Before I get told to search, I've lurked and read all that I could find before opening this thread. I have an '85 GS with a 12A that has recently seized. I plan on using it for Auto-X as soon as I have it complete, hopefully sometime this summer. I've decided on swaping in a Turbo II. I've recently got ahold of a freshly built street-ported Turbo II sans ecu and wiring harness. I should have everything I need except the ignition (plan on creating one with some LS1 coils), wiring harness (will create) and ECU (going to try my hands at using a MegaSquirt II). I still, however, have a few questions that I wasn't able to get clarified.

1. I will be using the stock trans for now, as I believe it has been recently rebuilt and has a nice aftermarket ceramic clutch (don't know which one as I bought the car with it). I've read that you can bolt the Turbo II to a 12A trans, however, I will need to change out the flywheel. Is that correct? Will I use the stock counterweight or will that need to be replace to? Any recommendations on the counterweight/flywheel?

2. I have a GSL-SE front plate and oil pan. Will I need anything else to drop the motor in? i.e. the respeed front cross-member or 12Ato13B adapter from Racing Beat? I've read some saying that the motor should just drop in without them.

3. Right now the car currently has a full Racing Beat exhuast from the header back. I know the header is no use to me but will the rest of the exhaust also be useless? I won't be able to bolt it to the stock Turbo II downpipe?

These are some of the big questions I have right now and I'm sure there will be more but I want to get started with the rest of my shopping list and get to pulling the 12A out,etc.

On that note, where should I attach the hoist chains to the 12A when I pull it? Should I pull the trans out at the same time so it is easier to connect back to the Turbo II before it goes in?

TIA

matt

 

1. the TURBO and non turbo flywheels are different diameters, so if you want to use a non turbo trans with a turbo engine, you need a non turbo flywheel that works with the series of engine rotors you have. s4 t2 needs an s4 flywheel, for example. the 12a flywheel is a different balance weight, so it wont work. if you use an aftermarket flywheel then all you need is the rear counterweight

2. you need the RB 12a to 13b brace, unless you want to bend/fab your old one

3. the FC and FB used different size exhausts so it won't bolt up. but any muffler shop can put the right flange on to make it work. the FB used 1.75" pipe and the FC is 2", the turbo likes even bigger... i have seen a couple cars run 3" to the rear muffler and then just use either the stock one, or RB one. seems to work ok

 

So I can purchase an aftermarket flywheel designed for the S4 Non-Turbo and use the stock counterweight?

 

All you need is a stock S4 NA flywheel. This will allow you to use the 225mm clutch and the S3 trans.

 

Or for about the same amount of work you could go 230+hp normally aspirated...

https://www.rx7club.com/1st-generation-specific-1979-1985-18/rx8-engine-into-1st-gen-rx7-668331/

(I know you already have the TII engine. Just pointing this out to others that might read this thread in the future)

 

So a stock non-turbo S4 flywheel. Any new aftermarket that might be cheap as well?

I thought about the RENESIS but didn't think be worth it. Rather just go buy an '04 RX-8 for $10k and save myself the headache. Insurance might be cheaper too since it is classified as a four door .

 

Also, I noticed that one of the coolant passages on my Turbo II lower intake manifold is blocked off. Is this a common mod? Weird chalky substance in the the passage not blocked off but seems just like regular coolant where it would attach to the block....Any ideas?

 

So I was able to source an 86 s4 N/A flywheel. That should work right? Any idea on a fair price for it? Also, should I have it machined or balanced before installation?

 

A fair price would be 0-50 bucks + shipping. Only machine work needed would be resurfacing.

 

Quick question. Since I am using the tranny that is already in the car, would it be easier to take the tranny out with the 12A and attach it to the 13BT outside the car? Getting ready to remove the 12A (have it pretty much all disconnected) and was wondering if I should pull the trans at the same time. I know on other vehicles it makes sense but not sure about the FBs, especially since it looks like the bell housing is so far forward. Any thoughts?

 

it is easier to mate em up on the floor, but its not super hard in the car either...

my last motor was actually the easiest, i pulled the steering center link, and just lowered it out the bottom. going in was the same deal, WAY easy. no hoist, nobody has to lift anything.

 

Well I have a hoist and I could get the car in the air as well (just on jack stands) I guess I'm wondering how difficult is it to remove both, cause I think I would rather have both on the floor like you said to mate them. I assume I would need to lift the front of the car to wiggle the trans out? Any advice on that?

 

No matter which way you slice it mating the transmission up to the motor is going to require the same effort.

I always mate the motor to the transmission with the trans still in the car and haven't really ever had a problem that wasn't easily worked out.

The last swap I dropped my transmission for no reason except to clean and paint and... I tried putting in the motor and trans together as a whole. Didn't work out to well. One of the trans mounts had a problem lining up the bolt and dammm near stripped it out. If I didn't have a re-tap/thread set I would of had more of a headache then I bargined for.

Not saying you're going to run into the problems I did, but both ways can either work fine or give you slight trouble.

I look at it as why remove the transmission if you don't have to, that's just extra work that's not needed.

 

Okay, maybe I'll go ahead and try pulling just the motor. If I have problems mating it together once I have everything ready to go in I can just pull the trans out I guess. Anohter quick question is if I wanted to thoroughly clean the engine bay, would the trans end up getting in my way or could I just put a sturdy plastic back over it and go after it?

 

if you're gonna clean it up i'd pull the trans. without the engine its only 2-3 more bolts anyways

 

The stock turbo is oil cooled and water cooled. The line for the coolant runs from the block through the intake then through a line to the turbo. Most people who run after market turbos block this off as a lot of aftermarket turbos are only oil cooled.

 

The stock TII intakes (both S4 and S5) only have one coolant passage through the intake. This is for water to the turbo. The return line from the turbo goes to the lower side of the water pump. If you have a TII engine that has never been apart, the front and rear housings are different. They are marked on the top with a F and R for front and rear. Only the rear housing should have the coolant passage drilled out. If you are going to use the TII water pump housing, you can use the 12A thermostat housing to be able to keep the stock 12A upper radiator hose.

 

Be easy on that tranny. It'll last for a while with a turbo engine but the harder you push the drivetrain the more you will shorten its life

One more thing... you need to port the wastegate on the turbo! Otherwise you are going to have boost creep problems.

 

Thanks everyone for the input. Currently I'm working on getting the 12A and Trans out. Last night I dropped the exhaust and man that thing is fricken' heavy. The RB header that is on it had to come off the block as I couldn't loosen the bolts between in and the rest of the exhaust. Ended up dropping everything from the header to the muffler all at once (left the muffler in the car). Currently working on getting the trans disconnected, I think I have everything for the motor disconnected. Wish me luck... As I get closer to putting the TII in the car I'll probably add some pics on what I am taking about on the intake.

About the wastegate for the turbo, any pics as to where I would be looking at internally for the wastegate, new to turbos and not sure what I need to be looking at. Tried looking at it earlier and coulding figure it out, might be just missing something stupid.

Thanks again guys for the help!

 

Quick question about the propeller (driveshaft as I would call it, book says propeller) I just take out the four bolts attaching to the diff and it should slide off the back of the trans? Need to worry about blocking off the end or is that just a uneccesary precation from the book?

 

the fluid will come out of the trans when you pull the drivshaft

 

Ah, that must be why you drain it first. Any seals I have to worry about messing up?

 

No need to worry about the front seal. The real seal is what the driveshaft slides through so be a little careful there. It's also easy and cheap to replace so now might be the best time to do so.

 

Yeah, I got the driveshaft out. Working on getting the boot, etc. off of the trans shifter. What all needs to come out? Am I going to have to take out the entire center console to get the rubber boot off as well? Does the chrome piece that the **** screws onto need to come off, it seems very well attached... Just confused as the the FSM doesn't seem to give much detail...

TIA

 

The plastic plate surrounding the boot, pry at the rear corners, it will pop up and slide back. Push the top of the boot down on the shifter to expose the lock nut to remove the ****.