In this article we cover the exhaust layout and system for Subaru Impreza Classic 1993-2000, New Age Blobeye 2001-2005, Hawkeye 2006-2007 and Hatchback / Saloon 2008-2013, and STI 2014-2019, along with gasket locations and diagrams.
Impreza GC8 1993-2000 Classic Models UK Turbo WRX and STI
The Impreza GC8 Classic Turbo uses a 3 piece exhaust from the turbo back. This comprises a long downpipe, originally fitted with a catalytic converter, a center section with catalytic converter or straight through for some JDM import models and a rear silencer. Bore size is approximately 2.5″ internal diameter and the exhaust was made from mild steel.
From the Engine the layout is as follows
- Exhaust Manifold
- Exhaust Uppipe to Turbo. A straight through pipe with no catalytic converters or silencers
- Exhaust Downpipe from Turbo to Centre Section. Originally contained a large catalytic converter element to pass emission regulations
- Exhaust Centre Section from Downpipe to Rear Silencer. Normally contained both a smaller catalytic converter and resonator / silencer (UK / Euro models) or just the silencer (mostly JDM imports). This is normally around 137cm flange to flange.
- Exhaust Rear Silencer, with 3 integrated hangers to hang on the exhaust rubber mounts.
The exhaust sections are joined together with a series of gaskets and bolts of varying sizes and designs. See our site at this link for details of these https://scoobyparts.com/subaru-impreza-wrx-sti-exhausts/subaru-exhaust-gaskets-and-bolts
Impreza 2001-2005 2.0 WRX and STI – UK models.
The later Bugeye and Blobeye 2.0 Litre WRX and STI models used a variation on the classic system, with a similar exhaust manifold and Uppipe. On WRX models the Uppipe was fitted with small catalytic converter, not present on the STI. Followed after Turbo by a shorter Downpipe, the addition of a Catpipe, a shorter 127cm length Centre Section and a redesigned rear silencer.
From the engine the exhaust layout is therefore as follows
- Exhaust Manifold
- Exhaust Uppipe to Turbo. A straight through pipe with no catalytic converters or silencers on STI models and a catalytic converter on the WRX models.
- Exhaust Downpipe from Turbo to Cat Pipe. Originally contained a large catalytic converter element to pass emission regulations.
- Exhaust Catpipe – fitted between Downpipe and Centre section houses a smaller catalytic converter.
- Exhaust Centre Section to Rear Silencer. Normally contained a resonator / silencer. This is normally around 127cm in length flange to flange.
- Exhaust Rear Silencer, with 3 integrated hangers to hang on the exhaust rubber mounts. This was a slightly different design to the Classic rear silencer
For more information on exhaust systems for the Subaru Impreza Blobeye WRX and STI see this link https://scoobyparts.com/subaru-impreza-wrx-sti-exhausts/exhausts-for-impreza-wrx-sti-01-05
Subaru Impreza 2006-2007 2.5 WRX and STI – UK models.
The 2006-2007 2.5 Litre Hawkeye WRX and STI models used a variation on the New Age 2001-2005 system, with same exhaust manifold and Uppipe but with a shorted downpipe and longer Catpipe. There was no catalytic converter fitted to the Uppipes on these 2.5 Litre models. Followed after Turbo by a short Downpipe, longer Catpipe, the identical 127cm length Centre Section and similar sized rear silencer.
From the engine the exhaust layout is therefore as follows
- Exhaust Manifold
- Exhaust Uppipe to Turbo. A straight through pipe with no catalytic converters or silencers.
- Exhaust Downpipe from Turbo to Cat Pipe. Originally contained a large catalytic converter element to pass emission regulations.
- Exhaust Catpipe – fitted between Downpipe and Centre section houses a smaller catalytic converter.
- Exhaust Centre Section to Rear Silencer. Normally contained a resonator / silencer. This is normally around 127cm in length flange to flange.
- Exhaust Rear Silencer, with 3 integrated hangers to hang on the exhaust rubber mounts. This was a slightly different design to the Classic rear silencer.
For more information on exhaust systems for the Subaru Impreza Hawkeye 2006-2007 please see here https://scoobyparts.com/subaru-impreza-wrx-sti-exhausts/hawkeye-wrx-sti-exhaust-systems
Subaru Impreza Hatchback 2008-2012 WRX and STI
The Hatchback models from 2008 to 2012 used a similar setup to the Hawkeye exhaust system, with again the same exhaust Manifold, Uppipe and similar downpipe but with a longer Catpipe, longer Centre Section and then either a single exit tailpipe for the WRX models or a twin configuration for the STI models.
- Exhaust Manifold
- Exhaust Uppipe to Turbo. A straight through pipe with no catalytic converters or silencers.
- Exhaust Downpipe from Turbo to Cat Pipe. Originally contained a large catalytic converter element to pass emission regulations.
- Exhaust Catpipe, longer than the Hawkeye model- fitted between Downpipe and Centre section houses a smaller catalytic converter.
- Exhaust Centre Section to Rear Silencer. Normally contained a resonator / silencer and of a completely different length and design to the previous Hawkeye models.
- Exhaust Rear Silencer, with either single (WRX) or quad exit tailpipes (STI)
For more information on the Hatchback WRX and STI exhausts please use these links
WRX – https://scoobyparts.com/subaru-impreza-wrx-sti-exhausts/hatchback-wrx-exhausts
STI – https://scoobyparts.com/subaru-impreza-wrx-sti-exhausts/hatchback-sti-exhausts