While I am certainly guilty of the same time dedication to my V8, I have
been asked many times. Why do you want to keep doing this to an MG? In my
case, my next car will probably end up being a ground up creation of my own.
You just reach a point where the time you need to do what you want to do to
an MG, would equal that for you to start from scratch.
I'm sure that the time you would need to get your supercharged B to the next
level would be less than that of putting a 200hp FI engine in place of it,
so I understand your position. Undoubtedly the change of engine would
change or end your racing ability, so you do have to either draw the line
somewhere, or you have to win the lottery. Unfortunately, even all of us
combined could not equal the time, money, and expertise that an OEM can put
into developing anything.
I can't help you with the other sensors, but again, you are creeping ever
closer to a FI system. Probably the most effective solution is to build up
a FI computer, add on a boost sensing fuel pressure regulator, and move from
there.
Car Craft did an article a few months ago detailing the features of all of
the aftermarket FI systems, including one DIY kit that they really liked. I
can't lay my hands on the article at the moment but I'll keep looking. Once
you built the kit you download the best profile off of their website as a
baseline and then you could adjust fuel based on throttle position, load,
etc, on a set of 3d graphs via laptop. It was a standalone fuel only
system, but I don't think it was the one being mentioned here on the list.
James Nazarian
71 MGBGT V8
71 MGB Tourer
-----Original Message-----
From: owner-mgs@autox.team.net [mailto:owner-mgs@autox.team.net] On Behalf
Of Larry Colen
Sent: Friday, April 30, 2004 7:35 PM
To: 'mgs'
Subject: Re: Fuel injection
On Fri, Apr 30, 2004 at 06:21:42PM -0400, James Nazarian wrote:
> Larry, what about a linear encoder, or rotary encoder with bellcrank? I
> would think that you could get one on the piston and a rotary encoder on
the
> throttle and log the two in reference to each other. I can't imagine it
> would be that hard. Being a computer nerd, you could probably even whip
up
> an RS232 app that could log it all to a laptop.
There is something odd about this SU such that if the cap is missing,
the car won't run. So, I went through all sorts of gyrations to make a
widget that would measure piston height and not bind:
http://red4est.red4est.com/jasaside/carbpist/
Then there is the issue that multi channel dataloggers are not
cheap. My dmm has rs-232 out (and it was only like $70 at Radio Shack)
but that is only one channel, without being able to compare it against
anything else, it wasn't too useful.
What I finally ended up deciding is that by the time I managed to work
out all the instrumentation I'd need to properly dial in the carb
needle, I'd have about everything I needed to control a fuel injection
system.
As long as what I've got works "well enough", I'd actually be kind of
silly to invest the R&D into getting it to the next level (whether it
be better tuning of the carb or FI) except as a learning project.
If I can find a few other people intrested in investing several times
the value of the car into developing 150-180 hp MGBs, the R&D costs
become more managable.
A couple other sensors I'm curious about:
NOx for on the car, to detect detonation. But I suspect EGT would do
nearly the same.
Mass Airflow for in the exhaust, I'm curious as to how that relates to
power, as well as MAF into the motor.
I'm sure I could have lots of fun if I had access to GM's engine
development lab.
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