4 Rotor weekend warrior... doable?
 

I'm curious if this is possible. A street-legal 4 rotor swapped into an RX-7 pushing out enough power for a 10 second quarter-mile (on street rubber of course) and good enough suspension to still be a killer in the twisties?

I know it's possible to swap a 4 rotor into an FD, I also know it's possible to get some crazy hp out of the engine, and I know RX-7s are quite good in the handling department. So can it all be fit into one car that's good for drag, autoX and track, and driven to those locations?

I was considering a 3 rotor but I think that perhaps it would be a little easier to obtain the necessary power using 4 rotors considering the extra displacement.

how much money you got? we're talkin big bucks for that engine.

Yeah I know it's going to be big bucks. Thankfully I'm not going to have very many expenses, at least that I forsee right now. I'm not looking into doing it now. I want to plan out the whole operation before getting into the thick of it.

What HP are you looking to get? You can run a 10 sec quarter with a 20b without any problems. Also any car you put a 3 or 4 rotor in will not be street legal.

-Destin

Ideally I'd like 700-1000rwhp. How is any 3 or 4 rotor car not street legal? It was my understanding that as long as you pass emissions it doesn't matter what engine you have.

You may find this interesting.
 

Here is any article from a NZ car magazine on a quad rotor rx7. The quality of the images isn't crash hot, as it was done with a digital camera with a flash in a badly lit room, but you can easily read it and make out most details in the photos.

Magazine cover with pic of car

Page 1 of the article

Page 2 of the article

Page 3 of the article

Page 4 of the article

Page 5 of the article

Page 6 of the article

I've also got a DVD version of a TV article on the same car but I need to covert it to DivX and find some host space.

It's fully road legal to my knowledge, but this is New Zealand getting the engine swap certified would have been the biggest issue. NZ has little to no emissions standards, if it doesn't blow huge clouds of smoke it's basically legal here, it's a common pratice to cut the Cats out of the exhausts systems of newly imported used Jap cars.

You can get that power from a 3 rotor from what ive heard...

Expect to spend over $100,000, wish I had that much discretionary income. The car will not be good at auto-x, nor will it be good at road racing because A. You will be put into a class with full out race cars and B. Racing is about 70% or more driver.

http://www.4rotor.com/

Its being done, top shelf EVERYTHING

$100,000 !?!?!? we can build one for a fraction of that cost! you could build and all aluminum r26b for less than that.

Everyone who has crack pipes, put them down now and step away from the computer.

-Destin

Yes, I've heard of that kind of power from 3 rotors as well. However, I'm not sure they're street legal. In any case, I think having larger displacement would help that power come on a little easier (less boost required) as not to put too much stress on some engine parts (i.e. apex seals).



On a side note I like my crack pipe and will continue smoking as I see fit. :p:

Sure.

Where do you get 100k from???? I have priced several 4 rotors for the USA complete with PPing, new plates & housings & rotors, assembly with ceramic apex seals, ecu etc etc for approx $30k USD.........

700hp can be made out of a single turbo 20b for a pretty penny. Get a different EMS to control the extra rotor and you can make the 4 rotor work w/o a doubt as people are doing.

Think about this....
if you are NOT getting a turbo manifold (as you would be in need of for the 3 rotor) and you are NOT going to have to pay for a nice large turbo ( something like a T 81 or True T88) you will NOT need a flywheel BUT....you will be spending that money on E-shaft and counterweight.

a 3 rotor e-shaft was quoted to me at 2200NZ so a 4 rotor one made by the same people must be a lil under 4000.ooNZ (conversion of 28xx.oo USD). If you take the 13b ya got and get another 2 housings and rotors, 2 rebuild kits and get to work you can built a 4-rotor.
The 4 rotor might end up costing you 5k USD but you dont need to spend on injectors or turbo manifold or turbo.

Both setups would need a subframe and some hacking done ofcourse....

just some more fuel to the fire.

BTW .....
13b of choice to build would be (my choice) 13B N/T 89-92 9.7 compression and 9.54lbs AND i bet you could trade someone your motor (13b-T or BREW) for that one with some cash.

You guys need to talk to someone who's actually seen, touched, and worked on 4 rotor engines. You should hit up Phil (Herblenny). One of the local shops that he know is one of the handful that actually has experience w/ these engines. The engines are VERY expensive, over $10K, and the amount of fabrication is ghastly. Plus, the car's handling will SUCK, since it's basically gonne be ALL front weight. There are concerns as it is w/ 3-rotors and changing the geometry of the car. 4 rotors basically destroys it. It's all for bragging rights at that point.

Destin, why do you say it won't be street legal? Pettit advertises their Banzai FDs as street legal... Is there some certification process that TAZ-NZ alluded to?

On a separate note, Prod, you up at UP? Goin to PSU? I'm a PSU alumnus. Damn good school, had a blast :bigthumb: I miss my UPark days...

This thread is f'ing hilarious. 4-rotor in a daily driven car, used for auto-x, etc. LOL

Any swaps made using a 3 or 4-rotor are NOT street legal, in any way, shape, or form. The 20B engine was never certified for use in the US, and is therefore, not legal.

couturemarc: All aluminum R26B for less than 100k... that's hilarious. Considering there's 6-8 usable R26B cores on the planet, and Downing owns 4-6 of them... and he paid Mazda around 50k apiece back over a decade ago... I'd like to see where you'd get one of the *cough* inferior iron ones for that kind of money.

There is a distinction between "4-rotor" and "R26B".

Hmm...good point. So I guess the Pettit Banzai is NOT street-legal, huh?

in all seriousness if your going to build a 4 rotor FOR FUN!!! do it out of 10a's
you will have room for it and you will be able to control it on the road.

4 rotor will never be streetable. I would love to see a dyno of one though... been looking.

If you have the money to burn on something like this then send me some!

...also w/ the 4 rotor...torque will be great (i expect) but it's too much HP!!! the nice part about my 3 rotor project is the est. hp value of 300-350hp @ 6psi @ 7500rpm. YOU CAN TURN THE BOOST DOWN 4-rotors you cant it's all foot control (im sure you get it)

that was fun....
i give a true est. of 50k on the swap (JUST TO ENTERTAIN THE THOUGHT) just to get it running.

Well, considering that many of those parts are available in the aftermarket, then yes, you could easily do one for under 100k. Do your research. You will find that you can probably build a couple R26B replicas for 100k. JHB performance does Cermet coating of housings, rotors, etc., Racing Beat produces aluminum intermediate housings, tons of people do dynamic balancing, variable length intake trumpets can be fabricated, individual throttle bodies can be had by a number of different manufacturers, plenty of standalone computers out there, Pineapple Racing can RAISE the compression of your rotors (if you wan that done), tons of people do dynamic balancing (even for 4 rotors), 90degree 4 rotor kits (e shaft mod and center housing mod) is offered by Pineapple racing and some guy in NZ... plenty of shit i missed, but 100k is a lot of money and building the engine is not as expensive as youd think. Oh yeah, why do you think downing purchased the motors? maybe to replicate their technology and sell it? its a posibility. sure there are plenty of other reasons for buying them as well, but im sure thats a majore one.

I know i guy here in NZ selling modified plates an shaft to build quad from 13B parts for NZ$3500 - around $2000.

Id stuff it full of RX-8 gear(which is excellent value) and keep it reasonably simple - still net 600hp +

Who said $100k + shame on you... think before you kill this dudes VIABLE idea.

Mean bro do it, I will soon!!

I agree with you. Every time someone mentions 4 rotor all hell breaks loose with comments like (you got 100k to spend?) BS! I think if you get creative the actual engine can be built for around 20k

2 used 13b engine cores $2500.00
custom e-shaft and modified plates & dowel pins $6,000.00 (max)
4 new RX8 rotors(for high compression) $1,300.00
2 13b RA master rebuild kits $2,000.00
Milled rotors for regular 13b apex seals $500.00
4 Rx8 stationary gears ? (shouldn't be much)
Dry sump $2,000.00

Thats around $13,000.00 rounding up just for the engine itself.

With about 7k more and being NA not much else would be needed to get this engine in a car and running

Same as when people say they want to go 3 rotor, you got to spend major money when i think you can get it done for less then 20k

For those that say its not streetable and that it would be too front heavy just look at the scoot 4 rotor.Two 12a engines joined together with two separate crank sensors set 90 degrees apart and ran by two power fc's.If you're gonna try this level of build then pushing the motor back the appropriate distance shouldn't be a problem.Kiwi re sells a 4 rotor conversion kit for @ 4000 nz so if your determined to do it then give it hell.I wonder with the advantages of a naturally aspirated 4 rotor why we haven't seen more development on this front?I know info is limited but this project would be mechanically no more difficult than a 3 rotor swap,it's just a matter of having access to an eccentric shaft that's the biggest bear.I say listen to the guys down under, they have more running 4 rotors than we do.