Cams/EFI

[Bruce Plecan]

-----Original Message-----
From: Jason_Leone at amat.com <Jason_Leone at amat.com>
To: diy_efi at esl2.eng.ohio-state.edu <diy_efi at esl2.eng.ohio-state.edu>
Date: Wednesday, March 24, 1999 1:41 PM
Subject: Cams/EFI

747s you can go open loop at idle if ya want.
Change MAP filtering rates.

I gotz 110dCL, 270 by 224 at .050, and .470" lift with stock filtering.


>My $.02 on the cam thing, for forced-induction:
>1) Large lobe center angle (114+)
>2) Longer EXHAUST duration (of have larger exhaust valves!)

Been there done that, ran better with stock exhuast sized valves.
Granted diesel, but 60PSI boost..

>3) High lift is fine
>My software for the Electromotive TEC II has a "blend" feature that is
meant to
>smooth out the idle in radical cam equipped engines. As we all know, Speed
>Density isn't the greatest EFI method for radical cam IDLE.

Oh...
Bruce

So, the "PAF Blend"
>software can use a percentage of the TPS signal and a percentage of the MAP
>signal to "blend" in a smooth idle. Do other equal price range aftermarket
>systems have this feature? I have 268 cams in my car (~224 duration @ .050"
>check), so they're a little bit on the "hot" side of things (for a street
VW).
>Exhaust duration is slightly more than intake, and lift is ~11.5mm or so
>(~.452"). When tuned right, they scream from 4.5k-7.2k rpm...and the
Schrick
>variable geometry intake manifold makes up for the low end torque (between
3k-4k
>rpm).
>Does this "blend" feature work? Idle hunts a bit, but I think it has to do
w/
>the lack of an IAC valve. Have to bump idle up to about 900 rpm (up from
650
>rpm), and tweak a lot of little variables in the software.  I think it
would
>work great in a big V8 NA engine w/ a radical overlap cam. Food for
>thought...for you V8 guys. I'm sure you guys have been there, done that
>though...
>Jason
>'93 SLC