ok, so as i'm usually doing on this forum, i'm reading like crazy and i've come to a little snag.

My goal is 350wph and I'll be running the BNR stage 3 turbos in sequential. I was just doing my vacuum hoses the other day and noticed that the stock system has the restrictor pills down in the wastegate control and turbo precontrol lines.

Through my reading, I've read that more restriction means more boost. Ok, since my goal is 350whp, I'm obviously going to need to restrict these lines more than the stock restrictor pills can since I'm going to need to run more boost for my goal, right?

I still have the wastegate and turbo pre-control solenoids. I don't really want to tear everything apart again to remove those two solenoids and then get either a boost control kit or some manual boost controllers. I wanted to use my PFC to control the boost.

So, my question is, with the stock restrictor pills installed, do they limit my boost to only 10psi?

Furthermore, how does the PFC allow you to turn up/down the boost with those installed?

Thanks guys.

 

Am i correct in thinking that the restrictor pills are percentage based?

Meaning that if you want to run 10psi and apply 10psi to one side of the pill, you'll get a restriction of 50%, so you'll see 5psi on the other side to maintain that boost. (hypathetically for my point of course, idk how much the restrictor pills actually apply.)

So, if I want to run 15psi, I'll see 7.5psi after restriction?

 

in for info, interested in running a similar setup in the future.

 

I didn't want to reply to your first post cause I wasn't entirely sure and didn't want to lead you in the wrong direction but I can say that this assumption here is entirely wrong.

I'm pretty sure you're right with saying more restriction = more boost but it definitely doesn't work in percentages like that. One thing I remember reading was sort of a concluding statement after a quick write up on the boost pills and it was something along the lines of "...and that is how the FD is able to make 10 pounds of boost on an 8 pound wastegate spring!"

What I gather from just thy closing remark is that the restrictor pills are along the same lines of an unadjustable manual boost controller designed for the car in factory state. If you want more you will either need to install an MBC or EBC. The pfc does act as an EBC but you need a solenoid wired and plumbed in. I don't think many people actually use this function though

 

You're right, i rarely hear anyone running the PFC boost control kit. So i assume they are running some other type of boost controller.

Just figured out i need to buy another part......

I'll probably just go with the PFC control kit since don't want a mess of electronics throughout my car. The PFC kit seems pretty simple.

 

I would PM argx, as I think he is using the PFC kit and is very knowledgeable about these things
https://www.rx7club.com/3rd-generati...-chart-952767/

AFAIK, you will not need the restrictor pills.
In stock form, the solenoids don't do much. The restrictor pills are the boost control.
With the PFC kit the added solenoid will actually control boost by modulating the pressure seen at the stock-solenoids/wastegate, which will make the pills obsolete/redundant.
But, keep checking. I've always run an external boost controller

 

By that link, it suggests that the PFC alone can control the boost on the stock FD, without the external boost control kit; utilizing the WG/PC solenoids.....

So, if that's the case then i'd prefer that, allow the PFC to control my boost.

But, what about the pills?

It seems the PFC boost kit is only used for single turbo applications. As the WG/PC solenoids would be removed.

I guess this is more of a thing to figure out when i get my car tuned.

 

I use the boost setting on my power fc to tune the boost, with no exteral boost controller. it works great for me.

 

^did you keep the restrictor pills in?

 

My suggestion is to ditch the turbo control and pre-control solenoids. Even with the PFC kit they do not react quick enough. Two nice manual boost controllers routed the way Damian recommended nearly 11 years ago, https://www.rx7club.com/3rd-gen-arch...attern-178136/, is still the best system for sequential twins.

The response, transition and control are pretty unmatched with the Hallman PRO RX. $170.00 will get you two Hallman MBCs and will work way better than what you are considering. Ive tried both and the manual setups work excellent when dialed in. No spike/creep etc. When you start running higher boost sequential the factory solenoids are too slow to respond.

 

Also had good success with the hallman controller. No electronics required!
If you skip the remote location package you can save some $$$ and not have to route anything in the cockpit. On the downside, you have to pop your hood to alter the boost, and those things can get hot!

 

I use a PRofec B Spec II to control my boost, works great with seq twins with ported wg on 15psi.

I do have 2 Hallman Pro RX MBCs for sale if you ever consider going that route.

 

I read through that thread, many a times. I'm not sure if I regret not getting rid of the WG/PC solenoids yet since I haven't personally felt the lag times associated with running higher boost on the stock solenoids. However, I am trying to keep the car as stock as possible. Next rebuild I guess, lol.

However, my question hasn't been answered yet.

Do I still need the restrictor pills?

I have a base map on the PFC right now but are the restrictor pills necessary to maintain 10psi until I get a tune?

Without them will I be restricted to 7psi?

I'd rather wait until I get a tune than waste money on getting the restrictor pills only to get rid of them when I want to run higher boost for my power goal.

I'm no tuner but from what I understand the PFC can control boost through the WG/PC solenoids by duty cycle. Hence why I need a tuner, but idk if the pills need to be installed either way.

 

Doesn't this depend on your exhaust setup too? I know this is irrelevant but I'm using the stock 99 RZ turbo with no pills but I'm running a full exhaust and my boost is around 13-14psi. I didn't port the stock wastegate so I'm getting the 13-14psi because of this. What are you boosting at right now?

 

My exhaust setup is DP, resonated midpipe, catback.

I'm not boosting anything. I haven't gotten the car back on the road yet. I was just doing the vacuum job the other day. Since i'll be getting it tuned soon, i'll need to know this stuff.

 

Ah I see. I think the best bet will just be to install a boost controller of some type and go from there.

 

The wastegate pill has a small hole in it. With your setup, it will restrict flow too much, making your boost too high. I suggest that you run without a wastegate pill to start with. I would use a stock pill in the prespool line.

Those two "adjustments" should put you in the ballpark to have your PFC boost controller work properly.

Your resonated midpipe may cause boost creep. Be cautious until you get the system dialed in.

 

Im using the PFC to control the stock boost control solenoids, with the upgraded control rack for the turbos other stuff. Works fine. Not 100% stable like im used to, wiggles back/forth between 14-15psi but doesnt spike and doesnt creep through 4th gear.

Downpipe/resonated mid/ganador catback.

Jason

 

ok, i'll run without the pills to start with to see what baseline I have to work with then go from there.

 

I think you made a typo, and actually meant wastegate and pre-control solenoids.

 

I have BNR stage 3's , i also ran the PFC with the boost controller add-on. The pills were removed when i installed teh PFC boost control solenoid. It also comes with an upgraded MAP sensor. The PFC can control boost without the kit but its limited by the stock map sensor, it also doesn't do a great job of controlling boost. the add on kit helps and allows for more adjustment. I don't have too much experience with it as i ditched the entire setup for an Adaptronics ECU using a mac boost solenoid and boost by gear.

 

^I have a GM 3 bar map sensor.

 

I've seen the PFC boost control work OK on one setup, and then be completely junk on another. I don't necessarily think that its the PFCs fault, but more the stock solenoids that are old and tweaked in conjunction with using a stupid pill to increase boost. My suggestion would be to go for an EBC. There are many that can be discrete and not a 'mess of electronics' on your ride.

-David Guy
MEP

 

just get rid of the pill and run a manual boost controller, that way you dont need to worry about what actual size pill you need.
Just turn the **** until its what you want.

 

Since you already have the GM 3 bar MAP sensor, Here's what I would recommend since you want to stay sequential.

1) Remove pills

2) Replace the factory 2 port precontrol and wastegate solenoids with 3 port solenoids. You can use the Denso/Apex'i ones but they are expensive, so buy two boost control solenoids from MAC, rebadged as AEM or other brands. The plumbing is the same as the Denso/Apex'i solenoids. You can buy plug and play connectors from ballengar motorsports Home » Shop » Connectors / Harnesses » Tyco / AMP » 2 - Way Receptacle Connector Pigtail

3) Tune the boost control with the PFC. You can use the Commander to switch between low and high boost mode, and you get individual control over the precontrol and wastegate.

For the purposes of this discussion, no other solution gives you individual control over precontrol and wastegate. When the PFC drives the precontrol and wastegate, it coordinates it with the turbo transition rpm setpoint. So you know exactly how the wastegate solenoid is behaving, how the precontrol solenoid is behaving, and when your turbo transition switchpoint is occurring. You can see it in your Datalogit datalogs. There's no mystery.

See this thread/post for starters

https://www.rx7club.com/3rd-generati...1/#post9637452

Basically, search for threads I have created in the 3rd gen and single turbo section. You'll find a bunch of stuff about this.

Now, is this the easiest approach? Compared to a couple MBCs, well you can't get easier than turning a couple ***** man. That's why people still love carburetors isn't it? But if you are willing to cultivate the skill of analyzing data and understanding what your ECU is doing you will have much greater control.