[mightbaal]

Alright well I want to do a Back end flash for my car I am fairly new to this I have done some research but I wanted a few questions answered before this.

1. Is there more risk with detection for a warranty (aftermarket) in being able to detect this after its flashed back to stock obviously... or is the risk about the same as having a JB4 alone and removing?

2. Can you hard brick the DME or ECU whatever u guys call it the for the car?

3. Does the JB4 backend flash reprogram something in the JB4 or the DME?

4. Am I limited to running strictly like E30 with a backend flash like if I go on a trip and cannot find E85 gas stations in that area or will that mess things up?

5. How long does it take to flash and do you recommend a battery charger connected to it because I think my charger shuts off once the battery is fully charged at 10 amp charge? Current sitting voltage is 12.1V (not running).

6. Are there maps for a car running E30-E40 with just a DCI and JB4?

7. If the DME was hard bricked is there a possible way they can tell how it happened and the warranty not covering it and could I put a used DME/ECU in my car as I see them on ebay for 175 ish.


My JB4 was just updated to latest firmware I have the cheapo D+Can cable thats white probabaly made in china I have the N54 Flasher bought can read codes Flash etc.

Any information would be great please be easy on me as I only looked at the basics and couldnt find everything I have been wondering. I have ran E30 on map 5 JB4 but my trims got way to high for to long and the car leaned out close to 15 A/F ratio on a couple runs.

[Chris@BoostConcepts]

1. Is there more risk with detection for a warranty (aftermarket) in being able to detect this after its flashed back to stock obviously... or is the risk about the same as having a JB4 alone and removing?

Answer: Not sure on this one.

2. Can you hard brick the DME or ECU whatever u guys call it the for the car?

Answer: I imagine this is always a possibility, but I think the risk is low if the proper hardware is used and caution is taken to ensure you have proper battery power in car and flashing device.

3. Does the JB4 backend flash reprogram something in the JB4 or the DME?

Answer: it flashes the DME the same as Cobb does. But requires setting changes in the JB4 to allow pass through, setting 4/2 on steering wheel controls with Backend Flash. Only Flash while jb4 is set to map zero.

4. Am I limited to running strictly like E30 with a backend flash like if I go on a trip and cannot find E85 gas stations in that area or will that mess things up?

Answer: for e30-40 you can run the pump or race Backend Flash. If you will go between e30 and straight 93 pump gas, you may want to try the pump Flash first and log and if all looks good move to the race Flash and log, if it's good you should be fine if not revert back to the pump Flash when running straight 93. Either of those will be fine with low mixes e40 and under most likely but logging should always be done to verify and only make one pass before reviewing to minimize hurting something on a bad combination.

In a pinch, you will be fine normal driving either of those flashes while in a trip with straight 93. You could also simply switch to map 1 or stock if you are concerned about it while on a trip without e85 access.

An e85 Backend Flash should only be used with access to e40 and up mixes as it requires the fueling scalers to keep trims more centered and allow for more movement with higher ethanol content.

5. How long does it take to flash and do you recommend a battery charger connected to it because I think my charger shuts off once the battery is fully charged at 10 amp charge? Current sitting voltage is 12.1V (not running).

Answer: Highly recommend battery charger. Even if it's only set on 2amps. Flash is dependent on your DME, my 2007 took 18 minutes the first time and under 2 minutes for all Flash changes after that (no charger required after first flash.)

6. Are there maps for a car running E30-E40 with just a DCI and JB4?

Answer: any map will work if the logs look good. Going a little at a time is the recommended method. Start with the pump Flash and work your way from map1 through map 5 logging each one and getting advice in your logs. The car will let you know if it's happy or not with the variables like octane, boost and timing. If everything looks good, you can go the next step. Keep good records of your ethanol content and mixes and know what content the stations are supplying for consistent tune results.

In this heat, multiple gear pulls will yield very high IATs so what is OK for a 3rd gear logging pull may not be so great on a 1-4 gear pull where the stock intercooler heat soaks and IAT's sky rocket. This should be logged until you find a solid combination of fuel mix, back end Flash and map setting. Methanol injection adds a much more repeatable result as it doesn't heat soak and will offer more stable IATs.

7. If the DME was hard bricked is there a possible way they can tell how it happened and the warranty not covering it and could I put a used DME/ECU in my car as I see them on ebay for 175 ish.

Answer: my guess is they would know something was up that caused it to fail. I always assume anything in doing will ultimately be detectable if someone looks hard enough for the evidence. In this respect, its good to know your tech and service manager to better understand their standpoint in these matters. Some are not as stringent as others. Warranty work is paid by BMW so most of the time unless it's glaringly obvious to someone they turn a blind eye. But know going in that moods change and its always a crap shoot. That's the risk of modding a car under warranty. Perhaps it's best to have a candid conversation to find what the line is with your dealership if it's a major concern for you.

Hope that helpsl!

Chris

[csu87]

Originally Posted by mightbaal

Alright well I want to do a Back end flash for my car I am fairly new to this I have done some research but I wanted a few questions answered before this.

1. Is there more risk with detection for a warranty (aftermarket) in being able to detect this after its flashed back to stock obviously... or is the risk about the same as having a JB4 alone and removing?

Supposedly once you flash back to stock, you cant tell you were flashed. Not sure if anyone has tried it yet in regards to warranty

2. Can you hard brick the DME or ECU whatever u guys call it the for the car?

As with any flash tune, you run this risk. But if you follow the MHD instructions, it is very hard to do.

3. Does the JB4 backend flash reprogram something in the JB4 or the DME?

Flashes the car, not the JB4

4. Am I limited to running strictly like E30 with a backend flash like if I go on a trip and cannot find E85 gas stations in that area or will that mess things up?

For e30, I would flash the Pump Flash, and you can use pump gas on it as well. the e85 flash is for e40+ blends

5. How long does it take to flash and do you recommend a battery charger connected to it because I think my charger shuts off once the battery is fully charged at 10 amp charge? Current sitting voltage is 12.1V (not running).

First flash is 17-38 minutes depending on the car. Some people can get away with no charger, some need it. Better safe than sorry. Once you do the full write, map changes take 2 minutes

6. Are there maps for a car running E30-E40 with just a DCI and JB4?

7. If the DME was hard bricked is there a possible way they can tell how it happened and the warranty not covering it and could I put a used DME/ECU in my car as I see them on ebay for 175 ish.

If its bricked and you cant read/write, I dont think they would be able to either.

My JB4 was just updated to latest firmware I have the cheapo D+Can cable thats white probabaly made in china I have the N54 Flasher bought can read codes Flash etc.

Any information would be great please be easy on me as I only looked at the basics and couldnt find everything I have been wondering. I have ran E30 on map 5 JB4 but my trims got way to high for to long and the car leaned out close to 15 A/F ratio on a couple runs.

Read up on n54tech in the MHD Flasher Thread for the BMS Backend Flashes. Read the MHD thread here for general info. Its pretty straightforward and easy to do.

See bold above.