Hi everyone,

I've searched with not much luck....I'm getting ready to purchase a JB4 for my E60 535xi and was wondering if anyone has found there to be an improvement in the throttle response?

My car like others has a bit of a delay and was hoping that would be eliminated with the JB4 ?

Thank you

JEC

 

Yes it will.

 

The JB4 is the miracle tool for the 535s! There is a bit of lack waiting for the turbos to spool but ocean, member on n54tech.com said he installed the AR Design downpipes and they eliminate that completely! I'm buying some once I come back from my trip in nine months

 

I have a JB4 and also a Cobb Access Port tuner for my 535. The JB4 does have a small amount of lag compared to the Cobb when it is set on Stock Throttle.

What I did, was install a Sprint Booster and it took care of that problem.
I run the JB4 cause I'm using E85/91 gas mix and JB4 has better mapping for that.

 

That was my next question if anyone was running a Sprint Booster with a tune...

 

yup i had my 535i with afe dci, custom section 2 going to umnitzas quad exhaust and ar catless downpipes, afteri put the downpipes there werent any turbo lag. the JB4 was super powerful and like what Chief Holley said "a miracle tool"

 

How are you running the Quad exhaust on a 535i, I have looked at the under carriage and just do not see how we can get pipes over to the passenger side. Got Pics?