Check N54TECH.COM : BMW N54 / N55 Turbo Performance forum. Quite a few people with no issues.

Interesting topic... I wasn't planning on tuning my diesel but I hear a lot of others using JuiceBox on their 335s with no issues...

Perhaps over in the US yous have better or a more milder version of the tuning boxes that we see over here in Ireland and UK. Over here, for a lot of people its all about pushing big bhp figures so the tuning boxes may have been pushed across some limits.
Do you get puffs of black smoke with one of them fitted whilst on high boost? Maybe you cannot see the smoke with the cat but most of them over here you can see trails of black smoke coming from the exhaust on boost.

As per the my generalized negative conclusion,, well if you binned as many as I did then you might have posted up something similar to what I posted:thumbup:

From what i've seen the JBD and similiar for the x5 over here are pretty mild...and obviously that can make a big difference in overal impact on the vehicle reliability,...the max HP tuners can obviously overshoot stock components....i'd be most worried about the trans life given the apparent limited torque rating above stock levels...that and i havent seen a stealth gauge solution to monitor parameters.

Related example on my truck the Smarty TnT-R version i run put's over 200hp/400ft lbs additional to the wheels and i can smoke at will (which i dont for the record)...it requires injectors, fuel pump, billet trans shafts, aftermarket turbo, cp3 mods,...to run at that level and not shred the truck....why? becasue it can disable the wastegate (50psi+), max rail pressure (>26k psi), alter timing, disable torque mgmt and disable rpm limiter....whole lotta fun, but if not supported with mods and common sense it can ruin a stock truck in minutes....and gauges are mandatory to monitor EGT's / Rail Pressure and Boost - otherwise you're blind and can max EGT's (motor melt) within a qtr mile....and for the record the 13.4sec qtr mile isnt on kill settings as even with all the mods i have i dont really want to break my truck as it's how i get to work!

Where did Lucky Charms come up with these inflammatory claims of tunes being simple "resistors"? Been hitting the scotch a little too hard ?

LMFAO @ "Lucky Charms"

Good one!

If you wish to buy one of those little boxes, pop them open yourself and see.

All I done was shared my first hand experience with the OP about these tuning boxes. If you think they are all programmed chips inside them then you do have abit to learn.
I don't mind sharing my experiences on here but I don't see why people are jumping into this thread to leave smart remarks about the info I have given?

Also, for your information, I don't drink alcohol.

Please do search online and see what they do.

Also, visit some warehouses over in Malaysia and China and you will see those little tuning boxes sitting there for sale. I just obtained a quote for 150 USD for 25 of them. The look the same but with no sticker on them off course.

Will I buy them and re-sell them? No. Most definetely not. I have a passion with the tuning I do. Not just out to find a quick dollar with a resistor in a box.

And yes it is a resistor in a box.

Aidan

Why don't you purchase one and send it to me. I'll pay you. I'll compare it to the ones being sold here and if you are right, I will eat my bowl or crow.

Aidan,

I appreciate your perspective, obviously you do this for a living and have a passion. Having said that, is it possible, that blanket statements are not accurate in all instances? Have you specifically looked at the JBD Tuner that the OP was evaluating? Do you own one? Prior to making blanket statements, it might make sense to do some research on the specifics in question. That way the OP has more info to go on for his/her particular inquiry. Rather than a blanket statement that they all suck, or are no more than a resistor in a box.