slayerx7

iTrader: (4)

That is my ultimate goal, unless I can squeeze 325Hp

My clutch went out so nows probally the time for me to do all this major work. I want to go with a 12A cause it seems EVERYONE has a 13b Turbo, nothing wrong with that, but who builds up a 12A?

So far I dont have too much of an exact plans, Im just floating around Ideas right now So heres what Im considering

Boraz racing clutch $329 www.rx7.com
P-Port with Weber (more power than Holley it seems) 52 IDA Or perhaps other porting with a supercharger (Thats like $2500)
I was wondering if a Pacesetter 2.5" Header is a good way to go?
Hi flo or no cat / muffler.
MSD Ignition
2 Blaster Coils
Alum. Flywheel
LSD rearend
Larger brass radiator
better pumps, steel hoses
IT said that a 2mm APEX seal was just fine for up to 300 horse, so perhaps a 3MM would be wise?

Also does anyone know if a Miata Tranny will bolt to a 12a???

Let me know any info you have!

Thanks

kgray

12AT. not pacesetter, get RB header. Hopefully FBII will chime in with his hp number.

candyassmiler

you cant use rb with 12at. talk to rene.

85TIIDEVIL

iTrader: (2)

12A is already 3mm apex seals..

Ggerg1186

I am the crew chief for this car:


It's a GT2 first gen RX7. It puts out 220 RWHP with a bridgeport and 48 Webers. 300 hp should be no problem.

It is awesome to watch Kurt drive this car around the track, he smokes all of the 500+ horsepower v8's.

Kurt also owns this car:

A 550 horsepower v8 Monte Carlo. Thats me holding the flag.


Anywho, GOODLUCK! all it takes is money.

680RWHP12A

12a... got questions? e-mail me or call me....... 300 hp is just the begining of the potential of a 12a...

robert@rotaryshack.com

KeloidJonesJr.

iTrader: (8)

Japan had some Turbo 1st gens. Not sure if it was 13B or 12A. Can someone confrim which one?

3rd and final 7

iTrader: (9)

yes japan did have Turbo 1st gens it was their SE model for japan and they were 12A was equiped with a small turbo and low boost so no need for a intercooler, and it was fuel injected. someone correct me if im wrong!

vipernicus42

iTrader: (4)

Lol, if you think you can rebuild a 12a for high power, P-Port it AND put an intake on it for $2500 you're seriously misinformed.

You can barely rebuild a stock 12a for that price.

If you want a reliable 300hp 12a, you're gonna need a HELL of a lot more money than that.

Add to that the transmission and rear end replacements you'll need in order to handle that kind of power.

How much money do you want to put forth for this project? I think it's a lot bigger than you realize.

Jon

Rx7carl

Welcome to the forum. Thats a lofty but noble goal if you plan to try to do it N/A. If thats your direction, tell us. I think everyone is alreay assuming your going forced induction. I dont think a Miata trans will bolt on, but the guts can be used in a FB tranny.

Devil is right, your already at 3mm on the seals.

Ggerg is right. Anything is possible with enough $$$. And Kurt Christies car has always impressed me as a really well built car, even though Ive only seen it on the net. LOL, I smoked a few of those rental GT1 Montes at drivers school in my IT7 car.

Rx7carl

Not true, you can get alot for $2500 if you do the work yourself.

TO do it N/A yes, thats a tall order.

I think from my readings that 300hp is about the limit on the stock drivetrain so thats on the edge but not out of the question.

Thats the biggest truth. Its a big money project for sure. And if you wanna talk about how to get there we can do that. But it wont be pretty or cheap.

slayerx7

iTrader: (4)

Thanks for your replies!
Its good to know that 300hp is realistic out of a 12A even if its not cheap. I was not clear earlier about the supercharger for the 12a, what I meant to say was that the supercharger alone is $2500, if thats the route to go.
I want to try to stay away from putting in a turbo, but if thats the best way to make a decently reliable 12A then so be it. The turbo will be my last resort.
Making this kind of motor will definately require an engine rebuild. I read that the 2MM apex seals atvantages over the 3MM are that they last a little longer, little better milage and so on. The disadvantage is that they can only handle up to about 300hp so Id be running them at their limit, which would suggest new 3MM seals would be the right choice.
Also I plan to do all the work my self, and customize any/everything that needs it. If I had the means to forge my own parts I would.
The use for this car will be a daily or semi-daily driver. I know that a PPort for this is insane cause it lasts what about 6000 miles before needing more work? So then it seems going with a bridge might be better. Or what http://www.mazdarotary.net/porting.htm calls an extended port, and working with the extended port to boost power to 300 and beyond...

Off the topic, can you pull off most the rats nest and have the car still run ok on a stock 12A? I havent had time to search for the 'proper emmisions removal forum'

Thanks

slayerx7

iTrader: (4)

One more thing. Ive heard that turbocharging a carburated car is something to avoid because "...The sealing of the intake is imperative to success, the pairing of a turbo a carb guarantees a long painful learning curve, especially if high boost levels are desired" Which would mean that the turbo lag with a carb would be very bad. I want to avoid lag all together, since the rotarys hurt for low end torque to begin with. I dont need tons of boost, just enough to get 300 horses.
But to get 300 at the wheel, Id probally need 360 at the flywheel to factor in a 20% drivetrain loss. The more the merrier, but My goals 300 right now, I can always worry about an additional 60 later.
Does anyone have a wonderfully running carburated, turbo 12A ?

trochoid

iTrader: (6)

Mazda did not go to the 2mm apex seals until 86. All 1st gens, 12a or 13b are 3mm. If you are not going turbo, the best header out the is the SDJ, pricey, but proven to produce more hp than any other.

If you choose to go turbo, you can easily get 300 with the right turbo and tuning and a large street port. Motor will last longer than a bridge or pp. For streetability and reliabilty, less tuning, concider going FI instead of carb. Not trying to start a fight here, but, depending on how much time one wants to spend retuning, FI is easier in the long run, even though it may take more investment in the begining.

Kim

If you are worried about the car running ok, you should not even consider thinking about just maybe going P.Port

300hp is possible with a peripheral port, but you need a few essential parts to make it reliable.
You will need race bearings, hardened stationary gears, upgraded oil pump, higher rate oil pressure regulator, a good oilcooler and probably a few more parts that i forgot.

You should be able to pull it off at a fair price if you can do all the machining yourself.
Thanks for reading up on the subject before posting, many a n00b could learn from this

Best of luck
-Kim

slayerx7

iTrader: (4)

Thanks again.
UPDATE: I Just found a 12a with Tranny for $500 - 45k on both in great shape - Awesome deal!
While Im considering that, Im definately getting a new hood to cut, And a Holley 650cfm
He said hed sell the Holley with a RB header for $150 \m/ $650 for all of this is a killer deal!! My 12A has 148k on it now, and the 2nd gear syncro is getting harder and harder to shift into. So rather than macining all of the housing and stuff on my motor, Ill get the 45k motor and tranny, rather than run into more expense later. And put all the racing springs, seals, rings, everything into this new(er) motor. Im going to stand by on the RB header for now and research the SDJ header first.
As far as fuel injection, your right, it would be quite the task to set up initially. If I go with F.I. Itll be in the future. It seems like opening up the ports and putting a Holley on with a header is insane performance! Apparantly Weber and Edelbrock have basically turned into the same carburator nowadays. Im told that you can do so much more tuning with a holley carb than anything else, eg, change air/fuel ratio easier, swap out the jets, set a certain rpm to open up the secondaries fully, ect ect. Plus the venturies are much better. So it looks like I was wrong about the Webers. Or perhaps that the Weber 52IDA was the best carb specifically for a P-Port.
Im going to get a chevy Cowl Induction Scoop, and scribe it to the new hood and cut that out, so it cools the whole engine by having so much more room to flow through than only the intake charge.
Also the LSD Diffs I just learned are remarkable! Posi for hard acceleration, and then it adjusts for hard cornering or normal cornering, its not in any one mode full time and can handle upwards of 450HP! Impressive! Wooo Go Mazda design team!
I am kind of skeptical but I hear you can run under a 12 sec 1/4 mile with as little as 250 hp!! If thats real, gotta love these RX7s!!

slayerx7

iTrader: (4)

Thanks again.
UPDATE: I Just found a 12a with Tranny for $500 - 45k on both in great shape - Awesome deal!
While Im considering that, Im definately getting a new hood to cut, And a Holley 650cfm
He said hed sell the Holley with a RB header for $150 \m/ $650 for all of this is a killer deal!! My 12A has 148k on it now, and the 2nd gear syncro is getting harder and harder to shift into. So rather than macining all of the housing and stuff on my motor, Ill get the 45k motor and tranny, rather than run into more expense later. And put all the racing springs, seals, rings, everything into this new(er) motor. Im going to stand by on the RB header for now and research the SDJ header first.
As far as fuel injection, your right, it would be quite the task to set up initially. If I go with F.I. Itll be in the future. It seems like opening up the ports and putting a Holley on with a header is insane performance! Apparantly Weber and Edelbrock have basically turned into the same carburator nowadays. Im told that you can do so much more tuning with a holley carb than anything else, eg, change air/fuel ratio easier, swap out the jets, set a certain rpm to open up the secondaries fully, ect ect. Plus the venturies are much better. So it looks like I was wrong about the Webers. Or perhaps that the Weber 52IDA was the best carb specifically for a P-Port.
Im going to get a chevy Cowl Induction Scoop, and scribe it to the new hood and cut that out, so it cools the whole engine by having so much more room to flow through than only the intake charge.
Also the LSD Diffs I just learned are remarkable! Posi for hard acceleration, and then it adjusts for hard cornering or normal cornering, its not in any one mode full time and can handle upwards of 450HP! Impressive! Wooo Go Mazda design team!
I am kind of skeptical but I hear you can run under a 12 sec 1/4 mile with as little as 250 hp!! If thats real, gotta love these RX7s!!

DeRFmAn

Sound's like you got some good plans. I plan on getting mine to about 200-250, anywhere in there and I'm happy, I just wanna stay N/A. Don't really need much to get moving with these. As for the rats nest there is a link to a write up in the 1st gen faq page but I think I have the link on my bookmarks. one sec................................ http://www.ten15.net/Maz.tutorials/ ......ahh there we go. Thats a great write up from a couple of the guys on this forum. If you look in the right places there is tons of info here. There is a guy on here goes by FB II he built a FB with a turbo/carb setup. I think he is pushing about 250, thats what it says on his cars page. Anyway good luck with the project.

Fred

chairchild

Just a thought - everyone keeps going on about you need uprated blah-blah, and hardened lah-de-dah to run a PP........


But what about if you limit the rpm's to around 7000-ish? Negating the need for mega-bucks parts to cope with high rpms



And another Q, would a semi-PP (uses the side ports as well a small PP, just so you know Slayerx7) be better than a full PP at those kinda restricted rpms?

Kim

Running the motor to only 7000 rpm makes no sense on a P.port motor
They usually make their power between 5-& 10000 and would leave you with a very short powerband.
Streetable yes but thats all about preference, if it runs - i will drive it
Peripheral motors likes unrestricted exhaust system, my guess is around 105db and up - not funny at all.

cds00bsmg

iTrader: (1)

Is there any paticular reason your staying away from a Turbo besides the whole carb. seal thing you read? You REALLY need to talk to 680RWHP12A and FB II. Search FB II under members, and make sure you search for posts started by him.

I guess the decision is up to you, but as far as drivability is concerned, his setup is the way to go.

~Chris

chairchild

So kim, any idea if a semi-PP would have a more suitable powerband?


might as well ask, since I'm considering doing this at some point in the future anyway

Kim

I have no idea.
All I know is that it either requires for you to make your own manifold or find one for sale $$$$$.

Id give it more boost its the solution for most problems ha ha

84gsNC

Dude, go w/ a turbo setup, use the nikki you already have and get a manifold from Rene and a carb hat from rotaryshack. Use a stock second gen turbo. Setup is super easy. I had my downpipe made custom for like 60 bucks at a local muffler shop. Beef up fuel pump and get a wideband air/fuel meter. FBII did my whole setup, drivability is better than the Holley that I had on there, plus the car hauls A$$. Even if you open the ports, put that Holley on there and a header, i doubt you'll ever hit 200 to the wheels on a streetport.

krew

I have a home built 12a BP. (small bridge)
Was running Holleys 456 & 650 DP. best HP was only 140 RW.
Switched to SDS. fuel injection 204 RWHP @ 8000rpm I run to 9000 on the street.
What about a little NOS on a street port??