I asked myself this question today and came up with my own answer that it wouldnt be worth it but i decided to throw the idea up in the air anyways. Would it be worth it for an NA purist who want power out of a rotary, but real power and high end and maintian the throttle response of having it non turbo, would it be worth it to throw a 20b and streetport the hell out of it and leave it NA and what kind of powerband and HP figures would we be looking at with an agressive streetport and of course a well tuned microtech Lt-12. Another figure would be expense and how much it would cost to do such a project. I know the swap in general is very expensive and cost prohibitive, but without all of the turbo issues with intercooling and all the extra goodies out of the way that eat up money, how much would it really cost for just the motor and the microtech and the motor mounts. SO basic question is for the ultimate NA would it be worth it to make an AwesomeNA out of a 20b, what are the power potentials and how much would it cost. Just an idea. I know it would make more sense to just throw in a t2 and leave it at that and spend the same money modding it and being faster, but for those NAsayers out there what are the possibililties. If this is a monster repost then im sorry. ReTed and AaronCake would be great if you could chime in......tanx

 

I did make a comparison list of the two. And for the money of buying a 20B and having it build would cost more than turboing an N/A.
And it woudl probably get you around 300rwhp.
I really wanted to do this with a motor similar to hitmans, but it just wouldn't be worth the money to me. Unless it was going to be run with a BP or a partial P-port.

 

i think u'll still have to custom everything ... since 20b only come turbo

guess its not as easy as the hood

i'd love to see it tho
btw hos the new front going ?

 

Read this a while back - maybe you should take a look at it...

http://www.iluvmyrx7.com/2ndgen/arti...ges/image1.htm

 

IIRC, someone posted a dyno sheet of their 'mild ported' 20B N/A hitting 280hp, can't seem to find the thread when I search though.

 

Read this a while back - maybe you should take a look at it...

http://www.iluvmyrx7.com/2ndgen/arti...ges/image1.htm

 

do a search on n/a 3-rotor

 

Well, it will probably cost more then just throwing it in with the turbos, since the engine must be disassembled to get higher compression rotors in there...The way I see it, if you're going to do that, why not just plop it in with the stock turbos and make 400 reliable HP and gobs of torque?

 

someone else is already doing it. I think its jesus padilla. he's racing in all motor class with a N/A 20B. I Know he runs 10's , but he's got the motor shoved in an FB.

 

Aaron, the way i see it, if you have the money to do a 20b swap, wouldn't you want to rebuild it before the install anyways? I know I wouldn't want to throw in a ~$3500 motor unless I know its exact condition. Sounds like a very cool idea to me, but still its gonna cost some major $$$.

just my 2 cents,
-Aaron

 

Not 100% sure, but I don't think he's running the 20b anymore due to the whining of other participants after he kept smoking them.

 

At SS5 I talked to Rob Golden (Pineapple Racing) about a NA 20B. We didn't get real specific but he recommended using S5 NA rotors in it. It can be done....but for a price.

 

as far as i can tell in the last numbers I saw, padilla is still running a 20b all motor. without a 20b, the all motor class is just untouchable for an rx7

 

20b N/A's are banned now and Jesus Pedilla ran 9's..amazing!!! He now runs 10's on an N/A 2 rotor...again, amazing!!!

I've thought about an N/A 20b for along time...What a great idea for the roadcourse, and there is a guy on the NOPISTONS forum that runs that with low-C rotors and dyno'd 300hp I think.... Great idea...someday!

 

basically to just throw it in there you save the cost of the intercooler. which you could eat up buying 9.7 rotors, and making a header.

the big plus is that na you should be able to keep it cool roadracing. which is maybe not possible on a turbo

mike

 

You could also recoup a couple hundred bucks by selling stuff like the turobs, intake and exhaust manifolds. Just think, put it on ebay as rare JDM 20B parts

 

thats exactly what i was thinking.....buy the 20b for 3500.....rebuild and build the hell out of it...1500 if you skim it and wo the work ur self.....then of course the microtech another 900........so 5500 and other crap.....but i mean most people that are serious about the 20b usually do it because of the 13b limitations....so most people that are throwing one in arent going to leave the trubos and those goodies stock....and when upgrading those thats when you get into the serious money....of course to me id rather throw a grand into a t2 motor and spend another 2g building it and still be much more powerful than a stock 20b before even its own cost....

 

this week!!

 

Good powerband, and probably up to 300hp.

Doesn't the LTX-12 have only 6 load bands for an NA?

About $4,000 for a used 20B-REW.
About $1,500 for the LTX-12 with hand controller and PC dongle, which probably isn't the best EMS for an NA, but to each his own.
About $250 for the mounts, assuming your current rubber mounts are still good.

So basically, for under $6K you would have a used engine of unknown condition and new metal mounts sitting in your garage, and an LTX-12 on your desk. Oh, did you actually want to install that in a car? Now you get to buy a custom hood or cut a gaping hole in your NA hood for the intake manifold clearance, and then cut another hole for the 20B thermostat unless you want to mill it down or use a 13B water pump, then you get to upgrade the radiator and install new hoses, install a high-torque clutch, make a custom anti-roll bar or oil pan, custom header, electric fan(s), etc., not to mention the engine rebuild and NA rotors you want to add. I think we are over the $10K mark.

Once again for those who missed the last 3 years of posts...

The 20B conversion is not cheap! It is not cheap with the 20B-REW, it is not cheap with an NA, it is not cheap with an aftermarket turbo, it is not cheap with the Cosmo front half, it is not cheap with the stock ECU, it is not cheap making a custom 3-rotor engine, it is not cheap with green eggs and ham.

 

oh i know it isnt cheap and im aware that it would not be cost effective at all for the power unless you had very specific needs or wants, but i was just curious of numbers for my own knowledge for just how much less expensive it would be minus al the turbo goodies and what kind of power a 20b NA would put out. So since we have covered that base what would the torque output be like in something like that? Would it be V8-esque with the highwind of a rotary all in one?

 

pdm-racing.com has an N/A 3 rotor FD that racing beat built. it has S5 rotors, mild porting and a custom header on and it dynod 300whp. not too shabby if you ask me.
honestly, if i had this stupid amount of money (rather than the inverse) i would prefer the N/A 20b because of the theorhetical longevity advantages it has over a 13B turbo. This is also because i live in florida, and the climate likes to claim rotary turbos left and right.

 

Well, it would depend what you did to the engine. The 20B Race engine is a peripheral port NA, and it puts out about 450-475hp at around 8500-9000rpm, and about 290 lb-ft torque at around 8000rpm. Strangely enough, the stock 20B-REW Cosmo engine has slightly more torque. I think what a lot of you guys don't realize is that the stock 20B-REW was specifically designed to spool up quickly and deliver a lot of torque to push a heavy luxury car through Tokyo traffic. As far as street cars are concerned, a non-turbo version of the engine isn't going to do much for you but make more noise.