DET, FMIC, radiator, and emissions ?s

PCT Hiker pcthiker@yahoo.com
Thu, 31 Jan 2002 18:19:15 -0600


Background: I have a 91 SE-R into which I've dropped a U12 Bluebird DET
engine.  I retained the US DE intake manifold when I did this, and put a
plate over the EGR tube inlet.  I just capped off all the vacuum lines for
the EGR/BPT/PAIR stuff.  Got the JWT program for my ECU.  FWIW, I've been
running it with topmount IC (no hood scoop) and 92- (now 91-)octane pump
gas in Calif. for 2 years with no difficulty or overheating (it does run a
bit warm on 95-degree summer days under load, and I don't push the car
under such conditions).  Plugs and piston crowns look fine; compression is
at spec.  I did not intend to do this when I did my swap--I imagined it
would be risky and dumb to run it that way, and it probably was.  Still,
the engine has weathered it just fine.

Q1
I'm now in the long-delayed second phase of the project where I'm adding a
front-mount IC (from the F-max kit) to replace the stock
top-mount.  Because it will be mounted partially in front of the stock DE
radiator, I worry about it occluding the air stream and contributing to
overheating.  Of course, I should be gaining some significant intake charge
cooling with the better IC, so perhaps these factors will offset
somewhat.  I'm at stock boost (7psi) and can only raise it a trivial amount
(say, to 10) before the T25 starts flailing.  Still I'm wondering if I
shouldn't go for a NISMO H/D radiator.  For those of you who have this
nismo part: does it take up more space? (already pretty tight in there with
the T25 and the stock fans...)

Q2
I'm also going to be re-enabling the US emissions stuff, and would like to
know how other DET-swappers here have done this.  My current plan is to
elongate the old EGR pipe and run it essentially vertically from the intake
to a threaded bung welded into the B-pipe ahead of the cat (i.e., after the
turbo).  I guess this will have to be heat-shielded so as not to melt all
the plastic and rubber stuff nearby.  I'm also thinking about routing the
AIV in a similar manner--perhaps via the same down-tube as the EGR unless
there's a good reason not to(?)  Any suggstions on the advisability of this
plan, tips on good routing, or where to physically mount the @#$# AIV valve
ass'y would be welcomed...

thanks,
pcthiker