I bought and installed the JB4 piggy back tune for my TX350. This was such a needed performance upgrade for this SUV! Running map 3 on 91 octane. Anyone else running the JB4? I have not tried anything higher than Map 3. But no issues! No lights and over 12,000 miles on the odometer. I would highly recommend if you want more power!

 

 

From what I've heard and read, those things over time will burn up/over heat the cats due to the exhaust temps going high. So while I've been a user of those in the past, I took it off fairly quickly and sold it due to those concerns.

 

Nice.
I have one on my '24 RX and love it. I also had one on my recently former Subaru with their 2.4T motor (for 40k mi.) That surely yielded better results than the Lexus T24A. That said, its adds just enough boost to make it more fun to drive. Most everyone won't understand, because the reality is that ppl dont buy an Lexus SUV for its power, rather its smoothness/comfort and 'lack of power'. I think that the JB4 adds just the right balance, and in the case of the RX, puts it right on par with the 500h. I also had the GruppM, but took it off. Instead, I purchased a cheap stock airbox off of eBay and modified it (cut out a large swore from the front and installed mesh) to increase the air volume with out the 'turbo noises' and alleged heat soak. I am hoping that someone will release an intake tube (other than the $6xx Exart one) and maybe charge pipe(s). Wishful thinking....

 

Those filters especially without boxes doesn't filter trash as well as the original. Also, the engine is loud enough for me. My other concern is that with a tune it will just make an excuse for Lexus not honor the manufacture warranty.
Everyone has their preferences with mods and add-ons with their vehicles. I am curious, did these mods improved your MPG, if so by how much

 

Do you remove the JB4 when taking in for service or service your vehicles at home?

Interested in JB4 but in a different vehicle

 

I won't speak for anyone else, but I have removed it 2x taking my RX for recall work. Takes 15min. I also go a step further and unhook my battery for 30min to reset the ecu.

 

No tx 500h models lol.

 

I remember back in the day, the dealers would pull the logs from the ECU (DME in bmw speak) and see the overboost/manifold pressure /egt logs and they'd use those to deny cracked blocks, blown turbos. i imagine the ECUs of today's cars log so much more.

 

I also remove my JB4 when taking the TX350 in for service. Agreed. Takes about 15 minutes. The dyno sheets showing the power gains on the JB4 website indicate about a 40HP gain with Map 2 for the TX. I run Map 3. It is just enough power to put the powertrain where it should be. It is a family hauler for me so I don’t do any real “racing” but it makes the car much more enjoyable to drive. I am also on the lookout for other intake options once available. The GruppeM is nice for this tune but not ideal long term.

 

You just have to watch the AFR's running MAP3 on straight 93. I run MAP2 and when I run MAP3 it will be on E30 (unless you have cheap access to 100oct). Running E30 puts you at 98oct using 93oct as the base.

Def run some logs and see where you're at.

 

Did you notice a difference in MPG's at all? Have any issues come up since installation?

 

Just sold me TX350. If anyone is interested in my JB4 system with the Bluetooth adapter at a discount send me a PM. The extra power is so worth it!

 

What are you replacing the TX with?

 

we replaced the TX350 with a 2023 Sequoia TRD PRO. So far we are a week into ownership. Wife wanted something a bit more commanding on the road and more capable off road.