Hi Guys

New to the site and new to the Impreza Owners Club. Have a 96 WRX STI which I already love.

However in this cold damp weather that we have had my car overboosted when on hard acceleration in 5th gear. Like the car hit a wall!! Having read some of the posts it might be that the car is either overboosting or overfuelling.

What do you guys suggest? Does the car need to be remapped to get the right map for the car? I believe the older cars are harder to re-map!

Any ideas of places or people to go to help. Im based near Hertford in hertfordshire.

Rob

 

You normally get overboost in 3rd, 4th and 5th, plus you have not said if your car has any modifications and/or at what speed you get the overboosting?

Tony

 

Havnt had time to really drive the car a lot as it's not my everyday car and I dont want to keep making the car hit the wall so to speak as i dont want to possibly break anything else.(very untechnical as well)

It has only happened in 5th when giving it some prob at around 80mph!?

 

Modifications or is the car standard? And what fuel are you running her on?

Tony

 

I know that the car has a cone airfilter. Not sure what else if anything as the previous owner wanted to keep it as standard as poss.

Only runs on optimax on high octane fuel.

Rob

 

have you a boost guage t see whats its psi

 

what exhaust is fitted is it decatted what fuel u running on without this sort of info its impossible to help u im affraid there are a few methods for curing overboost but more info needed first please

 

When I had my 96 STi the same happened but I had a full de-cat - has yours? I eventually cured mine by fitting a Blitz DSBC set a 1.3 bar - got the car checked for fuelling, etc and it ran like this for 30k with no issues into I sold it.
When it started happening I almost gave up - it just destroyed the scoob experience and I lost all confidence in the car. Stick with it - I'm sure you'll find a cure. If you go down the route I did make sure you get everything checked as ooposed to just cranking up the boost! My Blitz was actually fitted underneath the dash out of the way so once it was set up and all fine I was never tempted to tinker!
Good luck - I've had 10 scoobs and the STi3 was my fave - I still miss it!

 

The first port of call for me, as you have stated you have a sh1tty cone filter fitted would be to inspect the bottom hose on the BCS. There should be a restrictor pill in there that prevents boost spikes. The pipe will be, connected to the air box resonator, or hanging loose and venting to atmosphere, or at worse, been removed along with the pill.

My advise fwiw, remove the sh1tty cone and re-fit the OE airbox with a KnN or Green panel filter inside and re-plumb the BCS to OE. There is, in your case, absolutly ZERO gains to be had from the cone.

Here is a picture of the BCS and the location of the restrictor pill. The assembly is bolted to the f/o/s turret.

 

Ill check thats all in place. Anyone know of a good scooby place not to far from Hertford?

 

Is there a way to bypass/replace or use another method with this.

I have a VW t25 panel van with a 96 Subaru wrx sti turbo 2.0l which I am having an overboosting problem on, obviously putting a stock air box isn't an option on mine.
Any other options I can go for ?
A Electronic boost controller ? uprated BCS ?
Also have heard of someone else who added an exhaust mounted wastegate to tackle the problem ? not sure how that helped ?

Thanks

 

You could always try a pill with a bigger hole,or just drill yours.

 

Hello mate,

That's my neck of the woods too. I'll keep an eye out for you.

I use rich at fb tuning. It's an hours drive but completely worth it.

 

with a 3port solenoid to cure the overboost you want a smaller diameter pill, not a larger diameter pill.

with a smaller pill, less pressure is bled away from the wastegate so you get less boost (and less chance of overboosting). If your missing the pill then just find a suitably sized welding tip, stick it inside a bit of vac host and securely attach to the solenoid. Doesn't strictly need to be plumbed to the intake pipe - that's more to keep everthing air tight for emissions purposes.

If you have no pill at all, start with a 1.2 or a 1.1mm pill then work down to a 0.9 or 0.8mm pill - should be able to pick them up from your local welding shop or I think even halfords carry some sizes as well.