cordius

Okay so I have been considering buying an old 12a Rex. Of course, I want to turbo it. What exactly do I need to do to prepare the 12a for it?
I'm looking for big horsepower, so around 18 psi, maybe more. Not sure of the compression on these engines, but I want around 450whp, maybe more.

I also was told these are the smallest and lightest of all the 7s. Truth?

DivinDriver

iTrader: (15)

450 hp...

Stock horsepower on a NA first-gen 12a is about a third of that, or less.

t_g_farrell

iTrader: (1)

The 79/80 SAs are the lightest of the first gens. Hope you have deep pockets. It will take a lot to get that much hp to the rear wheels out of a 12a. Your talking 500+ at the flywheel.

Search on here for 12a turbo and look in the drag racing section for more details.

StealthGXL

iTrader: (1)

More like 1/4 of that..


Do some searching. There haven't been any how-to 12A turbo build-up threads that I've seen lately but there are some older ones still kickin around...

Here's one thread to get your juices flowing: Here.

It will take A LOT of work and money to reach your goal of 450rwhp.. Not trying to discourage but something to think about..

Fellow Masshole

OldSkoolFool

How fast do you want to go? What is the car's purpose? I don't think an engine tuned like that would be great on the street, would be good for a drag car. Unnecessary for a roadrace car unless the suspension is set up and upgraded insanely nice. An early 1st gen with even 200hp will be quick, those cars are light. With even 200hp, would be talking similar hp/weight ratio to an Elise if you remove a little weight from the RX-7. Check around here but people are probably getting mid 13's with that kind of power in a 1st gen. If you want 9's, then I guess 450hp would be the way to go.

blackdeath647

iTrader: (2)

like people have said, there's quite a few threads going around about 12a turbos. To reach that much HP tho you'll probably be better off doing some porting before boosting, that way you don't have to have such a big turbo and it may help with engine life..but i'm no expert lol.

Rotor_king

iTrader: (2)

at 450 hp, im feeling twin turbo P-port with big *** exhaust ports. haha

cordius

I guess I could live with around 300-350 for now then

Super82

iTrader: (1)

Seriously? Have you any concept of horsepower other than what you see in the car and driver magazines? Go buy the car and drive it, I bet you'll find 100 to be plenty for a while. These aren't mustangs or vettes, if you have a 200hp FB then you have alot. The amount of work to get a 12a to 300hp let alone 450 is ungodly.

DivinDriver

iTrader: (15)

And generally more than the structure, suspension, and aerodynamics will ever let you fully use.

cordius

Well, I know what 400 HP feels like, yes. I don't know what it'd feel like in an FB, I've never been in an FB before, I can only go by what I have heard.

DivinDriver

iTrader: (15)

G= ((P/W)*CsubT)*FsubP))

(Perceived G-force equals the quotient of power divided by weight, multiplied by coefficient of traction, all multiplied by the Pucker Factor)

maxvol

iTrader: (2)

I have a 12A Turbo... Street ported and Im going to be Happy to hit 220.. So do lots of research, it is DOABLE...

With DOABLE being DEEPPOCKETS

cordius

Starfox07

If you want 450hp, just save up $5-10k and buy a 13b-rew, street port and single turbo that, should get there just fine.

FirebirdSlayer666

iTrader: (3)

Then you need to spend another $5-$7k on the rest of the drivtrain and suspension to handle it, with brakes, wheels and tires. If you have a good cheese hookup, you might get some gospel from the lord himself of 12A turbo's

cordius

If I cant get there easy on the stock motor it almost seems like a waste of money. 5-7k is more than I think I would ever put into a car that old.

FirebirdSlayer666

iTrader: (3)

Yeah there's no chance in hell of getting there on a stock motor. You could probably do it but it wouldn't be easy and it would put it into the self destruct category

Jeezus

iTrader: (4)

Lol.



Basically, with 300 HP in a 1st gen RX7 (I don't care what gen/model...) you will be a force to be reckoned with.

littleredrotary

stage 3 weight reduction also and then we are talking business

iuno if id ever wanna take a sa/fb over 110... it kinda starts to float around 100. imagine doing 150+.

cant be to safe

speedracer_not

cordius, the real question behind your question is "how can i make my car go faster".

Mazdatrix.com has the answer.

cordius

Well, it wasnt going to be a street car. In theory, I guess I could, but that is a little too much power for new england roads. I realize I would have to upgrade the seals but frankly 5-7k is a lot. Like I said before, I don't know what an FB rides like as I have never been into one. I was just curious what it would take to get power like that before I buy it.

Jeezus

iTrader: (4)

GT42
A/A Intercooler
Methanol/C02/Alky/Water injection
Tank for above fuel additive or injection
Weber 48 or aftermarket ECU
Big streetport/bridgeport
dowelled
GSL-SE fuel tank or aftermarket fuel cell
Surge tank
A1000 fuel pumps
3/8 to 1/4 fuel lines
3-4 inch exhaust
Custom down pipe
Cage
Ford 8.8 / 9 inch rear, toyota tundra/hilux rear
TII Transmission
Custom driveshaft
MSD boxes
Colder plugs


Just few things.

DivinDriver

iTrader: (15)

Basically, it says that nobody knows "what 450hp feels like."

You can know what it feels like in a particular car under specific conditions, but by itself it doesn't have a"feel."

450hp in a 6000-lb truck bears no relation to the feel of 200hp in a 2000-lb car.

Plus, there's the "pocker factor;" as in, how much acceleration your particular rectal ringpiece can stand without permanently puckering your upholstery.

gsl-se addict

iTrader: (3)

Going to close this before it gets out of hand.

Basically it can be done with enough money. Many people coming from other cars will ask similar questions (like how can I get 500HP in my FB?). Really, set your sights lower. Shoot for more like 250HP. You'll probably find that to be more than enough in a 1st gen. If it isn't enough, you can always build from there. The real point is that 500HP will cost way more than say 250-300HP. As the power goes up, the $ per HP increases rapidly (harder to squeeze out HP, supporting mods (fuel, cooling, drivetrain, etc), etc.

You will need a turbo to get to these higher power levels. Lots of info on what it takes (money wise, parts, labor) can be found by searching the 1st gen section and the 1st gen archive. Seatch for terms such as "TII swap", "12A Turbo", "Blowthrough Turbo", etc.. Read, read, and then read some more. There is a lot of research involved for doing something like this. You need to set realistic goals and stick to a budget. Otherwise, you'll wind up with no money and a half-finished project because you tried to build more car than you could actually afford.

Good luck.