAT

Solara350

2018 Lexus IS
IS300 AWD: HP 260 hp @ 6400 rpm, Torque 236 ft-lbs. @ 2000 rpm
IS350 AWD: HP 311 hp @ 6400 rpm, Torque 280 ft-lbs. @ 4800 rpm

51HP and 44hp ft-lbs different, bring any IS300 AWD RR tune or whatever ECU tune and race with my bone STOCK IS350 AWD Fsport, and you'll see, Lexus IS and Mercedes C-lass de-tuned their 300 lineup for fuel-eco, but Lexus kept IS350 AWD with 6 aggressive speed automatic transmission for some reason, the computer tuning alone won't effects much in HP, unless you Turbo or Supercharge and re-flash ECU, keep in mind more Power = more Gas , you can't have an eco detune engine and have same HP like the 350, even Top tier gas is different in HP.

Full header and exhaust + Cold air intake do give some Horsepower 5-7 peak hp still not much

8 speed trans in Lexus IS350 RWD doesn't mean it will give more HP compare to 6speed, Transmission is to handle the power of the engine and speed, they don't give Horse power, more gear = fuel-Economy doesn't make you go any faster.

Save the money for Custom Turbo or Supercharge, the Ecu ODB2 tuned won't work, China Tech released a thousand of ECU-Tuned products for Lexus Infinity BMW Audi and Mercedes for 20$ usd each 50$ shipped, they all the same.

those Tunes are like having Sport+ mode like the IS350 F-sport, it opens wide throttle body makes the car little loud and aggressive but not Fast, i put Sport+ mode for AVS (adaptive Variable System) not speed (Normal Mode compare to Sport+ in speed = the same) Sport+ is louder makes you awake and better handling, speed is the same.

TRD Supercharge for my Toyota Solara if upgrade alone costs from 4000$-6000$ CAD around 3000$-5000$ USD back in 1999 including labor by Toyota Dealer, Stock PSI run only 4psi makes only 60HP more, they replaced the fuel-line and pulley too and then reflash ecu in order to gain 60hp. You think couple hundred bucks gives you that much Horses ? check Google China has it for 20-50$ same tune. Unless you swap out 350 Engine + 350 ECU like Jeff Lange.

rL-gT

My 300 tuned is easily quicker than a stock 350.. multiple people at my dealer also confirmed this

ALSO my tuned 300 gets better mpg vs my mothers 2016 stock IS300.

Panzer126

Really? By how much?

rL-gT

the chart says it all

jmull3r

iTrader: (1)

Solara350

Ya, let say 20hp more and probably with header+full exhaust and Cold air intake in order to get 20-25 peak HP, i mean the 2018 stock 350 has 51HP more. the custom Intake company like Injent, Apex and AEM claims their intake gains 15HP but when "Mighty Car Mods" performed a test on Honda S2000, the result wasn't like what the Makers stated, once again "Mighty Car Mods" Youtuber performed an ECU Chiptune test on Honda S2000, Horsepower stay the same ! watch this video
Like cold air intake claimed 15HP but Mighty Car Mods has a result of 3-5 peak HP like i always tell people, its business every owners says their product is best !

Check out Engineer explain
I'm not against Mods or people loving Mods, my point is i like to compare which better, you see with all these money$$$ you could do something bigger.

Solara350

Chris, that chart is from the seller itself, give me a chart from a Buyer/driver, ill find out if this work on Lexus IS, probably request Mighty Car Mods for a test with RR tuned, if this works, i will Tune mine IS350 too why not !

rL-gT

It made a huge difference in my own vehicle. I also helped another local member tune his 350 with the RR tune and he did notice marginally gains. He's slapping on headers this week so we'll see how his vehicle opens up

PS. The IS300 and IS350 motor share the same part number. (which has been confirmed on here before)

ClubLUser

iTrader: (1)

Any car guy can tell you that an intake isn't going to do much, and its widely known that OEM air intakes are one of the best. ECU Chips are also widely known to be fake, most just making the car run rich by tricking O2 sensors.
The forums are full of people with RR racing's tune and they are all happy.
Here is a dyno sheet of another user (leg3ndary) using their tune with just a catback system.
This is an is350 + mods, so a is300 + mods would show a greater increase.