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-   -   Turbo 2 engine swap question (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/turbo-2-engine-swap-question-1157765/)

mythbusters8 07-06-22 11:53 AM

Turbo 2 engine swap question
 
FYI I'm new to rotaries so please excuse my ignorance. So, my engine blew up. I have an 89 GXL that I now want to swap a t2 engine into. I want to know; can I use all the NA accessories on the t2 engine? I was looking and I want to get the t2 shortblock and then just buy a turbo upgrade + intercooler upgrade for it since I was never planning on using the stock turbo and intercooler anyways. The only other thing I can think of that I would need is the turbo 2 ecu. Would this work?

WondrousBread 07-06-22 12:20 PM


Originally Posted by mythbusters8 (Post 12525302)
FYI I'm new to rotaries so please excuse my ignorance. So, my engine blew up. I have an 89 GXL that I now want to swap a t2 engine into. I want to know; can I use all the NA accessories on the t2 engine? I was looking and I want to get the t2 shortblock and then just buy a turbo upgrade + intercooler upgrade for it since I was never planning on using the stock turbo and intercooler anyways. The only other thing I can think of that I would need is the turbo 2 ecu. Would this work?

Some accessories will work, like the power steering, alternator, ac, etc. But you need a few other things to make this work:

- Turbo intakes, throttle body, and throttle cable. A shortblock will not include these. BAC valve too.
- Turbo injectors, fuel rails, etc. For S5 turbos (keeping the swap in series is a good idea) you will also need the little boost control solenoid valve that mounts to the UIM.
- Turbo AFM, Turbo pressure sensor.
- Modify harness (I don't have the exact details, but they're out there if you search).
- Turbo II clutch, starter, slave cylinder, and transmission. The NA unit is known to break when behind a TII engine.
- Either a modified TII driveshaft to mate the TII transmission to the NA rear-end, or a stock TII driveshaft and complete TII rear-end. Differential and axles must match, so both need to be TII.

You also seem to want to run the stock EFI system but with an aftermarket turbocharger. This is not a good idea. The stock ECU has very little in the ways of engine protection, and no learning functions built-in. Putting an aftermarket turbo on an otherwise stock car is a recipe for a blown engine. Your good options are to run the stock TII turbo in which case you are better off just getting the longblock in the first-place, or to run a standalone EFI system. This will let you tune in the aftermarket turbo and set up proper engine protections, and allow you to ditch the stock sensors and harness entirely.

There are other methods of tuning on the stock ECU. You could find a used Rtek ECU, or add fuel where necessary with an FCD and an S-AFC. Neither of these is an ideal choice, but there are people out there using them with no ill-effects. Realistically they are only a good choice for mildly modified cars.

mythbusters8 07-06-22 01:17 PM

Thank you so much! So how much would it cost to do the complete t2 swap in the easiest and cheapest way? Money is the biggest problem, and I don't want to spend a lot of money just to keep a very slow engine

WondrousBread 07-06-22 01:35 PM


Originally Posted by mythbusters8 (Post 12525325)
Thank you so much! So how much would it cost to do the complete t2 swap in the easiest and cheapest way? Money is the biggest problem, and I don't want to spend a lot of money just to keep a very slow engine

If your NA engine is "very slow" then there is something else wrong. The NA engine is no powerhouse, but the car gets around fine and is still fun to drive. Although since yours blew, maybe it was not a healthy engine to start with.

There is no such thing as a cheap TII swap anymore. These parts are harder to find than they used to be, and more expensive.

How much it costs is nearly impossible to answer. A full TII swap recently fell into my lap for a great price and I'm still in the preparation stage, getting all my ducks in a row to minimize the downtime of the car.

Last time I was offered a full S5 TII driveline (prior to the one I got recently for a lot less) it was $4500. That's engine, transmission, driveshaft, diff, axles. Engine in used condition. Now I'm in Canada so prices are different, you will have to get prices near you. Engine importers may have them cheaper since they were more plentiful in Japan, but the engines are always suspect.

I don't know what the stock EFI parts in good condition, but if you're going standalone then MS3X + harness can be done for around $800 USD if it's a basic installation (using stock injectors, stock coils, reusing good connectors from factory harness, etc).

Then you still need a fuel pump which I forgot to mention earlier, and either a TII hood for the stock intercooler OR an aftermarket intercooler.

Like I said, there is no such thing as a cheap turbo swap.

mythbusters8 07-06-22 01:36 PM

Ok, thank you!

Dak 07-06-22 01:47 PM


Originally Posted by mythbusters8 (Post 12525325)
Thank you so much! So how much would it cost to do the complete t2 swap in the easiest and cheapest way? Money is the biggest problem, and I don't want to spend a lot of money just to keep a very slow engine

It's hard to estimate cost because of the unknown of how much you will pay for a TII engine. They are significantly more than a few years ago unless you can get a good deal on one locally. Easiest and cheapest way would be all stock. Sounds like that won't be enough power for you but it's still a good place to start. After that move to a standalone ECU. Depending on the make and model they go from about $600 to $3000 or more. I think Haltech has some models that will run a turbo rotary for under $1000. Fueltech's FT450 is $999. Megasquirt is cheaper if you want to DIY and build the ecu yourself. Probably add in a few hundred for injectors and such. IIRC you can make 250rwhp safely on the stock turbo which would be noticeably faster than the 200hp at the crank that the stock S5 turbo was rated at.


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