This is a recurring thought for me. I don't even know much about them, I dog on their lower output/higher fuel consumption vs other 2.6L engines...........yet I love the ridiculous sound a ported, high revving rotary makes.
It's also my understanding that rotaries tend to be the happiest when they are being beaten on, which is good for a track car.
But I've read the fab work needed isn't any easier than many other swaps.
So why do I want to do this?
i dunno, but the same bug bit me.
I have NO idea. 
Because it's what everyone thinks when they see the Mazda name on the Miata. "Why doesn't it have a rotary?"
Meanwhile, everyone who calls us up looking for performance always says they want more torque. Seems to me the two questions answer each other 
Anything will be an increase in performance over a stock ECU 1.6!
mmm torques
You want a rotary because they're capable of more performance either n/a or turbo than a Mazda B-series motor.
The sound. The torque curve. The Sound. The powerband.
Last year I got to drive a FB RX-7 with a nice bridge port 13b running through a 4.78 final drive.
This was after having spent a good amount of time driving a turbo 1.8 Miata with a 4.10 final drive.
These are both scca rallycross cars, so traction is limited. My immediate reaction was that the 13b might be 'better.'
This is what I told Evan: "The power is just everywhere: flat torque curve, and it goes on seemingly forever. "
If/when I get another miata, I would be very tempted to swap in a rotary.
Swank Force One wrote: You want a rotary because they're capable of more performance either n/a or turbo than a Mazda B-series motor.
This is true.
However, I just started looking at cost's to build a proper rotary.
And I thought building a nasty N/A B18 to around 165-170whp would pricey. The rotaries are on a whole other level of $$$$$
cghstang wrote: The sound. The torque curve. The Sound. The powerband. Last year I got to drive a FB RX-7 with a nice bridge port 13b running through a 4.78 final drive. This was after having spent a good amount of time driving a turbo 1.8 Miata with a 4.10 final drive. These are both scca rallycross cars, so traction is limited. My immediate reaction was that the 13b might be 'better.' This is what I told Evan: "The power is just everywhere: flat torque curve, and it goes on seemingly forever. " If/when I get another miata, I would be very tempted to swap in a rotary.
Stop making me want to swap a rotary in the Miata.
I still want to put one in a MGB or Midget.
z31maniac wrote:Swank Force One wrote: You want a rotary because they're capable of more performance either n/a or turbo than a Mazda B-series motor.This is true. However, I just started looking at cost's to build a proper rotary. And I thought building a nasty N/A B18 to around 165-170whp would pricey. The rotaries are on a whole other level of $$$$$
The price of getting a rotary to 165-170whp is significantly cheaper than building a BP to that power n/a, and the rotary will be much faster at that power level due to a much bigger powerband.
If i get sick of the F2T in my other Miata, i'm putting a bridged 13B in it with a turbo the size of my face.
Swank Force One wrote:z31maniac wrote:The price of getting a rotary to 165-170whp is significantly cheaper than building a BP to that power n/a, and the rotary will be much faster at that power level due to a much bigger powerband. If i get sick of the F2T in my other Miata, i'm putting a bridged 13B in it with a turbo the size of my face.Swank Force One wrote: You want a rotary because they're capable of more performance either n/a or turbo than a Mazda B-series motor.This is true. However, I just started looking at cost's to build a proper rotary. And I thought building a nasty N/A B18 to around 165-170whp would pricey. The rotaries are on a whole other level of $$$$$
Right a stock TII 13b with bolt ons is plenty in a Miata.
I dunno, I want to do it too. The only problem is that every time I "price" it out, taking into acount everything from gas mileage to weight to end performance and cost, a V8 or turbo just seems to make more sense.
Not that any of that matters. Rotaries just have a lot of soul that cannot be replaced.
crankwalk wrote:Swank Force One wrote:Right a stock TII 13b with bolt ons is plenty in a Miata.z31maniac wrote:The price of getting a rotary to 165-170whp is significantly cheaper than building a BP to that power n/a, and the rotary will be much faster at that power level due to a much bigger powerband. If i get sick of the F2T in my other Miata, i'm putting a bridged 13B in it with a turbo the size of my face.Swank Force One wrote: You want a rotary because they're capable of more performance either n/a or turbo than a Mazda B-series motor.This is true. However, I just started looking at cost's to build a proper rotary. And I thought building a nasty N/A B18 to around 165-170whp would pricey. The rotaries are on a whole other level of $$$$$
"Plenty" is subjective. I'm looking for a car that has a high probability of making me E36 M3 myself, or i'm uninterested. It's going to have a hard act to follow in the F2T. 
z31maniac wrote: However, I just started looking at cost's to build a proper rotary. And I thought building a nasty N/A B18 to around 165-170whp would pricey. The rotaries are on a whole other level of $$$$$
Street port gets you there and you can do it yourself with some $50 templates from racingbeat.
Whilte plenty is subjective, I made 321 whp on a streetported TII 13b with a Haltech E6k in the back of a 75 911, which cant weigh much different than an NA Miata. It WAS plenty as in pucker up.
crankwalk wrote: Whilte plenty is subjective, I made 321 whp on a streetported TII 13b with a Haltech E6k in the back of a 75 911, which cant weigh much different than an NA Miata. It WAS plenty as in pucker up.
I'm looking at more like.... 600whp.
I'm aware it won't be useful in any way.
crankwalk wrote:Swank Force One wrote:Right a stock TII 13b with bolt ons is plenty in a Miata.z31maniac wrote:The price of getting a rotary to 165-170whp is significantly cheaper than building a BP to that power n/a, and the rotary will be much faster at that power level due to a much bigger powerband. If i get sick of the F2T in my other Miata, i'm putting a bridged 13B in it with a turbo the size of my face.Swank Force One wrote: You want a rotary because they're capable of more performance either n/a or turbo than a Mazda B-series motor.This is true. However, I just started looking at cost's to build a proper rotary. And I thought building a nasty N/A B18 to around 165-170whp would pricey. The rotaries are on a whole other level of $$$$$
Not interested in tarbo'z for a track car where 3 months of the season are regularly above 100°
I recall a thread started by someone on another forum who actually did the swap. I vaguely recall the synopsis as:
"It's a lot harder than you'd expect, and the car sucks now. I wish I hadn't done it."
The right answer is turbo. The righter answer is LSx swap.
It's telling that there are a number of people who are serial V8 converters, but nobody ever seems to do a second rotary.
In reply to crankwalk:
Pics? I have a strange attraction to bastardized 911s.
Keith Tanner wrote: It's telling that there are a number of people who are serial V8 converters, but nobody ever seems to do a second rotary.
I wonder if the fact that there's an excellent all-inclusive V8 swap kit or two on the market sways those numbers at all?
You have to beat on a rotary regularly to keep it happy. Most people don't seem to understand that.
Swank Force One wrote:Keith Tanner wrote: It's telling that there are a number of people who are serial V8 converters, but nobody ever seems to do a second rotary.I wonder if the fact that there's an excellent all-inclusive V8 swap kit or two on the market sways those numbers at all?
I wonder if the fact there's an excellent all-inclusive V8 swap kit or two on the market is swayed by the ease/value of the swap.
peter wrote:Swank Force One wrote:I wonder if the fact there's an excellent all-inclusive V8 swap kit or two on the market is swayed by the ease/value of the swap.Keith Tanner wrote: It's telling that there are a number of people who are serial V8 converters, but nobody ever seems to do a second rotary.I wonder if the fact that there's an excellent all-inclusive V8 swap kit or two on the market sways those numbers at all?
The "ease" part comes with the kit.
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