[shadowvox6]

Group,
As many of you know, we have all been looking for way to get rid of the stupid design of the OEM exhaust manifolds on the 3.2/3.5's. I personally have tried LX manifolds to no avail. Others have tried LX headers only to compromise the gains by the ridiculous bends that are needed to accommodate the headers. Well, I am going to try to take a trip back in time (so to speak) I have recently acquired a set of 1G 3.5 exhaust manifolds. They are a traditional design, and I think they can be plumbed in to work in our cars.

Here, feast on some pictures...

First off, here are the OEM 2G exhaust manifolds..



Below the manifold is a header that a former member of the 300M Club made, his alias was "Gallotte"

The manifolds as I received them....












After a little media blasting...











Next will be Catalytic Converter selection

Any thoughts??

[crypt keeper]

They cleaned up nice Tom even the o2 sensors look good lol.

[TrepCruzin]

hmmmm very interesting.....those 1st gen cleaned up good.....where are you thinking of positioning the cats?

[trepnician]

what is the design flaw behind the 2nd gen exhaust manifolds?

[sc.intrepid]

I think the 1g design will flow better, but can you fit the cats in the 12 inches or so back the 1g header puts them.

[etfuller]

I will be following this for sure.

[gearhead291]

the flow isn't the best to say the least.
its a ass-backwards design.



i've been thinking of this as well, but im not sure which cats you can get to fit behind them, im sure you'll figure out something, cant wait to see the results !!!

[crypt keeper]

Not sure what size pipe you plan on running but these would be something to look into.

http://www.planetmagnaflow.com/shop/...54956-675.html

[shadowvox6]

What my thought was about the converter placement is this, come out of the manifold with a 45* bend, then place the converters. There should be room for a smaller, high flow converter in that configuration. It will allow for the O2 sensors to be nearly in the same location as the factory configuration. With them being further back, and down in the engine bay, heat should be less of an issue.

[blackrt1]

I've pondered doing this as well Tom. Just curious if using the factory 1st gen cats will work better molding to our factory pipes or to buy aftermarket ones?? Making nice progress tho I'm watching this thread for the end result! Pics please!

[shadowvox6]

I am going to use small, high flow aftermarket cats. Tuck them in near the factory location.
I am thinking that will work.

[300maximilien]

will be interesting to see if those can be made to work

[shadowvox6]

When I head up to Indy Monday, I am going to stop by and see my exhaust guru to see how much it will take to get this done. And, if we can reuse the factory converters or not. I would prefer to use them, but we'll see.

[blackrt1]

Sounds like a plan!

[DrDodge]

this is where you may run into a problem,, the main reason the put the oe cats so close to the engine, is so they light off faster, thus lower emissions, ok, if the ECM dont see a change into closed loop in such and such a time it will toss a code,, usually a po420 or po430, hoping Im wrong,,,