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Old 03 September 2014, 11:04 AM
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PlayFair
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Default Boost not smooth?

Hi guys,

Not really sure what the best way of describing this is. But here goes!

2001 bugeye wrx


When accelerating through the boost range it's like it's purging?
It will get to about 5000rpm, then pause for a split second, then up to 5500, then pause again, etc etc, all the way through the boost.

It's got a forge dump valve
Pro drive Ecu - apparently, but I'm suspicious it hasn't.
Pro drive inter cooler - again, I'm suspicious that it hasn't.
Full decated turbo back exhaust.

I'm about to go fit a standard dump valve to replace the forge one.
And have a standard exhaust to pick up in the week.

Any ideas?

Cheers
Old 03 September 2014, 11:07 AM
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fat-thomas
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yup your issue is unmapped mods.

your decat is causing overboost and running lean, potentially damaging the engine.
Old 03 September 2014, 11:10 AM
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PlayFair
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Okay. That sounds something I can rectify. I'll try not to push it too hard whilst I've still got the exhaust on.
Thanks.

How can I tell if I have a prodrive inter cooler or Ecu?

I also have a wagon, and they look identical?
Old 03 September 2014, 11:14 AM
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fat-thomas
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quite easy really as they are both made up by facebook page tools.
the intercooler is either wrx or sti, the sti one has sti sprayed on fins.

the ecu could have a ppp map installed on it if it has there is usually a sticker on door pillar and certificate with car.
Old 03 September 2014, 11:19 AM
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What kind of dump valve is it?
Old 03 September 2014, 12:17 PM
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PlayFair
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Dump valve off. Runs so much nicer already. Idle is less lumpy.
Will take it out later and see if it's helped cure the problem.
Old 03 September 2014, 01:42 PM
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PlayFair
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Nope, hasn't cured it.
hopefully the exhaust may help?
i was in 3rd gear about 4500rpm and accelerated out a bend and heard a bang. i assume misfire.
could this point towards Spark plugs?
Old 03 September 2014, 01:49 PM
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Grant Hay
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Get the car re-mapped and drive it off boost until then !

even if the ecu does indeed have the ppp map on it then it still wont cover the full decat you have fitted and you are at risk of damaging your car , like Fat Thomas has already told you , the decat will be causing overboost and the car is trying to protect itself.

Your issues is nothing to do with the bov , although a standard re circ will make the car drive a lot smoother as all the air that the maf has measured and the ecu calculated for is not being vented to atmosphere when you lift off.

Spark plugs although wouldn't do any harm in checking, again is not your problem.

Get the car checked by a reputable mapper, there's lots out there and many that travel to you.
Old 04 September 2014, 11:50 AM
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PlayFair
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Having the car looked at in about 3 weeks. I'll drive normally until that point!
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