jb4 and cobb

[zayzay]

a bmw mechanic told that you can combine jb4 with cobb to get max power. is this really possible without damaging the car? any opinion or advice will be helpful.

[bdaddylo]

You're better off asking this question on the N54 forums.

[Snertz]

Stacking the tunes is useful for certain conditions, e.g. - running meth, or bigger turbos pushing above 18.5psi, but on a stock turbo car it isn't really necessary.

On stock turbos, max power can be achieved using either by itself. Flash tuning like the Cobb AP gives you proper control over fueling and timing, and ease of install. A piggyback like the JB4 offers benefits like the gauge hijacking, meth failsafe integration, and ease of dialing in boost control.

Personally, I recommend going flash route first, then getting a piggyback when the need arises.

[zayzay]

i already have the cobb ap installed with a pro tune plus full bolt on. wondering if i could install jb4 with the cobb without damaging the engine?

[SpencerMH]

Originally Posted by zayzay

i already have the cobb ap installed with a pro tune plus full bolt on. wondering if i could install jb4 with the cobb without damaging the engine?

You can and as stated above it will give you more flexibility and features but other than the boost gauge on fuel gauge, and 1st and 2nd gear boost limits the jb4 allows the most valuable and really only purpose is I can easily raise and lower boost targets to compensate for different gases. I run a tune meant for 40-50% e85 and if I'm stuck with only 93 octane due to availability I can easily lower max pressure using my steering wheel controls to ensure I don't cause any issues.. That said it's a dog on the e85 tune running 93 octane but it's a bit safer then running the tunes full boost on 93. It's also useful for the track, I use the jb4s max cool mode and unfortunately on a hot day at the track I usually need to lower boost targets compared to street driving to prevent limp mode and hear soak. I run 18lbs on the street with e85 and 15-16.5 on the track, which would be tough to do without the jb4, it's also great for logging and remote tuning. If you don't need any of the stuff mentioned then skip it I'd say.