FirebirdSlayer666

iTrader: (3)

Yeah see my thinking is building a decent motor for $600 is cutting corners unless you can come across a master rebuilt kit for super cheap. I wouldn't use stock seals in a 200hp 12A, even though it doesn't sound like much, I hate the devils fingernails. I would want to ensure proper oiling internally, ensure strong enough bearings and gears, etc. Not to mention the fact that in order to achieve that 200 hp you need proper carb, intake, and exhaust

FBsliderseven

iTrader: (2)

j port it!
all you have to do is pull the motor port it buy bigger carb etc etc.
cheaper then going turbo i think.

vipernicus42

iTrader: (4)

The way I see it, if a stock engine rebuild kit costs $1000, there's no way in hell to double your horsepower and have a reliable engine for just $500.

Assuming you already have the die grinders and everything to port the engine yourself, $500 isn't even going to cover your carb and fuel system upgrades.

Honestly, $1500 is the budget that you should have for a stock rebuild. $5000 is the budget you should have for a 200hp N/A 12a.

Think about it. If you tear open the engine and find that you have chrome flake on one rotor housing (very possible) then you've just blown your entire budget on rebuild kit + 1 rotor housing.

I wrote this thread a while back about building the "Ultimate Streetable 12a". You don't need to do *all* this, but my goal with that is to have a 12a putting out 180ish flywheel horsepower N/A. Cost would be about $4k.

Easiest/Cheapest : save up $3k and drop in a TII.

Jon

vipernicus42

iTrader: (4)

https://www.rx7club.com/showthread.p...streetable+12a

cpa7man

iTrader: (2)

Were getting around 195 rwhp with large street ports and 48IDA webers, in race trim. Figure 100-103 db at full song. Some guys are gettting more but no one will say. Maybe 200+ with ceramic seals and all the tricks.

I just read Jon's post and he's right, I just paid $4.5k for a 12a rebuild, plus some other stuff, like port matching and carb rebuild.

Latin270

For about 1 hr. of fun you can get 150 shot of NOS. Cheap and will get you over the 200hp range.

kleinke

Depends how frugal, resourceful, skillful you are. Anything is possible. Eamon Hurley built his own Lappingmachine. I have a friend who manufactures his own parts to restore cars, rather than spend a Dollar. A Megasquirt can be built very cheaply, and intakes modified/manufactured at home if you have the inclination and time to learn how and do so. It's not hard to find cheap injection parts on Ebay that can be adapted.

LIRX

Thanks for all the insight everyone.

What is a realistic street 12A put out and how do you get there? Before anyone says search, I will and have already but we're on topic of 12a's right now and this is a forum right?

I would be happy with 160HP. It's not a drag car. I'm done with that for now. I just take it out on weekends and nice days but like mess around a little.

bad 83

iTrader: (3)

If you have are going to do all the work, all the fab, and all the tuning, you can turbo a HEALTHY 12A for less than a grand including all necessary supporting mods. Trust me......it can be done. But know this, it took me a good 6 months of being a scrounger, cheap bastard, and making everything myself. If you have a good healthy engine, turbo is the way to go to get that 200 rwhp. On the stock porting, you can get away with 12 psi pretty reliably. This is staying carbed, with no fuel injection. This is a slideshow vid of my transition from N\A to Turbo on my 83 GSL. http://www.youtube.com/watch?v=ZIjR84PZKP8 This vid is after I tuned it to 10 psi. http://www.youtube.com/watch?v=PNG6JRoqXu8&feature=user I know have it tuned to 12 psi, and let me tell you, it's more than enough.

Rx-7Doctor

iTrader: (13)

I already gave you the link for the closest you are going to get with bolt ons to the 160HP mark in post #13.

There is also the FAQ section that has the threads for bolt on HP.

RXDad

iTrader: (2)

Flywheel or rear wheel? Big difference. Haven't seen it defined in the thread. Maybe I'm just not observant.

RXDad

ultimatejay

iTrader: (1)

48IDA with a large bridgeport.

diabolical1

iTrader: (3)

i can't understand where some of you guys get the notion that rotaries are weak, but ... wow ... whatever.

there are some that will swear blind that 12A's are pound-for-pound better and "stronger" than all post-'86 13B's. now i won't get into that - and for the record i don't agree wholeheartedly - but there are some strong points that can be made.

anyway, there is no "strengthening" needed - no magic seals or anything. you can build a bulletproof motor with stock **** from Mazda, you just need to know what you're doing. it won't be cheap, but things worth building seldom are. port it, supply it with lots of oil, put it together and all you have to do is get it a way to inhale and exhale large quantities of air and fuel, then the most important piece ... TUNE it. 200 HP won't be easy, but it's really not hard either. you'll NEED radical (race-type) port configuration or forced induction.

85rotarypower

Ok, to break it down, without porting the stock 12A you are not going to get much more than 150hp, that seems to be the flow limit of the stock ports. Thats flywheel hp too, not wheel hp. If you streetport the 12A with all the bolt ons, you'll probably reach 170hp, but then that puts you at least $1000 over budget. Just getting the bolt ons may put you over the $1500 mark.

If you ask me, $1500 is an unrealistic amount to put down on getting power out of a rotary. If you want any real noticeable power, you want to spend probably somewhere around $2500. $1000 for RB streetport exhaust, $1000 for RB Weber 48IDA and intake manifold, then $500 for various other things.

steve84GS TII

Ill throw this in since it was my own personal setup and was very driveable,reliable,affordable and balanced.

Before going 13B and EFI turbo,I had a bone stock 84 12A with just about all the external stuff you can do.Most of the mods made considerable,noticable increases to power,and according to Paul Yaw,this very setup is good for 150HP....pretty much maxing out the stock engine ports. An average streetported engine with the same specs would make around 175hp.Keep in mind,this is all flywheel HP,since we are comparing against stock HP numbers,which are taken at the flywheel.Total cost of all this can be within your budget,but youll have to shop around, get some stuff used, or score some deals.Its also important that your engine is already in good shape internally.Low compression or excess oil consumption will just make it harder on the engine once you start asking it to make a 50% HP jump.

RB exhaust system......full header,presilencer,muffler.If you dont care about noise,then the muffler type is open game.No chance of smogging the car,so might as well strip the emissions systems off the engine.Saves a few lbs and maybe 1HP.

MSD-direct fire ignition......MSD6 box has capacitive,multiple spark output and if far more reliable than the stock ignitors.Run in direct fire mode with 3 hot coils for a substantial improvement over the stock 1st gen ignition system.Everyone has their own preffered directfire,"wasted spark" setup,but it all boils down to getting more,hotter sparks into the leading plugs.

Yaw carb.......I ran one of these units,which are quite rare nowadays.It was just an awesome,super responsive carb that had all the driveability of a stocker,but with twice the airflow.The Sterling carb is a similar unit,a stock Nikki carb that has been worked over to increase airflow.There are lots of other performance carbs out there like Weber,Holley,Dellorto and Mikuni...but many are getting scarce and nearly all have some sort of caveat.Either bogging due to lack of secondaries,or difficulty tuning,ect. Carb choice is up to you,many can match or exceed the modded Nikki in power,but few can match its all-around usability on the street.The stock intake manifold can also be smoothed out and worked for better flow,or just bolt on a 79-80 intake which is already a good unit.Youll also need a better fuel pump and regulator.I used a 7lb Carter and Holley 4psi regulator.....both are tried and true on our cars.

Light flywheel and clutch........this can be a pricey mod,but its SO worth it.The stock flywheel is quite heavy and doesnt let the rotary rev up like it wants to.The heavy stocker helps the small engine to run smooth and stay spinning when the revs are low,which helps average folk drive around town and through traffic.But it sucks for throttle response.A lighter flywheel will only require a mild change in driving habits and will let the engine rev up through the powerband like a 2-stroke dirtbike. And since youll be adding so much extra HP with all the other mods,consider a mild/moderate clutch upgrade to be a requirement.

orion84gsl

iTrader: (5)

That's so.... how do I say this... Naive. I take it you haven't yet learned how much these cars weigh? This isn't some domestic iron your playing with. RX-7's, especially 1st gens, are flyweights. I think about 2400LBs plus your weight behind the wheel. You can lower that still depending on what you want the interior/exterior to look like, but it gets pretty ridiculous after the first 80-100lbs. Plus the interior looks like *** unless your really meticulous. 200HP is plenty for these cars.

LIRX

I've read all the posts and followed all the links and I have to thank everyone for all the info.
I have to say, bad83 seems to have what I'm looking for. bad 83, is that your complete parts list in your sig?

rx7 doctor, thanks for digging up the old links and all the other info!

bad 83

iTrader: (3)

Not hardly.........There is alot of "little" things that have to be taken care of in the process. I used to think that all motor was the only way to go. I don't fault anyone who believes this, BUT get real, all motor will never make as much power as forced induction. All motor will never be as reliable as forced induction. All motor will never be as streetable as forced induction. Reason being.........with what you will have to do to a N\A engine to make good HP, it will always get crappy fuel mileage, never be tame under "normal" driving. Where as a turbo car will give you the best of both worlds. Good driveability, and fuel mileage under normal driving conditions, but with a kick in the *** when you punch it. I'm not trying to start a debate of N\A versus Turbo, because I have both and I know my N/A doesn't hold a candle to the Turbo. I have reced N\A street ports with not a bit of competition. http://www.youtube.com/watch?v=8LnqZVvQWmo

ultimatejay

iTrader: (1)

I'll agree with you on everything except the part where you said turbo is more reliable than N/A- that is not true.

bad 83

iTrader: (3)

Ok….Let me rephrase that........under normal driving conditions, a turbo IS more reliable than a BUILT N\A. Like I said, I have both, so I don't speak from what others have "told" me. I can speak from experience.

LIRX

I like that turbo car. Very nice.

nivekdodge

First off..., if your saying "I have a _____ and I want it to do_____ as cheaply as possible" you might as well be saying " I own this computer and all I can afford to do is ask questions about things that won't or can't happen". This is why the "tuner" wanabe's have the best mod pssible. Buy yourself one of those big, loud, shiny megamufflers and bolt it on your car. Power costs money. Period. This is also the reason nitrous id big. It is cheap for what you get. Until you blow your motor up.

Kevin

twinkletoes

iTrader: (17)

bridgeport

LIRX

NIVEKDOGDE,

I'm not 16, I'm 27 and have to completely disagree with you. I have built 11 second cars for under $3500 including the cost of the car. Both were mustangs. One was all muscle with a smallblock carb. and one was a supercharged FI smallblock. Both were 302 ci. You just have to know what your doing and do all the work yourself. I also bought all the parts used.

Maybe I don't sound like I know what I'm talking about in this forum but that's only because I am new to rx7s and the rotary motor but I'm smart and crafty so I'm 100% positive that my new toy will meet my goals.

Thanks for your input though......

joecoolly14

Well IMO unless you port the 12a you wont hit your mark...I would with a carb and exhaust you might be at 170 MAX but thats just an educated guess... My 13b is putting over 200whp.. I have yet to dyno it but with some small calculation it puts me at a little over 200.. But for $1500 def. a carb and exhaust and with the remaining money..well you can just send it to me