[mikeo]

Originally Posted by azwillnj

What kind of mileage increases are you seeing?

The OBC says you are getting better milage but the JBD makes those readings inaccurate. My mileage has lessened slightly (fuelly.com) but my smile has increased greatly ;-)

[mikeo]

Originally Posted by EYE4SPEED

Subscribed and can anyone here verify if the BT scanner can only be linked to one VIN or up to 3?

The BT scanner sold with the JBD is a 1-VIN tool. There are BT scanners for more money that are 3-VIN or Professional unlimited-VIN.

[EYE4SPEED]

Thanks Mikeo - BT tool is useful.

Can someone confirm that fault code 4674 is the tuner code triggered by the JBD at 100%?

Also, the two related shadow codes - 3F11 and 3F21 (accelerator pedal module potentiometer 1, 2).

[greentrbo95gst]

I apologize to bring up the old subject, but I have had my JBD installed since last May and the car ran great until December at 80%. Now I can hear something that appears to sound like knock (electrical) and the car registers 5.7 seconds 0-60. No codes. Any ideas?

[dak970]

How is everyone's experiences since 2012 with the Tune?

Any more 'long-term' updates? Have there been any issues or codes encountered?

I am going to put one in soon, but wanted to see if there were any more recent updates with users experience with the product, both positive and negative.

Thanks everyone,
David
Northern VA

[Hoooper]

50k+ miles at 100% running mine. Nothing but positive experiences.

[AzureHaze]

Originally Posted by Hoooper

50k+ miles at 100% running mine. Nothing but positive experiences.

+1. For a brief time I had it at 75% so I can gun it as soon as the car starts up and not get a limp mode. Then I kicked it up to 100% permanently and learned to be patient by letting the car warm up first.

[E_Fahlman]

I just bougbt a 2009 335d about 2 weeks ago and I'm eager to install the JBD Tuning Box to add a little extra power on the cheap. Does anyone have any experience with these much less expensive similar tuning boxes I found on eBay? Will they only work on European Vehicles?

http://www.ebay.ca/ulk/itm/181988331910

http://www.ebay.ca/ulk/itm/261877067163

[Thecastle]

Never heard of them. Most folks would say just buy a used jbd. I do notice they don't list a us spec 335d on their compatibility list.

Personally the jbd which I have works well and hasn't caused any issues.

[Hoooper]

They probably work just as well up to a point. Both say +35 HP so that means that they dont adjust up as high as the JBD does. It would be like running the JBD at 50% or so all the time and not being able to go higher.

[E_Fahlman]

Thanks for the response guys; I'm just going to get a Used JBD from someone on the forum as it's probably the safer option.

[caiken]

Does your JBD put codes in that need to be cleared before taking to a dealer? I am planning to run only at 75%. Not under warranty with BMW but I have a 3rd party warranty to 100k.

Would rather not spend another $120 on Carly + Wifi adapter to clear codes.

[caiken]

Originally Posted by caiken

Does your JBD put codes in that need to be cleared before taking to a dealer? I am planning to run only at 75%. Not under warranty with BMW but I have a 3rd party warranty to 100k.

Would rather not spend another $120 on Carly + Wifi adapter to clear codes.

Anyone?

[gavronm]

Originally Posted by caiken

Anyone?

I can't say for sure, but if you've ever gone into limp mode because you got on it too hard before the car was sufficiently warmed up, there are probably codes stored somewhere, even though you can easily cure limp mode by restarting the car.

If a dealer finds a code related to some type of fuel pressure irregularity, which is what the JBD would cause, the odds of the tech jumping to the conclusion that you had a JBD installed are probably low. That said, your safest bet, obviously, is to find a way to check for and clear codes.

[caiken]

Originally Posted by gavronm

I can't say for sure, but if you've ever gone into limp mode because you got on it too hard before the car was sufficiently warmed up, there are probably codes stored somewhere, even though you can easily cure limp mode by restarting the car.

If a dealer finds a code related to some type of fuel pressure irregularity, which is what the JBD would cause, the odds of the tech jumping to the conclusion that you had a JBD installed are probably low. That said, your safest bet, obviously, is to find a way to check for and clear codes.

Thanks. I guess I will have to see what happens after I install it.

[Hoooper]

Originally Posted by caiken

Does your JBD put codes in that need to be cleared before taking to a dealer? I am planning to run only at 75%. Not under warranty with BMW but I have a 3rd party warranty to 100k.

Would rather not spend another $120 on Carly + Wifi adapter to clear codes.

I saw that happen once, and only once. I have had the JBD installed for about 3 years now and the only time it happened was the first time it was plugged in.

FYI use torque instead of carly if you want to save, its much cheaper and has mostly all the same capability. Definitely capable of deleting codes.

[robnitro]

If you want a poor man's JBD/rail pressure mod, I found it out.

Electrically savvy, so I tried a voltage divider. Oddly, the ecu did the opposite. With more testing, I found a 39 Ohm resistor in line from ecu 5v line to the sensor makes the sensor report to the ecu as .43v lower. In the spec sheets, it's about 4v at 1600 bar, from what I recall. I lost the table, but .5 v is about 200 bar increase. So I'm a bit below 1800 bar, which is the reported max pressure.

It's a flat offset, with meter testing the .43 v doesn't change whether at WOT (when ecu requests 1600 bar) or idle. That means the sensor reads 200 bar low whether at idle of 300 bar or max 1600 bar. So idle 300 bar becomes around 500, and the 1600 wot becomes around 1800 bar.

At idle I did a fuel flow load test, 700rpm idle, AC on, defroster on, headlights on, fogs on, and trans in D. On torque BT tool, normal (jumped resistor for stock reading) about 2.0 l/h, with the resistor active it dropped to about 1.5 l/h.

This means that messing with fuel rail pressure will throw off your mpg readings on the dash!

Can someone try this with the JBD on and off? I'm curious, it will give a clue.

Of course this is not a real number with the mod- but relative. Since it is a linear offset, the low throttle , low load pressures have a bigger %. (500/300 is about 60% but 1800/1600 is 12%).

[robnitro]

Found the rail pressure vs voltage table that I wrote down on a paper and lost.

Pressure/ volts output of sensor/ Modded pressure 0.5v drop resistor (45 ohms IIRC) / % increase
At 0, 0.5 v (y offset of sensor)
400 bar 1.39v 625 bar 56%
600 bar 1.83v 825 bar 38%
800 bar 2.28v 1025 bar 28%
1000 bar 2.72 v 1225 bar 22%
1200 bar 3.16v 1425bar 18%
1400 bar 3.6v 1625 bar 16%
1600 bar 4.05v 1825 bar 14%
1800 bar 4.5v (not used ecu looks for "1600" and below)
2000 bar 5.1v

A tuning box would only apply the resistance as a curve to prevent adding pressure at idle. In some applications that is needed to prevent a loppy idle. On the x5 35d, it doesn't matter- idle is smooth. In D idling , instead of showing 1.2 fuel, it says 0.9 now which means the ecu is thinking it needs 33% less injection window. Of course the mpg display is wrong now.

Some benefits to this method. Idle burns cleaner, more pressure means smaller injection window for the same fuel. More NOx, and a bit more effective SOI because the EOI is earlier (shorter window).

If we see pilot injection as a set percentage of main injection, this makes the main vs pilot quantity a bigger difference, meaning less is wasted for pilot injection. I guess the same with post injection, but warmup and regen seems the same- no problems for the past few months.

Throttle response is much better, takes away that laggy dead zone which makes you want to push more to get brisk acceleration.
DS mode is not annoying anymore where it holds a gear with revs and you got to push the pedal down to get it to upshift. Transmission is fine, lockup works fine and smooth.

Butt dyno using torque shows approx 30 hp increase. Makes sense with the 14% increase on the top end: 265 * .14 = 37 hp if injectors flow linear to pressure. Approx 302 hp then, which is in line with JBD 50% IIRC?

In the future I plan to retune and dpf/egr/scr alphabet removal... But for now this works well.

Edit: added which pin/wire to modify. See picture attached.
The one with the square edge gets the resistor in series, which reduces the voltage that goes to the sensor. 45 ohms is about 0.5 v. You can check this with the ignition on, engine off. The voltage drop is constant, as the sensor is constant current. I've measured it with remote leads and it never changes. I even wired up a switch for testing when I first was finding what to use.

[lnxguy]

335d evry mod? lol Sweet!

[robnitro]

Originally Posted by lnxguy

335d evry mod? lol Sweet!

I added more detail on that post on what side of the connector to use.
It's up to you whether to cut the wire and solder/crimp the resistor inline or do as I did, using small female plugs to go onto the sensor pins and wire pushed into the ecu plug.

[Yozh]

Interesting and easy mod. Wonder how your fuel economy has done with this. Any data? And wonder if you are deleted? Sorry if I had missed it.

[robnitro]

I'm not deleted. When I delete I will return the connector to normal, no need for rail pressure mods then.

MPG is same overall if I check by fillup/miles but the display is incorrect, off about 15-20% depending on the driving.

I think the extra energy used to add 225 bar in low loads gets offset by the earlier EOI. The end of injection is done quicker in low and mixed loads. Figure if you needed "20 mg" to go X mph on a hill, now the ecu thinks you need "15" and does approx 25% smaller window for the same fuel. Poor man's ecu mod. My case, I just don't want to remap until after I can delete. I plan to gut the dpf, keep the doc part... and gut the scr. I don't trust going non stock for resale and or inspections. Even I would keep the EGR on to look the part, like I did with my TDI

Plus the transmission shifts earlier... figure 15-20% more sensitive throttle means the trans sees less pedal request and thinks to shift earlier. No problems though- it's far from pushing it. I assume the boxes are similar in feel as I read they change response too.

There's more room but I think 1825 bar is a safe space.
IIRC, TDIwyse found a problem with JBD at 85% and up making his request not match actual. That means the pressure was hitting the point at which the mechanical relief valve opens on the CP3. Do that too many times and that spring wears out. According to the cummins forums, the bosch safe rating is 2000 bar (30k psi) for pump/inj with relief around 1925 bar (28k psi). Since the pressure can have some spikes, I think it's best to stay 100 bar or so away from the relief number.
There are some in the cummins world who run more than 30k psi, by capping the relief valve. Not a good idea, can't always trust electronics to stop a spike that could damage things- mechanical reliefs are always welcome, even at work where we deal with boilers and huge pumps!