First time poster, long time lurker- M20 Swap

[Msaxon]

I have done some searching about the viability of running an M20 with a turbo and ITB’s. There’s a guy who has done it to an E30 but was wondering about clearance issues...? (I ran a search and didn’t see any posts about these two upgrades together.)

Anyone have any experience with this?

I know the driver’s side has the brake booster so a plenum may not clear.

Thanks for any info.

Edited January 28, 2021 by Msaxon

[Mike G]

A tii brake booster is about an inch less in diameter, the motor mounts you use for the swap will effect height too, they’re not all the same. You’ll have to make your own plenum or throw a pile of money at the guys that built Frank’s spaceship parts. Might be cheaper to buy a carbonfiber hood and ditch the torsion bar. I think all the existing plenums hit the hood bar or booster. It’s doable but you’ll probably be the first and I think you’ll be limited in the amount of boost or the shafts on the itb’s will leak. But I want to see it happen regardless, good luck!

[Msaxon]

24 minutes ago, Mike G said:

A tii brake booster is about an inch less in diameter, the motor mounts you use for the swap will effect height too, they’re not all the same. You’ll have to make your own plenum or throw a pile of money at the guys that built Frank’s spaceship parts. Might be cheaper to buy a carbonfiber hood and ditch the torsion bar. I think all the existing plenums hit the hood bar or booster. It’s doable but you’ll probably be the first and I think you’ll be limited in the amount of boost or the shafts on the itb’s will leak. But I want to see it happen regardless, good luck!

Thanks! I was also thinking maybe modifying the hood hinges. And was definitely going to go with the CF hood. Was also considering modifying the hood with an intake hood scoop... to be continued.

[Msaxon]

Just now, Msaxon said:

Thanks! I was also thinking maybe modifying the hood hinges. And was definitely going to go with the CF hood. Was also considering modifying the hood with an intake hood scoop... to be continued.

Or possible some custom trumpets with a bend... it’s all $$. ?

[Mike G]

Someone on the forum was making brackets to use these hinges, they cam over to lock in place and hold the hood up so you don’t have to carry a broomstick. You could make the bracket yourself pretty easy, just moves the mount about two inches. 

[Msaxon]

1 minute ago, Mike G said:

Someone on the forum was making brackets to use these hinges, they cam over to lock in place and hold the hood up so you don’t have to carry a broomstick. You could make the bracket yourself pretty easy, just moves the mount about two inches. 

Nice!!

[Msaxon]

This could work as well.. has the right bend-

[TobyB]

I'm not one to condemn history in context.

 

I'm also not one to advocate the marriage of two disparate antiques:

it always devalues both.  Especially if it's not period appropriate.

 

Now, an M20 with a distributor and a trio of DCOE's would be just fine-

put a fake timing chain cover on it, and call it retro.

 

But at the point you said 'turbo' I thought-  WHY???

The M20, like the M42/44, is a period development piece.

There's not an S20- for a reason.

 

The S20 is really the S54, and the M54 is it's radically- more- affordable

parent that makes 'substantial' powers- and the OE electronics are capable

enough to take significant boost.

 

So if you want to go M20, and are ready for all the NLA and WTF, please DO have at it.

It'd be fun.  But it'll be an odd duck in a foreign swamp.  (Gates has a 'racing' timing belt, fbi)

 

But if you're into the idea of twice the power in a reasonably modern package with tunability

for less than a third of the price (yes, more fabrication, but only incrementally)

modern parts availability from both dealer and aftermarket, and, oh, yeah:

 

                LESS WEIGHT

 

might I suggest an M54B30?  Or an N52?

Both are 3l, hardly any longer than an M20, and both make nearly twice the torques and

twice the horsepowers with better fuel economy.

And the OE electronics have been 'opened,' with many turbos going on both.

 

t

History in its place,

modern engines for powah.

Edited January 29, 2021 by TobyB

[Msaxon]

35 minutes ago, TobyB said:

I'm not one to condemn history in context.

 

I'm also not one to advocate the marriage of two disparate antiques:

it always devalues both.  Especially if it's not period appropriate.

 

Now, an M20 with a distributor and a trio of DCOE's would be just fine-

put a fake timing chain cover on it, and call it retro.

 

But at the point you said 'turbo' I thought-  WHY???

The M20, like the M42/44, is a period development piece.

There's not an S20- for a reason.

 

The S20 is really the S54, and the M54 is it's radically- more- affordable

parent that makes 'substantial' powers- and the OE electronics are capable

enough to take significant boost.

 

So if you want to go M20, and are ready for all the NLA and WTF, please DO have at it.

It'd be fun.  But it'll be an odd duck in a foreign swamp.  (Gates has a 'racing' timing belt, fbi)

 

But if you're into the idea of twice the power in a reasonably modern package with tunability

for less than a third of the price (yes, more fabrication, but only incrementally)

modern parts availability from both dealer and aftermarket, and, oh, yeah:

 

                LESS WEIGHT

 

might I suggest an M54B30?  Or an N52?

Both are 3l, hardly any longer than an M20, and both make nearly twice the torques and

twice the horsepowers with better fuel economy.

And the OE electronics have been 'opened,' with many turbos going on both.

 

t

History in its place,

modern engines for powah.

I absolutely appreciate the input and will have a look.

[gary32]

solid words Toby

 

You may have a chance at having the whole be worth more than the parts if you look a little more forward.

No more devaluating the marque suggestions from me.⁠Front Electric eDrive Motor & Transmission 12358641608 27208602091 BMW i8 14-17 | eBay⁠⁦‪ebay.com‬⁩.webloc

⁠✪ 2014 - 2017 BMW i3 i01 LI-ION ELECTRIC VEHICLE BATTERY OEM | eBay⁠⁦‪ebay.com‬⁩.webloc

[Msaxon]

16 minutes ago, gary32 said:

solid words Toby

 

You may have a chance at having the whole be worth more than the parts if you look a little more forward.

No more devaluating the marque suggestions from me.⁠Front Electric eDrive Motor & Transmission 12358641608 27208602091 BMW i8 14-17 | eBay⁠⁦‪ebay.com‬⁩.webloc

⁠✪ 2014 - 2017 BMW i3 i01 LI-ION ELECTRIC VEHICLE BATTERY OEM | eBay⁠⁦‪ebay.com‬⁩.webloc 1.68 kB · 2 downloads

Hmmm...

https://www.ebay.com/itm/Engine-Assembly-BMW-I3-14-15-/292008303474?_trksid=p2349624.m46890.l49292