 The difference between Early and Late Exhaust Systems, a Visual Guide, Or, what kind of Exhaust do I have |
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| gothspeed |
 Feb 16 2018, 03:27 PM
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#21
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Senior Member  Group: Members Posts: 1,539 Joined: 3-February 09 From: SoCal Member No.: 10,019 Region Association: None  |
2007 thread bump to 2018!
Does anyone know of any HP differences between early 2.0 and late 2.0 exhaust/exchangers? |
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| Dave_Darling |
Feb 16 2018, 04:26 PM
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#22
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914 Idiot Group: Members Posts: 14,990 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California 
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Yeah, about 7 HP. The 73-74 2.0 was rated at 95 HP DIN, while the 75-76 was rated at 88 HP DIN.
--DD |
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| gothspeed |
Feb 16 2018, 04:31 PM
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#23
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Senior Member Group: Members Posts: 1,539 Joined: 3-February 09 From: SoCal Member No.: 10,019 Region Association: None |
7-ish HP is significant. Did later 75-76 models have catalytic converters? I am thinking they no longer ran the 'hot dog' muffler as early models?
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| Dave_Darling |
Feb 16 2018, 11:19 PM
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#24
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914 Idiot Group: Members Posts: 14,990 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California
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Some of the 75-76 cars had cats; most did not. I think it was CA and MA only that had them. Most states used a bypass pipe in place of the cat, but the muffler was still the two-piece thing.
See post #7 in this thread for a photo of the stock 75-76 muffler--in that case, with a cat. --DD |
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| gothspeed |
Feb 16 2018, 11:49 PM
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#25
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Senior Member Group: Members Posts: 1,539 Joined: 3-February 09 From: SoCal Member No.: 10,019 Region Association: None |
Thanks for the response. That later muffler doesn't look very good. I wonder what percentage of the 7hp loss was the new muffler vs the new manifolds?
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| jcd914 |
Feb 17 2018, 12:02 AM
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#26
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Advanced Member Group: Members Posts: 2,081 Joined: 7-February 08 From: Sacramento, CA Member No.: 8,684 Region Association: Northern California |
Most of it is the header pipes and single pipe heat exchangers. They are not designed for flow, just a way to route exhaust from 2 cylinders in to one pipe in the heat exchanger.
I have installed aftermarket mufflers (bursh) on 75/76 cars and it makes very little difference. Backdating to a 73/74 style 2.0 exhaust does make a difference. Jim |
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| mtndawg |
Feb 17 2018, 01:58 AM
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#27
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Member Group: Members Posts: 414 Joined: 26-January 09 From: Granite Bay, Ca Member No.: 9,985 Region Association: None
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Is the shape of the pipe the same where it goes into the head? ... or are some oval and others round?
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| Dave_Darling |
Feb 17 2018, 09:39 AM
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#28
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914 Idiot Group: Members Posts: 14,990 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California
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They're all oval. They sometimes get called "round" because there are later Buses with ports that are pretty rectangular shaped. Those get called "square port" heads.
But all of the 914 exhaust ports are the same basic shape. You can fit any-year 914 exhaust onto any-year 914 head. --DD |
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| gothspeed |
Feb 17 2018, 11:39 PM
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#29
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Senior Member Group: Members Posts: 1,539 Joined: 3-February 09 From: SoCal Member No.: 10,019 Region Association: None |
QUOTE(jcd914 @ Feb 16 2018, 10:02 PM)  Most of it is the header pipes and single pipe heat exchangers. They are not designed for flow, just a way to route exhaust from 2 cylinders in to one pipe in the heat exchanger. I have installed aftermarket mufflers (bursh) on 75/76 cars and it makes very little difference. Backdating to a 73/74 style 2.0 exhaust does make a difference. Jim That makes sense, thank you for the comparison information (IMG:style_emoticons/default/smile.gif) |
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