M50 HP Goals with built block?

[luky672111]

I have a M50B25NV block in a machine shop. The machinist thinks I am over estimating the potential of the motor once built so I am asking what would a reliable HP number be in my situation?

84.5mm Wiseco pistons 8.8 CR (0.5mm overbore, does that limit my max psi because of the thinner sidewalls? Machinist said the block needs the overbore.)
135mm forged eagle rods
arp main, rods, and head
vac motorsports bearings (not sure if this matters)
cometic 85.5 mm MLS headgasket
PT6262 (first gen)
ECU Master classic with the m50NV adapter

plan on running pump gas, 93. I could run E85 in the future because the ecu master has a flex fuel option.

From reading on forums I seem to think this should be able to handle 30 psi no problem or 600-800 HP?
I plan on running 400 HP because the e30 axles/ 260G break at ~500 but I want the ability to go up to 600 once I replace the entire drivetrain.
I plan on using this as my daily driver/ weekend car.

Thank you for any feedback!

[varg]

Research it, 24V turbo has been done to death in E30s, E34s and E36s. You'll make more power than you can put down with a stock M50 bottom end, let alone an all forged build. Probably the most notable 24V turbo E30 that exists, Nisse Jarnet's AWD E30, makes over 800whp on a built 2.8L M50. You will need drag radials to put anything near 500whp down effectively, and with those tires you'll start breaking stuff and need an upgraded rear end, axles, transmission.

[TobyB]

Reliable?

1 bar.

That'll run forever.

Everything over that will deteriorate faster. By 2 bar, potentially explosively.

When in doubt, trust the person in front of you, doing the work, rather than the utter morass that is the internet, Varg excepted.

t

[Northern]

My take is that it should take 600 if nothing is missed, everything works, and the tune is good.

Pump gas and no knock detection is going to get you if you go too far unless the tuner knows the platform well.

84.5mm is no issue, plenty of these out there starting with S52 blocks at 86.5mm. Yeah they sometimes have issues, but it seems more age/corrosion/random.

If they haven't already line honed the block for the ARP mains, I'd send them back and just run stock main bolts. Save the machine work and the bolt cost. There's no benefit.


IMO I think you're going to want to throw some cams in and rev this thing higher. Some supporting mods required.

As much as I hate facebook, I can't recommend joining the usual E30/24V facebook groups enough:
Boosted E36 world
Boosted E30 world
E30 Forced Induction Crew (turbo, supercharged)

[Archibald]

The choice of Vac Motorsports Automotive bearings is a great one. They are known for being durable and resistant to high loads and wear, which is crucial when pushing the engine hard. These bearings are designed for high-performance builds and will help ensure that your engine runs reliably under higher RPMs and boost levels. With your rod, main, and head studs being ARP, you’re on the right track for handling the stresses that come with a high-boost build.