[DarthBMR]

I looked for as many reviews as I could before making my upgrade decisions for my 2021 540I M Sport, so I thought I'd share my experience.

Bought my JB4 and MAD Intake from Extreme Power House a little over 2 months ago. First off, want to give props to EPH for answering all my questions promptly and quality of the products. Shipment came pretty quick and parts fit up pretty well. There are plenty of videos demonstrating install of the JB4, but not many installing the intake. I found one or two that helped with install but I basically figured it out on my own, I'd say I have average tech skills with cars so it wasn't too too bad. Securing the fittings on the intake pipe was not the easiest as space is tight but I finally got it with a little patience. My intake didn't come with install instructions, maybe it was a fluke but I got it eventually.

The JB4 was easier, lots of videos on how to install on YT. I did have one of the fittings that was challenging, I was worried I was gong to break one as I had to really force it but it didn't break. I did the simple install routing the wire through the door jam and it has been solid since the install.

MAD Intake impressions. Not sure what kind of power if any I get from the intake, but it sounds BADASS!!!! Especially with the windows down!
Throttle response from the intake alone seems to have improved from what I can tell, it does seem to be noticeable. But that sound!! The turbo whistle and the blowoff valve sound are so cool...exactly what you want from your turbo car imo. Even people in cars driving beside me are slightly startled from the high pitch of the turbo especially with the JB4 tune on.

JB4 Impressions. I run map 3 on 93 octane pretty much most of the time unless I'm highway driving and wanting the best gas mileage, then I just turn it off with the app. Connecting the app and changing the map is very easy. No connection issues so far. The ability to check and clear codes is very nice as well.
The power gain is great...even exceeded my expectations. I have no idea what kind of power gain I got from the combo but it's a different car. Power delivery is smooth and linear throughout all rpm ranges mostly, I do think it falls off a bit after 5k rpms tho, but still stronger than stock. 2500 to 5000 rpms is really the sweet spot. No shifting issues, the extra boost almost feels like this is how the car should have been. Gas mileage does drop off a bit even with normal driving, this is why I really like the ability to turn it off as I drive to Houston a lot and gas mileage is important to me.
The only test I have with the combo is a highway run recently with the newest model M3 from 70 to about 140ish. I stayed even with the M3 for the most part, he did seem to inch away as we crossed 130. I was very impressed by that, I can only imagine the M3 owner was like "wtf???" Lol.

Overall Im very happy with the combo and would recommend. Great performance for the price of the parts.