Should I boost an M30 or M50?

[Mr. Burns]

What kind of top end headwork is in that dynograph?
Additionally this is a b34 block afaik which is a better choice if youre looking to boost right outta the gates

[LowR3V'in]

Gas mileage is going to be bad tough

[ThatOneEuroE30]

Gas mileage is going to be bad tough

If your boosted you aren't trying to get good gas mileage.

[Good & Tight]

What kind of top end headwork is in that dynograph?
Additionally this is a b34 block afaik which is a better choice if youre looking to boost right outta the gates

Stock B34 bottom end from 1986. Head is from a 1980 M90, which is a regular B34 head.
It has an old Shrick 280/284 cam with, double springs, titanium keepers, stock valves.
The intake ports were widened to match the B35 intake, no other porting of any kind.
ARP headstuds and .070" Cometic head gasket.
Nothing fancy or high dollar in it. The only fancy stuff is the exhaust and intake manifold.

You are correct, the B34 is a stronger block for boost, as the B35 block is prone to cracking around the head bolt area

[ThatOneEuroE30]

Stock B34 bottom end from 1986. Head is from a 1980 M90, which is a regular B34 head.

It has an old Shrick 280/284 cam with, double springs, titanium keepers, stock valves.

The intake ports were widened to match the B35 intake, no other porting of any kind.

ARP headstuds and .070" Cometic head gasket.

Nothing fancy or high dollar in it. The only fancy stuff is the exhaust and intake manifold.



You are correct, the B34 is a stronger block for boost, as the B35 block is prone to cracking around the head bolt area

You dont even have hd rocker arms?

[LowR3V'in]

If your boosted you aren't trying to get good gas mileage.

When you take it on a 2,000 mi road trip like he like to do then ya it does.

[Good & Tight]

You dont even have hd rocker arms?

stock rocker arms from the 80's bro, that's how I roll. :rofl:

[ThatOneEuroE30]

stock rocker arms from the 80's bro, that's how I roll. :rofl:

I love it. Just shows with these m30's you dont need to go balls to the wall with turbo builds they are tanks from the factory and you've proven that lmao

[nighthawk]

Don't know if it applies much since I'm NA, but I drove 2500 miles one way from Middle TN to the E30 picnic last summer with 3 other passengers and full to the brim trunk of luggage. I averaged about 350 miles per tank on 87 gas. It was about 25-26 mpg, fully loaded going ~70-75mph. The gas mileage is not THAT bad. M30b35 btw. I would assume a turbo'ed setup wouldn't decrease mpg too significantly, but that is just my thought.

[ForcedFirebird]

stock rocker arms from the 80's bro, that's how I roll. :rofl:

Welded? :p

[Good & Tight]

Welded? :p

You know it..!!!!!

[TimeMachinE30]

M30 is sweet. Glad it is going into my vert. This summer should be fun.

[CorvallisBMW]

In order of difficulty (and power output):

m20 n/a -> m30 n/a -> m20 turbo -> m30 turbo

If you're aiming for 250-300 hp, get a bolt-on m20 kit and be done. Any turbo setup for an m30 will involve lots of custom work and is not for the faint of heart.