Currently running Cobb Stage 1 in my 535 but I've heard alot of good stuff about the JB4.

Only other mod is the BMS Dual Cone intake.

Just wondering if there is much difference between the two tunes. You know how it is,

always looking for more.

I'm in Socal so all I can get is 91 octane and that's why I'm running Stage 1 91 tuning.

I've heard that the JB4 pulls harder up top, not sure about down low.

I like the increased sensitivity of the Cobb at light throttle, seems to improve city driving

gas mileage too. Does the JB4 feel the same?

What do you guys think?

 

I've been too lazy to install my HP intake so I've been running MAP 1. There is a slight to moderate increase off the line but the big difference is when you accelerate from driving speed. A slight increase on the accelerator and the car takes off.

The JB4 offers a variety of additional functions and several different MAPs depending on your setup. There is a MAP setting to integrate meth-injection as well as a user programmable MAP setting for serious tuners. Best of all its completely removable and can be reused on another x35 with the same motor.

I don't think COBB has all of these features.

 

This is what Terry at BMS sent me:


1) Our lagfix is fairly similar. But a bit smoother than Cobb.

2) CPS is available but not really suggested unless you run poor fuel
or have large turbos. Timing is retarded vs. stock with the JB4.
Generally performance between Cobb and JB4 is fairly similar on pump
gas. The JB4 jumps way ahead on race gas, meth, E85 mixes, etc.

Best,
T

 

Check out N54tech and you'll see a host of comparisons.