Which Engine to boost?

[Alpine e92]

why not just sell both engines get a s54 turbo/supercharge it im sure you would have no problem breaking 400whp and bieng a dealer of parts should be no trouble and a more exciting build

Thats something i will save for an e30 m3 shell.

[10Toes]

u didnt, clearly he missed something lol.

op, my vote is s50 turbo, freshen up the motor with bearings, mls hg, arp studs and as long as it is a healthy motor it will handle 400whp without a sweat....dont skimp on the tune, thats the most important part.

I didn't miss anything, the op just didn't post enough details.:)

I would use the US S50 and turbo it for anything more then 350hp for if you want less then 350hp I would supercharge it.

[Jean]

the biggest, with the biggest turbo you can afford/fit/make work .

[Jszy25]

Voted: S50

Install a .140" MLS head gasket (dropping compression to ~8.8-9:1). Use the block prep method outlined on bimmerforums. It involves using sanding stones to get a really nice, clean block mating surface which is crucial for MLS sealing. Also have the head decked at a reputable machine shop.
Install ARP2000 head studs
Drop in a Walbro 255 (in tank)
Get an OBDI remote tune package from TRM (60lb injectors, maf, maf saddle, harness)
Install quality turbo components (Precision 6262 turbo is a really good option IMO)
475whp all day, no problem

[Adrian_Visser]

why not just sell both engines get a s54 turbo/supercharge it im sure you would have no problem breaking 400whp and bieng a dealer of parts should be no trouble and a more exciting build

An s54 is a very expensive, very difficult engine to turbo charge, HPF charges upwards of $10k for their s54 turbo kits for example.

400whp on an s50 with MLS and studs is no big deal it's been done lots.

Voted: S50

Install a .140" MLS head gasket (dropping compression to ~8.8-9:1). Use the block prep method outlined on bimmerforums. It involves using sanding stones to get a really nice, clean block mating surface which is crucial for MLS sealing. Also have the head decked at a reputable machine shop.
Install ARP2000 head studs
Drop in a Walbro 255 (in tank)
Get an OBDI remote tune package from TRM (60lb injectors, maf, maf saddle, harness)
Install quality turbo components (Precision 6262 turbo is a really good option IMO)
475whp all day, no problem

This^^

[Alpine e92]

Voted: S50

Install a .140" MLS head gasket (dropping compression to ~8.8-9:1). Use the block prep method outlined on bimmerforums. It involves using sanding stones to get a really nice, clean block mating surface which is crucial for MLS sealing. Also have the head decked at a reputable machine shop.
Install ARP2000 head studs
Drop in a Walbro 255 (in tank)
Get an OBDI remote tune package from TRM (60lb injectors, maf, maf saddle, harness)
Install quality turbo components (Precision 6262 turbo is a really good option IMO)
475whp all day, no problem

This sounds perfect. Thanks!

[Jszy25]

An s54 is a very expensive, very difficult engine to turbo charge, HPF charges upwards of $10k for their s54 turbo kits for example.

$13,500 for their stage 1, to be exact.

This sounds perfect. Thanks!

No problem. Feel free to PM me if you have any questions.

[russhixmo]

Sell em both and buy an s52 =p, or I'm going to have to say build the s50 then boost it.

[Jszy25]

Sell em both and buy an s52 =p, or I'm going to have to say build the s50 then boost it.

Sure the .2 liter of displacement difference doesn't hurt, but then factor in converting it to OBDI. Not difficult, but cost goes up. Might as well start with an OBDI engine/ecu/harness.

[jrdeamicis]

M52 Bottom end, S50 Head.

[Jszy25]

M52 Bottom end, S50 Head.

M52 bottom end or just the 2.8 block? If you're doing a frankenstein, might a swell source an S52 crank bringing displacement to just about 3L, forged 135mm rods, forged low comp pistons...but then again, I dunno if OP is looking to do all of that or if its even necessary.

With a 400-450whp goal, a stock S50 w/ MLS & ARP combo will hold up just fine with the proper calibration and fuel.

[The Humjet]

450whp even on an m50 can be done easily as well.
I haven't heard much from miller lately but they can do obd1 tuning packages so if your boss is good on the laptops then he will have tuning your car with a Miller w.a.r chip. Also get yourself one of goodntight's manifold he is a member here and makes killer manifolds.
When it comes to turbo 24v motors the bimmerforums forced induction is the best place to get info. Very busy forum where lots of helpful guys can answer your questions quickly.
But basically what Jszy25 has mentioned is a popular recipe for an m5X/s5X turbo.

[Wanganstyle]

sell all random parts, buy and Boost a S54. - start with the best and most efficient if its in the budget.

honestly if you are doing a big boy build (not a r3v garbage turbo kit) you will spend about the same. Everything original needs to leave for a proper reliable (shop worthy) 400rwhp.

s54 Displacement = MORE. 91mm stroke. 87mm bore.



Crank/rods design = STRONGER - wider bearings, stronger stud design for head.
RPM capability = MORE
Head setup/capability/induction system = is this even a question???
Dual vanos vs single - not even close. Dual lets you spool up a large turbo much faster than single- compare Nonvanos to Vanos turbo spool mapping..


S54 + 6 pistons + turbo kit and your standalone of choice OR OEM s54 brain mapped for boost

how is this different than

m50/52/s50/s52 + 6 pistons + turbo kit + standalone of choice OR OEM s52 brain mapped for boost?

Boosting bimmers costs dough. dosnt really matter what you start with. Local guy just spent over 100K USD on re-building a M10 based powerplant.


when it comes down to it, if your target is big power (500rwhp-1,000rwhp)- built s50/52's are still searching for cam / valvetrain/solid lifter / headwork upgrades, a S54 needs none of that sillyness. cams, valvetrain, headwork, bottom end is incredible. just buy turbo pistons.

if budget is of concern; M52B28 complete. no hodgepodge franken engine required.

Boosted cars make power Via BOOST. a M52b28 100% complete no cams would be quite efficient as it can just take tons of BOOST. NA cars and high stress level of turbo cars (more than 180hp/liter) benefit much more from Cam changes than Medium tune state boosted cars.

stock 2J's make more than 700rwhp on stock valvetrain/cams/portwork (NA or TT head).

the factory M52b28 head settings (cams/induction) is as aggressive or more than a NA/TT 2j. there is no need to change the head if not going for incredulous power goals.

just ADD BOOST. shit tons of it, have it tuned well (professionally tuned OBD2 is ideal-smarter than obd1)

[Jszy25]

I respectfully disagree with many of your comments. Please see my responses below:

sell all random parts, buy and Boost a S54. - start with the best and most efficient if its in the budget.

honestly if you are doing a big boy build (not a r3v garbage turbo kit) you will spend about the same.

Not true. S54's are still several times more expensive than even a low mileage S52. M50 based engines are ridiculously cheap in comparison.

Starting with an S54 would raise his costs the amount of the S54 itself, minus his existing S50 (by selling it)...i.e., still several thousand dollars higher in total cost for the S54 build.

Also, factor in the availibility of turbo parts for the S54 like an exhaust manifold...only off the shelf ones are the Steedspeed ($1,050) and the HPF log manifold (~$1,000 + shipping). M50 manifolds can be had for as little as $190 haha.

The S54 intake manifold is not proven to hold more than ~10psi. Hence the reason why HPF includes their cast one even in their stage I kits. So plan on having to buy theirs ($995) or build your own sheet metal intake manifold if you want over 400whp. (There is a lot more that goes into the intake manifold discussion, but thats for another thread). The M50 manifold can hold 2.5x times that much boost.

Everything original needs to leave for a proper reliable (shop worthy) 400rwhp.

False.

MLS head gasket & ARP2000's, all else stock...400whp without a breaking a sweat, daily driven. No problem. Been proven over and over. I worked at a very highly respected BMW shop.

S54 + 6 pistons + turbo kit and your standalone of choice OR OEM s54 brain mapped for boost

how is this different than

m50/52/s50/s52 + 6 pistons + turbo kit + standalone of choice OR OEM s52 brain mapped for boost?

Please tell me who tunes the stock S54 ecu for boost???

I know of 1 and his software will ONLY be sold along with the turbo kit that he is helping to develop. (Not available yet)

The main difference is the cost of the engine itself as well as the price of stock ecu calibrations. You can get a complete tuning package from TRM for $1,500 for an m50 based engine (OBDI). There is no S54 stock ecu calibration available for purchase.

The price of an OBDI standalone PnP kit starts are $2,600 and then you have to pay to have someone calibrate it on the dyno...$$$$
Add S54's dual vanos into the mix and standalone price goes up.

when it comes down to it, if your target is big power (500rwhp-1,000rwhp)- built s50/52's are still searching for cam / valvetrain/solid lifter / headwork upgrades

a S54 needs none of that sillyness. cams, valvetrain, headwork, bottom end is incredible. just buy turbo pistons.

Stock S50 heads can easily flow 500whp. Stock pistons/rods have been pushed over 700whp before letting go...I'd say thats "incredible"

If you are shooting for 1,000whp...call Bavarian Solutions. Its all readily available for the M50 based engines. Solid lifters are not necessary either.

A stock S54 can make 400whp no problem...so can an S50. If you want 500, 600whp, you'll need a built engine whether its an S50 or an S54.

Also, S50/S52 turbo torque>S54 turbo torque