MyMiatas
MyMiatas Reader
2/4/23 11:44 p.m.

Can a 2006 Mazdaspeed6 engine be installed into a NA Miata. Will that engine bolt to the Miata transmission? I would think that it would fit a NB transmission. 

Mndsm
Mndsm MegaDork
2/5/23 9:26 a.m.

Short answer, no. Not easily. 

 

Long answer- there's a few things that make the DISI engine a bear to swap- the biggest among them is the fuel system. (One of) the biggest reasons we never saw it in the NC Miata was when turning the engine 90* to mate the trans, the secondary fuel pump and assorted shenanigans ran directly into the firewall. 

 

There was also the rumor that the engineers really wanted it but it would absolutely smoke the rx8 if they did it and they couldn't have that happen, but I am unable to confirm. 

 

The DISI is a wildly complicated bear with some interesting flaws that make it not an ideal candidate for any swap. Just about anything conventional you'd swap it into you're better off with a bp block. I've been a part of (the only swap I've ever seen) na mz3 to disi and it was difficult, and you basically needed an entire donor car to do it. Trans, wiring, ecu, fuel, engine, all of it. 

MyMiatas
MyMiatas Reader
2/5/23 8:36 p.m.

There is a Mazdaspeed6 for sale here and engine swap came to mind. (Maybe reading GRM Forum had something to do with that) I Googled it after posting and no one had anything about a swap to a NA /NB. But there were ones for a NC.  A NA/NB would produce as much HP or more as that Mazda6 engine.

BoxheadTim
BoxheadTim MegaDork
2/5/23 8:44 p.m.

My understanding is that you basically have two problems that need to be solved:

  • The engine is pretty tall, so it's unlikely to fit into the engine bay without a massive hood bulge. Same reason that I don't think anybody ever swapped an NC engine into NA.
  • I don't think there are any aftermarket ECUs out there that can run these direct injection engines, so you get the added fun of trying to run an NA or NB off the MS6 ECU

Given how much power you can extract out of a built-ish, boosted BP with an aftermarket ECU, I doubt the substantial effort to make an MS6 swap work is unlikely to be anywhere near cost effective if you want to drive the car this decade and even if your time is essentially free.

My somewhat uneducated guess is that it's going to be cheaper and easier to LS swap the car.

 

MyMiatas
MyMiatas Reader
2/5/23 8:50 p.m.

The NC forum article was swapping the Miata NC engine for a Mazdaspeed6 engine for more HP. But I did not read much more into it due to the fact that I do not own a NC.

I was looking on CL and came across a Camaro but it has a iron block LT1 and then the Mazdaspeed6.  Even the Mazda needs engine work so flush that idea down the toilet.

pres589 (djronnebaum)
pres589 (djronnebaum) UltimaDork
2/5/23 9:19 p.m.

Maybe easier to roll your own turbo MZR and build for power similar to what the Mazdaspeed 6 offered?  I think an NC MX-5 6-speed trans, a 2.5 out of a Fusion, a call to Garrett or whoever you like for a turbo with a stated power goal of XXX and you're on your way.

Mndsm
Mndsm MegaDork
2/5/23 10:23 p.m.

In reply to pres589 (djronnebaum) :

It's an ass to elbow scenario. There's a WELL documented path to ~250whp he'd get out of a disi swap, trying to involve the mzr family is just not worth it, unless you're trying to be weird, in which case there's better engine choices. 

MyMiatas
MyMiatas Reader
2/5/23 11:02 p.m.

I just like the idea that it was a new Mazda engine. It is in a 2006 Mazdaspeed6 and thought that can't be that much different than a Miata engine. But a lot of times they do not look to save money on building cars, they have to include all there employees. So cars get tweaked a bit from model to model.  I was dreaming that you could yank out that bolt it together and ta da you have a NA Miata with a newer engine with more HP. But that is not the case.

Keith Tanner
Keith Tanner MegaDork
2/5/23 11:52 p.m.

There's a pretty significant generational change from the NA/NB (designed in the late 80s with an engine family dating back to the 70s) to the NC (early 2000s with an engine from the same era). That's not Mazda being lazy or trying to keep all their employees involved. Over that 20-25 year gap, everything changed.

If you were starting with a car with an MZR, it would be easier. But you're starting by fitting the physically larger MZR into a chassis that never had it. The fact that they were sold under the same brand name doesn't make it any easier, which is why you just don't see many MZR swaps into NA/NB chassis. Since you're basically starting from scratch, why use the Mazda engine?

pres589 (djronnebaum)
pres589 (djronnebaum) UltimaDork
2/6/23 12:49 a.m.
Mndsm said:

In reply to pres589 (djronnebaum) :

It's an ass to elbow scenario. There's a WELL documented path to ~250whp he'd get out of a disi swap, trying to involve the mzr family is just not worth it, unless you're trying to be weird, in which case there's better engine choices. 

The 2.3 liter L3-VDT engine in the Mazdaspeed 3 and 6 is a member of the MZR group of engines.  Your reply seems to contradict itself. 

Didn't think a 2.5 MZR/Duratec with a turbo was that rare of a build, as there's been one on this forum that seemed pretty straight foward, but I'm not knee deep in these myself.  Definitely don't understand how that would be "weird" but whatever.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
2/19/23 4:43 a.m.

Having wanted to do this, the biggest problem is that everything hangs over the transmission.  Throttle body, turbo inlet, EGR plumbing, everything is over the trans.

The easiest way to do it is to start with a Ford Ranger Ecoboost engine, which also gets you a stronger block and rods compared to the Mazdaspeed engine.  And the fuel pump is on top of the engine, not behind it like in the DISI, and the Mustang for that matter.

 

Or, you know, pop a turbo on a BP and call it good for 5% of the effort smiley

Lambin_Lionout
Lambin_Lionout New Reader
3/1/23 5:57 p.m.

off topic a little, but I've been thinking about swapping the entire drivetrain of a mazdaspeed6 into a wagon body. Anyone have any insight into how different the rear end is between the FWD version and the AWD version?  

 

Mndsm
Mndsm MegaDork
3/1/23 7:05 p.m.
pres589 (djronnebaum) said:
Mndsm said:

In reply to pres589 (djronnebaum) :

It's an ass to elbow scenario. There's a WELL documented path to ~250whp he'd get out of a disi swap, trying to involve the mzr family is just not worth it, unless you're trying to be weird, in which case there's better engine choices. 

The 2.3 liter L3-VDT engine in the Mazdaspeed 3 and 6 is a member of the MZR group of engines.  Your reply seems to contradict itself. 

Didn't think a 2.5 MZR/Duratec with a turbo was that rare of a build, as there's been one on this forum that seemed pretty straight foward, but I'm not knee deep in these myself.  Definitely don't understand how that would be "weird" but whatever.

I realize I totally missed this but- he said na Miata. The mzr family didn't show up til the NC. They were still bp based back then. 

Mndsm
Mndsm MegaDork
3/1/23 7:48 p.m.
Lambin_Lionout said:

off topic a little, but I've been thinking about swapping the entire drivetrain of a mazdaspeed6 into a wagon body. Anyone have any insight into how different the rear end is between the FWD version and the AWD version?  

 

It's been done, and...you need two cars. You need to cut the floor out of the sedan and graft it to the wagon, among other things. The original one is actually either for sale or going to be soon. 

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
3/1/23 7:49 p.m.
Mndsm said:
pres589 (djronnebaum) said:
Mndsm said:

In reply to pres589 (djronnebaum) :

It's an ass to elbow scenario. There's a WELL documented path to ~250whp he'd get out of a disi swap, trying to involve the mzr family is just not worth it, unless you're trying to be weird, in which case there's better engine choices. 

The 2.3 liter L3-VDT engine in the Mazdaspeed 3 and 6 is a member of the MZR group of engines.  Your reply seems to contradict itself. 

Didn't think a 2.5 MZR/Duratec with a turbo was that rare of a build, as there's been one on this forum that seemed pretty straight foward, but I'm not knee deep in these myself.  Definitely don't understand how that would be "weird" but whatever.

I realize I totally missed this but- he said na Miata. The mzr family didn't show up til the NC. They were still bp based back then. 

And the NC had the PPF on the other side, no?

I guess you could use an NC five speed with the NA/NB tailhousing.

It still seems to me that turbocharging a BP would be much much easier. No need to reinvent the fuel system, no need to make engine mounts, or potentially modify the crossmember, firewall, or hood.  Plus my gut feeling is that the BP is a better engine for forced induction, given that it is an outgrowth of a Group A rally homologation engine from the tail end of the engineering era when it was still cheaper to overbuild than engineer to just good enough.

 

Other manufacturers make engine swaps to newer engine families easy if they reuse a lot of hardpoints. Chevy 4.8-6.0 engines have the fan, power steering pumps, and one motor mount in the same place (same parts largely) 89% of the same bellhousing bolt pattern, same oil pan considerations, etc. as a small block Chevy, because it was engineered to slot in to pre-existing chassis.  I found out that the Toyota 2.7l truck engine fits anywhere a 22RE was because they use most of the same hardpoints, too.

Mazda was not married to the BP in any way shape or form for previous chassis.  As the MZR filtered in to production vehicles, it largely went in as new chassis were introduced.  In this way they had freedom of design, they could reverse the cylinder head which is good for reasons, they could eliminate some things and introduce others.  I don't think anyone laments Mazda no longer sticking the oil filter where it was on the B engines smiley

Mndsm
Mndsm MegaDork
3/1/23 7:53 p.m.

In reply to Pete. (l33t FS) :

I've never actually looked at all of the logistics of the swap, so I don't know 100%.  I know there's enough problems with it that the engineers at Mazda didn't do it, and that's not encouraging. 

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
3/1/23 8:03 p.m.

In reply to Mndsm :

They didn't NEED to do it smiley When the NC was released the outgoing chassis was legally old enough to drive itself smiley They had a nice chassis in the RX-8 that was built with more modern engineering, design, and construction techniques.

IIRC the NC was the first industrial use of friction stir welding to join steel to aluminum.

Keith Tanner
Keith Tanner MegaDork
3/1/23 10:54 p.m.

MZR swaps have been done into NA/NB, but iirc they're not seamless with some fitment challenges. There are easier ones with better engines. The existence of the BP turbo kits makes any swap with less than 250 hp kinda pointless. 

Lambin_Lionout
Lambin_Lionout New Reader
3/1/23 10:54 p.m.

In reply to Mndsm :

floor grafting is what I'd assumed. I was hopeful that there was the chance that it wouldn't be required since I think there were AWD versions prior to the speed6 in other markets.  

1kris06
1kris06 HalfDork
3/1/23 11:21 p.m.

In reply to Lambin_Lionout :

There's a whole group on the book of faces. I say go for it if you can.

Lambin_Lionout
Lambin_Lionout New Reader
3/9/23 8:45 a.m.

In reply to 1kris06 :

That looks awesome. pretty much exactly what I would want to do. 

MyMiatas
MyMiatas Reader
3/9/23 10:36 p.m.

I have never seen a wagon version?? Looks pretty sharp. :0)

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