500whp e61 AT build--looking for advice

swag_on · 09-11-2023, 05:10 PM

Finally starting my build after much hand-wringing and anxiety but still feel unsure if I'm going about this the right way. End goal is a "modest" all-day-everyday500whp on e60/some e85 mixture. Running MHD, can also add JB4 if recommended.
Here's what I'm planning so far:

Fueling
Stg 2 LPFP
Motivmotorsport FF kit (necessary?)
That's pretty much it. Got lucky w/ previous owner, index 12s and fresh HPFP under warranty within the last 30k.

Lungs
ARM Motorsport 7" FMIC + Tial BOV/chargepipe (overkill, I know).
BMS catchcan (of course)
BMS inlets (are outlets totally necessary? hearing lots of contradictory information)
Stock airbox

Not willing to spend $$ on hot-air intake (cone) system--there's a company in Vancouver that makes a true CAI for e9x's and they're somewhat confident it should fit an e6x, and I've heard again conflicting reports on how much this actually matters for this power goal

Unsure if I'm missing anything here but it seems straightforward enough.

Exhaust
ARDesign downpipes

unsure if the extra $$$ is worth for the high-flow cats? ultimately I want this to "pass emissions" (LOL) without screwing around with too much stuff. If you have experience w/the high flow cats please let me know

Some sort of catback exhaust, though wouldn't mind not shelling out $$$ if the performance gains are negligible over stock (sound is a low concern)
Some sort of upgraded turbo

pure stg 1 seems asymmetrical in terms of cost for performance, RBturbo seems fine but at the price why not just go pure stg 2, but that's total overkill... see my dilemma?

Tidbits
Trans overhaul (fluid, solenoids, applicable gaskets)
Front & rear diff fluid (sitting at 130k right now, seems like a good time to do it)
Pump and thermostat (will do w/ turbos, no evidence of weakness or failure but I don't want to screw myself by being overly confident)
Random suspension stuff, bearings and bushings, blah blah blah

I've already replaced most of the tired cooling system along w/ getting the ports cleaned + oil pan and valve cover gasket and plan on doing an oil analysis within the month alongside the oil filter housing gasket. The car runs strong with no obvious issues/codes, comp/leakdown done earlier this year was spectacular and the only thing that I think bugs me right now is a slight vibration coming from the driver's front wheel.

So, lots of info, I've tried to keep from posting every second asking a billion questions already answered here. Am I missing anything? Am I getting ahead of myself? Ultimately I want this car to run well and strong despite its age and mileage and I'm willing to spend quite a bit to make sure it lives a good life whilst being fun. Will get a custom tune once everything's on the car and sorted (if anyone has tuner in CO that they love send them my way).

Thanks in advance!

swag_on · 09-15-2023, 02:15 PM

Doing some more research I think I'm going to just run the VRSF catless downpipes (won't complain about saving some coin) and have decided to cop the RBturbo TD03's later this year. It also seems like outlets are diminishing returns, but who knows--if you have great experience with an upgraded set please let me know.

I do have more questions regarding fueling, however, and I can't really seem to get any straight answers (or at least find a thread that doesn't devolve into people verbally abusing each other over DI/PI).

Some say you need a full supplemental DI kit (manifold or plate) for anything north of 450whp (even w/ an e85 mixture). Others say that an e85 mixture is fine. Others say still that you're stupid if you're not going VTT single-barrel shotgun HPFP. Regardless I know I'll need an upgraded LPFP (already covered) and probably a flex fuel kit for convenience/safety. I'm just confused on the conflicting accounts and would rather not spend more money on stuff that I don't really need to. Again trying to avoid methanol at all costs. Also, has the DI technology for this platform improved appreciably at all? I've been seeing talk from 2016-2019 about how awful DI piggyback solutions were and I can't seem to find much else within the last couple years.

Please let me know your thoughts, if I'm missing anything, or if I need to re-evaulate. Thank you a million

09-11-2023, 05:10 PM	#1
swag_on New Member 0 Rep 7 Posts Drives: 2010 BMW e61 535xi Join Date: Mar 2023 Location: Denver, Colorado iTrader: (0)	500whp e61 AT build--looking for advice Finally starting my build after much hand-wringing and anxiety but still feel unsure if I'm going about this the right way. End goal is a "modest" all-day-everyday500whp on e60/some e85 mixture. Running MHD, can also add JB4 if recommended. Here's what I'm planning so far: Fueling Stg 2 LPFP Motivmotorsport FF kit (necessary?) That's pretty much it. Got lucky w/ previous owner, index 12s and fresh HPFP under warranty within the last 30k. Lungs ARM Motorsport 7" FMIC + Tial BOV/chargepipe (overkill, I know). BMS catchcan (of course) BMS inlets (are outlets totally necessary? hearing lots of contradictory information) Stock airbox Not willing to spend $$ on hot-air intake (cone) system--there's a company in Vancouver that makes a true CAI for e9x's and they're somewhat confident it should fit an e6x, and I've heard again conflicting reports on how much this actually matters for this power goal Unsure if I'm missing anything here but it seems straightforward enough. Exhaust ARDesign downpipes unsure if the extra $$$ is worth for the high-flow cats? ultimately I want this to "pass emissions" (LOL) without screwing around with too much stuff. If you have experience w/the high flow cats please let me know Some sort of catback exhaust, though wouldn't mind not shelling out $$$ if the performance gains are negligible over stock (sound is a low concern) Some sort of upgraded turbo pure stg 1 seems asymmetrical in terms of cost for performance, RBturbo seems fine but at the price why not just go pure stg 2, but that's total overkill... see my dilemma? Tidbits Trans overhaul (fluid, solenoids, applicable gaskets) Front & rear diff fluid (sitting at 130k right now, seems like a good time to do it) Pump and thermostat (will do w/ turbos, no evidence of weakness or failure but I don't want to screw myself by being overly confident) Random suspension stuff, bearings and bushings, blah blah blah I've already replaced most of the tired cooling system along w/ getting the ports cleaned + oil pan and valve cover gasket and plan on doing an oil analysis within the month alongside the oil filter housing gasket. The car runs strong with no obvious issues/codes, comp/leakdown done earlier this year was spectacular and the only thing that I think bugs me right now is a slight vibration coming from the driver's front wheel. So, lots of info, I've tried to keep from posting every second asking a billion questions already answered here. Am I missing anything? Am I getting ahead of myself? Ultimately I want this car to run well and strong despite its age and mileage and I'm willing to spend quite a bit to make sure it lives a good life whilst being fun. Will get a custom tune once everything's on the car and sorted (if anyone has tuner in CO that they love send them my way). Thanks in advance!
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09-15-2023, 02:15 PM	#2
swag_on New Member 0 Rep 7 Posts Drives: 2010 BMW e61 535xi Join Date: Mar 2023 Location: Denver, Colorado iTrader: (0)	Doing some more research I think I'm going to just run the VRSF catless downpipes (won't complain about saving some coin) and have decided to cop the RBturbo TD03's later this year. It also seems like outlets are diminishing returns, but who knows--if you have great experience with an upgraded set please let me know. I do have more questions regarding fueling, however, and I can't really seem to get any straight answers (or at least find a thread that doesn't devolve into people verbally abusing each other over DI/PI). Some say you need a full supplemental DI kit (manifold or plate) for anything north of 450whp (even w/ an e85 mixture). Others say that an e85 mixture is fine. Others say still that you're stupid if you're not going VTT single-barrel shotgun HPFP. Regardless I know I'll need an upgraded LPFP (already covered) and probably a flex fuel kit for convenience/safety. I'm just confused on the conflicting accounts and would rather not spend more money on stuff that I don't really need to. Again trying to avoid methanol at all costs. Also, has the DI technology for this platform improved appreciably at all? I've been seeing talk from 2016-2019 about how awful DI piggyback solutions were and I can't seem to find much else within the last couple years. Please let me know your thoughts, if I'm missing anything, or if I need to re-evaulate. Thank you a million
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