Date:         Mon, 6 May 1996 22:16:46 -0500 
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         vwbus@TCPBBS.COM
Subject:      Type 4 FI performance questions.

Now comes the time in my feeble mind when as I'm about to
rebuild the '78 that I need to ask the always asked question.
Why cant I get more out of a T4 and keep the FI.  AVP and
Stephens simply say you can't and won't say why.  Articles
commonly say, the FI can not tolerate a more aggresive cam
blah, blah.  Why not?  What I'd like is a minor performance
upgrade, was thinking something like rebuilding the stock
1970 with 96mm P/C to get 2055 or so.  Now thats under 5%
increase in displacement not too much to ask the FI to handle.
But will I get no gain?  can the stock cam simply not move
enough air or will the FI not provide enough gas?  What limits
these guys?  Could you raise the fuel pressure in the ring main to flow
more fuel say in conjuntion with the torsion spring in the air flow
meter
adjusted for more resistance.  I do not want carbs or aftermarket FI.  I
simply seek to get the most out of what I might be able to and keep
stuff
looking and running right and hopefully allow myself to get up
some of the grades without falling to 3rd and 50mph.  Ive ordered
the Bosch FI bible to give some insight I hope, but I truly fear
the cam issue limits the matter and I seek some clarification.  Bumping
the compression may of course also help if I swore to run premium or
improved the ignition, but these things are known to knock anyway so
likely not a good idea.  One more odd question to tag along, on the '79
core I recently picked up from Steve Dolan the No 1 intake had pounded
its seat well into the head, the standard T4 failure mode right, now I
understand why No 1, reduced cooling and all being behind but why the
intake seat, seems sort of weird to me.  Did a heck of a job too,
pounded
in easily a tenth of an inch and dropped right out of the head after
removal
of the valve. Anyway somebody out there is running a kickin 3.1 T4 with
105mm jugs in a Bus, enlighten me, what can I do?

John
vwbus@tcpbbs.com