I hope I'm not giving misinformation here, but I'm building an n54 myself, and from researching everything the best I could, I have a small summary here: - Maintenance first, obviously, & upgraded pcv & catch can - Fbo with tune (downpipes, 5" intercooler, charge pipe, intake filters, stock turbos) should get you a nice 300-400hp that can be fun for a while - If you want to upgrade turbos and make 400-600hp you also NEED inlets, outlets, 1 step colder spark plugs, 3.5bar map sensor, a stage 2 or 2.5 lpfp, possibly port injection or helix overdrive. AND A TUNE! - Port injection or Helix overdrive? - do PORT, it's more money, but it's hands down more reliable & proven. Helixes have been known to shorten the life of the hpfp, which is not worth it. - Want to run e85? Great, you will make a crapload more horsepower on the same turbo setup, BUT since e85 gets consumed faster, you will need to upgrade your fuel system to pump waay more fuel. PI & a STAGE 3 pump is mandatory, as are upgraded fuel lines, 2-step colder spark plugs, an ethanol sensor, and a controller (s) for the PI & ethanol sensor. - Are you wanting to go 600-750hp? You need big twins or a single turbo, and you a HAVE to run e85 & more psi, with port injection, stg 3 pump, as well as a 7.5" STEPPED intercooler. You also might start to misfire at these power levels, or with e85, so replacing your ignition coils with fresh Eldors or Delphi ones, or upgrading to b58 coils might be a good idea - If you want more power now, but don't have the money to do it all at once, after fbo, you can just buy a single turbo kit, stage 2 pump, tune, & work with that for a while, but you're not going to take advantage of the power the single can really make until you get port/Helix, a stg 3 pump, & run e85 fuel. But until then, just run a conservative tune on your single at sub-500hp, sub 24psi. (talk to your tuner) - Do you want protect your stock engine? Don't go past 700hp or 26psi at all, and your engine will last (maintenance & driving-habits depending) If you want to run past those numbers, it's time to build your engine, replace your valve cover with a metal one, & do an external pcv. - Even with fbo, it's a good idea to address COOLING on these cars, and REAR END HANDLING. Get upgraded oil coolers, possibly a radiator (but oil cooler first) and replace old plastic & rubber parts with new metal ones & fresh rubber hoses. For handling, replace those rear subframe bushings with m3 or solid aluminum ones, transmission & diff bushings, get decent coilovers, and get a limited-slip diff. This is what I did last year and it solved the squirrely rear end when I accelerate in my 135i. Still need bigger fender & tires, but 335i guys should be able to fit good tires still. - All in all, if you want more power it takes money & research, & time. If you want no problems, you're gonna have problems, just comes down to how badly you want to get the build accomplished and if you can be smart & fix the issues or find help. But it's fun af & worth it when you do. Don't forget to enjoy the car if it starts up & drives, because I'm getting obsessed with this single turbo build, but sometimes it takes away from other things in my life, and I'm learning I can't let it do that, and there's something to just having a car that runs & drives, even at "only 300" horsepower. Driving & enjoying it and not watching it sit for weeks/months in a garage is less sad.
Isn't the stage 2.5 fuel pump rated for up to 650whp? The 5" intercooler also seems small for a 700whp build. For instance, VRSF rates that for up to 550whp. Also, aren't you concerned with heat management? You didn't mention any cooling mods like upgraded oil cooler or radiator. Looking forward to seeing your dyno run. Good luck with the build!
@@Purpz710 sure. I chose to upgrade mine because I don't think they handle that much power well, which is why I brought it up. So you're saying the stock oil cooler is good for 700whp?
Nice color for the IS. Please post your Dyno sheets. I am not see 700+ at the wheel here. If you are at 700+ with no cooling mods, no other support mods like forged clutches I fear your car will not last long. But Looking forward to more used mods.
i have a 335is as well and im looking to go single turbo soon, how is the dct been holding up with that much horsepower, and how many miles have you had with 700 hp?
Less than 500 miles but I’m about to do the new update for the single bank o2 sensor and that helps with Afrs and makes it safer to make more power. DCT has been great with the Xhp tune. It’s rated for 718 wheel torque!
Hi, not sure if i missed some information but i have pretty msny questions What kinda fuel blend you run? Do you have stock clutch? Do you have stock diffrential and if so do you think it will be able to handle well 700whp+? And finsl question whats the gas mileage at these 700hp n54s?
Hey there. I should have been a bit more detailed, it’s on stock DCT clutches with an Xhp tune that bumps torque capabilities to around 700wtq, Has stock differential which is pretty strong but I wouldn’t recommend too many launches. It’s on full e85 I get around 14mpgs.