Stack jb4 with Cobb ap
 

I had a Cobb v3 ap and wanted to stack jb4 on top of it for methanol but I can't seem to get them to work along with each other. Running ots stage2+fmic aggressive on Cobb and have the jb4 on map 5 auto tune and my engine just stutters and stalls, anyone have any suggestions? I've tried looking for a backend flash but the only one I found for Cobb was the single turbo map

you need a backend flash to run the jb4 with a flash tune.

Dont think you can load the JB4 backend flashes with COBB, but i could be mistaken.

So I need to use a bt cable to get the backend? I have the alpina flash on my car as well and hoping it doesn't overwrite that, but I was trying to use Cobb only with the jb4 still installed on map 0 and still stuttering and stalls

you sure you have the jb4 installed correctly? shouldnt have any affect on the car in map 0

Yes you would need a BT cable and the *********** software to do the backend flash or MHD and cable.

You shouldn't be running that map with a JB4 on map 5. If you had read up on it, you'd see that the back-end flashes are what you should pair up with the JB4 as a non-advanced user. Go read the JB4 threads on the other forum to see how you're supposed to run JB4 stacked. There's a few menu options to set.

And if your car is running bad on map 0; then you installed the JB4 wrong. :) And I'm not certain if back-end flashes support Cobb anymore. It's old and deprecated now.

Could you link me to them? I can't seem to find any of the flash maps other than the single turbo map for the ap to run with jb4, the jb4 alone on map 0 runs perfectly fine but as soon as my ap is plugged in it starts to stutter and not run smoothly

n54tech.com

Thanks I think I figured it out going to do it tomorrow and see how things go

Update: turns out the jb4 g5 I have is the ISO version so map 0 isn't truly a bypass map. So I can't run the two together while the jb4 is still installed. Just going to uninstall and sell the AP since I liked the jb4 more anyways. Thanks for the help!

Not sure I understand that. Putting the JB4 in map 0 disables the JB4. Map 4 is the bypass map.

So the jb4 G5 Iso still controls boost although in map 0, but it'll still act like stock bypass just not 100% bypassed as far as I understand

You can easily stack the two. It's no different than stacking it with any flash. JB4 does not know or care if you're DME is flashed by MHD, Cobb or BMW. You just need to read up on the latest JB4 settings (and be on the latest firmware). You don't have an off the shelf BEF like for MHD and BB but if your happy with the Cobb tune and just want the jb4 for meth no changes are needed to the flash. Just set the JB4 settings properly so that it only controls boost (like all BEF set ups). The JB4 has to control boost for meth reference so you can't simply use the jb4 in full bypass. Just leave the Cobb tune as is and tune the boost curve with the JB4 which is probably the easiest thing to do since it's ISO and you just plug numbers in (vs load based like a flash).

Can you elaborate on how to do this? Or just send me in the right direction

Just ditch the Cobb and get MHD for JB4 back-end flash.

Does that affect the alpina b3 flash? I uninstalled the ap already

When stacking use backend flash not the OTS maps

Do you know where I can find these flashes using the Cobb ap? I don't want to shell out more money for the bt cable etc

It will not affect Alpina flash. Go over to N54tech and read MHD sticky to answer your questions.

No, the JB4 will NOT control boost when on Map 0. It ceases to function at that point. If your car is running badly with JB4 on map 0, then it was most likely installed incorrectly.

Those will be difficult to find. The Cobb is obsolete and no longer supported as far as I know. You don't need a BT cable to flash via MHD.

I have checked and checked again the install and also compared pictures which I'll post of the jb4 harness, it is installed correctly. The thing is when I'm using map 0 and the ap my boost now limits to 5-6psi even at WOT but jb4 alone runs at 17psi. But I have decided to just ditch the ap, thanks everyone for your input and help!

Post on N54tech.com or contact Terry for these maps ... Not sure if he still supports Cobb