Experience with Tunes/Best ones? 2021+ IS
Thread Starter
8th Gear
Joined: Apr 2025
Posts: 8
Likes: 3
Experience with Tunes/Best ones? 2021+ IS
Hey everybody!
RR Racing and D3 have had tunes for the 4th gen is350/2GR-FKS for a while now and I was wondering what people's experiences with it were
I am particularly interested in knowing if either affect the transmission/shift times or if people are having problems with them with reliability or when taking them in for maintenance at the dealer etc.
I have a 2024 and obviously with it being a new car this seems like a poor decision thinking about it lol- nevertheless I'm curious!
Some have suggested when my mileage gets high enough to look into Reflash.rd too(His instagram looks solid)
RR Racing and D3 have had tunes for the 4th gen is350/2GR-FKS for a while now and I was wondering what people's experiences with it were
I am particularly interested in knowing if either affect the transmission/shift times or if people are having problems with them with reliability or when taking them in for maintenance at the dealer etc.
I have a 2024 and obviously with it being a new car this seems like a poor decision thinking about it lol- nevertheless I'm curious!
Some have suggested when my mileage gets high enough to look into Reflash.rd too(His instagram looks solid)
Rookie
Joined: May 2022
Posts: 31
Likes: 7
From: TX
So I've had the Loi 7200RPM Stage 1 tune with transmission adjustment on my 21 IS350 for about....almost a year now. It's a pretty good bump in power in the 3-4krpm powerband. For what it's worth I'm FBO except headers and estimate my whp to be around 270-280.
Transmission seems to be okay....though since I drive in manual mode all the time I do feel that it's a bit snappier but not too drastic. I will say, for some reason even though the RPM limiter is moved up to 7200, I still see the car shifting prematurely in auto @ 6800. Sometimes I do a sanity check and reflash to stock and back to the tune but other than that I've been enjoying it thus far.
Loi has a pretty good grasp on how much to push the car and offered me adjustments to my tune free of charge, so customer service is real good with him.
As far as reliability, it's been pretty solid thus far and have had no issues. All the CELs I got from more air flow from the exhaust and CAI have disappeared and the one time I brought the car to the dealer their techstream hasn't messed with my car or tune at all. I was still able to get my service done without issue.
I am curious to see what people will say about the RR Racing or MForce tunes on this car though.
Transmission seems to be okay....though since I drive in manual mode all the time I do feel that it's a bit snappier but not too drastic. I will say, for some reason even though the RPM limiter is moved up to 7200, I still see the car shifting prematurely in auto @ 6800. Sometimes I do a sanity check and reflash to stock and back to the tune but other than that I've been enjoying it thus far.
Loi has a pretty good grasp on how much to push the car and offered me adjustments to my tune free of charge, so customer service is real good with him.
As far as reliability, it's been pretty solid thus far and have had no issues. All the CELs I got from more air flow from the exhaust and CAI have disappeared and the one time I brought the car to the dealer their techstream hasn't messed with my car or tune at all. I was still able to get my service done without issue.
I am curious to see what people will say about the RR Racing or MForce tunes on this car though.
Driver School Candidate
Joined: Jan 2025
Posts: 19
Likes: 17
Hey everybody!
RR Racing and D3 have had tunes for the 4th gen is350/2GR-FKS for a while now and I was wondering what people's experiences with it were
I am particularly interested in knowing if either affect the transmission/shift times or if people are having problems with them with reliability or when taking them in for maintenance at the dealer etc.
I have a 2024 and obviously with it being a new car this seems like a poor decision thinking about it lol- nevertheless I'm curious!
Some have suggested when my mileage gets high enough to look into Reflash.rd too(His instagram looks solid)
RR Racing and D3 have had tunes for the 4th gen is350/2GR-FKS for a while now and I was wondering what people's experiences with it were
I am particularly interested in knowing if either affect the transmission/shift times or if people are having problems with them with reliability or when taking them in for maintenance at the dealer etc.
I have a 2024 and obviously with it being a new car this seems like a poor decision thinking about it lol- nevertheless I'm curious!
Some have suggested when my mileage gets high enough to look into Reflash.rd too(His instagram looks solid)
Loi and reflash.rd seem to be the top contenders for tuning. I recently went catless and will be getting a tune from reflash.rd soon sometime in the next few weeks so I can let you know how that goes.
BTW - the 7200 RPM shift point from these tunes do not apply in auto mode. Gotta manually shift for that.
Rookie
Joined: May 2022
Posts: 31
Likes: 7
From: TX
In my original comment I actually misspoke - I meant to say that the car shifts at 6800 automatically even when I am in Sport and Manual. I did a pull on my way to work today and noticed it again when it shifted from 2nd to 3rd and to 4th.
Driver School Candidate
Joined: Jan 2025
Posts: 19
Likes: 17
That should let you hit those higher RPMs. if it doesn't, I'd probably check to make sure your tune flash actually went through.
I just had to post here because I always love when I see different threads with all the "I heard" comments who don't have a Tune or has never been in anyone else car who has a Tune.
A Few things:
1. RR Racing Tune does shift at 7200rpm and so do some others, just depends. At least the two 3.5 V6 Lexus I drove in that had the RR Tune sure did. Some of the Tunes did not want 7200rpm shifts, so of course they do not shift at 7200.
2. D3 has 2 Tunes. A generic, and a Pro Tune to custom tune. The Generic has different configurations, for mods, like stock, Intake, Exhaust, Headers.
3. Loi Tunes from runs and adjust the files.
4. Reflash.rd is best with FI Tuning. - ex. S/C, Nitrous, Turbo's
Been in Lexus 350's, F, and 2.0T's that had each, and have the D3 Pro on my car for about 2 1/2 years now. Hope this clears up and helps some.
Also go find a 2GR 3.5 Lexus 350 V6 Dyno run. Look at the peak TQ, and peak hp. See if the power dives and falls off at 6400rpm's, 6600, 6800, 7000, or 7200rpm. See where you think it makes it's peak hp?
A Few things:
1. RR Racing Tune does shift at 7200rpm and so do some others, just depends. At least the two 3.5 V6 Lexus I drove in that had the RR Tune sure did. Some of the Tunes did not want 7200rpm shifts, so of course they do not shift at 7200.
2. D3 has 2 Tunes. A generic, and a Pro Tune to custom tune. The Generic has different configurations, for mods, like stock, Intake, Exhaust, Headers.
3. Loi Tunes from runs and adjust the files.
4. Reflash.rd is best with FI Tuning. - ex. S/C, Nitrous, Turbo's
Been in Lexus 350's, F, and 2.0T's that had each, and have the D3 Pro on my car for about 2 1/2 years now. Hope this clears up and helps some.
Also go find a 2GR 3.5 Lexus 350 V6 Dyno run. Look at the peak TQ, and peak hp. See if the power dives and falls off at 6400rpm's, 6600, 6800, 7000, or 7200rpm. See where you think it makes it's peak hp?
Last edited by jgscott; Sep 4, 2025 at 01:17 PM.
Driver School Candidate
Joined: Jan 2025
Posts: 19
Likes: 17
I finally got tuned by reflash.rd recently and I'd say it's been a great experience on the long drives I've been on since. 7300 RPM limiter for me and shifts between gears don't seem to lag as much anymore when driving in the manual paddle shifter mode. I like to give the gas pedal a little love tap when downshifting just to hear the noise so I can tell that there's not as much of a delay now compared to before lol. When going WOT flooring it in the standard auto mode, it's a lot quicker to haul *** on pulls. I hit over 71+ mph yesterday at the end of 2nd gear (short shifted a bit in 1st too, so numbers probably could've been higher).
Overall it doesn't feel as sluggish as it did before. Is it still a slow car compared to so many others? yes. but it feels exactly the way it should have from factory. We threw on a base map and did a couple runs and adjusted and everything took less than 40 mins. I didn't opt for the pop & bangs that everyone seems to run (lol). Was told I can sprinkle in some e85 if I want a lil more power without needing to make any upgrades to the fuel pumps/lines etc.
if you got $500 then it's worth it just to squeeze a bit of satisfaction out of it. The wife said it did feel quite a bit faster than pre-tune.
To get the most out of it I'd do all your FBO first ofc.
Overall it doesn't feel as sluggish as it did before. Is it still a slow car compared to so many others? yes. but it feels exactly the way it should have from factory. We threw on a base map and did a couple runs and adjusted and everything took less than 40 mins. I didn't opt for the pop & bangs that everyone seems to run (lol). Was told I can sprinkle in some e85 if I want a lil more power without needing to make any upgrades to the fuel pumps/lines etc.
if you got $500 then it's worth it just to squeeze a bit of satisfaction out of it. The wife said it did feel quite a bit faster than pre-tune.
To get the most out of it I'd do all your FBO first ofc.
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I finally got tuned by reflash.rd recently and I'd say it's been a great experience on the long drives I've been on since. 7300 RPM limiter for me and shifts between gears don't seem to lag as much anymore when driving in the manual paddle shifter mode. I like to give the gas pedal a little love tap when downshifting just to hear the noise so I can tell that there's not as much of a delay now compared to before lol. When going WOT flooring it in the standard auto mode, it's a lot quicker to haul *** on pulls. I hit over 71+ mph yesterday at the end of 2nd gear (short shifted a bit in 1st too, so numbers probably could've been higher).
Overall it doesn't feel as sluggish as it did before. Is it still a slow car compared to so many others? yes. but it feels exactly the way it should have from factory. We threw on a base map and did a couple runs and adjusted and everything took less than 40 mins. I didn't opt for the pop & bangs that everyone seems to run (lol). Was told I can sprinkle in some e85 if I want a lil more power without needing to make any upgrades to the fuel pumps/lines etc.
if you got $500 then it's worth it just to squeeze a bit of satisfaction out of it. The wife said it did feel quite a bit faster than pre-tune.
To get the most out of it I'd do all your FBO first ofc.
Overall it doesn't feel as sluggish as it did before. Is it still a slow car compared to so many others? yes. but it feels exactly the way it should have from factory. We threw on a base map and did a couple runs and adjusted and everything took less than 40 mins. I didn't opt for the pop & bangs that everyone seems to run (lol). Was told I can sprinkle in some e85 if I want a lil more power without needing to make any upgrades to the fuel pumps/lines etc.
if you got $500 then it's worth it just to squeeze a bit of satisfaction out of it. The wife said it did feel quite a bit faster than pre-tune.
To get the most out of it I'd do all your FBO first ofc.
Driver School Candidate
Joined: Jan 2025
Posts: 19
Likes: 17
He then takes remote control of your laptop and uploads a base tune map after looking at your diagnostics. After that you do a couple of runs and give him feedback and he adjusts everything live inbetween runs and flashes the updated map for you.
All the files are saved locally on your laptop for future reference too.
Intermediate
Joined: Mar 2024
Posts: 388
Likes: 153
From: NY
Loi tuned
I have a Loi map, it’s a can version based on a car he dyno tuned, as per his words. I’ve beber logged my vehicle, I should. Overall I’m satisfied with the results, the throttle response is notably sharp. I do think it does best in auto instead of me doing the shifting. Supposedly the rpm’s are raised to 7300, requires turning traction control off. I have not done so, don’t really want to rev the engine above factory specifications. The shift points are also supposedly modified on the map, bb bb bb bb. My experience comes from owning a factory detuned v6 is300, I also still have the oem exhaust and F Sport intake. Been an awd car the top speed still limited the same as oem, top speed is limited to 131mph, don’t know if the is also modified. An identical is350 is capable of 143mph. I’ll have to ask Loi about that, he is helpful.
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