575 exhaust upgrade for a newbie

https://www.instagram.com/crownsandcavallinos?igsh=MTh4cWR1eWY2Ym5reQ==

I forgot, I could just link you to my Instagram. Looks for the post with videos

 

If you two go full Fabio on your 456 cars I may come with you on that journey.I assume there would be a “Trev” tune required for Fabio’s cat-less 456M set/up (?).

 

When I asked him about a tune for my 2.7 456GT he said it wasn't necessary, even going catless. But I know you guys with the 5.2 system have a bit more complex logic running

 

OBD1 doesn’t require tuning / no real CEL concern (unless you really screw something up). Tuning will give additional mild power bump.
OBD2 likely requires some kind of tuning as risk for CEL is quite real. Tuning also will give additional power.
Trev does not offer tuning 2.7 or 5.2 systems.

if enough demand, he may offer for 5.2?

 

I would strongly recommend AGAINST going catless. As Eric said, I received my 550 with the catless version of Fabio's headers (and with no secondary air). Knowing Fabio from previously buying a 599 setup from him, he agreed for me to send them back to him to be retrofitted for secondary air and I also bought his cats. It made a massive difference. The smell was unbearable with no cats - it was very unpleasant to drive with the windows down. I am not sure why - I did not experience this phenomenon on my catless 355, Delta Integrale, or even old carb 308. For some reason, the 550 was just horrendous. Adding the cats fixed the smell immediately.
Your preferences may vary, but I would think very carefully about this before proceeding. My .02. Good luck!

 

I don't have smell issues driving with the windows down on my 550 with Fabio's race headers and no cats. The smell is strong when starting the engine from cold and you don't want to stay behind the car then, but no issue when driving. Deleting the secondary air fixed a tedious whistle I was getting in the cabin when driving with the windows down by half an inch and over 60 mph.

 

That sounds like it’s a running rich problem and warrants mitigation through tuning.

 

So without doing the Full Monty on the exhaust of my 2003 575M, I'm trying to decide whether to replace the center muffler with a Fiammenghi H pipe or the rear mufflers with Fiammenghi Straight Tips? I'd prefer a low growl ala Ferraris of old vs the high pitch scream of current ones (someone here said us old guys should leave it stock, well I have a few choice words for the impudent young whipper snapper). I already did the TAZ bypass so the muffler valves are open all the time and its much better but it still needs a bit more sound.
Recommendations from those in the know please.

 

If your assembly number is below 51797, you have the center resonator/cork that is eating a lot of your exhaust music. Replacing that with an H-pipe will open up some sound and hp, and Fabio's will not resonate. Sound should be like what you have now, only louder.

If your AN is above 51797, you have straight center pipes and no resonator, and an H-pipe will improve the sound, but not be much louder, if any.

 

For low growl, you definitely need to replace the OEM center muffler on an early (pre midpipe delete) 575. You didnt mention your SN so not sure if your car already has the midpipe delete or now. If it does, I would just do the headers+cats and see how you like it with OEM midpipe delete and open OEM valves before buying everything.

If your car does not have the delete (aka pre 51798ish), I would get the H pipe + overaxle pipes and keep your OEM mufflers w the values open

 

Assembly Number 50034 so has the center muffler.

 

Then I would get the H pipe and over axle pipes but leave your mufflers

 

Why the Over The Axle pipes? Restrictions or part of H Pipe?

 

Restrictions and effort if already swapping H pipe is minimal

 

Affirmative, the factory over the axle pipe is severely constricted. Either Fabio or Supersprint make good over the axle pipes. If getting Fabio's H-pipe, might as well get the matching over-axle pipe.