[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Svo] How to adjust Throttle Body {1}

On Fri, 10 Oct 1997, Mike Fleming wrote:

> Good question. From a design point, if you're gonna not use the KS then
> you MUST stay away from the detonation side. If you do run a KS, again
> from a design point, then you can "bounce off" the detonation limit and
> stay right on the hairy edge - without breaking anything.

How do you figure?  its not like the EEC will only take out the amount of
timing it needs to elimintate detonation, and run the car rite on that
mark.  if It were that way, the timing spec would say "Slap the
distributor until timing is between 10, and oh, lets say 50 degrees
BTDC....doesn't matter if spout is in or out".
Granted, if you dont hook up the knock sensor 100% of the time, its not a
good idea to have the motor knocking all the time..Noone said it was.
But, from a design and REAL WORLD standpoint, the KS will not let the car
run rite on the edge of detonating.  it is not like a O2 sensor that
samples the situstion, and optimises it. If you think thats how the KS
works you apparantly know very little about the EEC.  

Excerpt from "KS operation for D*****s"

When the motor is running and senses a knock, the engine pulls out a
fixed amount of timing.  it will slowly bring some of it back, but will
not restore all of it until the engine returns to idle or cruise or
something...But in no  way will it jump rite up to the detonaiton limit.

 There is still
> some power to be made with a detonating engine - look at anything
> running a nitrogen-based fuel like NOS or nitromethane - both serious
> octane degreders. But how long do they last? [Answer to rhetorical
> question:] Some do, some don't.

Rheotorical question: What is a fuel? what is an oxidizer? What is
nitrogen based?
Anser:N2O is not a fuel, for one.  And it is not nitrogen based.  Do you
know what the nitorgen in nitorus is used for? it has nothing to do with
power.   it cools the reaction.  thats it.  n20 is not based on nitrogen,
its based on oxygen.  And the reason they dont last is becuase of improper
tuning, and most of the time people running it too lean.  Running a NOS
motor to a lean meltdown is the same as running your factory SVO at 100lbs
of boost...not enuff fuel.  Its jus easier to miscalculate fuel needs with
nitrous, becasue you dont have the same volume of airflow making 400hp as
you would with a striagt turbo makin 400hp. its not as intuitive.

> > For the record, I gained 2 mph and 0.3 sec when I disconnected mine,
> > with no hint of detonation at that boost level.  I AM running the
> > early 85 manifold and computer...
> Again, a litle detonation isn't necessarily bad - but whose yardstick
> are you gonna use to say what a "little" is? 

Boy, its good to know you came around to my way of thinking and we agree
on this...I have been saying all along that a little detonation is not
bad, but you have been saying until now that al detonation is bad...geez.
But heres a newsflash for ya.  The damage prevention capabilties of the KS
are limited.  If the engine s gonna knock hard enuff to cause damage with
the KS d/c'd, the KS is not gonna save it if it was connected.  its not
that fast, its not that much of a help.  the KS is designed for people
that drive around with the car goin "clack clack clack" and their limit of
action is "boy the car makes a hell of a racket when I hit the gas" but
never doo anythign about it.

In some engines if you can
> hear it, you're walking home but the 2.3L EFI Turbo is more like a truck
> engine so it stays together a little longer. 

Again, same as I have been saying...

Don't try this with the
> Porsche 930.

Whos talkin about porsches? Im talkin about SVO's and the 2.3 in general.

> The early manifold design (and associated EEC strategy) allowed for
> engine-generated noises very poorly. THe later stuff is much "smarter".
> On a stock engine you can gain at least 1/2 second in the quarter by
> LEANING the fuel supply at WOT cause it's WAY too rich for max power on
> petrol. Same for all years - the EEC commands a 10:1 air/fuel ratio and
> this is too fat. If you coule find an easy way to lower it to say 13:1
> then you;d gain about 25HP.

Yep, but thats not what we are talking about..unless you want to say that
the reason Ford made the A/F ratio so low is "damage control"....the same
reason they put on the KS....reduce chance of warranty claims by boneheads
who wouldn't listen for a knock.

 Anyway detonation can only occur between 5 and 20
> degrees ATDC so there's no reason to listen during the remaining 700
> degrees of rotation for that cylnder. In a 4-cylinder engine, that comes
> to 680 degrees of "don;t care" rotation. The 84/85 strategies
> (recognized by the early manifold design) weren't selective enough and
> the "hammer" test would retard timing easily.

So what your saying is the 84-85 stuff is more prone to false alerts than
the late stuff, but that still says nothing...You still haven't proved
that the late stuff is NOT prone to falsing, and that is the whole problem
with the KS(How many times have I said that??).  So what the window is not
as wide...if anything impacts the block(noisy valve train example again)
in that window, say bye bye to the timing you set the car at, cuz now its
like 20 degrees back....

> Now, from a testing viewpoint, did you reconnect the KS and notice the
> same documentable decrease in performance? 
Thats like sayin "You went from a air filter that was caked with mud to a
new one, and yeah your times improved.  but did you put the old filter
back on to see if the power went away again?"

Nice smoke screen, btw, but you still never gave an answer as to how
running the KS will not hurt performance whgen running near the edge, and
how the KS can discriminate between a knock and something striking the

I admit I dont know it all.....maybe some others would be so bold to admit
the same thing........

->71 Pinto stonestock 2.3 EFI Turbo T5, 13.67@99 on generic radials
->86 Escort..A/C, tinted windows, Alloy wheels, 5 speed, good shape 
->85 Merkur--Someone get this Escort of mine! I WANNA DRIVE MY MERK:)