I have found a dealer that will do the JCW Flash and was looking for some feedback from others that have had it done.

I have the following mods:
15% Pulley
CAI
Miltek
DT Bypass valve

Please dont make this into another JCW Flash vs MTH. I am just looking for some feedback from others that have had it done.

Did it affected your gas milege?
Did it smooth things out?
Your opinion of the upgrade? (benefits or issues)

 

I just did it. The difference, at least for my '06 car, was minimal. Not worse, but nothing special.

So I reflashed it to stock (ver. 44).

But maybe it was related to my car's mods. I have 15%, 3% crank pulley, Alta CAI, m7 DFIC, m7 400cc injectors, m7 Cosworth head, one grade colder NGK plugs, Ceramic coated header, Milltek exhaust.

Looking forward to having Lucky Dog Garage tune the ECU on Monday.

Taking the 3% off before the trip, so it'll be tuned for a 15%, with the harmonic balancer back in place.

 

The mod: 15% pulley, intake, exhaust, plugs and injectors.

Pretty smooth all the way throughout the power band, I can feel the different: before and after. Gas mileage is pretty much to same, may be because of my heavier right foot.

LDG or GIAC might be a way to go if you want to go aftermarket. They might give you better in performance.

 

Make sure you post your impressions of the new ECU software.

 

I'd suggest getting the 380 injectors too if doing the jcw reflash.

 

Will you notice any difference with the JCW flash if you only have a 15% pulley and Denso IK22 spark plugs?

 

They are on sale at Outmotoring - $249