replacing front exhaust on Discovery II
#11
The Magnaflow exhaust arrived in 2-pieces, which was great under my circumstances. If you can't get your frame cross-member off then this is the best route to take. When you go to the Land Rover dealer to buy your new manifold gaskets, do yourself a favor and spend the $40 to get 6 new studs and flange nuts. The old ones are likely in poor shape and the new ones make installation of the new exhaust a breeze. In case you're wondering, the long threaded end of the stud goes on first, followed by the exhaust, topped off by the flange nut. Note that all 6 studs will need to be secured very well in order to eliminate exhaust leaks at the manifold. Even a single loose stud will cause audible leaks.
The Magnaflow #93689 was a perfect fit for my 2004 truck, and it's my understanding that ALL Discovery II's use the same exhaust, so you should be able to fit this part if you have a 1999-2004 MY. Also, the design of the exhaust is very good, and the clamp provides proper joining of the two pieces without the need for any welding.
The Magnaflow #93689 was a perfect fit for my 2004 truck, and it's my understanding that ALL Discovery II's use the same exhaust, so you should be able to fit this part if you have a 1999-2004 MY. Also, the design of the exhaust is very good, and the clamp provides proper joining of the two pieces without the need for any welding.
#12
I appreciate your zeal, but stating that something isn't correct isn't useful unless you can supply the correct info. According to the LR dealer parts dept., the same exact part number is used for the front exhaust for all Discovery II's from 1999-2004. I personally asked for the 2004 and 2002 part numbers for confirmation. Can you educate us about where I went wrong?
#13
Sorry, I was eating lunch and was only using one hand to type, I just didn't want people to think that was the case. Here are the range of 99-04 Discovery II front exhaust pipes:
WCD106210
WCD000500
WCD105880
WCD000200
WCD105900
WCD001220
WCD105890
WCD000210
I don't really want to go through describing each one, but just know that there are different(several) downpipes for the 99-04 DII.
WCD106210
WCD000500
WCD105880
WCD000200
WCD105900
WCD001220
WCD105890
WCD000210
I don't really want to go through describing each one, but just know that there are different(several) downpipes for the 99-04 DII.
#14
Must add, any exhaust leaks before the upstream O2 sensors will throw off the engine's F/A ratio while downstream O2's are only for checking how efficient the Cats are functioning......~~=o&o>.......
Last edited by BierNut; 09-16-2019 at 02:20 AM.
#15
Next step replacing the flat right side and round left side miss matched Cats LR installed with a matching set of Magnaflow's 94305 Cats, OB1 D1. These Cats can handle up to a 377 cu/in engine per Magnaflows literature. Running with complete 94305's vs a pair of gutted out 94305's it was hard to detect the difference in performance, they flow. Again another performance increase as well a 12*F drop in cylinder head temps. Tested with cylinder head thermal probe washer under the spark plugs, now the engine has equal cylinder head temps also left and right banks vs factory Cats as the right bank was running hotter by 8*F. Already installed a larger custom radiator (180 stat) so cooling wasn't the problem as well a matched and balanced set of injectors. Another "Butt-O-Meter performance increase then the biggest a Mark Adams "Tornado" chip now properly fueling the engine. Final upgrade yanked out the POS 3.9 and installed the 4.6 engine. Port blending with minor porting from the ram tube intake to the outlet ends of the exhaust manifolds including the down pipes. Another performance increase. After engine break in time spent recurving the mechanical advance to what the engine wants and can handle hence another performance increase. This a fired by distributor ignition 4.6 allowing timing alterations.
Overall between 1.9 and 2.3 mpg increase depending how i'm stirring the stick, a 95 D1 a 5 speed. Much more fun to drive than a boring automatic. Yup she's a keeper.
This photo will explain why LR engines need a lot of help to run properly as several small improvment details items add up to one large gain in performance without installing a big cam which is useless if the heads don't flow. Picture below shows how ugly the head ports are. Photo from RPI V8. Installing Bosch 4 hole injectors vs Lucas's obsolete 1980's single dribble design another improvement .........~~=o&o>......................
Last edited by BierNut; 09-17-2019 at 03:23 AM.
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