F355: Exhaust pipe dreams

Since sorting the problem I created with the MAF sensor and the blow in the exhaust the Ferrari has been running beautifuly.

The Nouvalari sounds amazing when accelerating hard or at high revs but around town and driving slowly it's boomy and still noisy as hell after a while it gets a bit much. The standard exhaust was very civilised and didn't on the drive back up from London it wasn't once too intrusive. But I did change it in the first place, so perhaps it was too civilised...

I'm starting to think I should look at other options. The problem is there are so many options and without hearing them it's going to  be hard to make any sort of decision. I'm thinking Capristo will have a better "engineered" noise but they come in 3 levels.. I think level 1 would be enough for me. Then there is Tubi, Gothspeed, ITO and I also got offered a Kreissegg for $4500 (!) Too many options and not enough decision making power!

F355: Oh joy!

After hooking up an OBD II reader (the later 5.2 Motronic ECU F355's are partially OBD II compliant, but I'll post more on that later) and after some help from the forums it seemed that my MAF reading was about 3 times what it should have been reading at idle at 30g/s where it should be nearer 10g/s.

It seems my car was thinking it was getting a lot more air than it actually was and overfuelling to compensate. Here's the fix. I had put the MAF sensor on in the wrong direction! Turns out it doesn't work so well like that!

The car is now running perfectly again! Heart attack cancelled.

F355: Oh oh...

After reading a post on Ferrarichat or ClubScuderia about slight blows in the F355 exhaust system making a huge difference to the "boominess" of the exhaust note I checked mine and noticed a blow coming from the bypass valve. (The bypass valve is closed under a certain rev range for noise regulations and opens up above this range to really make the system howl.)

I decided to change the gaskets on the bypass valve. A quick check on Eurospares: £51 each! For a metal ring. I phoned a few places but nobody could supply them. I had nearly given up when I emailed Capristo. They have their own ones for 12 Euros each! Excellent. So I emailed back two order two up and asked  to advise on payment. Two days later 2 gaskets show up in the post! Capristo never took any money off me, thumbs up to them! I also ordered a new bolt kit from Superformance.co.uk. Ended up being around £30 for a couple of nuts and bolts, 2 springs and spacers.

I removed the bypass valve, to get at it you need  to remove the airboxes, MAF sensor and exhaust heat sheild. The old gasket rings were very flat and caked into the valve, I did however, manage to pry them free and position the new capristo gaskets, refitted the gasket with the bolt kit. Reassembled the car and fired it up! Still blowing!

I took it all to bits again and applied a little bit of exhaust paste around  the gaskets and refitted everything. The blow appears to be gone but now the car is idling too low around 750rpm and runs really badly up until about 2000/3000rpm.

When I initially fitted Nouvalari the car did run slightly oddly at first but turning the battery off and letting the ECU relearn did the trick. I will give this a try at the weekend along with hooking up an OBD 2 reader to see if I've done something to the MAF sensor!