Rotary Resurrection - Tech Section
 
NA TO Turbo II CONVERSION

Please read all information found on this page before calling or emailing me with questions about a turbo conversion. I have worked hard to develop this section of the site due to the high volume of requests I recieve personally as well as see being asked on other tech forums. Please take time to familiarize yourself with what you are getting into before asking me about it. IF you ask me a question that I have covered already on this page, you will either be directed to come and read this page (if I am in a good mood) or ignored altogether (if I am busy). This is not to be rude, but just to avoid repeating myself over and over, as I get anywhere from 2-10 emails/calls per week asking about this stuff. If, after reading this page in it's entirety, you have questions feel free to contact me."

What is the turbo conversion?
So what do I need to buy?
So I know what to buy. Where can I find it? Can you sell it to me? Can you install it?
Do you have any turbo conversion packages available now? When will you have them?


What is the turbo conversion?
When people refer to a turbo conversion on a 2nd gen RX-7, it could mean one of 3 things:
1)
custom fitting a turbo and other required parts of the system onto the nonturbo engine, keeping the drivetrain stock. This is the least expensive (in most cases) method for turbo'ing your NA car, however it is also by far the least desireable. Keep in mind most people's nonturbo is still on the original engine, or at very least a high mileage replacement. Adding the additional stress of boost, even if done properly, is asking too much from a tired old engine. Not to mention that nonturbo engines are high compression internally, and the intake is not set up for boost (6 port variable intake). There is also much custom rigging involved in this setup, and by the time you do everything that needs to be done you have a hacked up engine bay and almost as much money as a true turbo conversion (see below) could have cost you. The only way this setup is to last is to keep boost way down, or rebuild the engine beforehand, either one is not much fun. For some information and parts list on this type of swap, you can check out the following thread posted by a fellow who did this and photo documented the process. Please give all credit to the original author. This writeup is not to be taken as "the only way" to do the swap, but gives you a good idea of what would be expected to make it work.

http://www.rx7club.com/forum/showthread.php?s=&threadid=88540
2)
Take all the stock engine parts out of a turbo II to put into your car, just the engine itself and all the electronics that are required to operate it in stock form, not the turbo drivetrain (for instance if you cannot find one). This would retain your nonturbo drivetrain. This is not highly recommended, but can be done successfully depending on the driver. To do this you would need, at very minimum, an upgraded clutch and pressureplate to avoid major slippage of the clutch under boost. You just bolt an NA flywheel onto your new t2 engine and everything bolts together just like it did. Below is a parts list that is the basic minimum for doing this type of swap, along with basic instructions.
3)
Take all the stock parts out of a turbo II to put into your car, everything from front to back including the drivetrain. This is considered the "proper" way to do the conversion, and will result in the longest lasting choice. Below is a parts list along with basic instructions for this swap.
 
So what do I need to buy?
Here is a helpful guide to what you need to look for.
**The following list is for the "engine only" swap as listed in #2 above.**

**Note that there is a BIG difference between the 87-88 turbo parts that fit 86-88 nonturbo cars, and the 89-91 turbo parts that fit 89-91 NA cars. IT is not adviseable to try and mix and match any of these parts. IF you have an 86-88 (s4) car, you need to obtain all 87-88 matching turbo II stock parts for use in the car. IF you have an 89-91 (s5) car, you need to obtain al the 89-91 matching parts for use in your car. Note also that 89-91 turbo parts are becoming EXTREMELY RARE AND EXPENSIVE. IT is much easier to find and afford all the 87-88 turbo parts in contrast to the 89-91 parts.**

••
Complete turbo engine with intercooler
••
Left-hand drive spec turbo wiring harness
••  
Turbo ECU (jspec ecu will work)
••  
*only for 87-88 turbo* knock control box, a small silver box up inside the passenger kick panel that plugs into the wiring harness. On 89 and later setups, the ecu handled this function.
••  
turbo boost sensor.
••  
Turbo throttle cable. 87-91 are interchangeable.
••   turbo brake boost vacuum pipe (or you can simply run a longer rubber hose to your existing pipe)
••  
Stock turbo fuel pump (87-91 turbo pumps are the same, but the bracket is not) or upgrade such as walbro 255. A rewire for full voltage from the fusebox is also recommended, as well as a re-ground in the hatch to bare metal, a new pickup screen and fuel filter.
••  
Stock turbo intake duct with blow off valve (if not present on engine already). The 87-88 TID is smaller than the 89-91, but either can be used in place of the other. Blow off valves are slightly changed but basically the same.
••  
Stock t2 precat/downpipe and midpipe (bolts to main cat) or aftermarket/custom equivalent.
••  
T2 hood with scoop (unless you go front mount intercooler from day 1)
••  
Turbo air flow meter (your old nonturbo afm will get you by if you cannot find one, however the turbo afm is calibrated for slightly higher air flow on top end so it is something that might matter once you begin to push the car).
••  
Aftermarket boost gauge is recommended. Even though 89-91 owners can install the 89-91 turbo gauge cluster and the gauge will work, it is still not very helpful. 87-88 owners cannot install the stock turbo gauge cluster and expect it to work, the wiring harness differs in this area, though if you were really worried about making it work you could run your own wire to accomplish it.
••  
Aftermarket upgraded clutch and pressureplate. Remember, you're buying this for a nonturbo, not a turbo, since you're using your old NA drivetrain still.

Keep in mind that you need to put the NA flywheel on the turbo engine. 86-88 NA flywheels mate to 87-88 turbo engines, and 89-91 NA flywheels mate to 89-91 turbo engines. Do not mix and match flywheels between series (s4 and s5), they are weighted differently.

You also have to do a bit of rewiring for this to work in the 87-88 cars (in the 89-91's it is a basic plug and play).

You have to run 2 wires from the back of the alternator inside the cabin by the ecu. Compare your old NA wiring harness and trace the wires that used to be at the alternator back to the plug they ended at (one of the 2 large orange ones inside the car). These are black and white wires. Now compare these pin positions with the current harness. Cut (or remove and re-pin) whatever wires are presently there (theyre not doing anything important) and splice in your 2 newly run wires. Be sure to cut and insulate those old wires, so you're not backfeeding through some other circuit. This keeps all your idiot lights from staying on all the time (this is normally an indication of a failed alternator, and the car thinks it has failed because the wiring was missing).

You also have to run 1 wire about 6 inches. On your old NA harness, find the yellow/red temp sensor wire that went under the oil filter. Now find it's pinout position on the orange plug that was inside the car. Compare this to the turbo harness' plug. Now trace the same wire on the turbo harness in the car. Cut or re-pin that wire on the *engine side* of the turbo harness, and jumper it over to the wire that is in the pin position the old NA harness had the wire at. Be sure to cut this old wire and insulate it to prevent backfeeding through that circuit. Now your dash temperature gauge will work like stock.

OK, that's what is required to run the stock turbo II engine by itself.
**What if you want the whole drivetrain as well (as listed in #3 above)? Here is the additional list for those parts:**

••
Turbo flywheel appropriate to the year/series engine (86-88 or 89-91)
••
Turbo clutch kit
••  
turbo slave cylinder
••  
Turbo tranny
••  
Turbo starter
••  
Turbo driveshaft
••  
Turbo rearend
••  
Turbo halfshafts
You CANNOT mix and match any of these parts with nonturbo parts. Everything is different. You either change ALL the parts listed above, or none of them. Note that other than the flywheel, the drivetrain parts really arent specific to any year. Basically the only small changes made to these parts from 87-91 do not matter to performance. In otherwords, it doesnt matter if you buy an 87 transmission and a 91 rearend, or any other combination, it'll still work just fine.
 
so I know what to buy. Where can I find it? Can you sell it to me? Can you install it?

There is usually no one source for all the parts unless you find an entire partscar, which is the best route if you can find it. Buying one piece here, one piece there, all from different sources is not the most desireable way. You can look at the online forums such as rx7club.com/forum, teamfc3s.org/forum, nopistons.com, ebay, thepartstrader.com, etc. to find all these parts individually or as a package.You can also check with jspec engine importers who can often source many or all of the parts.

Alternately, **ON RARE OCCASIONS** I might offer a complete turbo conversion package. The ones that I get are 87-88 cars. Basically what happens is I find a complete t2 in need of an engine, or wrecked, and I part it out. I gather up all the required parts and sell them together. Usually I rebuild the engine before selling the package. On the rare occasion that I have such a package for sale, it usually goes for around $2500-3000 rebuilt (usually to customer spec), plus installation or shipping. Installation of turbo conversions (you bring the parts yourself) usually runs $1000. I can also offer some trade for your old NA drivetrain/engine/electronics, but this price depends on each situation. Shipping a complete t2 conversion usually costs $225-450 depending on your location. No core charge/core is required for the conversion package, but credit will be given for any cores that are traded in, be it N/A or Turbo.

 
Do you have any turbo conversion packages available now? When will you have them?
Rest assured that if I have a package available, it will be posted conspicuously on the rx7club.com forums which is where they seem to sell the quickest. Go there and do a recent post search for my username "rotaryresurrection". IF you dont see anything posted about me having one available, it means I dont have one. When will I get another? I have no idea, honestly. I seem to have pretty much "bought up" all the turbo rx7s in my local area, and I just don't run across them like I used to. I havent found one to part out in about 2 years now.
 
Rotary Resurrection - Tech Section
 
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