So I have a fairly mint 10th AE at my house and I'm looking to have the 13BT rebuilt or purchase a Mazda Reman with a 12 month/12,000 mile warranty. I have not 100% decided on the shop that I will have these services performed through, but I am also trying to finalize on which 13BT I will be going with. I know that I have the S4 version of the RX-7, but I know that the S5 version of the 13BT has a few better differences. With the S5 having lighter rotors, higher compression, better flowing upper intake manifold, and a larger exhaust side wheel in the turbo. I know the S4 has 182hp and the S5 has 200hp. Is this really the only differences between these two versions? Does the S5 13BT just drop straight into the S4 and plug in fine with S4 engine harness plugs? If the S5 motors is able to be placed with no problems into the S4 version of the RX-7 I was planning on doing this setup on my 10th AE...

S5 13BT
BNR Stage 4
NPR Front or V-Mount Intercooler - I am unsure how I want to mount it yet.
Microtech LT-10s with 3 Bar MAP
Electronic Boost Controller - Undecided
Cork Sport 3 1/8" Turbo Back Exhaust
ACT Prolite Flywheel with propper Counter Weight
ACT XTSS Clutch Kit
13B REW Upper Intake Manifold with Throttle Body
Trust Intake Elbow for 13B REW
Upgraded Fuel Rails with use of AN Fittings and High Pressure Fuel Lines
Aeromotive FPR
Primary/Secondary Injectors - Undecided

This is a short list that I have made so far for what I'm planning to do while doing the 13BT Rebuild or Conversion. Please answer any of the questions above or give insight to the list that I have prepared for my project.

 

If you are going to install the Microtech at the same time you swap the engine, it won't be a problem going to S5. Otherwise, it's a real pain to put the S5 engine into the S4 chassis.

 

Ok can you please be just a bit more specific on why? Will I be able to use the plugs off of my S4 engine harness on the S5 sensors?

 

Use all the sensors, injectors, intakes ect off your S4 and put them on an S5 block. Simple as that. I've done it several times.

 

Is it completely possible to just have my S4 motor rebuilt and have the better S5 rotors installed? I mean since I'm replacing the FC upper intake manifold with the FD upper intake manifold and doing the BNR Stage 4 turbo upgrade. This would basiclly turn the S4 into the S5 13BT correct?

 

The S5 has slightly different timing, the spark plug location was actually moved. You S4 block can be built with S5 rotors as long as the front counterweight and flywheel are S5 also.

Physically the S5 shortblock is the same, with exception to the front cover, and all the S4 components will bolt right on.

 

Well If I was upgrading the flywheel to a light weight style and propper counter weight then couldn't I just have the S5 rotors installed with out any worries?

BlueTT - I actually just found your website a few mins before looking at this thread and was thinking about giving you guys a call... Looking forward to your insight about this S5 rotor conversion...

 

Still curious about some of your guy's thoughts