<VV> Re: Turbocharging using EFI

[Chuck Riblett]

Craig Nicol wrote:

<snip>

Hi Bill,
I think the leading guy in Corvair turbo EFI is in Denver; his name is Chuck
Riblett, Blackhawk Engineering.  He has the Turbo EFI setup (including
programming) and it's about half of what Clarks wants for their 140 setup. I
don't have his email, but you can get it from Steve Goodman,
(rearengine.steve at worldnet.att.net)

Also, here's a link to a thread on the topic. (Using "Mega squirt ecm)

http://www.vv.corvair.org/pipermail/virtualvairs/2007-October/067175.html

A couple of points to ponder:
Most of the Holley TBI units that are for sale used or uninstalled are their
first gen units.  These were basically 100% unsuccessful and AFIK, all have
been removed.  This system is characterized by an ecu with three knobs for
low/middle/high or some such.  The system was reliant on a throttle position
sensor that lacked stability and didn't have the required sensitivity. Every
change of weather or temperature required recalibration of the ecu.

<unsnip>

Hello Craig and Bill,

I actually bought a Holley Pro-Jection TBI system for my truck 10 or 15
years ago.  Shortly thereafter I started reading about all of the CPU
failure problems that others were having.  I concluded that installing this
system on a commuter vehicle was not going to get me to work reliably.  I
still have the Holley system in the original box, never used and available
cheap if someone is really brave and wants to try this.  The Holley system
was really designed for a small-block V8 of about 300 HP.  Installing it on
any other engine would be a large stretch.

There are a lot of guys on the MegaSquirt forum who replaced their Holley
controller with a MegaSquirt controller after the Holley controllers failed.

I would also add that this is a huge throttle body for a small engine (670
CFM).  EFI systems do not have accelerator pumps like carburetors.  The
acceleration enrichment comes from adding to the fuel injector open time.  I
think that this would be very difficult to tune, especially on a Corvair
turbo with all of the extra intake manifold volume to fill.  The 4 barrel
carburetors used on turbos by Warren LeVeque have small primary venturis and
large secondaries and would be much easier to tune since just the primaries
would be used off-boost.

Another thing to consider is that the TBI systems are all downdraft.  They
should not be mounted sidedraft since the gasoline will fall down at low air
flow rate due to gravity.  I had this problem with the first design of my
throttle body.  It leaked a lot of fuel at the air filter joint.  This means
that you will need a right angle adapter between the throttle body and the
turbocharger.  Once you put the throttle body on top of the adapter, there
will be very little room for an air filter.  Air filters are especially
necessary with turbochargers to prevent wear or damage to the impeller.

Another source is Ray Sedman who has done a variety of custom EFI systems on
Corvair engines and is very knowledgeable.
http://www.american-pi.com/corvair/corvhome.html

I have finally regained control of my website and hope to have a fuel
injection section on there within a few weeks.

Chuck Riblett
Black Hawk Engineering
www.blackhawkengr.com

'64 Monza 180 turbo with MegaSquirt EFI
'74 Deserter GS with a Corvair 140 engine soon to have MegaSquirt EFI also