M30b34 E30 twin-screw supercharged muscle car

[Ether-D]

i think ive seen this thread go through about 7 name changes already

I've only changed the name of this one twice. To more accurately reflect changing content. The M20 supercharger thread did change about 7 times.

And I'd just like to say, what a well thought out post.

[itskingsteelo]

i think ive seen this thread go through about 7 name changes already

[Bullhead]

Where's the daily update up in this mofo???? Hope your doing well brosif!

[Ether-D]

For my own curiosity and records:

Getrag 240 (m30) with a 2.93 rear-end in an e30:
1st gear at 6500rpm = 41.3863636 miles per hour
2nd gear at 6500rpm = 77.8965909 miles per hour
3rd gear at 6500rpm = 117.138636 miles per hour
4th gear at 6500rpm = 155.795455 miles per hour
5th gear at 6500rpm = 192.338636 miles per hour (as if...)

And for comparison:

Factory Getrag 260 (m20) in an e30 with a 3.73 rear-end:
1st gear at 6500rpm = 32.5113636 miles per hour
2nd gear at 6500rpm = 61.1897727 miles per hour
3rd gear at 6500rpm = 92.0113636 miles per hour
4th gear at 6500rpm = 122.37500 miles per hour
5th gear at 6500rpm = 151.086364 miles per hour

[Ether-D]

And an e28 would have had bigger tires so the taller diff (in my car) and smaller tires of the e30 should be a nice match if the transmission ratios are similar. So at 5000rpm in 5th, I should be approaching 150mph! lol...

[Andy.B]

I can't speak for your math, since I've had a few beers this afternoon...

But the rear end that the b34 was paired with was a 3.25. I plan on swapping the diff from the 535i donor that the b34 I'm swapping in came from.

[Ether-D]

Doing some cyphering, I've come up with my speed vs. rpm for this car when complete.

Gear ratios for getrag 240 from an 83 320i:
1st - 3.764
2nd - 2.00
3rd - 1.33
4th - 1.00
5th - 0.81

2500RPM in 5th = 2500 divided by 0.81 (fifth gear tranny ratio)= 3086.4 (driveshaft RPM)
3086.4 divided by 2.93 (diff ratio) = 1053.4 (wheel RPM). Wheel circumference = 6.18 feet
1053.4 x 6.18 = 6510 feet per minute. 6510 feet per minute = 74MPH

That sounds nearly freaking perfect. Any flaws in my math?

[Ether-D]

It is a lovely day in middle TN today and I wanted to be messing with some car stuff. So I went out there and fitted the stock m20b25 driveshaft. It is confirmed, it fits perfectly with the g240 trans. I also learned while I was under there (by counting) that I have a 2.93lsd. That may be a bit long. I've heard a 3.73 is a bit short. But we'll just have to see, won't we?

[Ether-D]

I ordered a stack of parts from Arizona Autohaus and I gotta say, they take fucking forever. I placed my order last friday (8 days ago) and they didn't even ship until the following Tuesday. I won't get my parts until Monday, ten full days after I placed my order. I may be a little entitled princess, but that shit is unacceptable.

[Ether-D]

The beheading…

I beheaded my m20 car this afternoon. It had 6 bent exhaust valves. Just barely, but enough to let the water seep that I poured into the exhaust ports. This may just solve the mystery of the unidentifiable rattle. I've never been so happy to have 6 bent valves.

This is where the magic happens…

[Ether-D]

Nice jack stands !

I've been waiting for someone to fear for my life…

Edit: Unless that was in reference to the Eiffel tower ones made of plywood, in which case, Thanks!

[Jean]

Nice jack stands !

[Ether-D]

Werd.

I've gone and decided to try and fix my supercharged m20 car before the Brodeo in two weeks. It's got 10,000 miles on the supercharger setup, but is making a bit of noise between 2000-4500rpm. It's been getting worse over the past month. It sounds like a cross between a valve tapping a piston and super mild rod-knock.

Irrrrrregardless, m30 swap going on hold for a minute...

[ThatOneEuroE30]

Different plug

[Ether-D]

Yup your gonna need to change the coolant sensors and oil pressure switch as well.

Easy enough with the litany of m20 bits around here. So does the oil pressure switch have a different plug on it or does it read differently?