550 vs 575 max speed.

On the 550/575 I don't believe Tubi's help any with power, the design is very poor and not condusive to flow. They work in the same fashion as the old Turbo mufflers from the '80's by bouncing the exhaust pules off a metal plate and reflecting it to the exhaust outlet.
After checking the 575 does seem to have a 250rpm higher rev limit than the 550, which does explain a higher top speed. This does not change the fact that it is physically impossible for a stock 550 to reach its manufacturer quoted top speed. The rev limit on the 550 is not 7700rpm it is in fact just under 7500 with a soft limiter coming in at around 7200rpm, which cuts out 1 bank of cylinders. As Vmax requires max power you are not going to be able to exceed the soft limiter at top speed. I have the exact details from the service manual but can't be bothered looking it up right now. The 7700rpm limit is coming down the gears, so is rather a recommended max rpm for the motor rather than an electronic rev limit under acceleration.

 

Lee thanks for the vote of confidence. Coming from you, praise indeed!

 

No idea on the 575, but I would assume so. I am trying to have my soft limiter lifted to 7700rpm, but there isn't much use on a standard car as peak power is at around 6800rpm real and falls away from there.

 

Also interesting point about the tubi's. Why do Ferrari owners not use high flowing mufflers.. Where I come from kids put performance exhausts on their ricers with gains of 5bhp-20bhp ( 20 from turbo cars ). Do tubi's really add nothing ? What about capristo ?

 

No idea on Capristo, Cargraphic, Fuchs etc. I had a set of high flow mufflers made, but the noise was unbearable, even with cats and resonators.

 

As in far too loud ? Can a larger diameter pipe be made for the full exhaust.. then use stock mufflers ? Or is the pipe optimum or would that even make a noise difference ?