drb1988

I own a 1990 13B FC. this is my first RX-7. I have a the non turbo convertible model. I am currently looking at engine mods because i want a mild 300-320 hp. I know a guy who is going to street port with a half bridge my rotary. I was just looking for ideas to get that 300 hp all motor. so far i only have a stage 3 F1 clutch and i have a turbo 2 tranny that is going in the car soon. i am currently looking at my fuel system and a piggy back ecu set up. ANY IDEAS?!?!

ramses666

iTrader: (1)

Dream on....

Ramses666

p4nc7

iTrader: (1)

Get a turbo.

theedn

iTrader: (2)

lol...really

SmokinRx-7

no first u should swap for a t2 motor cuz if u just turbo the N/A ur just looking for problems... the main reason i say this is because the N/A motors produce more compression since they are N/A from factory... the t2's have less compression for less chance to blow ur motor... getting the idea? jsut please to save some headaches do a full t2 swap ( which means t2 tranny, motor hopefully s5, driveline, rear end, brakes, and main harness) mayb some other miscellaneous but thats basically it

Boost or Bust

iTrader: (1)

I think the only way you can probably hit that number while still keeping it all motor would be a renesis swap. Considering how costly it would be, I suggest a T2 swap or even a 13B-RE since you already have a T2 tranny.

The smartest choice of all would be to buy a original TII and save yourself a lot of headaches.

InsomniacFC

iTrader: (4)

It can be done. You better start saving now. Search for peripheral port, crispeed, and Jesus Padilla.

found these...

https://www.rx7club.com/showthread.p...eripheral+port

http://www.youtube.com/watch?v=FWlaF...eature=related

sc0rp7

iTrader: (3)

It cant be done with 2 rotors, N/A, and streetablilty all being maintained. Sure, you could build an insane 2 rotor N/A, but then it wouldnt be very streetable. you could do it with a street ported 3 rotor N/A, but then it wouldnt be 2 rotors, and its expensive as hell.

The easiest path to accomplish the power goals you want is to go forced induction. The most reliable way to do this is to either get a turbo vehicle, or do a full drivetrain swap. There are other options, however, those are the most preferred.

- Chris

rotary#10

iTrader: (38)

its difficult but not impossible to build a n/a with 200 hp at the wheels and or crank
let alone how will you make 300- 320 hp?
a 3 rotor n/a runs around 300 - 360 hp ? i think ? correct me if im wrong folks
n/a rotary are hard to make power compared to turbo'd rotaries. thats my 2 cents

basically were trying to tell you turbo motor is where you power is going to be at.
of course you'll need to swap in all the internals t2 engine, harness , t2 tranny, driveshaft rear end , drive axles ect. parts are easy to find. there is just more pros goin in a turbo than modding an n/a
n/a tranny's don't last very long with a n/a motor pushing out 200hp + bolted to it, there not designed to take that type of power and beating.

go t2 you won't regret it
thats what i would do if i had the time and money to do it.
but im a n/a guy

ps were not trying to flame you just help you down the road in rotaries

nunchuckgun

who doesnt love to hear a bov?! seriously, turbo ftw

ericgrau

iTrader: (1)

Practically speaking, lower your goals, try insane weight reduction (to get faster w/o so much power) or go turbo. 300 is possible with an NA but you'll have to blow major $ and make other sacrifices.

I'm somewhat serious when I say "lower your goals". With all the overweight, tall geared american cars out there, people think 300 is a moderate goal. 300 is in fact very fast on a light weight short geared RX-7. Shave off a couple hundred pounds, maybe make the gearing even shorter, maybe lighten the flywheel a little, and 200 at the wheels (~230 at the flywheel) should be pretty dang fast already. Almost as fast on the 0-60 as the super tall-geared and heavier 400 HP Corvette anyway. Seriously, that thing is geared so tall and has so little low rpm power it's ridiculous. OTOH those techniques do save gas, and once you finally get up to speed and into the mid-high rpms you do get your 400 horses. Uh oh, I better run off now in case a Corvette lover flames me.

Making a practical off-the-track 200wHP NA is difficult but not impossible. I'd say that's the border between "I should stay NA" and "I need a turbo".

dot_txt

iTrader: (1)

For the money you would put into an N/A to get 200 HP you could drop in a turbo'd engine and then some extra goodies and still have it idle on its own at stoplights..

Juiceh

iTrader: (4)

Wait, you drive an S4 NA and your saying a v8 has no low end power?



To the original poster:
A 300rwhp all motor 2 rotor will be INSANELY LOUD, have very poor drivability on the street, will be difficult to accomplish your goals with, and won't be cheap. You are much better off doing a Turbo swap. You can have drivability, a tolerable exhaust note, and you will easily be able to hit your goals at a reasonable cost.

gkarmadi

iTrader: (20)

I really think rotary meant to be boosted....

drb1988

Wow i thought you guys would be helpful. i dont know where you get your ideas from but dang... I know a guy with two 12A's both with slightly bigger carborators, street ported, and headers. both cars are N/A and make 230 rwhp dynoed un-tuned. He ported those motors in his garage. SO 300 hp out of a 13B is not insane or inmpossible. i have seen videos of N/A 13B's with alot of hp for next to nothing.

Well when I get my street ported/ half bridged ,larger injectors, my t2 tranny, flywheel, and get it tuned to make 300 hp for under $1500 (depending on parts avability) Ill post videos and laugh at all of you.


And if this post doesnt get me kicked of all keep you all up dated on what i do and how ill do it.

300 hp N/A all the way.

ericgrau

iTrader: (1)

You'll get 250-280 with a full bridgeport. Gl getting that far with a half-bridge. And on a full bridge your mpg will drop to low teens and the only way you'll pass smog will be bribes. Plus other off-the-track issues. Carbs make a little more peak power but less power across the band. You can't really "tune" a carbeurator - which is purely mechanical and has no electronics - like you can tune a fuel injected car's computer. The "tuning" is built into the carb already; you could alter it I guess but the vendor probably did that already. That 12A is about as tweaked out as you can get on a street port. Just search the forums and look up examples. A street port with 250 is the unacheivable (but still hopeful) dream.

Above I was talking mainly about the Corvette, as the prime example of what people think is fast and high horsepower. The Mustang V8 OTOH, with only 300 HP, is just 0.3 seconds slower on the 0-60 but it's also a little heavier. Even then that car is a lot heavier than the FC. At 2/3 the weight, a mildly lightened FC could be as fast with 2/3 the power: 200 at the flywheel or ~170 at the wheels. That's why I'm saying 300 is a lot more than you think it is. 300 on the FC would be like 450 on a Mustang or almost 600 on a Corvette (only off the line or other times that aren't purely high revs, though). That's just crazy.

Sources: these forums, Consumer Reports performance tests.

solareon

iTrader: (1)

tall geared yes. that's how it gets 30mpg.

6-speed Manual Coupe, Convertible and Z06
Gear ratios
First gear 2.66
Second gear 1.78
Third gear 1.30
Fourth gear 1.00
Fifth gear 0.74
Sixth gear 0.50
Reverse 2.90
Final drive ratio 2.56

but it's a torque monster

drb1988

hey. i wasnt knocking your advice eariler ericgrau. i just get mad when other people say dream on and stupid stuff like that. I know that 260-280 is the full street port numbers. But im going with a full street on the front and back housings. then a bridge port in the middle housing. im get the t2 intake manifold, 550cc injectors, the t2 tranny/ flywheel/ couterweight, MSD blaster2 coils, 2.5 inch ehxuast with gutted cat, headers (no sure what kind yet), and a good tune. I just dont see how that is going to cost over $1500 with my hook ups. And 300hp just isnt impossible.

joeylyrech

iTrader: (11)

300 HP NA
series 6 motor with the secondaries bridgeported,street port primaries and 2 small P-ports,NA S5 rotors,ITB,fully balanced assembly running on rollers and you might hit 300,blaster coils,what for?Just ask Judge ito he has a all motor drag RX3 and he does not make over 300 HP,AGAIN A FULL RACE MOTOR

rglbegl

Subscribing.

I want to see the results. I love N/A motors, and just started ordering the parts to build one for an FC.
Living in California, I need to make sure I can still pass smog, so my HP goals are a little lower, But I would love to see how this turns out

Andrew.

iTrader: (4)

joeylyrech

iTrader: (11)

holly **** i want one of those 230 whp 12A,not even a turbo 2 running a full turbo back exhaust make that kind of numbers,again on a turbo 2 you need full exhaust,fcd,bigger injectors,boost controller to hold steady boost in order to get decent numbers so how the f%&&* you get a 12A with a streetport to put down 230 whp(dyno was broken maybe)give me yours friend phone numbers so i can order some of those 12A so i can take out my pathetic S4 NA with a 140 tired horses(very tired)and install the deadly streetported 230 whp 12A and kill some turbo 2s and FDs

Alak

iTrader: (9)

I know a guy making 240WHP out of a more mild perhiperal port 13B with a setup about as good as it gets. He said in his travels, he came across a 13B perhiperal port making 340WHP or so, which was the idea for his project.

Is it possbile to break 300 N/A Power? Yes.

Does it cost alot? Lets just say you could buy an FD, and a garage to go with it.

I know guys that spend $1200 on a TII swap and make far more power, and its far more reliable.

Not saying dont do the N/A build. Just realize it costs alot of money and time. Alot.

TheAbsence

iTrader: (19)

Please, go for it. If you can make 300 HP out of an N/A FC 2 rotor, please inform us how.

In all honesty, you're going to need a Peripheral Port, and even then, I'm not sure if you're going to make 300hp at the wheels with any and all other mods you can think of. And at that point you're looking at a 3000 mile engine. Good luck though.

I've got a streetport and am probably looking at around 140-150 hp at the wheels. Granted, I don't have any supporting mods (intake, straight exhaust), but I don't think those would add more than 20 hp to the wheels with a streetport. Where are you getting your numbers? Some of the members here have a lot of experience and might be able to correct you (if you are indeed a little off on your numbers).

SpikeDerailed

iTrader: (7)

We say that because you're not the first person to have some lofty goals like that. If you have friends that can port and rebuild rotaries then by all means buy a spare keg and go nuts. Even if you dont get close to your goals it will be a great learning experience for you. Like everyone else was saying a TurboII will have a much easier time hitting that goal you have, it can be done cheaper and would be a more streetable(as much as I hate that word) car.