boost sparks / overboosting
23 January 2003, 11:31 AM
#1
Scooby Regular
Thread Starter
Join Date: Jan 2003
Posts: 932
Likes: 0
Received 0 Likes
on
0 Posts
Hi all,
I have heard/read reports from UK and Jap Subaru tuners and importers that fitting the replacement downpipe like the scoobysport downpipe can cause boost peaks of up to 1.5bar. The reports read that unless the cars have been preped for this kind of unexpected occuence it can have serious effects on the engine.
In fact, the Jap tuners recomend that exhaust replacement should only be done from the cat back, because the flow restriction stops the overboosting and this was the way the car was designed.
Does anyone have any comments one this?
Should I be wary about buying an STI-6 with a replacement downpipe, especially if the mileage is over 30K.
I have heard/read reports from UK and Jap Subaru tuners and importers that fitting the replacement downpipe like the scoobysport downpipe can cause boost peaks of up to 1.5bar. The reports read that unless the cars have been preped for this kind of unexpected occuence it can have serious effects on the engine.
In fact, the Jap tuners recomend that exhaust replacement should only be done from the cat back, because the flow restriction stops the overboosting and this was the way the car was designed.
Does anyone have any comments one this?
Should I be wary about buying an STI-6 with a replacement downpipe, especially if the mileage is over 30K.
23 January 2003, 02:18 PM
#2
Guest
Posts: n/a
When I fitted a fully decat 3 inch exhaust system,my car fully stock at that time apart from the exhaust,did not suffer from overboost.The downpipe which is from HKS has a flat piece just like the stock d/pipe covering the turbo wastegate outlet.Then when I fitted BPM twin dump d/pipe which opens up the turbo waste gate outlet,my car was suffering from overboost.Cut the story short,fitted a EBC,problem solves.
Chan
Chan
24 January 2003, 08:03 PM
#7
Scooby Senior
Join Date: Oct 2000
Location: Zurich, Switzerland
Posts: 3,105
Likes: 0
Received 0 Likes
on
0 Posts
STi7's suffer big boost peaks following a decat, that don't seem to be picked up by fuel cut - are you getting confused with this?
On the calssics, a decat can cause boost oscillation - I wouldn't have said it was dangerous per se, just bloody annoying
On the calssics, a decat can cause boost oscillation - I wouldn't have said it was dangerous per se, just bloody annoying
Trending Topics
24 January 2003, 08:09 PM
#8
Scooby Regular
Join Date: Jan 2002
Posts: 11,581
Likes: 0
Received 0 Likes
on
0 Posts
My MY93 was suffering with boost spikes, but this was down to a dodgy bleed valve being fitted. I've now removed it and have no spike problems, just a happy 14.5psi.
Fitted with a full Scoobysport system from the turbo back.
Fitted with a full Scoobysport system from the turbo back.
Thread
Thread Starter
Forum
Replies
Last Post