http://youtu.be/xD6xyaaeGeU Just got it last week, but I'm wondering if my exhaust bypass valve is opening (does it open when revving?). I've been watching videos of other f355s on youtube and they sound louder than mine. Could be placebo because my last car had a modified exhaust and was pretty loud.
Is that a stock exhaust, actually it doesn't even sound like the the bypass is opening (maybe you never revved it high enough when yo took off there?) If you had a tubi with the bypass open you'd DEFINITELY know - so would your neighbors, and their neighbors - and the people one or two streets over... I have had many many loud cars and I still find my tubi with open bypass quite loud, I want to try it with a functioning valve now... or if mine does not work I want to add a controller to it.
Bypass doesn't open when reving as far as I know. It opens when it hits a certain rpm and load on the engine. I experimented with a vacuum gauge that I ran from my engine compartment to the drivers seat once. Sounds normal to me.
i am normally not a fan of modifications but the sound of the stock exhaust is a little flat. a 355 with tubi or similar system is one of the best sounding Ferrari ever. go for it and upgrade yours!
Thanks guys. I would have posted a video of a longer run, but I couldn't find any safe or secluded road to get a video on. I'll probably be doing cat bypass pipes soon.
the bypass do not open ..... there is a clear difference in sound when it does.... and be careful with upgrades. Try to get a ride in some cars with different systems before decision and dont listen to advice ... listen yourself the bypass open around 4000 rpm
The bypass does not open while revving the engine. The wheels must be moving. Bypass valve opens up when the throttle is at 80% or greater and at these RPM's: 1, 2, 4, 5 & 6 th gear = 2800 RPM 3rd gear 4000 rpm You should hear an audible difference in a deeper tone. You can test it, as I did, with a vacuum gauge spliced into the by-pass line and run into the cockpit. You can see it kick in and out on the gauge under the conditions described above.
I don't know if the Tubi puts in a different bypass valve, but I've read that you can manually wrap some strong wire or something to force the valve open. I've also read that you need to reprogram the ECU if you do that, or else it runs lean? That may be the course I take in the future if so, I don't care about a stupid valve, just leave it open!!
Tubi does not replace the factory valve on the 355. I have seen a spacer that replaces the valve on some cars but I dont know who or where they are from. You can saftey wire the by pass open but there has been alot of discussion on here and you should search it out and do your own research before making your choice of wired open or not.
eventhough the bybass valve opens at 4000RPM, i still don't think my tubi is loud or even sounds like a formula 1 car.
The bypass valve should open at 4000 RPM when revving the engine you can actualy see the actuator rod move up and down when the valve opens.
Yep! Mine is totally stock and the valve opens whilst reving at standstill, it has nothing to do with the "wheels moving" the ECU takes into account gear selection, throttle opening and revs, nothing to do with speed or motion.
Really? The owners manual states the RPM's I listed above. So it uses 4000 for neutral? Funny it does not reference that anywhere.
I agree with the RPMs listed, not really sure what RPM it is when stationary though. Have you never been asked to rev your car whilst stationary??
Of course not!!!! In all seriousness, running the revs up past 4k in neutral is not something I would do very often....if at all. Even at a stop light with idiot-du-jour next to me. Guess I need to go give it a look.... and update my Owner & WSM once completed. Thanks!
Get rid of your cats and bypass and you will hear and feel the differance. Mine have been off for 12 years at least. These 2 items are the main reasons for your OEM headers cracking. I just pulled my cats and bypass valve off the shelf and they are in great shape if anyone is interested in buying them.
Well when I got home from work I decided to take a look at the bypass valve. Everything under the hood is in great condition. I reached downed and was able to manually open and close the valve myself. After doing it a bunch (mainly to ensure it was easy to do and not stuck or anything) the little bar came disconnected. This allowed me to place the valve in open or closed and stay there. I drove around a bit with it open and it sounds a lot better, more aggressive. I also have a high idle issue, so I'm still tackling that, but I couldn't detect any holes or cracks in any of the tubes, so I'm wondering if it's my idle throttle thingy that is connected to the top of the ypipe.
Wiring open your bypass valve will throw a P1448 CEL code after about 50 miles or so. Too many posts here about possible engine damage if left wired open. Still think the 355 sounds awesome even with the stock exhaust system.
Your car sounds just fine. If you want it louder, find yourself a Challenge Exhaust...frickin' awesome.
