theNeanderthol

iTrader: (1)

I have been thinking of going with a simple turbo setup for my 12a. I already have the turbo prepped weber sidedraft. I have been considering using a used second gen turbo. I have heard of people using this turbo and the manifold. They just cut the original manifold and weld a 12a flange on the 2nd gen exhaust manifold so it will bolt up. Has anyone had success with this?
I am also considering going with a custom fabricated exhaust manifold and the same turbo, but that will cost a pretty penny. (especially along with the wideband sensor I will probably need to tune eveything anyway.)

Has anyone had luck with the first setup before? It sounds kind of ghetto, but I have heard people say that it has worked for them. I will probably use the stock 5.5 psi setting, and fabb an intercooler from some junkyard stuff.

Any ideas, comments, advice, wanings?

inuissus_cendi

I've researched this quite a bit, and alot of people have done it. First of all theres no way you'll get just 5.5psi. The internal wastegate of the 2nd Gen turbo is way too small. You can port it out quite a bit to get it to flow alot more, then you could get you boost down, but I still dont think you could get it to 5.5 psi.

Oh and I'm not sure about with a Weber side-draft setup, but some people talk about having to use spacers on the exhaust manifold to get the turbo to fit.

Check rx3mist.com for custom headers, the make just about any header for a rotary, and I think they have alot of experience with the header you would need. Oh and rotaryshack.com will have the carb plenum you'll need.

Other than that you'll need to beef up the fuel system with a high pressure pump and boost referenced return-style regulator.

Oh and you'll need an oil feed and return line for the turbo.

Thats all I can think of right now.

Good luck and let me know how it works out for you, as I want to do the same thing eventually. Maybe I can learn from your mistakes

81gsl12a

iTrader: (1)

yes this set up will work nice... FBII has more or less the same thing set hes boostin 15ish on a stock port motor... the weber should work fine im goign to run a dellorto on my turbo 12a..as for a turbo header you can buy racing beats weld together header for like 89 bucks and make your turbo header with it all you will have to do is fab up at plate for the turbo to mount to....this turbo set up is good for about 200-250 hp maybe a lil more its all in tuning the motor....wideband is a very very good idea

FirebirdSlayer666

iTrader: (3)

I'm gonna run this setup. Get an S5 turbo off the 89-91 TII. Good for up to 15psi at least and WAY less complicated than the S4 turbo. I'm just gonna get the S5 turbo echaust manifold and fab it but a custom turbo header sounds intruiging LOL. When I get more money maybe LOL. Depends on how much boost you finally decide to run as you'll probably need to strengthin the driveline. Transmission, rearend, driveshaft, things of that nature. You'd probably want to upgrade breaks slightly too, just to make sure you can stop. Yeah FBII and Steve84GS TII are great turbo 12A info guys

FB II

using the stock TII exhaust manifold is easy. there are a couple ways of going about this: First; don't waste your time cutting the flange off (you will waste many hours trying to do this), instead just oval the mounting holes in 5mm and the exhaust port holes in about 5 - 10mm as well. then it bolts right on. if you are using an S4 manifold then cut out the flapper door crap and weld the holes shut. while you're at it port match the inlets on the turbine as well. and of course port the ever loving hell out of your wastegate (mine is insane, but i can get 4psi all thru 3rd gear with no boost controller if i want, but why would i??? )

Second; = spacing the turbo out.... you could either use two RB exhaust flanges which are about a little under 1" thick each and will clear a side draft manifold.... OR you could bolt the manifold right up to the block and create a 3" spacer in between the manifold and turbo. either way is easy, one might be a bit cheaper than the other. if you go with the spacer between the turbo/manifold idea then you need to probably make a custom downpipe as the TII aftermarket ones will probably hit the firewall.

DO NOT SKIMP OUT ON THE FUEL SYSTEM!!!!!

i can not stress this enough, i was hard headed when mexico was telling me this before, but i have learned the hard way. BYPASS the stock feed line, the little white regulator piece under the tank, and return line. use all new lines that are beast. it will be worth it!!!!! even tho the pressure may be rising, the VOLUME isn't there.

anywho, enjoy your project.

85TIIDEVIL

iTrader: (2)

What size fuel lines would you consider "beast"..? Should i just make the feed and return the same size...?? I'm doing my fuel set-up right now as we speak... I was advised not to use the braided steel lines being the rubber eventually will detioriate under the braided protection and you can save mucho $$$ by just routing upsized aluminum lines and fuel injected rubber hose wherever a connection needs to be made vs AN fittings (again = mucho $$$).

vxturboxv

iTrader: (2)

Save your money and buy a 50 shot... You'll go faster with half the work... 5.5 psi won't do much and woul dbe alot of work. A 20lb bottle of nitrious lasts for a very long time if your only spraying a 50.

perfect_circle

5.5 psi wont do much, but how about 15? and thats power you can always have.

inuissus_cendi

exactly, and he wont have just 5.5 psi like i said before, he'll probably get at least 8, and more if he wants. With 8 psi you'll get more power than a 50 shot and you'd have to upgrade the fuel system for nitrous anyways. So that brings the price up, not to mention the cost of a 50 shot nitrous kit (around $400-$500). PLUS the cost of the upgraded fuel system, and a turbo done ghetto enough could cost less, and give you constant power, not to mention not having to refill the nitrous bottle.

FB II

i often run 5 - 6psi and it pulls very hard. i actually come off the line much better since the tires don't spin nearly as much

also, atleast make sure all the feed line is 3/8". when i went thru mine it was mostly 5/16 which = the suck.

trochoid

iTrader: (6)

Instead of ovaling out the holes, or buying the weld up header, buy a 13b and 12a header flange and weld 2 short pieces of steam pipe between the 2 flanges, bolt it up and go.

inuissus_cendi

here's a thread to read just to make you think twice before you do turbo your 12a, not to scare you off but it's still something you should read.

https://www.rx7club.com/1st-gen-archive-71/engine-how-build-high-output-12a-turbo-without-blowing-up-your-motor-380353/

theNeanderthol

iTrader: (1)

You guys are awesome. and trochoid, the 2 flange idea is genious. I'm definately gonna go for it. Although I wish I didnt have to run bigger fuel lines, I guess I will. I was thinking of going with the 5/16 because 1. it is already there, 2 my turbo prepped OER carb has those fittings, and 3. I'm going to buy an insane fuel pump anyway. But, as volume goes, bigger diameter is always better.

LokiRx7.1

iTrader: (1)

Just outta curiosity but how do you put 32 psi into a 12a????? good god I mean 12a rotors are what 9.4:1? what are they doing using JDM 12A-T rotors? I'm just a little confused wouldnt that be waaaay to much

vxturboxv

iTrader: (2)

You really don't have to run biger fuel lines or a killer pump. If I were you I'd go with an alcohol injection kit. That way your car will drive normally under non boost conditions and as the boost kicks in, so does the alcohol. This will also help fight against detonation and save your engine! Here is a link to one of the best kits around IMO.

http://devilsownonline.com/

Call them up they are very helpful.

I run 24 psi on a te-61 on 91 octane in my FC. It's awesome! (although it's not a rotary i couldn't run over 16 w/o detonation before the alky)

FB II

meth injection is amazing. just remember you MUST tune to it. it's not something you just spray on top of your tune and expect it to work right. it can hurt your power as it actually richens the mix and greatly reduces EGT's. this is good, but you need to change your tune to accomadate this or you will not be gaining as much as you very well could.

inuissus_cendi

woah, I certainly hope you're not on meth FBII, at least not while you're driving your beast of a car. haha, sorry just had to point that sentence out.

FB II

oops, yea that did sounds kinda scary ahahahaha!

i'm gonna have to video tape some of the cars out here using methanol injection hitting high boost on pump gas. it's quite amazing

theNeanderthol

iTrader: (1)

OK I remeber you guys talking about spacing out the turbo and manifold. I can't quite picture this though. I have never actually seen a Turbo II FC. Anyway, do you say this because it need to clear the intake manifold??? I am actually running an OER carb with the wrap around style intake manifold, not the down draft, or the sidedraft manifold that leaves the carb on the right side of the motor above the headers. Rotaryshack's setup.
Will this make a difference? Will I still need the space it out as much as you guys have mentioned??

FB II

yes, just get two racing beat flanges and longer studs for the block. that will set you up perfectly. one spacer will clear but it's very close and will cause alot of heat soak on the manifold.. two spacers is just right

perfect_circle

or rx3mist.com

theNeanderthol

iTrader: (1)

OK guys. I'm gonna go for it. I'm in the process of getting the turbo.

Now let's talk cooling. I think I'm going to start beefing up the cooling system right away.
What do you think? Is it necessary running only 8psi?
I am thinking of going with one of those auxilary radiator coolers. It is the same priciple as buying a bigger radiator, or one of those $500 aluminum pieces, but way cheaper. I am thinking of doing the same with the oil cooler. An inexpensive aftermarket oil to air cooler. It will be bigger than an early model 12a oil to air cooler, (which I have sitting around), and fairly inexpensive.

saltyslug

hey Neanderthol man, what size is your dcoe? that is the same carb I am gonna use. what jets you running?

I am not gonna run much more than stock for cooling. Just make sure what you have already is up to par. Anything extra could probably help aslo.

good luck

theNeanderthol

iTrader: (1)

I'm gonna have to take a look. I dont remeber the combo. I beleive the main jets are 155, but I'm not sure. It is a 45.

FB II

if your cooling system is in good working you will be fine with the stock setup. my car always runs no higher than 175 degrees using a 170 thermostat.