Is a TII turbo(T18?) @ 5-7psi too much for blow-through 12A?
 

Custom manifold, and straight through exhasut
Nikki with sterling mods
Air-Water IC
Alky injection(cheaper than race gas)

Anyone have a compressor map of the TII turbo as well?

can i get away with 7psi with the high comp rotors?

ask the 2nd gen specific forum for the compressor maps. I would not try boosting a carbed car but lots a people do do it. It just sounds like an expensive way to blow up a 12a.

It'll take more than Sterling's mods for that carb to work. Plus you have to make a hat for it, intercooler, etc.

But can a 12a high compression handle 6-7 psi? I would kinda like to know cus i am going to be messing around with this stuff pretty soon.

CJG

I dont see why not, depending on how good your motor is :) 6-7 psi isnt a whole hell of a lot... :D Go for it is all I can say :)

well isn't the 2nd gen comes with stock 6PSI boost??? So if you run the turbo on a 12a, it might be too much for engine, but you won't know until you do it :D

I'm running a blow though Weber side draft with a NPR front mount and a 88' turbo at 9 PSI.

i plan on running 5-7psi on a yaw carb(yea yea) with either a t3 custom trimmed or the TII t18

as i stated before blow through to maximise carb size,
Air water Ic
alcohol injection(or i might just convert to alky anywhose it aint too expensive) (to combat detonation and give me a small safety net)

i will be fabbing most the parts and hope to complete the project for about 1.5k or less(yes i am looking for a bargin DIY turbo kit, i have no worries if the 12A pops seeing as I am looking to get another full race J-Port/or large Bridge motor for track use only and am looking for fun in the mean time.)


I am wondering wil the yaw carb have problems runing at ~10-12psi? to compensate for the boost im am running through it.

Also I see alot of confussion on return line/FPR palcement,

am I correct in thinking that the correct order for this application would be

---> FUEL FLOW
====[FMU]===[FPR]====(carb)
.......................| |
.......................| |
...................return line
........................| |

with the return line branched off the FPR?


and please ignore the ("..." 's) i couldnt get the diagram to line up

sry for the ruff sketch and common/dumb question but i cant think all too well seeing as my damn cousins are keeping me awake, ugh 8am class.......

Wow isn't that kind of a lot for high compression? or did you have your rotors dished? Also what size of carb are you going to run? is that the 45 DCOE? I just picked up a turbo 12a exhaust manifold and it has a "rajay" turbo on it. have any of you heard of this turbo? i have been doing a lot of looking around, and they are still made. But i think this one is realy old cus no one can get the serial number to come up. I havent raly made my mind up what kind of motor i want to build for it. I am thinking either a raly big street port and then rebuild that turbo to go on there. Or building another pp12a engine, but then i would have to buy a realy big turbo for it and likely go to a custom manifold. but who knows, i have my hands full just getting my car to run with the motor i have now. I think i will start on the next engine this winter.

CJG

6 Lbs on High compression - Okay.
8 lbs on High compression - pushing it, even with plenty of fuel.

Now, if you were running EFI...

WHAT??

For the sake of aurgument, please justify the use of EFI over carburation in a turbo charging application, and don't forget to factor in the cost.

Rototuner,

Some might think that 9.4:1 with 9 psi is a little high for a rotory app but what about the third gens running 9:1 at between 15 and 20 psi.

I am using the 45 DCOE.

I don't know much about the factory 12AT, except that it is offten refered to as "kind of small". Oh yea and the mani won't bolt to a series 4/5 turbo. But I have never seen them up close.

Ryan

Ya more mazda is very right in saying that that carb turbo is not a bad way to go. Are they good to go commute in every day? Probably not, but there is definitely a lot of CHEAP power to be had with a carbed turbo set up.

CJG

Cheap Power - Yes. I am all for it.

If you throw in cost, then everything does not match up.
There is more to Power than an HP Numbers and 1/4 mile times. Just like running a 14 sec 1/4 mile in an FB has a "lot more violence" than doing the same 1/4 mile times in a Northstar V8 Caddillac. :)

Superioirity over a Carb include:

Welcome to the Present.. Basically all the benefits of a good EFI system are multiplied in a turbo application. There's nothing wrong with blow throughs, they just aren't as flexible as a good EFI system. You can only "tune" a carb so much, and with a Turbo, you are pretty much stuck with a running rich all the time syndrome.

Seriously, I personally know a few (3 guys) with Blow through Turbo Holleys. 2 first Gens, and one 91 TII.
They are all Extremely Fast. They are also very tempermental vehicles. They run different in the rain, hot day, cold day, etc. They always smell like somebody spilled a portable gas tank in the back. Power delivery is not very smooth or linear. Again, THIS IS FINE, for HP numbers or 1/4 mile runs. For daily drivers or that extra tunability, you can't beat a good EFI system (like the Haltechs, Wolfs, SDS, etc). Piggyback chips are crap.

I remember what cinched EFI over carbs for me in the past. I was at the private street races (warehouse district) when the Police showed up, freaking everybody out. Everybody got in their cars, trying to leave, and I was in a custom Turbo 240z with the owner. He flooded, and couldn't start it. We were sitting ducks for the police. Sucked.

Please keep in mind, that I do like all factory EFI (if the car came that way) and would not recommend an OEM EFI system on a car that didn't bring it (12A rotary). For those special applications, I am a firm believer in an aftermarket EFI ECU with the good OEM throttle body.

As to your original question, yes Cost is a factor.
SPEED=MONEY
RELIABLE SPEED=MORE MONEY

I could not aggree more with this right here^^^.
I do still think though for some of us out there there are cheap alternatives. like big ports, blow through turbos etc. that are very cost effective and are somewhat easy to build and use. but yes your totaly right drivability and reliability is sacrificed. But most of us that go this rout in the first place understand that these are not the kind of set ups that we go out and just turn the key and expect to run perfect every time and to commute in. But yes with unlimited budgets anything is possible. However there is always us budget guys that can go fast with very little $$$.

CJG