m20b30 turbo size

[Mhigh]

Hello there currently building m20b30 and cant figure out which turbo to use for it.
Before this build i had m20b25 fully forged 8:5.1 CR ton off other engine mods etc ,with BorgWarner S200SX 0.83 A/R and it did 20psi 430hp @ wheels full boost was at 3500rpm it had lsd diff 3.73 and on pump gas 98

So now Building M20b30
Litlle bit of engine specs

ECU MS2PNP
and AEM Double meth injection kit

Polish and Ported 885 head with oversize Supertech +1mm valves (Int/Exh)
Stage 3 M20 valve springs good up to 9000+rpm
Forged Steel Rocker arms
Dbilas Dynamic Camshaft 282°/270°
1600cc Bosch injectors
ARP Headstuds
PPF Factory T4 Custom Turbo manifold
Custom intake manifold with 90mm throttle body
Will use Cooperring HG 85mm
M54B30 crankshaft
DP Custom Forged pistons 85mm 9.0:1 C.R
DP H-Beem Con rods
ARP Main Studs
Elmen Racing Billet caps
6.2kg light flywheel
Diff LSD 2.79

Sure there is allot more things just dont come in mind now!


So im not realy shure which turbo shuld i use i will still use BorgWarner there is two turbos in my mind now the (S363SXE 87/80 with 0.88 T4 Single or 0.91 T4 Twinscrol) or (S369SXE 91/80 same here 0.88 single or 0.91 twin)
The goal is to aim 500-700hp with pump fuel and meth injection @ 20-25 psi and redline will bee set to 8000-8500rpm

Can someone share some info on those two turbos?
Thanks

[Northern]

an S257 will make virtually 500.
S363 is at least good for 650 but might need more than 25psi to get there?. I'd probably go for whichever of those two turbine housings fit your manifold (divided/undivided).

Might need to look at larger A/R if you're revving that high but I'm really not sure. I would personally run the .8x-.91 and see if power drops off up top or not, then make a decision from there.

[Northern]

Compressor Map for S363 8780




S369 9180:

[McGyver]

While we're on the topic of BW turbos, I'm finally ready to pull the trigger on a turbo for my car. This is my first turbo build/car and I'm a little overwhelmed with options.

The car will be controlled with my DIY MS2. It currently has a stock m20b25, which I don't expect to last long. The replacement engine currently being built will use an m20 block (decked ~2mm), seta crank and rods, b25 pistons, and b25 head with a mild cam. It'll be a 2.7 liter engine with about 9.4:1 compression. My goal is a fun streetable/auto-x car that spools quick and makes ~250-350whp. I plan to start with low boost and work my way up as I learn.

A friend recommended I go with a BorgWarner S257 SX-E, .63 A/R T3 Open Inlet and 3.625" V-Band Outlet. It seems like this is a good selection for anything from 10-25psi on a 2.7L engine.

Any thoughts/suggestions so I can make the right choice the first time?

[Northern]

I don't know how knock limited an M20 is in boost (I mean people make 400 easily on stock CR), but bumping the CR up 0.6 of a point might cause issues as you up the boost unless you're running E85.

.63 AR should give you a good usable powerband, but the s257 is maybe a little large if you're looking for 350 max?