Owner's experiences with BMS JB4.

[challer]

I recently picked up a CP '13 F10 BMW M5. Looking for the best bang for the buck without compromising reliability. The car currently has ~45k miles. I'd like to see 100k miles, or ideally 120-150k. How does the BMS JB4 perform? Are there any 0-60, 60-x or 1/4 numbers to compare stock vs. BMS JB4 only? Have you seen any degradation in reliability? Thanks.

[scott135i]

Originally Posted by challer

I recently picked up a CP '13 F10 BMW M5. Looking for the best bang for the buck without compromising reliability. The car currently has ~45k miles. I'd like to see 100k miles, or ideally 120-150k. How does the BMS JB4 perform? Are there any 0-60, 60-x or 1/4 numbers to compare stock vs. BMS JB4 only? Have you seen any degradation in reliability? Thanks.

It's the quickest and cheapest way to add power, especially the stage 1. Adds more power in the upper rpm range more than down low as peak boast is increased.

Ecu tune is arguably "safer" but hard to quantify. The jb4 "tuning" concept has been around for years with reliability when following guidelines.

Ecu tune is great, but involves drilling your ecu to gain access. On a lease car I would do it, but not on a car I own. Not worth the risk even though it's tiny. Dealers and BMW NA know you need to drill the ecu. They can easily check if they want to - more easily than they can detect JB4 as I've been told by the head tech of my local dealer who is my family friend.

With all tunes, the likelihood of needing more frequent oil changes, spark plug replacement and injector replacement goes up from my experience. Your and others mileage may vary but I've owed 6 tuned BMWs since 2008 - several different models both with piggyback (jb4), ECU tunes, and both combined.

[allmotor_2000]

Originally Posted by scott135i

It's the quickest and cheapest way to add power, especially the stage 1. Adds more power in the upper rpm range more than down low as peak boast is increased.

Stage 1 does not have RPM based control, so it increases boost the 'same' across the RPM range.

[scott135i]

Originally Posted by allmotor_2000

Stage 1 does not have RPM based control, so it increases boost the 'same' across the RPM range.

Yes and the larger impact is at the higher rpm range where peak boost is higher.

With and without jb4 you hit roughly the same boost from idle to 3000 rpms vs say 5000 rpms with the jb4.

That's been my seat of pants impression and dyno experience at least.

[Mike@N54Tuning.com]

Originally Posted by challer

I recently picked up a CP '13 F10 BMW M5. Looking for the best bang for the buck without compromising reliability. The car currently has ~45k miles. I'd like to see 100k miles, or ideally 120-150k. How does the BMS JB4 perform? Are there any 0-60, 60-x or 1/4 numbers to compare stock vs. BMS JB4 only? Have you seen any degradation in reliability? Thanks.

Like mentioned above, whenever you tune you will need to pay attention to the maintenance of the car more, and ensure its running well (filters, spark plugs, oil, etc.) There are 200,000 mile N54 cars out there which have had tunes since pretty much day1 so overall useful longevity of a car shouldn't be affected as long as car is properly maintained, but that could be said for perfectly stock cars as well.

Mike

[allmotor_2000]

Originally Posted by scott135i

Yes and the larger impact is at the higher rpm range where peak boost is higher.

With and without jb4 you hit roughly the same boost from idle to 3000 rpms vs say 5000 rpms with the jb4.

That's been my seat of pants impression and dyno experience at least.

It is additive to the load request from the DME. 0-3K RPM the turbos are spooling so flash, JB4 etc. aren't doing anything unless you have changed the turbos or done something else to speed up spool.

Once the DME load target is reached (typically 2.8K to 3K), JB4 will be additive, so if the target is 15psi and you have +3 on the JB4, car will try to hit 18psi.

[scott135i]

Originally Posted by allmotor_2000

It is additive to the load request from the DME. 0-3K RPM the turbos are spooling so flash, JB4 etc. aren't doing anything unless you have changed the turbos or done something else to speed up spool.

Once the DME load target is reached (typically 2.8K to 3K), JB4 will be additive, so if the target is 15psi and you have +3 on the JB4, car will try to hit 18psi.

Yes. That's my point exactly. But it feels more exaggerated down low vs up top in the range vs ECU tune.

[mike@x-ph.com]

Originally Posted by challer

I recently picked up a CP '13 F10 BMW M5. Looking for the best bang for the buck without compromising reliability. The car currently has ~45k miles. I'd like to see 100k miles, or ideally 120-150k. How does the BMS JB4 perform? Are there any 0-60, 60-x or 1/4 numbers to compare stock vs. BMS JB4 only? Have you seen any degradation in reliability? Thanks.

If you are looking to a tune only, Go with BMS stage 1
If you are going FBO, get the JB4

JB and JB4 are proven to be safe tunes, no need to worry about reliability

[sdf10m5]

Originally Posted by challer

I recently picked up a CP '13 F10 BMW M5. Looking for the best bang for the buck without compromising reliability. The car currently has ~45k miles. I'd like to see 100k miles, or ideally 120-150k. How does the BMS JB4 perform? Are there any 0-60, 60-x or 1/4 numbers to compare stock vs. BMS JB4 only? Have you seen any degradation in reliability? Thanks.

I left mine untuned as long as I could.. Once the warranty expired, I went with the bms - I then fell in love all over again with my M. It is easily adjusted and I have gradually moved up from the default boost setting, to now running 4.5+ over stock (with 101 octane). It put down 609 whp on pump gas with 2 gallons of 100 added on the default bms boost setting, much higher now. You must let the car adapt and perform proper maintenance as has been previously stated, but other than that just make sure to add some 100+ octane if you increase boost- and in my experience it has proven very safe.
The car is now an absolute monster.. It pulls insanely hard, however just be aware that if you go with the bms and eventually bump up the psi - on the oem rubber, it doesn't hook until about 60.

[kjdeion21]

I have purchased the JB4 Tune and I was wondering what everyone had with the overall experience and the horsepower gains... I have a BMW F10 M5 and I have catless downpipes, one of the best cold air intakes out there and a muffler and resonator delete. What are recommendations for me on this set up?

[ajm55]

I have ECU tunes from Evolve and BPM. The Evolve tune is wild but makes too much torque low down for my liking - over 1000nm at about 3.200 rpm if I recall correctly. The BPM tune is a torque limiting tune which is preferable for everyday driving. JB4 is an option of course but I’ve just popped the motor on my n54 335i running the BMS 500 hp package (which includes a JB4) so while it has inbuilt safety features, it is by no means fail proof. I’d go with an ECU flash from one of the reputable tuners on the forum

[M6Roar]

I run JB4 with BM3 stage 2 93Oct. The only reason I added the JB4 is to compensate for the boost drop due to aftermarket chargecooler, Terry helped me fine tune it to match what BM3 boost curve suppose to be. In addition to a killer map (26 PSI) provided that I can keep the car on the ground lol and I do agree with ajm55 a tune is what you should go for

[byebyev8]

I currently run jb4 on map 1 pulls hard above 5k rpm. Maybe it’ll be quicker when I attach the bcm. But your limited to around 620whp it seems like without going to an actual tune or install a meth kit. I have an aftermarket warranty still for 2 more years which is why I didn’t flash it. Mhd and trans flash for the price seems to be the best deal and no drilling of the Ecu.