[JNevs32]

I have been emailing performance shops around my area to get quotes for installing my AA downpipe, Dinan intake, and JB4. I have been told by every shop that they would either not install the JB4 due to issues other customers have had, or would strongly recommend against it.

This has made me question my purchase and I am considering returning the JB4. Am I being too cautious, or is this an actual concern?

[Rbcmima]

Theres mixed reviews. If you're running the proper fuel it should be okay. If you're running Map 1, 2, or 4, thats even better since they aren't really pushing the limit. Dont go above map 2 without access the e85.

I ran one for 6 or so months.

[rons e92]

Interested in hearing feedback from guys who have one of these installed ona G42 M240i. I had mine installed last week (along with AA DP plus I have an Eventuri intake) and still haven't switched it off of map 0.

There really isn't any sort of definitive guide for best practices with the B58TU our cars have. I've heard all kinds of different conflicting bits of info.

BMS seems to say that you should avoid the additive maps (1-3) with these cars because G chassis BMWs already command higher boost. I have 93 where I am and I only run Shell 93, so I could probably get away with map 1, but BMS saying to avoid it makes me a bit nervous.

Then we move to map 4 which is an absolute map. All of the BMS information I've seen says 93+ for map 4. I'd be very concerned if I got a slightly off batch of 93 that I'd risk blowing the engine/turbo.

So I'm stuck at a standstill while I try to learn more. Glad you made this thread.

[heelsmj]

I have been running a JB4 on my M340 for 3 years. I have had it in map 3 the entire time. I didn’t know that probably wasn’t the best option but I’ve never had any issue. I have since moved it to map 4. I live in south Florida and can easily get 93+. BTW you don’t need a shop to install it. It takes 5 minutes to do. It’s a few plugs on harnesses.

[mike@x-ph.com]

Originally Posted by JNevs32

I have been emailing performance shops around my area to get quotes for installing my AA downpipe, Dinan intake, and JB4. I have been told by every shop that they would either not install the JB4 due to issues other customers have had, or would strongly recommend against it.

This has made me question my purchase and I am considering returning the JB4. Am I being too cautious, or is this an actual concern?

Find another mechanic and enjoy the Jb4.

It's been out since 2009 with over 200 000 users, I use it on my G82 M4 as well.

it's an excellent tuner, the best piggyback on the market, hands down.

Do a proper install, run the recommended map and you are set.

[MPR]

Shops are probably tired of dealing with people that run a tune that they shouldnt and then coming back to them asking for a repair 'on the house' when bad stuff happens. I don't blame them from wanting no part in it, honestly.

If you run an appropriate tune given your setup/fuel then I agree it's likely safe.

[XC3LLR8]

Absent of an easy DME unlock option, I feel sorry for people not running a JB4. I even loved the JB+.

[MPR]

Originally Posted by XC3LLR8

Absent of an easy DME unlock option, I feel sorry for people not running a JB4. I even loved the JB+.

For my daily driver I'm more than happy with bone stock power, plus the comfort knowing that no shenanigans can be pulled on me from a warranty perspective. The car is plenty fast out of the box IMO.

[XC3LLR8]

Originally Posted by MPR

For my daily driver I'm more than happy with bone stock power, plus the comfort knowing that no shenanigans can be pulled on me from a warranty perspective. The car is plenty fast out of the box IMO.

I don't disagree, but after having it, and then going back to stock (just to feel the difference) is enough of a change that I wouldn't want to lose it. The power just feels so much more effortless, and I swear it even feels smoother - although I'm not sure why this would be?

[jbazz]

FWIW - I ran my JB4 on my B48 powered X3 for 3 years zero issues on map 2 the entire time, premium (93 octane US)

[Zemzam]

Originally Posted by rons e92

Interested in hearing feedback from guys who have one of these installed ona G42 M240i.

Hi there. I have a JB4 in a G42 M240i, a long with the AA catted, and an intake and Ethanol sensor.

I legitimately thought that the JB4 was broken when I tried Maps 1-3. Car would cut power mid run everytime. It was awful. With or without E85 didn't seem to matter. Firmware was up to date, but I just couldn't get it to work so I went back to the Carbahn piggyback (which is ROCK solid).

BUT....then I found the forum thread about the NEWER G-chassis cars having a real issue with the 1-3 maps, and I decided to try Map 4 and 5.

Removed the Carbahn and put the JB4 back on. Put it into Map 4. PERFECT. Been running it there for three months. Map 5 works well as well but the car does pull timing a little even on E35 so I went back to Map4. Car feels great. Some of the newer G platforms just HATE the 1-3 maps.

That's my experience. Hope it helps!

[rons e92]

Originally Posted by Zemzam

Hi there. I have a JB4 in a G42 M240i, a long with the AA catted, and an intake and Ethanol sensor.

I legitimately thought that the JB4 was broken when I tried Maps 1-3. Car would cut power mid run everytime. It was awful. With or without E85 didn't seem to matter. Firmware was up to date, but I just couldn't get it to work so I went back to the Carbahn piggyback (which is ROCK solid).

BUT....then I found the forum thread about the NEWER G-chassis cars having a real issue with the 1-3 maps, and I decided to try Map 4 and 5.

Removed the Carbahn and put the JB4 back on. Put it into Map 4. PERFECT. Been running it there for three months. Map 5 works well as well but the car does pull timing a little even on E35 so I went back to Map4. Car feels great. Some of the newer G platforms just HATE the 1-3 maps.

That's my experience. Hope it helps!

Thank you! Do you run E on map 4 or is it okay with 93?

Just saw your other thread. Wish I could help, that's nightmare stuff. Hope you clear it up soon.

[Zemzam]

I always run E30-E38 or so just because I have it available. I cannot speak to using 93 only, but I believe that BMS recommends E30 & DP for Maps 4 & 5. I can confirm that it works very well under those conditions with fuel trims and AFRs looking good.

[Zemzam]

And thanks man. Me too. So frustrating.

[XC3LLR8]

Originally Posted by Zemzam

BUT....then I found the forum thread about the NEWER G-chassis cars having a real issue with the 1-3 maps, and I decided to try Map 4 and 5.

I don't guess I've seen that thread, but I did have an issue with Map 2 when I accelerated hard from a light. The car suddenly felt like it hit a wall, accelerated hard again, hit a wall again. Only did it that one time.

Prior to that I used Map 1 on a 3,500 mile road trip since I only had access to 93-91, and it ran great...but I never did any hard accelerating from a stop.

Anyway, went back to Map 4 with E30 when I got home and all's well. The lesson for me is I'll stick to Map 1 when away from 93/E85, and stick to Map 4 with E85 access.

[Zemzam]

Originally Posted by XC3LLR8

I don't guess I've seen that thread.

I'm terribly sorry, but I am still looking for it to repost here. I went through so many different support forums for the B58 platform and the JB4 trying to find a solution that I am not sure where I saw that. But I will try to find it and link here.

Originally Posted by XC3LLR8

but I did have an issue with Map 2 when I accelerated hard from a light. The car suddenly felt like it hit a wall, accelerated hard again, hit a wall again. Only did it that one time.

This is what maps 1,2, & 3 did for me, and what led me to deep dive into support forums to find an answer. But Map 4 has been solid.

[Zemzam]

Originally Posted by XC3LLR8

I don't guess I've seen that thread

FOUND IT. This is a really good read for those of us with newer B58s:

https://g20.bimmerpost.com/forums/sh....php?t=1951893

Map 4 and Map 5 are essentially the same Map, with Map 4 being a slightly lower absolute boost target. Either of those are apparently suggested for later B58s.

[XC3LLR8]

Originally Posted by Zemzam

FOUND IT. This is a really good read for those of us with newer B58s:

https://g20.bimmerpost.com/forums/sh....php?t=1951893

Map 4 and Map 5 are essentially the same Map, with Map 4 being a slightly lower absolute boost target. Either of those are apparently suggested for later B58s.

Good find - I just read it.

Maybe Mike @ X-PH will see this and chime-in: My son has a '23 Supra with an AA downpipe and JB4, but only has access to 91. Should he be running Maps 4/5, or 1/2?

[mike@x-ph.com]

Originally Posted by Zemzam

FOUND IT. This is a really good read for those of us with newer B58s:

Map 4 and Map 5 are essentially the same Map, with Map 4 being a slightly lower absolute boost target. Either of those are apparently suggested for later B58s.

Originally Posted by XC3LLR8

Good find - I just read it.

Maybe Mike @ X-PH will see this and chime-in: My son has a '23 Supra with an AA downpipe and JB4, but only has access to 91. Should he be running Maps 4/5, or 1/2?

Since the G chassis run a high boost from the factory, I recommend going with either map one or absolute map four as a start.

If you wish to run the more aggressive additive maps, you can do so, but I strongly recommend data logging.

I did the same on my G82 M4, starting with map 1, then map 4, then map 5, then went back to map 2 with some modifications for a clean delivery.

[335i E92]

I plan on getting a JB+ and setting it at the 1 o’clock position which is circa + 3psi.

The car will run on V Power 99ron only which is equivalent to 93ron US.

Should be safe enough!

[XC3LLR8]

Originally Posted by 335i E92

I plan on getting a JB+ and setting it at the 1 o’clock position which is circa + 3psi.

The car will run on V Power 99ron only which is equivalent to 93ron US.

Should be safe enough!

If you're running 93 (US), I'd leave it at the default 3 o'clock position. I've done that myself and it ran great, so great in fact I sometimes wonder why switch to JB4.

[mike@x-ph.com]

Originally Posted by 335i E92

I plan on getting a JB+ and setting it at the 1 o’clock position which is circa + 3psi.

The car will run on V Power 99ron only which is equivalent to 93ron US.

Should be safe enough!

Yep