second restrictor pill r34 gtr exact location?

[syd_gtr]

I believe there is a second brass air flow restrictor pill somewhere, I think it damps the feed of manifold pressure to the stock boost control system. Does anyone know where it is, and if its the same diameter as the famous one that is often removed to get 0.9 bar?

I remember a post saying one is under the intake manifold, I guess in a tube feeding manifold pressure, but someone else posted it is built into the metal pipework..

If one is reverting from an ebc and both pills have long gone, would like to know where it is supposed to be fitted, and if they are interchangeable. 

[GTSBoy]

Is not a replacement pill something one could make with a short bit of brass rod and a ~1mm drill?

[BK]

2nd boost restrictor ? News to me.

[TXSquirrel]

There is a second restrictor, and it limits boost to roughly 22psi.  However you won't find it in any normal engine as it's only added to Nismo S/R engines.  I guess that's how Nismo decided to increase boost without active boost control device.  I don't know much about it, I just happened to see one in a Nismo S1 engine under the intake plenum.

Edit: This S1 engine was in a R32, so it's not limited to just R34.

Edited May 3, 2021 by TXSquirrel

[syd_gtr]

10 hours ago, TXSquirrel said:

There is a second restrictor, and it limits boost to roughly 22psi.  However you won't find it in any normal engine as it's only added to Nismo S/R engines.

thank you! in S15s according to a digram on nistune the two pills supposedly bracket the boost that the solenoid works with, via a ratio of one to ‘tother dia. Would this second one logically be larger or smaller than the normal one? I guess its function is to raise the boost floor the stock system works within.

on an s1/r1 would the normal one (the one commonly removed on stock r34s), have a larger hole than standard?

(am helping a friend get his r1 boost control system back to stock. in the dark with these two restrictors, a bit)

Edited May 3, 2021 by syd_gtr

[TXSquirrel]

When I said I don't know much about the this, I should have said I don't know anything at all instead.

That R32 was just a customer's car at a shop I visited, I thought it was bizarre so I took a picture.  They did confirm first pill was still there before they took the engine apart, but I didn't ask any other detail about it.  I guess you will just have to figure out the diameter through trial and error.

Edit: I doubt you need both pills to control boost at a higher psi.  Nismo may have left that first pill in place for originality and could be redundant. 

Edited May 4, 2021 by TXSquirrel

[syd_gtr]

Interesting. A restrictor would function for pressure reduction if there is airflow, but also a damper of some kind to moderate the function of the solenoid, which has a duty cycle. Guess I'm going to have to try to find out from someone in Japan what's up with all this and/or some trial and error as you say.