Does anyone know what this black box is for? Also that hose and green filter are connected to it. It appears to run from that black box to the back of the y pipe.

 

I’m not FD3 proficient but am going to gander that it’s a pressure vacuum chamber and that’s a check valve in the rubber line for it.

 

The black box is your pressure chamber. It stores up excess pressure for the turbo systems to operate correctly.
The thing you're holding is a check valve that has broken. You will want to replace that to avoid a vacuum/boost leak.

 

Yep, that's a check valve, the ones in the nest are super prone to splitting. Don't buy the oem mazda ones, plenty of rotary tuners sell packs of viton check valves that cost the same as one for a pack of five.
Viton 1-Way Check Valve 5-Pack

 

A copy of the Factory Service Manual is available on-line for free.
http://wright-here.net/cars/rx7/manuals.html

 

So im guessing there is no deleting this box? Not sure if it matters but the car was converted to non sequential before i bought it.

 

If it was running fine, then I wouldn't bother removing it. They rarely fail, so there is only more chance of something going wrong trying to delete it out.

 

No.

 

Are you SURE it was converted to non-sequential? If so they really didn't do a proper job if that pressure tank and the line with the broken check valve is still there.

Or it's just not boosting properly so they gave you a lame excuse?

With that check valve broken the sequential system will not function. Also non-sequential is a dumb way to go, you just give up a TON of low end power.

If you do want to try and fix it and get the car running right I sell aftermarket check valves, you can PM if you would like a set.

Dale

 

It was done in Japan before importing. As far as i can tell it only has 1 actuator, there is a flapper that appears to have a bolt in it with tac welds, several hose are already capped off.

 

Looks like a pretty janky NS conversion.

May be worth getting a new Y-pipe and getting it working sequential again.

Come up to Deals' Gap Rotary Rally end of the month and drive my car, you can see what a good sequential system feels like. Power EVERYWHERE!

Dale

 

So I have purchased a banzai delete kit and I'm trying to remove anything that isn't necessary. Since this has been converted to non sequential and the rats nest has already been simplified. Is the black box necessary or can it be deleted as well?

 

OK, what if I told you there was a mod you can do to your car that would give you 50 hp between 2000 and 4500 RPM. And it didn't cost much!

THERE IS. It's called "make the sequential system work again".

You should only need a handful of parts and some troubleshooting to get the system working right. You don't have to accept it as it is.

That said, if you DO want to continue down the non-sequential road, that pressure tank is not needed. There are also a ton of how-to's on it.

It's a leftover from 30 years ago when there were no good single turbo kits and people were trying to find ways to make more power. You can make some more power up top but you sacrifice so much low-end power. A car with working twins is AMAZING to drive.

Dale

 

It blows my mind how many "tuners" and "builders" try to push non sequential. I honestly think it is mainly because they do not want to deal with or do not understand the system. Anybody that has driven a properly running sequential and a non sequential can tell you its a night and day difference. Anybody that has a high school education in physics or even basic logic can also tell you the energy needed to spin one of these tiny turbos (which creates boost at low RPMs) is much less than the energy needed to spin both of them up at the same time. Simple logic should be able to alert you to this as well, so when I see these "tuners" try to argue against thermodynamics and physics and claim their "non sequential" tune gives you the same powerband as a sequential, they are automatically checked off my list of trusted entities.