Re: SCT X4 "Jake Brake" option
I have never tried the "jake brake" option in any of the SCT canned tunes, but I do have an IDP custom "towing tune" with the brake option that I had them add for me. For towing stuff, its' ok. You might be able to feel it slow you down a little when you are off the gas and coming to a stop, but basically, it just tried to keep your turbo spooled up when you are coasting to a stop.
When you are not towing anything, it's kind of annoying.....you hear the turbo whistling a little when you are slowing down.
I didn't like it very much, and I didn't felt that it make much difference at all.
2005 F250 6.0 PSD, ARP Studs, Felpro HG's, EGR Delete, IPR Coolant Filter, Bilstein 5100s, Blue Spring Mod, IDP Custom Tunes