JB4?

[Drnick]

Questions in regards to JB4 piggy back
System; being my cars ECU is locked,
And I don’t want to possibly jeopardize
Warranty,I’m considering purchasing
This, any advice on this product? Thx

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[SD_MK]

Questions in regards to JB4 piggy back
System; being my cars ECU is locked,
And I don’t want to possibly jeopardize
Warranty,I’m considering purchasing
This, any advice on this product? Thx

It's a hit or miss... some people say that the electronics system is too smart that even a JB4 can't fool it because it looks at other values like speed, iat, map pressure and speed monitoring via "transmissive data" as stated on the sticker near the dome lights.

but the JB4 is a piggyback, it's suppose to fool the monitoring systems sooo i don't know.. ??‍ It's still up in the air for me based on what i've been reading...

 

[OneTimeAccount]

It's a hit or miss... some people say that the electronics system is too smart that even a JB4 can't fool it because it looks at other values like speed, iat, map pressure and speed monitoring via "transmissive data" as stated on the sticker near the dome lights.

Interesting. Those values could be thrown off with some spirited driving and track days though, couldn’t it? Toss on some R comp tires, go to the track and in one session a lot of those values will look strange haha.

 

[SD_MK]

Interesting. Those values could be thrown off with some spirited driving and track days though, couldn’t it? Toss on some R comp tires, go to the track and in one session a lot of those values will look strange haha.

I think the biggest one would be IAT and MAP sensor registry... if your boost pressure is manipulated, the system won't register it but the MAP sensor will since it measures based off of barometric pressure from the turbo. Idk if speed really factors into it but the biggest ones are those 2

 

[Drnick]

So, there is no confirmation wether this actually does what is advertised? No before and after dyno pulls?

 

[zagain]

So, there is no confirmation wether this actually does what is advertised? No before and after dyno pulls?

Hi Nick,

My butt dyno says it works. I've had it for a year and a half with no issues on my 2020 and I'm very happy with it; I can feel the difference between stages 1, 2 and 3. I have it installed along with a CAI and charge pipe, I have a catless downpipe the I will install soon; but you can clearly tell the difference the JB4 makes.

 

[Chgu]

I recall there being dyno numbers on the forums somewhere. Also check n54tech, where they do support for the JB4. It definitely adds torque, but I never got mine on a dyno while I had the JB4 installed.

 

[hotsaucewizard]

It absolutely works.. I am running a catless downpipe, intake, full exhaust, JB4, and an e85 blend and it SCOOTS.

 

[hotsaucewizard]

I haven't bothered to monitor the boost levels but I'm running map 3 which is an additive +6 PSI map.

There's no level of "smart" to a wastegate. ECU is looking for a voltage signal (or whatever it's reading to determine PSI) indicating a certain level of pressure has been reached. Piggybacks intercept and modify that signal (among others) and sends to the ECU, it's a simple as that.

Hell, you can even tell the difference between maps 3 and 5. One is additive PSI, the other is absolute PSI.

The only drawback I've run into so far is a constant CEL for catless downpipe. I have advised techs at Toyota to not plug my car into any Toyota computers but I also work for a dealership so I'm at a bit of a luxury there. I'm not sure if Toyota would even be looking for such a thing and how they could distinguish between a catless downpipe and 02 sensor failure but I figure this keeps me on the safe side of things.

 

[OneTimeAccount]

There's no level of "smart" to a wastegate. ECU is looking for a voltage signal (or whatever it's reading to determine PSI) indicating a certain level of pressure has been reached. Piggybacks intercept and modify that signal (among others) and sends to the ECU, it's a simple as that.

So does that mean there is no increased barometric pressure the MAP sensor reads and stores that could be pulled up and read later?

Trying to understand how the JB4 works.

 

[hotsaucewizard]

So does that mean there is no increased barometric pressure the MAP sensor reads and stores that could be pulled up and read later?

Trying to understand how the JB4 works.

PSI would be increased everywhere on the cold side of things, there's no way around that.

I can only assume that the MAP signal is manipulated as well. There is a plug in the JB4 harness for the MAP sensor. I can imagine based on some CEL codes I've seen in the past that there might be a code for an "out of range" PSI but that's pure speculation.

Any sensor the JB4 is plugged into it'll be intercepting and modifying the signal.

 

[SD_MK]

PSI would be increased everywhere on the cold side of things, there's no way around that.

I can only assume that the MAP signal is manipulated as well. There is a plug in the JB4 harness for the MAP sensor. I can imagine based on some CEL codes I've seen in the past that there might be a code for an "out of range" PSI but that's pure speculation.

Any sensor the JB4 is plugged into it'll be intercepting and modifying the signal.

then what about the MAF sensor? Does it account for the increase of air volume that is inducted with higher boost..? There is also an internal torque limiter within the system that kicks on when the car is pushed beyond factory torque. I don't think the piggyback accounts for these... these are data that can be transmitted from the car to BMW or if not, stored in the ECU and overlooked by the dealership when it comes to warranty work.. this subject is very touchy when it comes down to it.

 

[VA90]

So, there is no confirmation wether this actually does what is advertised? No before and after dyno pulls?

I don't think I have ever seen a straight before/after dyno for JB4 on a 2021 3.0, either here or on N54tech. That said, the Burger site has dynos for some of the available maps: https://burgertuning.com/collections/2020-toyota-supra/products/jb4-for-a90-toyota-supra. There is nothing specific to a 2021 but they do have the 2020 Z4, which is a decent proxy. The HP gains on pump gas are modest but the torque gains are significant. The HP/torque gains on ethanol blends are substantial. There is a fair bit of discussion on JB4 here in this forum if you search.

But if you are worried about your warranty, you should consider keeping your ECU/motor stock. Just depends on your risk tolerance. These cars seem pretty stout but there is always a level of risk when you start changing things...

 

[Axix23]

Questions in regards to JB4 piggy back
System; being my cars ECU is locked,
And I don’t want to possibly jeopardize
Warranty,I’m considering purchasing
This, any advice on this product? Thx

The answer is no! Wait for a proper ecu unlock.

 

[zrk]

The answer is no! Wait for a proper ecu unlock.

I mean, it's fine if you, or someone you know knows what they're doing. Just like any other flash or tune, you have to watch your logs, check things, make sure the car is behaving, etc. JB4 is just a tool, and it works well. The out of the box maps are decent, but not great.

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