M30b34 E30 twin-screw supercharged muscle car

[Ether-D]

^Werd.

On another note, I picked up a m54 crank pulley today to modify and make fit to run the charger. Little by little...

[The Dark Side of Will]

Not sure with boost, 85% is a rough guess of a NA 2V engine.

I think 85% is too high.
VE relates volume of air through the engine to the engine's volumetric pumping rate. We'll assume for the sake of this discussion that air through the engine is the same as air trapped in the chambers and used for combustion. Air trapped in the chambers for combustion translates directly to torque... so specific torque is a proxy for VE.

An S54 makes 85 ftlbs/liter. That's the highest specific torque from a naturally aspirated production engine I've ever come across, so I call that 100%. An M30 at 210(?) ftlbs and 3.4 liters is 62 ftlbs/liter. 62/85 = 0.73, or about 73% VE.

So if the engine has 73% stock, then 140% represents about 14# of boost, assuming ideal intercooling efficiency.

I think 140 is reasonable as a goal for the final state of tune of the engine.

[Ether-D]

In order to get a runner size of 1 5/8", it had to have a VE of 140. That doesn't seem to crazy right?

[Ether-D]

That's what was troubling me, the boost part. So it will be over 100 when forced. I'll run the calculator a few more times with 100+ as the VE and see what that gives me.

[LJ851]

Not sure with boost, 85% is a rough guess of a NA 2V engine.

[Ether-D]

:hitler: Damn you LJ. Offer some info. Don't just say what it's not. It's also not 1000. I know you at least know a ballpark figure…

[LJ851]

The only figure on that calculator I was unsure about was the volumetric efficiency figure. What would that be on my motor? I have no idea. I guessed 100.

Not 100.

[Ether-D]

The only figure on that calculator I was unsure about was the volumetric efficiency figure. What would that be on my motor? I have no idea. I guessed 100.

[Ether-D]

It was e23 then. But mine is still different. It looks to come out straight like the one you posted, but that part is blocked off and then it jogs upward, which is open. I'll post a pic.

I found a header calculator online that needs a bunch of crazy specs that I didn't know existed. But I found them magically and plugged them in and that's how I got those sizes.

[The Dark Side of Will]

Can you find the part you mention on RealOEM? I looked at the E32 735i diagram and it had the same block off plate as my E34 535i has.
Did you mean E23?
It appears to use the same part as the E28... http://www.realoem.com/bmw/showparts...91&hg=11&fg=15

If you're looking for 300 HP (which should be very reasonable with that engine and supercharger), that's 50 HP per cylinder. A V8 with 50 HP per cylinder makes 400 HP. Headers for a 400 HP V8 typically have 1 5/8 primaries.

Buy a header design from Burns Stainless. They'll need cam displacement, cam specs and some other details of the engine. Last I checked, the design service cost about $80, but that's been a long time.

Also, that early E28/E12 manifold you found is pretty awesome.

[Ether-D]

Yeah, the ones on ebay for the m5x's are mostly 1 5/8" header runners, which makes me think they may have gone too big.

About the heater outlet, the e32 one is on there and I had intended to use it. It stubs out to the passenger side though, but I figured I'd just go over the top of the valve cover and into the heater core that way.

[The Dark Side of Will]

The header diameter is related to power per cylinder more than port area at the head.

//

M30's have poor coolant circulation to the rear cylinders. I suggest running the E28 heater supply fitting in order to enhance coolant circulation at the back of the engine. Do you have firewall clearance for that?

#11 in this photo:



http://www.realoem.com/bmw/showparts...92&hg=11&fg=15

PN 11121253208

[Ether-D]

Been doing some research on header fab. I found a calculator to find length and diameter for the runners. It's saying 35.12" long runners that are 1.5" in diameter. 1.5" in diameter? This seems very small to me.

edit: the ports in the head are like 1 5/8" x 1 3/8" so maybe it's closer than I thought…
and after some measuring and some math n shit, the cross-sectional area of a 1.5" runner is 1.77 square inches. And the area for the ports in the header flange are 1.73 square inches. So there you have it.

[Ether-D]

So these came in the mail today. I might give this a shot sometime.

[Ether-D]

Mmmm-k. Good. I guess that means I should get off my ass and do some shit. I got the winter depressies. I do feel a bit of productivity comin' on.