does anyone sell an exhaust piece to remove the bypass valve?
None that I know of. The reason is probably because it is bad for the car. Removing the bypass valve or "wiring open" changes the flow of the exhaust under normal driving conditions. In short, less exhaust travels past the o2 sensors than designed for and this effects how the car runs negatively.
Actually I have heard opposite. Ferrari used to stock this part but not anymore. Interested why you think that way. More knowledge is better for me
Don't do it. The car needs the bypass valve. I'll try to find the thread with advice from Brian Crall on this.
Contact Daytona Auto in Toronto and ask for Alex. They have the replacement piece to take the place of the Bypass which BTW can be removed and is one of the contributing factors in header failure. I know some will not agree. My bypass was removed 15 years ago my car runs great. All challenge cars do not have a bypass valve.
Challenge cars do not have it so I agree with you. Would Ferrari sell this part if it would grenade your engine ?
"NEW" By-Pass Valve Delete Spacer....Ferrari PN17068 and NEW Exhaust Gasket....Ferrari PN159906 Super rare part that is NLA from Ferrari I have this for sale in classified section Image Unavailable, Please Login
I know a 99 that has had the valve open for 15000 miles with no issues and runs great. Car has 25,000 total miles. I wonder what the real answer is here? I suspect no one really knows and people only speculate what they "think".
I don't have the time to locate the thread / post but I read removal can effect back pressure in a negative way. Dave Helms and I also had this conversation. I suggest you research this well before you pull it out.
Dave you may be correct, But some 355's came from the factory without it...if what your saying is true that you need more back pressure at low RPM's then test pipes or flow through cats I'm assuming would cause the same problem. Look at the 355 challenge it both a bypass delete and a better flowing exhaust. So my question is what is the actual problem it causes? Do all challenge cars suffer from this same problem?
Challenge cars have a different ECU - right? I'll try and find the post / thread later. Or, give Dave Helms a call - he is a nice guy and would probably chat with you about it.
I have a BY Pass Valve FOB that opens it, I purposely kept it open for about 30 minutes. I assumed that the Y-Pipe Cats would overheat and the Slow Down light would appear, BUT...it never did? Im still not taking a chance, I only leave it open when warming the car up.
Hi guys This is my first post on the forum but as I was reading and taking more informations about the F129B engine I wanted to jump in this conversation! Correct me if im wrong but my assumption was if you got a faulty unit the EXT valve would be closed all the time. The issue will be more at high rpm's were there is a lot of back pressure and heat building-up if the valve stay closed. If the valve is open all the time you will get less torque through the powerband, and probably O2 false reading if your not WOT. But at high rpm's and WOT the engine should behave just at it should. I guess that's why you can remove the exhaust valves if you use the car for racing as it stay high's rpm's all the time.
Why would your cats overheat with a better flowing exhaust? They should be cooler. One thing that leads to header failure is build up of heat from back pressure that's why people on here use flow thru cats to prolong header life
Yea, I don't get the whole back pressure concern when people are removing cats and mifers with no issues and several other exhaust set ups.
Mine ('95) was wired opened when I got it. It ran fine, though I'd get sporadic CEL lights esp when coasting down hills with no engine load and above idle. De-wired it and no more cell lights. So I too would recommend doing your homework before removing the valve. But if challenge cars didn't have it and their ECU programming is the same as street - then Ferrari probably put it in for noise reduction and everyday driving and if a challenge car was on the street for everyday driving...I'd expect it to generate CEL lights too
Might want to read this thread and others. Within it is the quote from Brian Crall about removing the valve. http://www.ferrarichat.com/forum/348-355-sponsored-bradan/302576-355-bypass-valve-removal.html
Challenge cars do not have any secondary pipes, and therefore do not need to have bypass valves. That is a different design from the stock cars. Comparison is not relevant.
Challenge cars do not have any secondary pipes.. Mitch they do have these Image Unavailable, Please Login
The challenge doesn't have a "muffler" so there is no difference in back pressure between the primary and secondary pipes. The stock F355 does have a pressure difference within the internal baffling in the stock muffler. If the bypass valve is removed or "wired open" too much exhaust will take the path of least resistance, the secondary pipes, than designed and not enough (as designed) will take the primary path which has the 02 sensors. Is this not correct?
I reading the old thread Dave posted, there were people that wired the exhaust open back in 2010. Are anyone of them still here to comment on miles and issues?
