Need suggestions for Cat Conv replacement on e34 v8.

[bimerguycw]

I need to replace my Catalytic Conv and wondered what option I have fo rmaybe better flow or just straight through since the emmisions on this 95 540 is not neasured anymore.

Are there universal Cat Conv for these cars or some that actually improve flow noticably,,,not just by spec numbers?

Thanks Guys.

[Tiger]

Magnaflow... Boon.Msi just did his.

[winfred]

most of the aftermarket replacement cats i've seen for the v8s suck and are over priced, some high flow units welded to your head pipes would probably work pretty good and maybe save some money

[Boone.Msi]

just had mine done with magnaflow, 2 singles or 1 dual in/dual out will cost you about $100 usd. I can't say theres any performance gain, except a noticable weight savings. Get rid of even more weight by cutting out the resonator, that thing alone weighs at least 40lbs.

heres the one i bought, cheaper and lighter than two, works just fine if they swell the tips.

http://cgi.ebay.com/ebaymotors/Magna...03751527QQrdZ1

Wait untill theres less than 24 hours on the auction, then offer $70 shipped, they should take it. I got mine for $60 shipped from the same seller.

[Tiger]

I don't know if less than $100 is considered high priced... but ya know... that high priced units are made with the same cheap cats and usually undersized... which tells us how cheap they are and that they don't care how long their cats will last... just more $$$ in their pocket is what they cared about.

[Boone.Msi]

that high priced units are made with the same cheap cats and usually undersized... which tells us how cheap they are and that they don't care how long their cats will last... just more $$$ in their pocket is what they cared about.

Where do you get your info? If your referring to the one i bought you should look at the specs and compare the single to the dual. Its the same exact thing, but with 2" tips to be a universal fit...

I talked this over with my exhaust guy before purchasing, he said it flows the exact same as the single 2.5's, your only gonna know a difference if you have a 500hp+ 5.9liter engine, which you will never see. Plus theres an even better weight/space advantage to using the one piece.

Undersized cat? what would be the point of making a large cat? their purpose is to filter not store gases, like i said, its not gonna make a difference on a street car, unless your pushing some serious power...

as far as quality goes, i did my research. Magnaflow cats are the only aftermarket cat BMW owners have had good results with, the other "better quality" cats honeycomb filters deteriorate in less than 2 years.

[bimerguycw]

I used your link and called them and got the 94005 model which is the single 2.25" for each header side and will have a local weld them in and remove resonator.

Your photos look like the cat was much narrower than what I have now with the OEM cats that take up almost all of the trans tunnel width even without a cat side flange. Was this dual cat much narrower than the OEM cats you replaced or is this photo show the same amount of space on the width of the tunnel shield?

Thanks for all the info.

[Boone.Msi]

It is narrower, if you flip the cat over you can see two 3"(i believe) tubes. The singles are more of an oval flat shape, with large side flanges, flows the same as the dual.

[bimerguycw]

I wanted to maximuze flow of the 4.0L so will use the (2) ovals and angle the flanges to minimize the width in the trans tunnel. I measured approx. 12" width available so I expect the Exh welder can make a fitment for these since they are a direct universal replacement per Magna flow and the seller.

Thanks again and maybe I can get some sounds of the exh for the 4.0L with this setup to compare for you guys to check out.