Re: MAP signal damping/more cam help

["Jeff M" <tystorm@email.msn.com>]

> I've never heard from anyone who had any luck with the Turbo City devise,
> and I won't be buying anything there, again.  Only good thing about Turbo
> City, was that they got me mad enough to figure out EFI (non oem) for
> myself.

Come on Bruce, we're all family here, tell us what you really think, we can
take it ;-)
Sorry to hear you had such luck with them, will consider this in the
future.

>      I've had some rich running motors, and I'd find it hard to ruin a set
> of rings in a 20 min cam break-in with a poor calibration.   Not saying it
> couldn't happen, but there would be signs of problems.  If you want to
> have a break in MAP signal, just use a Pot and a couple series resistor
> with it. Say a 1K on each side of a 10K pot.   Or disconnect say the CTS,
> and set the mixture with FP.
>     I haven't done the above, mixture wise, since I haven't had one that
> bad.
> Grumpy

I recall old mechanics that used to reply to how a new or rebuilt motor
should be broke in and they would say "Ahh, just drive it like you plan to
and it will break in just fine".  But I believe that even a properly fueled
engine would benefit from having a respectable break-in period exercised
that allows the rings to break-in properly and as fast as safely possible as
the best choice.  I know that a few here on this list have said that GM
programming is at times a bit lame (I can also attest to that ;-) and we
enjoy making it better, same for after one of us spends 2 to 5 grand for a
good performance rebuild (or more), that we want what is best for our engine
and respect following a sensible break-in approach.  There can be no
arguing that new rings generate a bit of friction at first start up and
until they finally seat into the cylinder walls, and as we want them to
wear in properly (why to use mineral oil at first then synthetic later)
prefer not to wash the cylinder walls with a solvent (gas) right off the
bat ;-).

I like your idea on the resisted map signal, now that I think about it, may
be a better choice than the adjustable map as their device might be more of
a buffered sensor than one that allows a vacuum adjustment to handle loppier
cams?  Like I said, I had not called them to qualify the function of this
sensor but had a suspicion its purpose and possible applications.  I would
still consider those in need with loppy cams still call and check out the
function and approach behind this map as if it is a buffer setup to smooth
out a common fueling problem, it may lead someone here to make it better and
offer their findings to the list.

Jeff M


> > Kinsler does have a tremendous selection of unique and far reaching
items
> > (many sources and unique suppliers including many custom).  I recommend
> them
> > highly as well, there catalog is big and as I recall, they have an info
> > packet too (more reading).  Also, TurboCity has a unique item that may
be
> > what is needed here for you long legged cam users.  They have an
> adjustable
> > MAP sensor (1 BAR for sure, 2 BAR maybe, I want to call soon on this 2
> BAR)
> > that is used to compensate for longer duration camshafts in EFI systems.
> > The other bigger use I see for this item is, once you decide to make big
> > changes to an engine including some or all such as a bigger CAM/Lifters,
> > head work, bigger turbo, bigger injectors, PISTONS AND RINGS, is that
you
> > know your chip is going to be quite a bit off from optimum fueling and
> > timing (and such) right off the bat till you can drive and tune (a few
> > hours!).  Now, you do not want to start a new engine that runs too rich
at
> > start up and during first break in hours, all that fuel dumping in is
not
> > good for new rings.  Real rich mixture will thin out the oil supply
> > viscosity and such and can cause cam break-ins period to be broke or
> ruined
> > cams!  So, take this little device and toss in lots of simulated vacuum
to
> > keep things on the lean side, then right after things start up, if the
> > engine stalls, raise the vacuum reading from the adjustable map till she
> > just runs, then give her a little less vacuum (more load/fuel) to keep
it
> > running properly while watching the o2 hoping it lights off soon, and
> while
> > watching your tail pipe for a rich condition, rev up and break in that
new
> > cam.  Then take out that motor and break in the rings properly, then
drain
> > out that oil and give her another good mineral refill.  Then with this
> > adjustable map, have time to get a lot closer to safe fueling and timing
> as
> > we bring back the vacuum reading to what IS going on in the engine, and
> then
> > that which is only needed for that nasty cam.
> >
> >
> > Jeff M
> >
> > > There is a commercial product from Kinsler Injection (248)362-1032
they
> > > list as a Map Damper, pg 24-s of catalog #29. No part number is given
> but
> > shows a small Vac can looking Item.  Have no experience with the damper
> > myself just noticed it one day on the EFI page in kinsler catalog. They
do
> > have lots of unique EFI components and there guys seem to be
> > knowledgeable(not intended to be a plug for kinsler) I've just had good
> luck
> > with them.
> > >
> > > my .02
> > > john
> > > gmman@eskimo.com










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