How can I make 200HP with my 12A?
 

Hey Everyone,

I just picked up a 84 gsl. It only has 70k on the clock and is in great shape besides fading paint. It's all stock besides a header, exhaust, and suspension upgrades. I have been dooing a lot of research on these cars for a while and kind of come up empty. I'm getting info but its not as easy as I'm used to. I really just want to know the easiest and cheapest way to make 200 HP or close to it. Does anyone have any ideas or other info for a newbie?

Thanks in advance.

turbocharger?

TII swap would be the cheapest and easyest. But You could always street port and turbo (or supercharge) yours. Or even go periferal port n/a if you have the money. Any way you go speed costs money. how fast are you willing to go?

That's the thing. I don't really want to do a motor swap$
I have been trying to find out how to make more power with the 12A. Preferably all muscle.

12A with no turbo and in its stock build form will never make 200hp

Port the motor and put a big carb on it and you are still going to come up short (probably)

Either way the motor is going to have to come out, be it to port it or to swap it.

A TII motor is the fastest most reliable way to 200hp

It's prob cheaper to stick with the 12a and upgrade it to come as close as possible to 200hp thought right?

^^^ wasn't that what I said...lol .Yep your gunna have to take the engine out no madder what you do. Im going for 200-250 with my SE. It will have bridgys, Itb's and sqeaze. Probly wont break 250. all for 3k

edit

i was agreeing with mike

Depends on what your willing to spend. How much are you willing to spend?

Not much. maybe $1500.

I have no problem with pulling the motor. I just don't want to spend the money. I've done Honda swaps before and from my experience, you always end up spending a fortune when all is said and done.

Honda=cheap, rotary=expensive get used to it. That might get you a TII, maybe.

HP costs money. Remember that you are starting with a little over 100 HP and you want to double that. It takes money to do that.

This is where you need to start and then see how you like it.
https://www.rx7club.com/1st-gen-archive-71/engine-easiest-way-make-hp-stock-12a-686989/

There is also the FAQ section. There are threads on how to make HP. That is what you should of done first. Which is read and then read some more.:)

Now that the title is changed to reflect what information you are looking for. Go to the bottom of the page and you will see 5 related threads that you can click on a get your answers. :-)

Only way you're going to hit 200hp for $1500 or less is with some Nitrous. Building the 12A yourself to hit 200+hp N/A will still cost more than $1500. If you consider a turbo, then the cost drops, but it's going to take some creativity

Jay Lenos Cosmo 110s has a 12A that is putting out 200hp. From what i know it was built by mazdatrix and is NOT turbo'ed or juiced in any way.

Lets be a little more realistic ... T2 swap don't put out 200hp at the wheels anyways ... so you can match it up with a ported 12a with something like ITb's and stuff. 170whp with a 12a is very doable and is where i'm trying to get at, so that would equate to about 195.5 flywheel hp.

Proof or GTFO!!!!!!.......................................J/K, but seriously..proof


Getting a 12A to 200hp without power adders isn't that difficult, but it costs a hell of alot more than $1500

For only 200hp, you definitely don't need a turbo or nitrous.

The Mazda Atlantics 12A's made about 220hp with a street port and no intake restrictions. With a bridge port the 12A's made about 250 hp with carb and restricted 38mm chokes.

If the engine isn't being built to conform to some arbitrary racing class regulations, it's much easier to make power. However once you move to peripheral ports and custom EFI intakes, much more power, but more costly. Not the best choice, only if rules say you need to stay NA for 300-350+ hp.

In any case, even a street port would require pulling and rebuilding the engine.

Well, C. Ludwig started a thread on the other forum about his entry in the GRM $2006 challenge, which included the cost of the entire vehicle. He was using a 13B, and mentioned a $600 engine budget and goal of over 200 whp on the low end. It wouldn't be unreasonable to expect 200hp from a 12A for $1500. You can read the details over there; the thread is called Intellectual Exercise, $2006 4-port j-bridge NA.

Even building it yourself, you would need to strengthen internals for double the original hp. 13B's can get away with it because they produce power a little more easily and there are more options for power cheap i.e. S5 N/A rotors for higher compression. I honestly just think it would simply be more than $1500 done right.

fuckin leno
 

only if we all had the money to go get tuned by mazdatrix...fuckin jay leno and his enormous chin

S5 6 port engines make 200rwhp with a good streetport and tuning.

Bridged 12A with a good exhaust setup, IE, loud, and good EFI and tuning will probably make over 200.

Meh, what internals do you think need "strengthening" for a mere 200 hp? The 12A is pretty stout and a fresh engine with a take that with no problem. An old tired one, not so certain.

As far as the cost, he was just describing his plan which did not necessarily include S5 rotors. I tend to believe, due to the reputation of the person making the claim, if he could build a $600 13B making more than 200 whp, that he could build a 200hp 12A for $600. But this is some faith and speculation so if you think it would cost more, I can't prove you wrong. Sometimes it's preferable to spend more $ than to cling to every penny, and the time spent looking for cost savings does have a cost itself.

For $1500, I will get a Sterling carb, RB header/presilence, Borla Muffler, 2GCDFIS w/TT, and suspension (depends on whats your plan for the car).

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

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.

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

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.

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

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.

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.

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.

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.

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

RXDad

48IDA with a large bridgeport.

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 shit 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.

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.

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.

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 ass unless your really meticulous. 200HP is plenty for these cars.

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!

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 ass 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

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

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.

I like that turbo car. Very nice.

If your 16, living with your parents and this is your first car...
 

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

bridgeport

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......

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 :)