My turbo is an '86-88. I'm not sure of its designation. The switching valve
is internal, but is not the wastegate. It controls flow to one side of the
twin scroll.
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I'm with you now.  Did you choose this version of the turbo for a reason?  I
was under the impression that the 89-91 was a better choice, which is why I
bought one.  I do know that the wastegate on yours is very small compared to
the later version.  When the RX-7 guys start opening up their exhaust
systems, they run into boost creep, which means they can't keep the boost
down even with the wastegate wide open.  The fix is to port the wastegate as
large as you can without making it larger than the flapper valve that closes
over it.  The RX7club.com site has a few threads on this, along with
pictures if you search for them.

The later version that I have might still have a problem with boost creep,
which is why I keep asking how much boost I will have with the wastegate
fully open.  I've never received a reply, either here, or on the RX-7 forum.
Perhaps no one really knows.


Ps. I recall that you were also interested in using an electric water pump.
I'm currently arranging with Leon to purchase one from Davies Craig. I will
let you know the results if you are still interested.
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I am still interested, though maybe not as much as I once was.  The mount
I'm having made shouldn't have any clearance issues with the stock pump, and
my pump brand new.  I also won't be running excessive RPMs, so I really have
no need for the electric pump.  Also, with my small cowling, I'm starting to
worry about the radiator more and more, and think that I might have to keep
open the possibility of running full time electric fans for proper airflow,
and that will be another large electrical load that I don't need.  No way I
could have an electric pump, AND electric fans, unless I tether the plane
with a really long extension cord :-)

Thanks,
Rusty
Turbo 13B powered RV-3... Be Afraid :-)
1993 RX-7 R1... Stock (for now)