Someone had posted a question about towing with a Subaru wagon (something I am currently interested in) on a mailing list I subscribe to. I have posted the question and response below. Can anyone help me to understand the respondant's answer? I am very confused by how the intake design and the EGR affect engine performance when towing. It sounds like the engine retards timing when under load. I have read the response several times, but I'm just getting more confused. Anyone who can clarify this is my hero. Thanks.
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Re: towing with my 1986 GL wagon
Posted by: "bargd73" *********73@verizon.net bargd73
Wed Oct 3, 2007 1:30 pm (PST)
--- In subaru_18@yahoogrou ps.com, "elfdowney" wrote:
>
> hi all...
> anyone know the SAFE towing capacity for my 1986 GL Wagon(FWD, N/A,
> manuel trans)?
> anything I would need to beef-up to tow a #2000 trailer?
> thanx-in advance
> elf
>
I did find a bolt on hitch for that model.. I was going to use one
for light duty. Not for longer trips because of the restrictions
subaru built in to the ea engine, but if to change a few things...
The n/a intake is insane. Can't keep it cool enough (and that means
it is working the way subaru intended). The more load the engine, the
more the air cool for the engine is hot before it gets there! It is a
built in engine retarder. (No wonder they go twenty years).So that
means when putting too much on the old buggy, when it is needed most,
it retards itself. This is AFTER removing the even crazier EGR
valve.The fuel pump: if it is carbed is too small for longevity in
towing many miles. The spfi has that crazy hot maf, but there is ways
out of that and it has a decent fuel pump. I got an spfi intake cool
enough for the fuel return line to actually be used(that was a good
sign). But again, the engine retarded itself with the crazy intake
design, until I did my tricks to a lightweight hardly strained 2wd.
That was a fun car and made the ea82 very nice and quietly powerful
enough- just couldn't do heavy things with it.
There is mpfi heads for n/a, but there is something not strong with
the head itself. even Subaru replaces the casting entirely and does
not rebuild them I am assuming for this weak flawed reason, es
pecially with turbos.
BUT... and this is what I have always wanted to do, not just for
towing, but 10% grades for *miles* and loving it..
mpfi on a 9.0:1 simply in a wagon body. The XT was always fun and
no complaints with power with this setup by OEM, except for the ECU
and its functions being stupid ALot. So... return the mpfi heads to
carb cams, side draft a hacked carb on a spider intake, or a carb on
the mpfi double runner (weber) and go with it for all its worth. Or
find a way to hack the single runner intakes to get that godforsaken
insanely hot fluid out of the darn fuel/air path. Thinking of extra
cooling will not work. It will throw off a thermostat to the pint of
no open, and there you have it, the retarder of heat at you again (I
would not know how to balance that out after say a bigger radiator) I
am sure a 180 degree from an ea81 with a clean rad would helpo, but
you will encounter the infamous restriction- it seems to be
hopelessly built in, unless you want to hack with ingenuity.
I have thoroughly thought about this, and that is the answers. It is
a fantastically genioused econo engine, to heavy duty it would
require hacking. Intake seems to be the very very obvious problem.
Raising lift on cams is simple without changing them etc etc. That
darn intake has baffled me forever(pun intended).