I was wondering if its possible to hook up two aftermarket turbos sequentially using the stock FD hardware design (solenoids, hoses, etc.). This is purely theoretical; trying to overcome airflow issues with the stock twins and response issues with larger single turbos. Obviously, there would be fabrication and "retrofitting" (for lack of a better word) of some kind, but could it be done using mainly what was supplied by Mazda for the FD?


(Mods: If this happens to be in the wrong section, feel free to move it; just figured it would be best suited here)

 

You mean like BNR Stage 3 turbos? lol

 

Aside from BNR Stage 3's....


There have been other platforms where this was applied.... and usually, this ends up being at least a $10k endeavor, from what I've seen.

Simply too expensive.

BNR Stage 3's with heavy duty solenoids via AEKnights. Done.

 

What cptain said, plus 2 3-way mac solenoids to replace the precontrol and boostcontrol.

21 psi capable with the right support mods, and 400+whp on tap in seq.

 

I'm guessing it wasn't done on a street car then, considering the cost. Could it be a possible alternative to a single on (for example) a 20B track car (20B swaps are fairly expensive by themselves, anyway). I'm really only interested to see if its possible; just a curiosity thing. Financially viable, it obviously is not--for most, anyway.

 

Yes, it's possible. However, the main restriction with the stock turbos is not really the turbos themselves, but the stock manifold. Knightsports and a few other companies have offered "over the counter" twin turbo upgrades in the past that work with a majority of the stock components. However, as single turbos improved responsiveness over the years; the need for sequential setups and their complexity diminished.

Is it possible? Yes. Is it desirable given what is available today? No.

 

To summarize what's been said a different way, the limitations of the stock turbos are 1) power, 2) heat 3) complexity/reliability.

A single turbo of various sizes improves on all 3. An aftermarket twin turbo (BNR's) improve on power and heat but are really the same packaging and are usually chosen as an easy drop-in upgrade over a set of burned-up stock turbos.

For a true aftermarket set of twins, you'd need to replace the turbos as well as everything that valves around it if you intend to maintain the sequential operation. By far this is the most complicated solution - and while it can probably be done to improve on heat, reliability, and power, it would take a lot of work and nobody has a "kit" for it. It would be interesting to see if you could find weld-in valves and doors that can withstand the raw exhaust temperatures that the stock system puts up with.

David

 

As stated by others but in another way.

The bottleneck on the stock sequential turbos seem to be the shared turbo outlets which deadhead into each other and turn 90 degrees into the downpipe.

I cite as evidence that people have made 400RWP but not much more at varying boost levels on-

stock ports & stock turbos
ported motors & stock turbos
ported motors and larger compressor/exhaust wheel turbos in stock housings
non sequential larger compressor/exhaust wheel turbos with ported/modified manifold/external wastegate in stock housings

If you eliminate this stock layout you are into the complexity and custom set up that will cost a lot of money and/or take a lot of time/skill.