FD BNR Stage 3 installation notes and tips
 

Recently installed a set of BNR stage 3 turbos on a '94 FD and just wanted to make note of a couple installation tips and issues that I ran into that may assist people in the future. Most of the issues are related to the fact that the BNRs are slightly longer than the stock twins though still mount up the same.
I opted to buy a new ceramic coated housing since mine was cracked in all the usual places.

The full procedure to remove and install the turbos can be followed in the FSM and adhered to with the BNRs.
The part #s are pulled from the below picture from another thread.
https://cimg9.ibsrv.net/gimg/www.rx7...848865d736.jpg
Original thread had the part #s circled.



Parts to keep:

• 2x Oil return lines (14-290)
• 2x Coolant lines and hoses
  • (13-530A, 13-540D, 13-536, 13-546)
• 1x Oil hard line (14-280)
• Rear portion of Y-Pipe with actuator
• Y-pipe O-ring if you're planning on reusing (50mm diameter roughly if you want to buy a non-OEM one, OEM are around 18 dollars from mazdatrix/atkins)

Things I left on the turbo when shipping:

• Turbo inlet/outlet studs
• Turbo actuators

• Include your Y-pipe so that it can be lengthened

Parts I got back from BNR:

• Assembled turbos with actuators mounted
• Lengthened Y-pipe
• Cleaned up turbo inlet/outlet studs
• Crush washers for all hardlines to the turbo
• 2x gasket for the oil return lines

Installation notes:

-I have an aftermarket solenoid rack so many of the vacuum lines were readily available to be worked on post turbo installation into the car. That being said, most of the outlets and nipples are pretty accessible so vacuum lines can be addressed after getting the turbos and Y-pipe in the car.

-Install and torque down the coolant hardlines, hoses AND oil return pipes onto the turbo BEFORE you start turbo installation into the car, they are night impossible to get to once the unit is mounted to the exhaust manifold

-Coolant and Oil hardlines will be slightly too short in its stock configuration due to the lengthened housing, you will need to bend them into place. I do not have pipe bending tools available but went with the following:

• Method 1: Mount up one side of the hardline and then very carefully used a pry bar insulated with some towels to pry the line roughly into place, you'll have to decide if you're ok trying this.
• Method 2: The coolant lines are relatively malleable, you can stabilize one end (I used my foot) and bend the piping manually pretty easily. It's very easy to bend it too much or too little, suggest bending little by little and retrying the fit until it's right. The oil hardline has a heatshield around it which makes it a bit harder to bend.

-If you still have an airpump:

• The lengthened housing causes some clearance issues with the Y-pipe and the airpump. I found that after installing the Y-pipe, the airpump would sit on top of the Y-pipe, barely allowing the mounting bolt on the belt tension bracket below the air pump to be installed. This meant I could not fit the alternator/water pump/air pump belt on due to it being set at max tension. My solution below is not the best but without the ability to shave down the Y-pipe, it's what I had to do to get it to fit.
  • I uninstalled front portion of the Y-pipe, removed the primary turbo outlet studs.
  • Installed the airpump first, then installed the Y-pipe. I used M8 bolts on the primary turbo outlets instead of the stud/nut combination. This let me "force" things into place a little and torque things down without having the Y-pipe grind the threads away on the studs as I'm pressing things into place.

Other than that, the BNRs were a pretty straight forward installation. I would suggest replacing your turbo mounting and downpipe studs while doing this job as, for some reason during the removal, many of mine became rounded and unusable. That being said, if they're stuck in the exhaust manifold and the exposed threads are ok, you may want to leave them. I had to cut and extract the small N391-13-456 stud because the two nut extraction method I tried rounded the shit out of everything.


Very excited to have these in the car and big thanks to Rich and Bryan.


Z

I'll add that on first startup you should carefully check for coolant and oil leaks. I installed my BNRs a few weeks ago and had an oil leak caused by the front oil return line not being flush with the block after bending it. I did not have any issues with my air pump whatsoever

If you have the OEM intake setup, you will also need to wrestle with the rubber intake hoses particularly on the front turbo. It's possible to get them on, but it feels like you need 3 hands.

Absolutely. Case and point, no leaks on initial startup a week ago but did another inspection last night and seeing coolant leaks from the turbo side.