Idea: rotary in a miata

[yellerandahalf]

Hey, I'm pretty sure other people have had this idea before, and I've heard of it being done before. I think it might be cool to put a rotart motor in an M1 miata. I have a Spec Miata, and am obviously used to driving it, and absolutely love it. Correct me if I'm wrong, but mazda made 2 RWD transmissions, with the same casing: one for the miata, and one for the rx-7. Obviously, the RX-7's is stronger, because people push it pretty hard on the dragstrip and it holds up remarkably well. The questions are: is that information even right? how different are the mounting locations of the engines and transmissions? might it be possible to rig up a way to put a rotary motor in a miata? I know it would proabably have to sit really low to match up the eccentric shaft with the input shaft. Any other thoughts?
-Mateo

 

[ChefChris]

13bturbomx5 has a Rotory Miata, thats turbocharged I have seen it a few time before it is pretty badass. If you dig around the picture thread from the Florida meets you will see it, theres lots of pictures of it. Its green!

 

[jred321]

there was one for sale on ebay last month, it was in SCC a few years ago. definitely a cool thing but given the strength of the miata engine i think it's more of a cool thing than something that has real advantages

 

[Lt. Dan]

The biggest issue I can see is with where the motor and tranny sit... Because the tranny bolts to the "center" of a rotary, I don't know what you would need to do for clearance, etc...

 

[yellerandahalf]

cool, good to know it can be done for sure, I'll have to check out those cars. It'd certainly be more of a novelty than a real performance advantage, i'd think. How much power are people making with miata engines on track?
-mateo

 

[ChefChris]

I have seen that car I was talking about run, ti goes like a mother^&*(er, I am not sure how track worthy it would be but it can get up and go with the best, of them. I care to bet it can take an Modded RX7 or 8, in fact I bet it can take alot of cars being as light as it is.

 

[KYLiquid]

the tranys in the miata are built by aisin (spelling) its part of toyota I think, the miata 5sp,6spd and rx8 6speed are all made for NA cars, and dont hold up to much more power than stock.

If you were going to be pushing the car hard, you would want to mount the RX7 diff and trany, the 5speed, as it is a much better unit.

 

[yellerandahalf]

agreed. I was definetly thinking of going that route. Am I right in saying that the exterior dimensions of the rx-7 tranny are the same as the miata and other na trannies? or are they different?

 

[_Sloteg_]

http://www.mazsport.net/html/step1.htm Here is something that, might help you out....

Edit:This page show's you all the parts you will need.
http://www.mazsport.net/html/rotary_conv_parts.htm

 

[yellerandahalf]

3 THOUSAND DOLLARS for just little brackets and shazzle? goodness gracious!

 

[KYLiquid]

its not the easyest swap, but it is a sweet result. saw a 99 miata with a turbo2 rx7 motor, it was stock, but the tq and hp and power curve made it one hell of a car.

 

[yellerandahalf]

it's interesting, if you don't turbo the rotary, it honestly doesn't make much more power than the BP engine. However, if you turbo a BP, you don't get nearly the power output of a rotary. It last longer, though. interesting tradeoffs.
-Mateo

 

[KYLiquid]

it's interesting, if you don't turbo the rotary, it honestly doesn't make much more power than the BP engine. However, if you turbo a BP, you don't get nearly the power output of a rotary. It last longer, though. interesting tradeoffs.
-Mateo

the NA rotary vs NA BP is a pretty even match, you have nearly the same power output and nealry the same weight but the engine does mount father back and lower, so there is the handling increase. Also even though the power output is similar the power curve is differnt and the rotary car would be a little faster because of the way the rotary puts down the power.

If it were me, I would spend the money on the BP motor. ITB setup, header, exhaust, timing, and some way to tune fuel/timing. You would get a nice increase in power and I think it would be money well spent.

If you want the cool factor, or the ability to put down more power then go with the rotary.

 

[yellerandahalf]

good thoughts. I don't have a lot of experience with BP's, as the only thing I've done with my miatas have been intake and exhuast, so to stay in class (BSP and Spec Miata). Any vague idea how much power the aforementioned setup would put down?
-Mateo

 

[KYLiquid]

lets say its a 99 motor.... (best flowing head with no vvti crap and good 9.5:1 comp) They put down around 110-115hp and around 100tq to the wheels stock.

Header 10whp
cat-back with high-flow cat 5whp
ITB setup is around 1250 for a setup that is good to go with all the stuff you need. The stock injectors are fine. That can net you about 30whp when tuned....and you will need something to fine tune it such as an SAFC....figure 250 for that.

You would be taking the car from about 115whp/100wtq to about 150-160whp and about 115-120wtq. For an investment of maby 1800 bucks if you get some deals. If you want more you can go with a mild set of cams and get another 10whp.

About 170hp is the most I have seen someone make on a tuned BP staying NA. That was all the bolt ons and ITBs. You could get into the 180whp with race gas.

For that cost you could go turbo with the BP and double the power vs adding 50-60whp NA.....and thats about the max with out going stroker or higher compression.

I think if there was no expense 200whp and 140wtq is the MAX the BP could do stock on pump gas. And for the cost that would take, you could be making 300+whp with a turbo kit.

Its all about whats best. I like turbo, but for autox or tight road courses, a well tuned ITB-BP miata with some weight reduction and good suspension/tires is awsome. MO-MEN-TUM!!!

For bigger road courses or sreet turbo is more fun....IMO

 

[TheMAN]

the tranys in the miata are built by aisin (spelling) its part of toyota I think, the miata 5sp,6spd and rx8 6speed are all made for NA cars, and dont hold up to much more power than stock.

If you were going to be pushing the car hard, you would want to mount the RX7 diff and trany, the 5speed, as it is a much better unit.

the Y16M-D (6 speed) is an aisin, the M15M-D (5 speed) is not
the M5M-D used in the FC is practically the same as the M15M-D... but if you want a brute force tranny, you'd want the R5M-D from the FD

doesn't matter anyway... the M trannys are known to be pretty damn strong.... the general limit seems to be around 400whp