Ok, after some searching, I think it would be a nice choice to turbo my 12A. Which setup, a s4 or s5, turbo and manifold, would be a better approach?

Or would it be a more optimal idea to simply use an aftermarket t3 flanged manifold for a 12A (if they make them) or a 13B? I do have a new garrett t3/t4 with a huge turbine side, which would be perfect for a rotary.
Thanks!

 

s5 is better in every way except price

 

The only problem with a T2 manifold is that it is awful close to the engine, and the stock intake manifold will interfere (heavily) with the turbo.

If you can source a 12AT intake manifold, you'll be fine.

 

So if i choose to run an S5 manifold + turbo, i really cannot make it fit properly as it will interfere with the intake manifold?

 

it will fit, just have some heating prob

 

anybody know about clearance issues with a rb holley manifold and an s4 or s5 turbo/mani?

 

No, it won't. You obviously have not *tried* it, or seen how pinched a 12AT intake manifold is (and the turbo still just *barely* clears).


The thing you'd need to do with any intake manifold that isn't 12AT is to fabricate a short spacer to move the exhaust manifold away from the engine. (MAAAAYYYBE the one-piece, curls-over-the-engine single sidedraft intake manifold would work... but not having seen/tried it I can't say for sure) Go to the FC section and look for Aaron Cake's long putting-a-turbo-on-an-N/A post. The clearance issues for the 13B EFI N/A intake are similar to those of the 12A N/A intake, and you can see how he worked around that.

edit: clarified intake/exhaust manifold in explaination

 

After a little investigation the other day I have to fully agree with Peejay; there is no way in hell that manifold would fit without a spacer. I nearly looks as if any turbo at all would not fit! It appears as if we can get spacers/flanges from racingbeat which might do the job nicely.

S5 turbo+manifold seems to be the way to go as well... anyone selling one or knows of someone selling?

 

Gonna revive this same thread, rather than start a new one... :-)

Found a an 88 s4 turbo and manifold... So, if what I am reading is correct, I can bolt this onto my 1985 12a when I put it into my 83 LE, and will need spacers to use the s4 manifold? Could I buy RB headers that will accomodate the s4 turbo on my 12a?

Once I mount the turbo, I assume the output gets routed to a Carb Bonnett, right???

Sorry for dumb questions, but I hope to get a couple smart answers... :-)

edit: Anyone have DIY plans for a carb bonnett?
THANKS AGAIN!

 

u cant use headers....ur using a turbo manifold....you gona need to get or make a down pipe to have a shop connect the rest of and exhaust system to it... yes the output can either go up and into ur carb hat or route it to a intercooler and route outa that to the carb hat (but cause more turbo lag). another thing ur gona need a new carb setup up for boost along with a waste gate and i would suggest a BOV----i would suggest a HKS SSQ BOV (bro has it on his WRX....sounds so tight)

 

What you 12a guys will need to do is go to the racing beat website and buy two exhaust header flanges. 1) 12a header flange, and 1) 13b header flange. then you weld a section of pipe between each exhaust port hole, and voila

1) you've got a bolt-on conversion for s4/s5 turbos
2) you've got a spacer.

Both problems solved in one step. You can now bolt up the s4/s5 turbo to the car w/o too many difficulties.

 

Or better yet just use a 13b--especially if you want a S4/S5 turbo setup. I really don't see any reason to go with a 12a-imho.

 

I see a reason... I've got a strong, running 12a already in the car. ;-)

 

Well, since I last posted I've come up with a 13b from an 86... It's N/A, and still has the injection on it. I've also got an S4 turbo Manifold I picked up for this project... SO, must I use S4 turbo, or can I also use S5? Can I use any aftermarket, or other types of turbo's on this manifold? Can I keep the same injection? If so, how do I make that connection?

Sorry for all the dumb questions. I wanna go FAST! :-)

 

You can go either way S4 or S5 turbo--S5 is preferred due to the larger wastegate.

You can go with the same injection setup but need bigger injectors.

One other problem is the 6 port vs 4 port. Turbos are all 4 port (and so is the LIM). So you may need to try and find some irons to convert back to 4 port. I think everything else is still good to use. Also note you will be running higher compression with the NA rotors--so be careful.

Best luck finding solid answers is to search over in the 2nd gen section.

Scott

 

Also something to consider is the search button, I am not trying to be wise, but if you were to search (and it way take a couple tries with different word combos) you would probably come up with more information than you really need. I bet you would get answers to questions you didn't even know you had. When you find really good threads pop it into your favorites for future reference. Good Luck. I will also be doing this in a couple years.

 

Yep... I searched and searched. Most of my questions and curiosities are taken care of with searches.

This thread was closest to answering my question, and I just needed one or two more clarifications. Now I've got a starting point... Time to have fun!