weird color smoke with flow throughs..

do the new cats have a coating inside or out?

 

I bet the cats had some kind of residue on them.....how long has the brown smoke ben noticeable.......my guess is is that it will burn off. 0.02

 

How many miles have you put on the car since the install ?
Something burning off of the cats due to heat or just being new ?
WOW a 355 running to cold, we can fix that fast enough. Sell me your challenge grill for half of what you paid for it ...... Boom Confetti ... Problem solved.
Bet you can still cook eggs on the engine cover

 

CAT's need to heat up to work properly. That's probably what you are experiencing. The lack of CAT effect until they heat up.

 

I am assuming you mean high flow CAT's and not test pipes? If so, yes, they are CAT's with less restriction.

I don't understand what you are asking about temp.

 

Look up Gothspeed's poll thread

 

Nitrogen dioxide is brownish in color. This could be an indication of improper open loop fuel mixture.

 

Randy, I appreciate your trust in me, however I promise you Goth knows way more than I do. That thread rocks! My car happens to fall right in the recommended range.

http://www.ferrarichat.com/forum/348-355-sponsored-bradan/377706-355-owners-only-more-data-samples-needed-anonymous-poll.html

 

Randy,

I'm the guy that sold you what you are calling "flow through cats". Although they have a cat like shape, they are not cats at all. They are made by Top Speed and are basically just test pipes that don't do anything to the exhaust except pass it through. I don't believe they could be in any way responsible for the smoke you are describing. There's nothing inside except the 2" SS perforated pipe centered in the bulkheads that are welded to the outer SS housing. They never did anything like that when they were on my car. The odor you are smelling is normal, just unburned hydrocarbons and fuel, typical when you don't have cats to oxygenate the exhaust stream.

As far as the temperature goes, my 5.2 355 runs the same as you are describing, both with and without cats. At highway speeds, its about 3/16" below the 190 mark. In town, in stop and go driving, it sits at 190 with the fan coming on and off keeping it from getting above that mark. With the fan running, it drops about 1/16" or so below 190. When the fan stops, it creeps back up to 190 but never goes above, even in very hot weather (95 or so).

Hope this helps.

 

So these were basically test pipes, not cats?

Just scratching my head...

 

The hollow factories sound amazing I think with the straight pipe you get a little more silencing. Did you change the bypass valve or stop leaving it open?

 

So you deleted the cats and it got quieter?????

 

I think because the straight pipes are a 2 inch internal diameter, the hollow factory unit acts like an echo chamber and the car screams , try running bypass open see how it is.