Hey, not only Maxton, some of the bumps I hit at Bonneville last year could
trip the switch too.
John Beckett, LSR #79
----- Original Message -----
From: "JAMES CANNON" <dr.piston@worldnet.att.net>
To: "Joe Amo" <jkamo@rapidnet.com>; "Jonathan Amo"
<webmaster@amoproductions.com>
Cc: "dahlgren" <dahlgren@uconect.net>; <land-speed@autox.team.net>
Sent: Tuesday, February 08, 2000 3:05 PM
Subject: Re: Cut off
> Might work out west but at maxton the condition of the track could very
> possibly trip the switch.
>
> Jim from Salem VA
> -----Original Message-----
> From: Joe Amo <jkamo@rapidnet.com>
> To: Jonathan Amo <webmaster@amoproductions.com>
> Cc: dahlgren <dahlgren@uconect.net>; land-speed@autox.team.net
> <land-speed@autox.team.net>
> Date: Tuesday, February 08, 2000 2:39 PM
> Subject: Re: Cut off
>
>
> >Dave, Jon and others, how about having the inertia switch isolated from
> the circuit until
> >it is armed after push off and "car is under its own power moving on down
> course", I know a
> >little more sophistication with the circuit, but have the driver arm the
> circuit after the
> >push off. Joe :) :)
> >
> >Jonathan Amo wrote:
> >
> >> Dave,
> >>
> >> You may be correct on the G factor rating, but isnt this what all the
> chating is about,
> >> if in fact of a wreck everybody wants a postive way to kill power to
the
> fuel pumps.
> >> These fuel injection inertia switches can be mounted anywhere on the
> vehicle, can be a
> >> safe way to kill power to fuel pumps. And Like you say these are
> triggered by a small
> >> amount of G rating. And the driver in case of a wreck can point his
> attention more to
> >> bracing for impact or keeping his hands where he needs then instead of
> trying to pull a
> >> cutoff switch, lets the inertia switches do the work. Being in several
> wrecks myself, my
> >> mind isnt there going thru a checklist, im more curious on whats
> happening, but those
> >> that have been in a wreck, it goes by to damn fast to react sometimes
> anyway. So in my
> >> mind those inertia switches are a postive unit on any car. Just my
> thoughts though, and
> >> who am i anyway to question???
> >>
> >> Jonathan Amo
> >>
> >> dahlgren wrote:
> >>
> >> > You hit the reason why in your question.. "Sensitive little
switches.."
> >> > These respond to some fairly low G ratings..If i bump a car in the
> >> > parking lot youare liable to set some of them off. So if when pushing
> >> > someone off I bummp you a bit it may trip. And to my knowledge these
> are
> >> > not adjustable to suit racing needs. if my memory is correct I had
> heard
> >> > that a 5 or 10 mph hit is like 5 g's...The info i remember is from
the
> >> > old State Police crash simulator stuff of years gone by that was used
> to
> >> > remind people why they need to wear a seat belt.
> >> > Dave Dahlgren
> >> >
> >> > Jonathan Amo wrote:
> >> > >
> >> > > Just out a curiosity why cant or dont people use the fuel inertia
> cutoff switch for
> >> > > the fuel pumps as all fuel injection cars have, in event of a wreck
> these sensitive
> >> > > little switches will automatically trip and cutoff power to fuel
> pumps?
> >> > >
> >> > > Jonathan Amo
> >> > >
> >> > > Joe Amo wrote:
> >> > >
> >> > > > Dave, thank you very much for the tech info. It is very much
> appreciated to
> >> > > > hear such details, I am sure at times many refrain from
expounding
> about a
> >> > > > particular matter, but many of us truly soak up the discussions
> from the variety
> >> > > > of sources on this list
> >> > > > Thanks again, we are all the wiser (and safer) for it
> Joe :)
> >> > > > :) :)
> >> > > >
> >> > > > dahlgren wrote:
> >> > > >
> >> > > > > With an EFI System if it is installed correctly and the
> controller is
> >> > > > > worth anything at all should control the fuel pump. The normal
> mode of
> >> > > > > operation is as follows..
> >> > > > >
> >> > > > > switch on:
> >> > > > > power up injector relay
> >> > > > > power pump relay for 8 to 10 seconds to prime the fuel lines
> >> > > > > shut off pump relay
> >> > > > >
> >> > > > > start position:
> >> > > > > crank engine
> >> > > > > if RPM is greater than 100 power up pump relay
> >> > > > > engine starts
> >> > > > >
> >> > > > > run position:
> >> > > > > keep injector relay powered up
> >> > > > > check for RPM if less than 100 shut off pump relay
> >> > > > > else power pump relay
> >> > > > >
> >> > > > > switch off:
> >> > > > > shut off injector relay
> >> > > > > when RPM drops below 100 shut off pump relay
> >> > > > >
> >> > > > > Do this over and over until you are tired of racing today, ran
> out of
> >> > > > > fuel, or blew the engine up....
> >> > > > > A very quick check to see if this is installed correctly is to
> turn the
> >> > > > > switch to the on position..If the fuel pump runs for the 5 or
10
> seconds
> >> > > > > and then stops it is installed correctly..If your EFI does not
do
> this
> >> > > > > there is one of a few problems.
> >> > > > > #1 you installed or wired it incorrectly bypassing all the
safety
> >> > > > > methods built in to it.
> >> > > > > #2 You intentionally thought you knew more than the engineers
> that
> >> > > > > designed the system and put in a manual switch.
> >> > > > > #3 the system is so unsophisticated that it ought to be pulled
> from the
> >> > > > > market as it is a safety hazard..
> >> > > > > This method works for every production car that i am aware of
> that has
> >> > > > > not been tampered with. The reason they(the auto companies) do
it
> this
> >> > > > > way is to avoid the exact problem we are discussing. Fuel pump
> running
> >> > > > > in a crash or with the engine off. They do also use an inertia
> switch to
> >> > > > > shut off everything in the event of a crash but this is NOT
> suitable for
> >> > > > > a racing car..
> >> > > > > The simplest way for the tech guys to check for a correct
> installation
> >> > > > > is to have the driver have only one switch to make the car run.
> Have the
> >> > > > > driver power it up and listen for the electric pump. It should
> run for
> >> > > > > the 5 to 10 seconds then stop. If it does not do this send them
> to the
> >> > > > > end of the line and have them fix it correctly. The
installation
> will be
> >> > > > > safe when it passes this test..
> >> > > > >
> >> > > > > Dave Dahlgren
> >> > > > > Engine Management Systems..
> >> > > > >
> >> > > > > BTW I am not reading from a user's manual on this.. I have
> installed
> >> > > > > tuned and designed EFI for the last 15 years...and write
computer
> code
> >> > > > > that is inside EFI units that are for sale today....
> >> > > > >
> >> > > > > John Beckett wrote:
> >> > > > > >
> >> > > > > > Chris
> >> > > > > >
> >> > > > > > With EFI you really need a separate fuel pump shut off
> switch. The Cut
> >> > > > > > Off Switch we have been discussing on the list, in my
opinion,
> should
> >> > > > > > disconnect everything electrical on the vehicle. But its not
a
> replacement
> >> > > > > > for an individual fuel pump switch.
> >> > > > > > The worst thing you can do is put in some sort of barrel
> valve to stop
> >> > > > > > fuel flow only. The problems created...increased line
pressure
> and current
> >> > > > > > draw...will make things much worse.
> >> > > > > >
> >> > > > > > John Beckett, LSR #79
> >> > > > > >
> >> > > > > > ----- Original Message -----
> >> > > > > > From: "Chris R Harris" <yesford@clear.net.nz>
> >> > > > > > To: "land-speed" <land-speed@autox.team.net>
> >> > > > > > Sent: Tuesday, February 08, 2000 1:17 AM
> >> > > > > > Subject: Re: Cut off
> >> > > > > >
> >> > > > > > > List and especially Dan Warner,
> >> > > > > > > I already
have
> a battery
> >> > > > > > > isolating switch on the dash of my roadster in easy reach
of
> the driver
> >> > > > > > and
> >> > > > > > > will install a second in series in a location like the back
> of the car
> >> > > > > > like
> >> > > > > > > the consensus suggest. My additional question is, with EFI,
> will the dash
> >> > > > > > > mounted battery isolater switch fill the requirement for a
> fuel shut-off.
> >> > > > > > > The dash switch will shut-off all current to the electric
> pump, EFI
> >> > > > > > > electronic control unit and ignition, or do I still require
a
> positive
> >> > > > > > > mechanical barrel valve style fuel shut-off.
> >> > > > > > > Chris Harris C/GR #397 New Zealand.
> >
> >
> >
>
>
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