Direct swap larger throttle body M20?

[rvaughnp]

Is there a direct swap lager throttle body for the M20? As I am going with the b28 crank, I will also be installing the miller maf war chip combo and probably a 272 cam. The cam will more than likely come after the motor is up and running. Anyway, I would like to have the motor able to breathe however much air it wants; knowing the limit on the intake and the valve size... those being the only two items that will not be replaced or upgraded, just want the motor to breathe as much as possible.

So, is there a direct bolt on upgradeable TB?

[IRON-E]

Not direct bolt on but my buddy has developed a spacer to fit the M30 throttle body to the M20 and will be on display and for sale after BFest..........his SN is e30Sdw, look for his thread. Hopefully that'll help.

[325ix]

Not direct bolt on but my buddy has developed a spacer to fit the M30 throttle body to the M20 and will be on display and for sale after BFest..........his SN is e30Sdw, look for his thread. Hopefully that'll help.

I'd be interested in this.

[IRON-E]

I'd be interested in this.

I think you commented on his thread and were waiting for Dyno #s

[325ix]

oh maybe I did, don't remember now, is it the individual set-up?

[jlevie]

The mass flow limit on an M20 is primarily the head and secondarily the intake. From the throttle body on out nothing you will do will significantly improve mass flow. So fitting a larger throttle body is a wasted effort.

[digger]

Better off with a BBTB that uses the M30 throttle butterfly no mounting issues at all and should be all your 2.8L will ever need.

[digger]

The mass flow limit on an M20 is primarily the head and secondarily the intake. From the throttle body on out nothing you will do will significantly improve mass flow. So fitting a larger throttle body is a wasted effort.

The M20B25 is a well designed engine, no one 'bolton" thing will gain you alot you need to alter the whole system. However i wouldn't call it a wasted effort, you'll atleast gain some responsiveness at small throttle openings and maybe some small amount of flow just don't expect the gains you get on poorly designed engines.

[Lunner]

Better off with a BBTB that uses the M30 throttle butterfly no mounting issues at all and should be all your 2.8L will ever need.

What is this now?

[IRON-E]

The M20B25 is a well designed engine, no one 'bolton" thing will gain you a lot you need to alter the whole system. However i wouldn't call it a wasted effort, you'll at least gain some responsiveness at small throttle openings and maybe some small amount of flow just don't expect the gains you get on poorly designed engines.

This is partly what his debate was before the R&D for his product.

[Dagamus(NM)]

This is why I want this. I have extensive head work, cam, 3.0L stroker, log manifold. I don't want to stick a small tb on it.

[IRON-E]

This is why I want this. I have extensive head work, cam, 3.0L stroker, log manifold. I don't want to stick a small tb on it.

You should hit him up he's a humble and down to earth guy., he just doesn't want to let all the info out until it hits the market on May 22nd @ BimmerFest.

[nando]

What is this now?

it's about as simple as it gets, bore out the M20 TB and use an M30 throttle plate. you'll have to port the manifold a bit to match it up.

[Dagamus(NM)]

The downside to this is that the walls of the brittle old tb become thin and the spring assembly at the top can shear off easily. The block aluminum is it made from is much different than the thin aluminum used to make charge pipes etc.

[nando]

I've got one, that seems pretty unlikely. it's definitely thinner but it's not that bad. it's still thicker than a typical charge pipe.