mbmsg
New Reader
4/27/19 9:31 a.m.
Looking at a NC(2008)would like to keep it a 4 cyl. Any options to up the power in these? See lots of turbo options for others, nothing for NC. Any particular reason, they don’t boost well? Made of glass?
Am I just missing the options with bad searches? I’m more interested in a package that includes everything needed than piecing something together.
Anybody out there with a NC and traveled this road?
_
Reader
4/27/19 9:38 a.m.
Plenty of power options. All of the usual ones. Someone here did a 2.5 swap on one. I believe it was the GRM guys with Goodwin racing. And they did it in a day and on a budget.
NickD
PowerDork
4/27/19 9:59 a.m.
Kraftwerks makes a Rotrex supercharger kit for them, includes all the belts, brackets, hoses, intercoolers, etc. I installed a Rotrex blower on my NA last year and I absolutely love the thing.
A Rotrex on a 2.5 would probably be a nice combo.
STM317
UltraDork
4/27/19 6:53 p.m.
Cosworth sold a twin screw supercharger for the NCs, and at some point after they stopped selling them, Flyin Miata sold something that looked nearly identical. It looks like they're not currently selling them either, but you might be able to find one for sale somewhere on a forum or something.
The SC was an FM product far longer than Cosworth had their name on it. We even got an EO for it. But the manufacturer has changed their minimum quantity and the NC market isn’t strong enough to make it a viable product. Too bad, it was pretty sweet and we are looking for ways to bring it back.
We’ve played with a couple of centrifugals but they’ve got some characteristics we decided not to adopt. They would play better with a 2.5 or 2.3 swap than the positive displacement blower. We do have an EO that would apply to a turbo so that’s always a possibility.
I have a 2.5L swapped NC and a FM SC that will be going on soon.
2008, like the other NC1, had the weaker internals. FI on the stock motor will be rolling the dice, and eventually you will ventilate the block.
2.5L is slowly becomming a foundational mod on these cars. Most of the 2.5L engines have forged internals from the factory. NA you CAN make 200whp on a 2 5L with cams, exhaust, and some other bolt ons.
That SC on a 2.5 is a torque monster. Not a peak power dyno queen as the blower starts to top out, but very grunty.
Keith Tanner said:
That SC on a 2.5 is a torque monster. Not a peak power dyno queen as the blower starts to top out, but very grunty.
That's what I hear. It is an autocross car, so that should be ideal. Should i have any concern keeping it cool for the occasional HPDE?
In reply to NordicSaab :
Hoping to see it at an event soon.
In reply to Floating Doc :
Lol, yeah, me too. Building the house has taken most all my free time. I should be moving-in in 49 days, but who is counting?
NordicSaab said: 2.5L is slowly becomming a foundational mod on these cars. Most of the 2.5L engines have forged internals from the factory. NA you CAN make 200whp on a 2 5L with cams, exhaust, and some other bolt ons.
SHH! I haven't bought mine yet.
If Good-Win Racng is trustworthy, you can break 200whp with an internally stock 2.5l, AND the restrict-o-matic NC intake manifold, with nothing more than a tune and decently proportioned headers.
Of course, I'd prefer to set my 2.5 up with ITBs, possibly in the 48-50mm range, but given that you should always aim for where you want to hit, and that a certain Pinto/Lima builder made close to 400hp with one of their three liter 8v engines with 55mm ITBs, that's where I'd set my minimums.
dxman92 said:
Keith Tanner said:
The SC was an FM product far longer than Cosworth had their name on it. We even got an EO for it. But the manufacturer has changed their minimum quantity and the NC market isn’t strong enough to make it a viable product. Too bad, it was pretty sweet and we are looking for ways to bring it back.
We’ve played with a couple of centrifugals but they’ve got some characteristics we decided not to adopt. They would play better with a 2.5 or 2.3 swap than the positive displacement blower. We do have an EO that would apply to a turbo so that’s always a possibility.
What does eo stand for?
It's shortspeak for "We certified this to be emissions legal in California", which is not a small task.
In reply to Knurled. :
Especially for a niche market like ours, that's really impressive. Flyin Miata is serious!
Forced induction may make having an automatic Miata hurt less.
Rodan
HalfDork
4/28/19 6:31 a.m.
Knurled. said:
If Good-Win Racng is trustworthy, you can break 200whp with an internally stock 2.5l, AND the restrict-o-matic NC intake manifold, with nothing more than a tune and decently proportioned headers.
I looked at the 2.5 swap pretty hard when we had our NC, and while I still believe it's a good option, I don't believe the above claim was ever duplicated by a customer. Goodwin's test car on their dyno was the only car (I know of) to reach 200hp with no internal mods. A lot of folks weren't even reaching 200whp with cams. It's been a while since I've paid attention as we sold the NC over a year ago, so things may have changed, but I would plan on doing internal mods if I wanted 200hp n/a.
Like Keith said, the 2.5 with an FM supercharger is a torque monster. There are also a couple of turbo kits out there...
Fab 9 turbo kit
Xero limit turbo kit (I don't know anything about these)
In reply to Rodan :
I think the key thing is making sure the VVT is tuned correctly. There's a lot of power to be had, or lost, with cam timing, and getting VVT tuned well is not as simple as getting the fuel curve or even ignition curve right.
Also, there is a degree of variability in cam timing when the cam and crank sprockets are not keyed. VVT is only on intake IIRC.
Either way, enough people have made 200 crank horsepower with non-VVT 2-liters with a good header and ITBs that I'd feel good about the same treatment on a 2.5 with its larger ports.
So the 2.5 head is also an upgrade in port size? I've seen the 2.5 cams described as truck cams, how do they compare to the miata 2.0 cams?
There have been difficulty duplicating Goodwin’s dyno results on the ND as well, unfortunately.
There has been a lot of work done on tuning the Duratec in the UK, it should be possible to build something pretty interesting. It’s worth noting that a lot of the hi-power crate engines seem to use the 2.0 VVT as a base.
It's no secret that GWR puts out numbers that can't be replicated. It's not the first the time.
It's why I trust companies that aren't GWR.
Personally I don't get the whole 2.5L thing. Like mentioned, people rarely if ever hit the 200 whp claimed post 2.5L swap, yet the 2.0L with factory forged rods (unlike the 2.5L) has been proven to make 180-190 whp with bolt-ons, ECUtek and E85. It's not exactly a bolt-on swap, it's actually pretty involved for a bit of torque and some HP.
The 09+ 2.0L is a great motor, and the fab9 Tuning turbo kit makes a great EFR kit if you want a reliable 300whp.
In reply to goingnowherefast :
Re: rods. I was under the impression that the 2.5s all had forged rods and the 2.0s all had powedered metal.
Apparently there is a "stock casting rule" engine that will do silly amounts at the crank with a stock 2.3 crank, 2.5 block, and 2.0 direct injected head... along with better pistons, rods, cams, intake, and such. But no porting
Knurled. said:
In reply to goingnowherefast :
Re: rods. I was under the impression that the 2.5s all had forged rods and the 2.0s all had powedered metal.
Apparently there is a "stock casting rule" engine that will do silly amounts at the crank with a stock 2.3 crank, 2.5 block, and 2.0 direct injected head... along with better pistons, rods, cams, intake, and such. But no porting
No. All the 09+ 2.0L's have forged rods. Source: https://www.miata.net/faq/brochures/2010/specs_MX5.pdf
Also according to this the 2.5L rods/crank are cast. https://en.wikipedia.org/wiki/Mazda_L_engine Which makes sense, since it was literally never put into a performance application (the 2.5L that is).