Making your own hyperflows...

Thanks for the compliment. I have found a way to fit newer MAFs to motronic 2.5 and 2.7 cars... makes them much cheaper (search for my posts on MAFs and how to set for the optimal CO screw setting).

Secondly, I'm not British, I live and pay taxes here, bu I was born in Modena, about 25 miles down from Maranello. In fact I have blood relatives working there... Wearing red overalls ;-)

Thirdly, I did put the O2's closer to the core area so that the overall area less their protrusion is still greater than the 2 inch pipe so to not cause a constriction.

In what I know of gas dynamics and flow rates through a pipe and orifices (in the muffler), our dear 3.4 liter engine produces gas at a rate of 5620 liters of gas per minute at 7000 rpm's. The theoretical output of a 2 inch system is about 6000 liters per side per minute. Given the engine actually has 2 x 2 inch systems (each 4 cylinder banks), the exhaust leaves us with quite a margin of capacity as a stock system. Reduce the efficiency by 50% due to orifice dynamics in the muffler, bends, pipe roughness, boundary layer thickness increases etc. I still cannot see too much theoretical gain for the effort. Unless the rpm's go up, or the exhaust is pressurized by boosting the inlet.

For now, I'm satisfied that in terms of value for money and intellectual entertainment, I have reached the end of my experimentation with the exhaust.

Marco

 

Italian stooge then. You will notice my surname which hails from Grizi, Sicily (just up the hill from Palermo. Don't stop in your experimentation. I am always curious as to what you will come up with next. I am jealous that you can take your car over to the continent for a weekend and rocket down to the Italian Rivera when you like, you rat! Cheers, amico!

 

Boys I think we have us a new Stooge. What do you say Oz? All we need is three yes' votes and Marco is officially in the Stooges.

1 vote from ernie.

 

Guess 33% is better than 0%...

Got my second gear box today. I'm going to start the take apart tomorrow. Turning it from the clutch shaft has a tiny amount of play, but all looks absolutely fantastic.

I'm expecting this 12K miles box from '93 to be the better model than my 20K miles '89 box (though I put 9K miles on it in the last 12 months).

It s going into my Mondial t, so I will let you know how its accell changes. I will put the Mondial t box in the 348, and expect the pinion gearing difference to get the 348 off the mark faster ;-)

Marco

 

It doesn't exactly work that way. What you will find on most post '95 systems is a close coupled catalyst that is located as close to the manifold as possible for cold start. The engineering challenge is getting it up to operating temperature as fast as possible as that is where most of the emissions happen, especially in a test like FTP. The second catalyst (the "underfloor") is for clean up of any breakthrough from the first one (more cost effective than adding length to the first).

 

Actually it's 66.7%. Vince already called you the Italian Stooge.

 

Right... My Mondial t is an '89, most of the 348's here were born before '95 and a few of the 355's, even post '95 still had the twin cat system like the 348 until the 5.2 motronic version.

So this post needs to be taken in context of these cars and not the wider market. As far as I can tell though, Ferrari still has long headers in all their models, and puts emissions second to performance ;-) That works for me!

Thanks for the 66.67%

M

 

Until you get the other vote, I'm gonna call you "Agent 67".

 

Magnaflow confirmed to me this AM that the 59954 is a 200 cell count CAT.

"What you will find on most post '95 systems is a close coupled catalyst that is located as close to the manifold as possible for cold start" by Judge4re makes a good deal of sense.

Explains the pre-cat location to headers.

 

I have been searching for the thread where Marco was talking about the homebrew comparator circuit but can't find a schematic. Does anyone recall a schematic being published? The cat ecu's are missing from my 89 Mondial t and I would like to have something hooked up to the slow down lights. Any input would be most appreciated and I would be happy to share the circuit board and layout.