For those interested I thought I would show the process of putting together a set of cats and y-pipe for my 95B. I will build headers for it as well but that will wait until the next engine out. For now the plan is to build replacement cats with Magnaflow 59904 metallic cores. I would do test pipes but prefer to keep the exhaust smell to a minimum. I'm also going to build a new y-pipe. Materials are ordered and flanges are being cut by a local water jet company. (I couldn't find any ready available with the proper bolt spacing). First step is as pictured, building simple fixtures off of the original parts- Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
If I'm building something from scratch, no problem building on the car but if I have a factory part and I want to match the dimensions, I find it easier to fixture the part and build it on the bench. This way I can also avoid tack welding the tubes in the car. Still waiting on some parts. Cats have not arrived yet and the flanges I'm having made are also not finished. I did start on the y-pipe. Using mandrel bends and merge collector from SPD. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Very smart-looking welds there. I also had my cats rebuilt with aftermarket metallic cores (my 5.2 cats cracked). Aside from cost, there's no reason to ride dirty with today's sport cats. May I ask if something is wrong with your original Y-pipe, or the reason you wanted to build a new one?
Thanks Chan. I don't like the fuel smell with no cats which is the reason for keeping them on the primary side. As for the y-pipe, no problem with it, I just wanted to build a replacement for better flow, sound and lighter weight. I don't think the metallic cores in the y-pipe are restrictive but the "Y" section could be improved upon as the internal transitions are not very smooth. Much to be gained in power? I doubt it, but it's winter so it gives me something to do
I purchased one from Bradan but never put it on the car. They did a thread awhile back with dyno results. Fabspeed claims between 5-8 hp. I bought another OEM Y pipe figuring I would keep the OEM look and gutted it, but did not put that on the car either after hearing from others that they didn't notice any gains other than a change in sound. http://www.ferrarichat.com/forum/348-355-sponsored-bradan/313866-bradan-f355-2-7-y-pipe.html
Looks great! I would like to do the same, cats on primary and secondary open. Should help calm my exhaust sound in normal driving as well.
Lookin good so far! I've always liked to look of the Kriessegg Y-pipe if you haven't seen it yet. Kreissieg M2.7 Y-Pipe Ferrari F355 94-99
Thanks Ken. That Kreissieg piece looks really nice! I originally thought about doing it that way (build the merge out of the mandrel bends themselves) but SPD was going to charge me another $250 for setup to do 2 60deg (I think that's what it was) bends as they are not a stock item. I do like the look of the 2-1 merge collector as well, takes up a bit more real estate
Thanks! I finally got my flanges today and was able to finish the y-pipe. I wasn't able to find flanges in the correct size so it ended up costing me $50 each to have them water jet from .600 304 stainless and machined with a bevel. Simple part, easy to make. On to the cats now. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Thanks Jim! Seyhan, 5.2 is a bit more work but shouldn't be too bad I fabbed up the cats tonight. All the parts are ready now. Just have to wait for my Capristo 2 to arrive so I can install all this stuff. Also I showed a few pics of backpurging with argon to prevent sugaring. (This shields/protects the root of the weld). You can see how the inside of the pipe at the weld joint is shiny when this is done. I also welded a scrap piece and took a photo so you can see how it gets crusty inside with no back purge. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login