csvimports

I love the fact a 1.3 litre can crack down the quarter faster than a hell of a lot of v8s and since the p plate rule came in meaning no turbos, v8s or superchargers it left me with one sensible option............ RX7!!! now i was just wondering a few things. I have heard that the 20b is infact a 13b with an extra rotor 3x654cc or sumthing like that if so is it possible to add an extra rotor to a 13b?? Now porting would the best option for a daily driver be bridge porting or would you suggest another form??? thankyou for your help all feedback is welcome!

z-beater

not really familiar with the rules but all 20b's and all 13b-rews were turbo'd. Sorry to burst your bubble. There are tons of options with going N/A though.

Welcome.

~Z

csvimports

The Australian delivered models were all Naturally Aspirated.

calculon

iTrader: (29)

unless the 20b was custom fabbed with an aftermarket eccentric shaft kit like the ones from kiwi-re, or was modified, it is not NA. all the 20bs from mazda came twin turbo in the cosmo

csvimports

So is it possible to somehow get hold of one of the rotors and add it to the 13b to increase it to 3x654cc instead of 2x654cc?

andrew lohaus

technically yes, you could make your own "home brewed" 20b, or even a 4 rotor 26b, it has been done. but considering the number of part you would have to fabricate (well essentialy duplicate from a 20b) it would be silly to not just buy a real 20b.

you can make a 20b non turbo by just taking the turbos off and making a header, if thats what you are after.

apperently it doesnt even drop the power too much since the stock turbos are said to be quite undersized and restrictive.

csvimports

Thanx for that. How rare would the 20b's be to get hold of?? are they only from the cosmo? And once the turbo's (or turbo) were taken off the 20b would that 20b then run a different compression ratio???

MPM

20B engines generally run about $4000. Sometimes less but then you end up with basically a short block. The short block route is a good thing if you plan on running the engine N/A. Be prepared to spend about $8000-10,000 above the price of your car to get an N/A 20B running and close to $15000 for a turbo setup. The more custom work you need the higher the price gets. If you have good fabrication skills the price could be a few thousand less. It ain't cheap. Not to insult anyone but have you considered a V8 swap? Cheaper and more HP in N/A form. You can spend $2000 to $10,000 if you want to. Good thing about is that it fits many budgets. Makes for a great daily driver.

csvimports

Yeah it's just i Live in NSW, Australia there P platers (17,18,19 yr olds) can't drive turbo's, V8's, or supercharged car hence the reason for a N/A rotary. I will be purchasing either a series 4 or 5 13b n/a. What type of porting would increase power very decently whilst not comprimising too much practicality as this will be my daily driver.

cbrinega

Since I doubt you have $10k (US) to go with a 20B, why not get a nice S5 13B with a mild street port (or even stock)? You'd probably be surprised at what you could do with the car with a good exhaust, refined intake, piggy back or stand alone ECU, higher rear gears or shorter tires, and lightweight everything.