Turbo 'shudder' in 02 WRX.

[Uzi]

That's fascinating.

I'd love to do this myself, but I'm unfortunately not familiar enough
with the placement of parts on my vehicle to know exactly where you ran
from. Call me - intelligent but uneducated. ;-) Negative post on the
battery, then?

From the negative post to a bolt on the intake (a silver coloured
metal tube that is in front of the intercooler and is about 2-3"
thick. It is ~15" to the left of the negative post. The bolt on the
intake already has a wire going to it. The bolt is located at/near a
90 degree bend in the intake. It is very obvious as to which one it
is. Go to the Nasioc link earlier posted. There is a picture in the
last couple of pages that is pretty clear. The picture shows a number
of connections daisy chained around the engine. It probably isn't
necessary to do that. The one connection was enough for me.
Today I put in a #4 wire that I bought at the autoparts store. It was
premade 18" long with a couple of clips. It was made to connect a
starter to ground. I just used a cresent wrench to take the bolt off
the intake, cleaned things up, bolted it down, and then applied some
dialectic grease with a disposable brush. Same thing with the battery
terminal. I also cleaned up the ground to the inside fender right next
to the battery.

 

[Bugalugs]

From the negative post to a bolt on the intake (a silver coloured
metal tube that is in front of the intercooler and is about 2-3"
thick. It is ~15" to the left of the negative post. The bolt on the
intake already has a wire going to it. The bolt is located at/near a
90 degree bend in the intake. It is very obvious as to which one it
is. Go to the Nasioc link earlier posted. There is a picture in the
last couple of pages that is pretty clear. The picture shows a number
of connections daisy chained around the engine. It probably isn't
necessary to do that. The one connection was enough for me.
Today I put in a #4 wire that I bought at the autoparts store. It was
premade 18" long with a couple of clips. It was made to connect a
starter to ground. I just used a cresent wrench to take the bolt off
the intake, cleaned things up, bolted it down, and then applied some
dialectic grease with a disposable brush. Same thing with the battery
terminal. I also cleaned up the ground to the inside fender right next
to the battery.

Have a look here. Description and photo.


http://stcimages.tripod.com/earthingsystem.html

 

[BD]

Great stuff - that makes it very clear.

Thanks, both Uzi and Bugalugs !! I'll give it a go!

 

[k. ote]

1. Yes, you should be using the higher octane fuel in a Rex.

A normal WRX does not need any more than 91 octane. We're talking North
American AKI here, not RON. ONLY the STi needs the higher 94 stuff..

2. You should be using a high quality branded fuel from one of the
majors with an advanced detergent package.

Petro Canada is nation-wide and has generally good gasoline. In the areas
that have it, PetroCan does stock a good '94. I would rate it #2 only after
Chevron. Certainly both PetroCan and Chevron have better gas than Esso or
Shell.

 

[BD]

Certainly both PetroCan and Chevron have better gas than Esso or Shell.

I've gotten the same vibe over time, but can't really cite specific
reasona.

Jury's still out on whether the 94 helps with the slight shudder. I'll
run a few tanks through it and see how it goes...

 

[k. ote]

I've gotten the same vibe over time, but can't really cite specific
reasona.

Jury's still out on whether the 94 helps with the slight shudder. I'll
run a few tanks through it and see how it goes...

Be sure and let us know the results.

I've found that Chevron, once burned, smells more pleasant and appears to
smooth out engine operation on my WRXs. Running 94 PetroCan was fine as
well. Moving to 91 PetroCan was definitely of lower quality ride, smell,
and feel, than other 91s, and I drove all the way up and down the Oregon
Coast running 91 in my WRX.

I'm going to take a trip up the Alaska highway in the summer with the "new"
STi. =] I called up the Whitehorse Subaru dealership (!!) and they said
they've already sold like five STis up there. Wild eh? I asked them what
kind of gas their STi drivers use, and they said, "Normal 91.. that's all
we can get up here."

"Without any octane booster?"

"The STi will retard its timing to deal with the lower-quality gas, but one
of the STi owners will still add octane booster to every tankful."

"Wow."

So I'll bring some booster and let you all know what it's like. Heh heh. I
heard the Alaska highway is all smoothed out and paved now, though.. maybe
I should take it up to the Dempster!

Maybe not.. suicide isn't my middle name.

 

[BD]

Your car is suffering from a poor diet and lack of exercise.

Just a quick update - I've run a couple of tanks of 94 now, and overall
behavior seems significantly better. The 'shudder' I'd complained about
in my initial post has not recurred - though that's not 100% conclusive
yet because it was kind of intermittent anyway - and there's more 'jam'
to the power band overall.

I'll keep it on 94 for awhile, and then maybe go back to 91 to see if I
observe a change in the opposite direction.

BD