Hesitation Found: Ecu Crush Mod Really Works

[Motorsport-SVX]

Originally posted by immortal_suby
My wifes 92 did not have them either - see the pic in my locker. But her's did have a chip in the slot where mine was empty. Her svx was manufactured 6/91 and it does not hesitate a bit - looks identical to the ECU you have in your locker.

Which chip are you referring to ? can you circle it and post
a pic?
So far Ive seen ECUs with:

1 ECU w/ tan resistor (some cut, some not yet)
(whats cutting this wire suppose to do?)

1 ECU w/ tan and black resistor (with the black one crushed)
just leaving the tan one intact AND not cut...
(I know this should help with the hesitation)

1 ECU with no resistors and a chip in some ROM location
which shouldnt be touched.

Also, so this message:
"... clear the memory using the select monitor."
Hows this done ?

thanks...DG

[immortal_suby]

Here's the pic with the chip circled
http://www.subaru-svx.net/photos/fil...suby/11479.jpg

[CDG]

Whats the Chip do?
Or whats it for?
looks like an old fashion Eprom, the kind anyone can read and write to?
Is this where the Region Mapping is done?
Mapping of Altitude compensation, fuel Mixture, etc?

[ensteele]

There is a How-To in the locker with pictures.

[CDG]

Thx Earl. But I'm still lost. (As usual)
Can you help me narrow down which How-To I should look at for the ECU Chip details?

[Motorsport-SVX]

Originally posted by CDG
Thx Earl. But I'm still lost. (As usual)
Can you help me narrow down which How-To I should look at for the ECU Chip details?

seriously dude, who knows who cares...
some engineer for Subaru knows what its for and why
its there. Thats not the type of info thats commonly
found out by joe shmoes like us. All I care is that its there for a reason and the cars price tag didnt jump up because of it.

[ensteele]

Gee Chris, you are gonna' miss out! We are having an engineer come and lecture our group at the next meet (Drive and campout). They will take it apart and put it back together for us and let you touch it and everything! jk

I don't think the how to details the chip itself, it only shows it. The name of it is "ECU Mod (Noise Suppressor Bead Crush)" That's all there is.

[CDG]

Thanks Earl,
Give the Guest Engineer my best
Oh, and finish writing that How To on Owning 5 SVX's

[ensteele]

[immortal_suby]

The local subie tech told me the chip would show a noticeable increase in performance on my svx. He said all he needed was my vin to order one for me. I was concerned about it adding a speed limiter or something so I did not do it on mine.
I have, however, swapped ecu's between my car and my wife's car (her's is chipped, mine is noise suppressor crushed with no chip) and saw no difference in either car's performance. I did not test the top speed though.

[Trevor]

Originally posted by CDG
Trevor, I think its actually an inductor or coil(can't remember what they are called, but opposite of a capacitor), and we can't remove it, we just crush it a little, which I would expect reduces its inductive charactoristics therefore changing some logic decision.
Capacitance/inductance.

Anyways, I'll give it a shot, and see where it changes the so called hesitation, maybe everywhere???

I have been watching this thread and have checked the " how too " info and although I have not sighted the animal in question I am prepared to say that what is being crushed is most surely a ferrite bead.

Every thing points to this. There would be danger in givong instructions to crush an inductor as this would more than likely break the circuit which it is clear is not intended. The official instructions refer to " noise suppressor " and " bead " which ties in.

[CDG]

Since my ECU has no bead, I'll never know.
But if someone can take a macro shot of it, and see if there are markings, we could identify the bugger and look it up. I might even have one in my bucket of electronic parts.

It also appears that many(no idea how many) have done the mod, and I haven't heard of anyone toasting their ECU, although I would think there must be someone who has destroyed the ECU, from static or other, while doing the Bead Crush???

[elninoalex]

Originally posted by Trevor


I have been watching this thread and have checked the " how too " info and although I have not sighted the animal in question I am prepared to say that what is being crushed is most surely a ferrite bead.

Every thing points to this. There would be danger in givong instructions to crush an inductor as this would more than likely break the circuit which it is clear is not intended. The official instructions refer to " noise suppressor " and " bead " which ties in.

Yup, its definately a ferrite bead.

[oab_au]

The Ferrite bead is an inductor with a single turn winding.
It is used to slow the rise time of a signal to the computer. Removing it just allows a faster response to the signal. The size of it would suggest that its effect would be in the low micro sec range.

That said, I have no idea what signal it is or what the signal is used for.

Harvey.

[Chicane]

Originally posted by Motorsport-SVX
From a dead stop, when you take off
many 92 cars experience a hesitation
for a split second before the car actually
takes off.......
Sometimes the hesitation is also caused by
transmission woes when the cars cold
but thats a whole different ballgame.....

This could explain my poor reaction times and 16.7 second 1/4 mile times at the drag strip. I've used a 'practice tree' before and usually get .5-.7 but at the strip the best I could get was a 1.3 or something pathetic like that, and it seems like the car was like "uhh... hmm... OH YEAH! GO!!!!!"

So should I crush this sucker AND install the shift kit??

- Rob