So i picked up an exhaust off an F355 from ebay yesterday. It has three inlets for exhaust from the engine. One for each bank, and a separate one that is supposed to be operated by vacuum. On the ferrari if came off, It opens at around 3000 rpm for extra flow apparently. It has me thinking that maybe the the normal 2 ports wouldn't be enough flow to support the 3800 without the third opening. I am trying to figure out a way to incorporate this third port into the rest of the exhaust in some way. I have an idea, although not sure how it will work out. The plan would be, since I am running separate manifolds, to run a "Y" off each exhaust bank and bring them together via another "Y". Then, before running into the third port, I have to figure out somewhat of a vacuum operated exhaust valve, or something i can hook a cable to and hook it in conjunction with the throttle cable so that it opens as the throttle opens. This is the area I am looking for help in. Anyone have any ideas?

Here is a link to a discussion I found online. Hopefully it will work:

http://www.google.ca/url?sa...YSB1Boko6lElmuAiknyg

So I'm assuming you're the guy that won the auction for $50 on ebay, and commented asking how big the inlets were on my Facebook post? Sorry I never replied to that I've been super busy lately. That's the guy I got mine from. When I got to his place he had 2 of them sitting there. Kind of made me wonder how he got them. I offered him $60 for the one I got since there weren't any bids on it yet. I actually thought about bidding on it after I got home with the one I bought since I knew he had 2 and it was listed for free shipping. He's got to be taking a loss shipping that thing, especially to Canada. Good luck with your install and be sure to share pics and such. Mine may not be installed for a while, I need to get my swap running right first.

Zach

Yes I am the same person who commented on your Post on Facebook, but I didn't get the one for 50$. That one was on auction that ended during the afternoon, I was at work and unable to babysit the computer till the final seconds to make sure I won it. I ended up getting another one that was on there for 150$.

I did a bunch of reading on on the exhaust, and it appears that the 3rd port may have to be used as well as the other two to get proper flow at higher rpm....but not 100% sure.
troy

Will be watching this thread as I will be running an F355 muffler on my 3800SC swap.

Thanks

Here's a diagram of the exhaust on the Ferrari:



What are the diameters of the two lower ports? I would be they could flow enough for the 3800 without the bypass.

Here's an archived thread on the exact same muffler (might even be whomever sold you the muffler, that started it): http://www.fiero.nl/forum/A...120111-1-083674.html

quote Originally posted by dobey: Here's a diagram of the exhaust on the Ferrari: What are the diameters of the two lower ports? I would be they could flow enough for the 3800 without the bypass. Here's an archived thread on the exact same muffler (might even be whomever sold you the muffler, that started it): http://www.fiero.nl/forum/A...120111-1-083674.html

The image doesn't seem to be working for me. I found this one in the archived thread.


This is basically how i am planning on running it to incorporate the bypass port. I am not sure on the port sizes yet, since I have yet to receive the exhaust. It is on it's way from rochester. Probably another week or so before it lands here.

this is a vacuum valve that i found on ebay. This particular one is 3", but i seen them in 2.5" as well. I am thinking something like this might do the trick for me?