[M340i Pride]

I'll keep this short here, since first one was soooo long lol!

Went to a road trip, had a BLAST. About 250 mile one way. Lots of uphill, over taking cars at &^% mph (lol)

ONLY THING: check engine light came on briefly, for few hours that I was at an elevation (6000+ ft) and it went away as soon as I went back down to/around sea level. Then it hasn't come back. I do not know why... may be someone could chime in on this

Never at any time did I feel any thing amiss. No loss of power. Rather, power was insane.

I am keeping it on

Ill up the boost all the way in a few days and write another update. Thanks guys and happy driving.

[rrfitness20]

Glad hear more about the JB+ lol.
Could be a few variables. Could be boost spikes that triggered the CEL, these cars are so sophisticated that it's hard to tell unless you were data logging.

[M340i Pride]

Originally Posted by rrfitness20

Glad hear more about the JB+ lol.
Could be a few variables. Could be boost spikes that triggered the CEL, these cars are so sophisticated that it's hard to tell unless you were data logging.

True. I am not too worried about it... it had to do something with the higher boost for sure. went away pretty quick. And it was never triggered while i was in LA.

I think going up and down in a elevation real quick was the reason why it detected an unusual spike, just like you said.

[rrfitness20]

Yeah I'm sure it's nothing to worry about.
I'm in the LA area as well

[Gdiddy23]

Appreciate the follow up review!

My concern would be the dealership seeing the CEL shadow next time it's in for service. I know the whole "tune vs warranty" discussion has been discussed ad nauseam but I'd still be paranoid about it.

Curious to hear how your experience continues to go tho, as I'm still waiting to make a decision on a tune for my M340

[Merami fan]

Originally Posted by Gdiddy23

Appreciate the follow up review!

My concern would be the dealership seeing the CEL shadow next time it's in for service. I know the whole "tune vs warranty" discussion has been discussed ad nauseam but I'd still be paranoid about it.

Curious to hear how your experience continues to go tho, as I'm still waiting to make a decision on a tune for my M340

Took my car for an oil change this morning and overheard a SA and customer talking about the JB4 on his car. Customer said, 'Well I thought it was fine, and I can just remove it.' SA said, 'Look, I have one on my own car, but I can't say you are guaranteed to be covered by warranty with any 3rd-party stuff going on.'

So that's another data point towards 'install at your own risk.'

[M340i Pride]

Originally Posted by Gdiddy23

Appreciate the follow up review!

My concern would be the dealership seeing the CEL shadow next time it's in for service. I know the whole "tune vs warranty" discussion has been discussed ad nauseam but I'd still be paranoid about it.

Curious to hear how your experience continues to go tho, as I'm still waiting to make a decision on a tune for my M340

absolutely! I feel you on it. I am just like you, I would have gone up to JB4 from the get go but I feel like that's going close to that line.

I'll do another update as soon as I try the dial all the way up and drive for a day. Its still at 3'o clock.

[M340i Pride]

Originally Posted by Merami fan

Took my car for an oil change this morning and overheard a SA and customer talking about the JB4 on his car. Customer said, 'Well I thought it was fine, and I can just remove it.' SA said, 'Look, I have one on my own car, but I can't say you are guaranteed to be covered by warranty with any 3rd-party stuff going on.'

So that's another data point towards 'install at your own risk.'

As with anything, if one goes too much above the stock perimeter, things will break. When I had my C6 vette, 600 whp was kind of that line for the LS2/LS3.

Superchargers were set to 550-575 whp on purpose, knowing that the stock internals were at more of a risk after that point. Though 650 whp was easily attainable with just a pulley change and a tune. If going higher (like say, 800 hp at crank), people re-sleeved and went on to the forged route. When one got close to or pass that line, things started to break.

So the B58 also has 'that' line and I don't know exactly what it is, but i don't think 30-40 hp/tq will be that. Unless you are drag racing and tracking it ALL THE TIME. Then even the stock motor needs regular parts change lol.

So when adding a 'significant' power (i'd say more than 70-80 hp), take it easy. Enjoy the power, but also have a care and have some moderation in mind when pushing the throttle

[Merami fan]

Originally Posted by M340i Pride

So the B58 also has 'that' line and I don't know exactly what it is, but i don't think 30-40 hp/tq will be that. Unless you are drag racing and tracking it ALL THE TIME. Then even the stock motor needs regular parts change lol.

So when adding a 'significant' power (i'd say more than 70-80 hp), take it easy. Enjoy the power, but also have a care and have some moderation in mind when pushing the throttle

The B58 is pure gold, as is the B48 that's based on it. 10% higher HP/TQ is very minor, considering these are probably heavily de-tuned from the factory. I'd be more worried about my license than the engine. Still, just the off chance that something goes wrong is scary, knowing how expensive engine work is on BMWs.

[VipinLJ]

Originally Posted by Gdiddy23

Appreciate the follow up review!

My concern would be the dealership seeing the CEL shadow next time it's in for service. I know the whole "tune vs warranty" discussion has been discussed ad nauseam but I'd still be paranoid about it.

Curious to hear how your experience continues to go tho, as I'm still waiting to make a decision on a tune for my M340

I had a JB+ and now have a JB4. Never got a CEL with either of them. BUT. I did try and flash my car with BM3 in December and they didn't know about locked DMEs then. My car was bricked for 3-4 days before PTF did anything about it. It had a CEL and tons of error codes. I took my car in for an oil change a month back. I removed the JB4 around 100 miles before the car was due to be taken in. When I took the car in, they said they'd scope it, which means they'd connect the car to their software that scans the car and warns them if it has been tuned. I know because I asked him what scoping means and if tunes will be detected and he said yes, even if the tune has been removed and car flashed back to stock. I was a little worried that they'd find out that I had tried flashing the car way back even though I couldn't flash it. They scoped my car and when I got it back, asked them what the result was (I didn't tell them about the piggy back or the failed flash attempt). He said the car came out clean and no warning popped up and that it wasn't flagged. But that is just my experience. It could be different for someone else.

[M340i Pride]

Originally Posted by Merami fan

The B58 is pure gold, as is the B48 that's based on it. 10% higher HP/TQ is very minor, considering these are probably heavily de-tuned from the factory. I'd be more worried about my license than the engine. Still, just the off chance that something goes wrong is scary, knowing how expensive engine work is on BMWs.

lol on license!

absolutely. considering how 14 year old N54 engine was able to handle 450+ hp with just a tune / downpipe and the engine was fine. I can't see how B58 would be more delicate than that engine.

I had the JB+ on my 07 N54 335i for a few years and had no issues at all so I am pretty sure that I won't have any problems with just a JB+. But ill do updates to let everyone know how it goes, hopefully that could help making decisions.

[M340i Pride]

Originally Posted by VipinLJ

I had a JB+ and now have a JB4. Never got a CEL with either of them. BUT. I did try and flash my car with BM3 in December and they didn't know about locked DMEs then. My car was bricked for 3-4 days before PTF did anything about it. It had a CEL and tons of error codes. I took my car in for an oil change a month back. I removed the JB4 around 100 miles before the car was due to be taken in. When I took the car in, they said they'd scope it, which means they'd connect the car to their software that scans the car and warns them if it has been tuned. I know because I asked him what scoping means and if tunes will be detected and he said yes, even if the tune has been removed and car flashed back to stock. I was a little worried that they'd find out that I had tried flashing the car way back even though I couldn't flash it. They scoped my car and when I got it back, asked them what the result was (I didn't tell them about the piggy back or the failed flash attempt). He said the car came out clean and no warning popped up and that it wasn't flagged. But that is just my experience. It could be different for someone else.

out of curiosity, cracking the DME vs piggy back... JB4 cannot duplicate what a tune can do? would appreciate the info.

[Fuel-It!]

If you care just read the fault code, but a code that comes up and goes away on it's own isn't a big deal. May not even be JB+ related.

[lucasplagenza]

Just tested the jb+ on my stock car for the past couple days, works great and definitely a decent up in boost. 0-60 feels the same but flooring it at highway speeds feels much faster. Decided i didn't really like it however, the boost comes on a bit too aggressively and the car in sport+ is a bit jerky. I like the stock driving characteristics more, but it's all preference. I'd encourage everyone to try it for the $200

[VipinLJ]

Originally Posted by M340i Pride

out of curiosity, cracking the DME vs piggy back... JB4 cannot duplicate what a tune can do? would appreciate the info.

I don't have an M340i. Mine is a 330i. JB4 works really well for me. I've read quite a few posts about it not working on M340is but I have no idea why.

A JB4 can't duplicate a tune in the way it delivers power. My stock 330i is almost linear when it comes to power delivery. A tune is the same way, just more power all through the rev range. With the JB4, it feels like stock below 2k RPMs and then it flies when the turbo spools up.

I have spoken to someone who had a BM3 stage 1 tune on his car and had to get a JB4 once his DME was updated. He said the JB4 made the car feel much more powerful than his OTS BM3 stage 1 and that he wasn't going back to BM3 even though he could if he bench flashed his car.

I am running a custom map 6 and my car feels really good. I also have an EWG connector and that honestly made the car feel much smoother. I wasn't expecting to feel anything (and was planning on attributing it to a placebo effect in case I did) but the EWG cable helped. Car is also faster as per logs. The best quarter mile time I've done is 13.15s (don't laugh M340i owners - I know it's slow compared to a stock M340i stock car on the same road under similar conditions did it in 13.9-14s). I haven't done a run after I installed the EWG connector since I had to return my dragy. But I can't wait to get one again and time my car.

When it comes to the M340i, I know there are a lot of nice tunes available (MP, BM3 etc). Those cars put out good numbers. I've only seen a couple of M340is with JB4s and while it isn't bad, I believe tunes have the slight upper hand (stage 1 for stage 1; though most people on here have stage 2 tunes).

[M340i Pride]

Originally Posted by lucasplagenza

Just tested the jb+ on my stock car for the past couple days, works great and definitely a decent up in boost. 0-60 feels the same but flooring it at highway speeds feels much faster. Decided i didn't really like it however, the boost comes on a bit too aggressively and the car in sport+ is a bit jerky. I like the stock driving characteristics more, but it's all preference. I'd encourage everyone to try it for the $200

Just took it to vegas and back... I was pleasantly surprised how smooth it was on the fast lanes of I-15 (lol). And for me personally the boost kicked relatively early (anything over 2k rpm). Not jerky for me. But the boost in on the stock level on my JB+ so I'll turn up the dial and see what happens soon. JB+ is definitely worth it for me.

[M340i Pride]

Originally Posted by Fuel-It!

If you care just read the fault code, but a code that comes up and goes away on it's own isn't a big deal. May not even be JB+ related.

I am not an expert but I do think it was the higher level of the boost. It went away pretty quick as soon as I got back to sea level. Also, the engine light was only on for 2 hours where I was going up and down on the pretty high elevation (6000+) so yes, I dont really worry.

[Evo9m340]

Originally Posted by Gdiddy23

Appreciate the follow up review!

My concern would be the dealership seeing the CEL shadow next time it's in for service. I know the whole "tune vs warranty" discussion has been discussed ad nauseam but I'd still be paranoid about it.

Curious to hear how your experience continues to go tho, as I'm still waiting to make a decision on a tune for my M340

my tuner says since all our cars are connected now, Bmw will flag our cars once the car detects Gforce beyond stock.

I myself haven't confirmed yet, but may figure out soon. I am having issues with my entertainment system and will flash back to stock and bring her in.

[M340i Pride]

Originally Posted by VipinLJ

I don't have an M340i. Mine is a 330i. JB4 works really well for me. I've read quite a few posts about it not working on M340is but I have no idea why.

A JB4 can't duplicate a tune in the way it delivers power. My stock 330i is almost linear when it comes to power delivery. A tune is the same way, just more power all through the rev range. With the JB4, it feels like stock below 2k RPMs and then it flies when the turbo spools up.

I have spoken to someone who had a BM3 stage 1 tune on his car and had to get a JB4 once his DME was updated. He said the JB4 made the car feel much more powerful than his OTS BM3 stage 1 and that he wasn't going back to BM3 even though he could if he bench flashed his car.

I am running a custom map 6 and my car feels really good. I also have an EWG connector and that honestly made the car feel much smoother. I wasn't expecting to feel anything (and was planning on attributing it to a placebo effect in case I did) but the EWG cable helped. Car is also faster as per logs. The best quarter mile time I've done is 13.15s (don't laugh M340i owners - I know it's slow compared to a stock M340i stock car on the same road under similar conditions did it in 13.9-14s). I haven't done a run after I installed the EWG connector since I had to return my dragy. But I can't wait to get one again and time my car.

When it comes to the M340i, I know there are a lot of nice tunes available (MP, BM3 etc). Those cars put out good numbers. I've only seen a couple of M340is with JB4s and while it isn't bad, I believe tunes have the slight upper hand (stage 1 for stage 1; though most people on here have stage 2 tunes).

I see. thank you for that info. and seriously, 330i or 340i they are just a engine hp/tq in difference. the bones are the same, and are superb cars.

cutting down .8 sec in a 1/4 is huge. So Jb4 is a pretty significant tune itself (though not a true tune) . Most people lease BMW's (or more do than not) and tune seems very detectible, which isn't good for a lease car.

13.15 is pretty damn legit for anyone. M340i owner or not, no one should laugh... I know I wouldn't. thats fast still.

My GT2 stinger ran 13.2 in average on most publications... and it was a damn fast mid 4 sec car. And mid 4 sec beats most cars out there. So you are probably faster than F30 340i, which is a mid 13 sec car. That's very impressive. Not to mention carrying around less weight in the front, your car is probably more nimble than M340i.

I am happy with (more than) stock, so JB+ is just a additional cake for me. Might look into JB4 before the year is up, but I do not plan to install a downpipe so more likely not.