<VV> Re: Anyone using Megasquirt on a Crovair ?

[Marty Scarr]

Hi Dan

The relay board is off the the side of the engine compartment, where
it is slightly cooler.  The components on the relay board are minimal,
and not particularly heat sensitive.  There are 3 relays, 4 fuses and
2 capacitors on the board, along with the cable connection and
terminal strips..  GM has put the same relays underhood on their
vehicles for years.  I do have a plastic cover for my relay board, it
is there more for protection against flying fan belts than anything
else.  You can see a picture of the completed relay board here:

http://www.bgsoflex.com/mspower/mspowercomplete.jpg

Regarding the turbo installation, I will be using a 2 barrel throttle
body made by GM as used on the 305/350 V8 engines.  It will have an
adapter to mount the throttle body to the turbo, it will be 90 degrees
as compared to the regular orientation.  That means the injectors will
squirt sideways, but they will work just fine.  This installation is
(again) due to the constraint of the rules in my class; no head
modifications allowed.  If/when I move to Prepared class, I can modify
the heads and use port injection.  I will use water injection for
cooling the charge, also controlled by the Megasquirt (rpm vs boost).

Cost for my turbo installation should be just over $400.  Used TBI
pump (low pressure), $20; good used 2 barrel throttle body, $75;
Megasquirt (MSI) and relay board kits, $210 (I build my own); adapter,
fuel lines, filter, wire, comm cable and other misc, $100.  If you
don't have a PC laptop to run Megatune, you can get one on ebay for
less than $50.  Megatune will run on a 386, 200MHz machine.  Sorry, no
Macs, but MegatUnix is available.

I'd be happy to share my configuration file,  but you will probably
have to tweek it.  I think that tuning is one of the funnest parts of
the project - it's great to get your engine running in the sweet spot!

I'll keep you posted.

Marty Scarr


On 10/29/07, rocklord at suddenlink.net <rocklord at suddenlink.net> wrote:
> Marty,
>
> Read your link on the Megasquirt/TBI conversion, very nice.
>
> One question I have concerns the installation of a a circuit board in the engine compartment.  Aren't you concerned on the durability of the board with the amount of heat in that area, and the possibility of water getting on it?
>
> I am really interested in your future endeavor, installation on a turbo.  I am in the process of rebuilding my '64 turbo engine and am still batting around which carb to run.  A TBI system for around $600-$700 wouldn't be that bad, as long as someone like yourself already had a Megasquirt file worked out that could be shared.  I wouldn't have the patience to sit in front of a laptop and create one.
>
> Dan
>
> >
> > Hi Don
> >
> > Here's a little writeup on my conversion:
> >
> > http://thescarrs.com/corvair/efi.html
> >
> > Was it worth it?  Definitely was worth it for me.  I was after better
> > performance and the ability to fine tune my engine beyond 60's
> > technology - and got it.  I'll be doing a turbo conversion in the
> > future, and with programmable fuel and spark expect it to be lots of
> > fun.
> >
> > Regarding time and money - the spirit of Megasquirt is DIY, and I did
> > it all myself.  It's a very fun project, with lots of support, and I
> > learned a lot along the way.  I kept costs low by using used parts
> > where I could, and have less than $500 in the project.  If you're
> > satisfied with the way GM built your Corvair then it's not for you.
> > If you can't do the work yourself, it's probably not for you.
> >
> > Differences - better starting, better overall operation.  Idle, cruise
> > and acceleration were all improved.  There are no smog checks in my
> > part of Oregon, so I can't report on emissions.
> >
> > regards
> > Marty Scarr
> >
>
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