Sequential Parts List - Fix The Last Owners Mistake
 

So the last owner of your car went non-sequential on your current car, and that's probably why the last owner doesn't own it any more.
#1 because they couldn't afford to get the suquential system working properly and #2 because the car is now no longer fun to drive.

I'd like to put together a list of solenoids and parts needed to properly set up the sequential system as good as new.
I will be doing this with emissions blocked off and using the simplified sequential setup, I hope everyone else can too.

Is there a list out of there of items needed to do this job? I will likely be working through it in the next weeks.

Thank you.

Hard to make a list, as it all depends on how nuts the previous owner went. You're just going to have to dig in there and see what was removed.

The doors could simply be wired in place with actuators removed, or they can be cut out, welded shut, etc. Also, connectors on the harness could be totally cut off or still there.

I would probably start with a turbo pull project, look around the turbo and see what you need. Might need a new manifold with a turbo control door, and you'll have to see what was done with the precontrol actuator on the turbos. Same goes for the Y-pipe, the back half with the butterfly valve.

Then, start in on the rat's nest.

Dale

Dale in my case the twins were just pulled off rather than being converted to non-seq.
So I need to focus only on the rats nest area, is it as simple as adding back a couple solenoids and vaccum lines in my situation?

I was just trying to get a worst case scenario write up for others to follow. This seems to be a common concern on the forum lately, I've seen many people state they wished to return to sequential but that it seemed like something they couldn't handle.

3 rats nest solenoids
turbo control solenoid
2 check valves
vac tank
pressure tank
turbo control actuator
turbo precontrol actuator
charge control valve
charge relief valve

Then like Dale said, it depends on what was done to the manifold and secondary turbine housing.

Great, Thanks a lot guys! Someone should make an aftermarket return to sequential kit with all of that stuff together.

Sequential Parts List - Fix The Last Owners Mistake
 

Cosigned. This is my long term goal. Prob won't do it this winter but I'd really like to. My car is pretty good at full tilt but laaaaaaags on the street even with a "full" sequential and most of the common spool-helping mods in place.

Sequential Parts List - Fix The Last Owners Mistake
 

So my car, for example, has the actuators on the manifold and secondary turbo actually removed and the holes welded closed. As I understand it this is what's referred to as "full" nonseq.

So I'd basically need a whole new turbo/manifold setup, right? At least new manifold and secondary turbo? If so, what's the most economical $/value option there?

I'm assuming the Y pipe part can be sourced used fairly easily. They're often included with stock y pipes sold pretty cheap. Good time to mate that to a kouki ("efini") y pipe if not already there.

You can buy a set of stock twins for like $300 (+shipping?)

You should be able to get good prices. Everyone's going single so they are unloading twin hardware. I've got a stock Y you can have gratis if you want to pick up or cost of shipping. Might even think about letting go my spare turbos.

Sequential Parts List - Fix The Last Owners Mistake
 

So maybe this is wrong but it seems like anecdotally from reading on here that a large percentage of second hand turbos end up being junk or at least very short-lived. Not true?

And the price of BNR/99s new at 2-3k is significantly higher (obviously) than used stock turbos. What's the smart way to go?

I've had good luck with used turbos, but you have to take them apart and inspect the exuhaust turbines for lost apex seal damage before installing. I've heard good things about the 99 spec turbos from posts on here.

As with any used part... it's used and could have been mistreated and has a shorter life expectancy than new.

Shaft play is a false measure of wear unless you have an actual play specification to measure to. They have bronze float bearings so they inherently have some play.

Used turbos can be a crap shoot. But, you can take turbos apart and mix and match parts. The actual cartridge of the turbos aren't touched on the NS conversion, just the cast iron turbine housings/manifold. You can swap the cartridge from your turbos to a good sequential turbine housing.

Or, if you get a set of twins with one bad turbo, you can just swap that out.

PB Blaster and a camera are your friends here. Also, you have to be sure the turbos are clocked correctly so the oil feed/coolant lines fit right. Just take your time with it.

Dale

So almost 6 years later I decided to actually take this on!

I've been gathering parts and will try to document some of the process here in case anyone takes this on in the future. If you're experienced and know these cars, none of this seems like it should be that complicated. But if you're not much of a wrench, then it can be a little daunting. That's certainly why I put it off for so long. I didn't want to screw with a running car. Hopefully this can help someone else take the plunge, or maybe you guys can help me when I get this bolted back together and nothing runs right!

My car has a "full" nonsequential, so the engine and turbo manifolds (and y-pipe too) had been modified to remove or weld open the flapper doors for the stock sequential system. Most people eliminate almost all of the ancillary emissions systems when they do this, but my car still has a functioning air pump and ACV, and a few other things. I'm going to convert back to simplified sequential, which should be a much easier job than bringing back the full vacuum hose array.

Here's what I've got on the list so far. This is specific to my case, and may not be comprehensive for all cars, depending on your individual nonsequential setup or boost control plans for sequential.

• Exhaust manifold ('93 Parts Fiche p. 1-C4)
  • 1x Exhaust manifold (N3A1-13-450A) (plentiful used for cheap and usually fine to use)
  • 1x Exhaust valve actuator (N3A1-13-70Y) (also easily available used)
    • 1x Actuator bracket (N3A1-13-468A)
    • 2x Actuator bracket bolts (N350-13-164) (to attach actuator mounting bracket to manifold)
    • 2x Actuator bracket nuts (9YB10-0601) (to secure actuator studs to bracket)
  • 2x Exhaust manifold gasket (N3A1-13-461) (I'm told these are usually re-usable, so this is probably optional)
  • 5x Studs (NF01-13-708A)
  • 1x Stud (N391-13-456) (these six studs can be re-used but it seems like the safer path is to replace, and I wanted to replace them while I had everything out
• Turbos & turbo manifold (1-E4 to F4)
  • Turbos on manifold (N3A1-13-700) (But you're not buying new ones. You only really need to replace the manifold that's been modified, so you could get a used manifold and put other good turbos on it. I got a set of lightly used 99s with manifold as part of this project.)
  • 4x Studs (NF01-13-708A)
  • 5x Nuts (JE10-40-355) (for exhaust manifold studs)
  • 1x Nut (E5B6-13-461B) (for exhaust manifold stud, not sure why this one is different)
  • 1x (N3A1-13-710) Exhaust manifold to turbo gasket (left) (very expensive and it seems like used OEM are OK to re-use)
  • 1x (N3A2-13-710) Exhaust manifold to turbo gasket (right) (very expensive and it seems like used OEM are OK to re-use)
  • 4x (N3A1-14-293) Oil pipe gasket
  • 1x (N3A2-14-293) Oil pipe gasket
  • 1x (N3A1-13-53X) Water hose
  • 1x (N3A1-13-54X) Water hose
• Downpipe
  • 4x Nuts
  • 1x Downpipe gasket (N3A1-13-491) (supposedly reusable but I had a DP exhaust leak and don't want to mess with this again)
• Y-Pipe and Intake Connections (1-G4 to H4)
  • 4x Gaskets (N3A1-13-712) (for intake pipes and y-pipe connections)
  • 1x Control valve (rear y-pipe section) (N3A1-13-36Y) (To replace piece modified for non-sequential. Don't buy; easily available used.)
• Solenoids and vacuum stuff (1-G5 to N5)
  • 2x Charge Relief and Charge Control (1480-13-240A)
  • 1x Turbo Control (at Solenoid Rack) (N390-18-741)
  • 1x Turbo Control (by the ACV) (N3A1-18-741)
  • 1x Turbo Precontrol (N3A1-20-285) (I'm doing version 1 sequential boost control, using a EBC for main control, so I only need one solenoid of this pair)
  • 1x Vacuum Chamber (N3A2-20-339) (plentiful and cheap used
  • 3.5mm silicone vacuum hose
  • Brass t-fittings

For the record, at today's prices, just the solenoids, gaskets, nuts, studs, and such in the above list come to just over $1k at internet parts supplier prices. That's not with the turbos, manifolds, or anything like that, which I've all sourced new. I'd really like to use entirely new gaskets, because I don't know how old the existing ones are, and I don't want to track down an exhaust leak when I get this all back together. So I'll probably eat the cost and get new everything. But I've hesitated on pulling the trigger so far.

I'll update this as I move through the process.

nice! Thanks for the detailed info!
Gonna follow your progress as i'm in the same boat as you, albeit more green to what to do tuning wise.
I'm not a gearhead by any means but I jumped into my first RX7 last month so now trying to see how to correctly upgrade the twin turbos while getting decent power.

Not to high jack the thread but do you guys have any recommendations? Mechanic is recommending i replace my TT to 99 efini or bathurst TT to pass smog.
Is there an alternate setup I can go where I keep her Twin Turbo'ed with an aftermarket set up AND still pass smog?


Thanks a million!

If you're looking for a part list for the solenoids/fittings/hose of a simplified sequential setup similar to how other forum members have done that uses aftermarket solenoids like Fabco, this is everything you will need.

https://docs.google.com/spreadsheets...it?usp=sharing

Thanks, this is pretty helpful. Also reminds me I'll need some viton check valves.

But what's the benefit of going with aftermarket solenoids? It looks from this like the prices are not much less than OEM, and you have to chase down a vendor that doesn't want to sell to individuals.

Also, does anyone know where you're supposed to use 6mm vac hose instead of 3.5mm? I think everything in my nonsequential setup is on 3.5mm right now.

Newer tech, less plumbing since you can manifold them, and you can mount them remotely so they don't fry above the engine like the stock mounting location. Just an overall cleaner install. Mine are mounted next to the ABS.

Who knows how long NOS parts have been rattling around in parts bins? People have reported a high failure rate for NOS solenoids.

Using other people's used ones, probably isn't a winning gambit.