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AaronM AaronM is offline
Ornery Bastard
 
Join Date: Sep 2001
Location: South Sound
Posts: 2,880
Quote:
Originally Posted by v2rocket_aka944 View Post
for the record, mechanically, all 2.5L 8v 944 NA motors are identical.
As long as you don't consider the pistons to be a part of the engine, you're essentially correct. Personally I'd consider the later, higher-compression pistons to be noticeably different. The 10 HP peak difference isn't much, but the overall torque curve feels a little more solid on the later engines.

As for being "plug and play" if the DME and AFM match, again I disagree.

Yes, the car will run as long as the DME and AFM match, but it will not run properly unless you're using the right DME for the engine. Pre-85.5 cars use ML 1.1 or ML 1.2, while post 1985.5 cars use ML 3.1. While the AFM is indeed the primary difference between the two, the pinout does differ for the harness connection, specifically with respect to the altitude compensation signal.

There's a bloody big difference between just getting it to run and getting it to run right. If you want to do things the right way, you will mate an 85.5+ engine to an 85.5+ ML 3.1 DME and you will mate a pre-85.5 engine to a pre 85.5 ML 1.1 or 1.2 DME. Taking shortcuts by frankensteining things and using two different systems is fine if you need to limp to a mechanic's in an emergency, but it's just not the way to do things long-term.
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Old 12-25-2010, 11:03 PM
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