Good day, all. I've finally picked up my new to me F355 GTS and the exhaust bypass valve is rattling at idle. I'm also reasonably confident that it's not opening - I have not driven it much, and taking it easy on the vehicle as a new belt was just installed. I've read through the numerous threads on here, and wanted to get some opinions from from those that have replaced.. (1) Is there a benefit to the Capristo bypass valve over the OEM one in terms of reliability? (I don't plan on using a remote). (2) Would you hesitate to purchase a used OEM valve (Car has about 10,000km) for about half the price of a new OEM replacement (from a a trusted seller)? Any other feedback / suggestions are welcome. Thanks as always!
hi there.. if you cant distinguish the valve opening by exhaust tone alone.. may be harder if you have stock exhaust.. the best way to check if it opens.. is at idle.. if you blip the throttle nicely multiple tips.. the valve will open at idle.. you need someone to look in the hole of the heat shield under the air boxes.. to see if the valve stem is moving up/down.. if it does.. the valve is working.. the oem valve.. will 100% rattle at some point.. back in the day, I've read they rattled/buzzed, in the dealer when car was brand new lol.. some have "claimed" to rebuild the oem valve not to rattle.. which I bought one few years ago.. first start up after installed.. it was buzzing lol.. fine not as bad as the previous one.. my original valve rattled like bolts in a can.. the apparent rebuilt valve is more of a buzz.. so not as bad.. ive learnt to live with it.. for now.. as I refuse to pay the absolutely unacceptable pricing of the capristo valve.. that said, I may eventually crack one day.. as the capristo valve is the only 100% solution..
Is Capristo the only option? Somehow I don't like their reversed functionality. Kreissieg makes a part (also not cheap) but I didn't confirm if it's specific to their muffler or is universal. Nobody else makes the part or has an interchangeable one?
The reversed functionality makes it "safer". The Ferrari 360 adopted a similar philosphy (valve opens if the vacuum or electric system fails)... although on the 360, the ECU has to constantly energise the solenoid valve to keep the bypass valve closed at low rpm. The Capristo does have an issue with the angle of the vacuum pipe on the capsule. It points upwards, not sideways. I think I would pay that for "originality". Did you mean km or miles? 10,000km is almost brand new.
I have the Capristo valve and it's been trouble-free. Works perfectly and has never buzzed. I am sure it is a higher quality part than the factory item.
Another + for capristo valve, its also so easy to just disconnect the hose in 1 second if you want to rig it for loud sound all the time..
I have no doubt the capristo valve is very good quality.. but I just checked the site.. it looks they are following with inflation.. its even more then I last remember.. now at $1400USD.. that is truly an unacceptable price gouging.. fine that's the "mrsp", and can probably find a bit cheaper.. with a vendor.. but with current USD/Cad exchange, shipping, duties etc.. this would hit almost 2k cad.. for a freaking valve.. honestly.. for something their cost.. is likely not more then $150 at most.. this has been beaten to the ground for years.. a couple exhaust manufacturers like Armytrix, weld the valve into the y-pipe section.. but its not sold separately.. and some years ago.. a well regarded member here.. produced a valve.. that looked very promising.. but after some time.. it even had some issues.
Ageed, There are plenty of alternatives. And for the difference in the cost of the valve a machine shop could make a couple of adapters and you would still come out $1000 ahead. I've never had a problem with my bypass valve but if I did it is the path I'd take. https://www.google.com/search?client=firefox-b-1-d&q=vacuum+operated+exhaust+bypass+valve Image Unavailable, Please Login
appreciate the enthusiasm.. but if it was that easy to fit an ebay valve... I don't think we'd be here with 15+ years of discussion about the 355 valve. I read a poste long ago.. someone tried to go this route.. to retro fit an ebay valve.. and it didn't work out. im not a mechanic/engineer.. and would like it not to be so complicated.. for a relative simple mechanical piece.. but somehow it has kept the 355 community hostage forever, with very limited solutions lol..
Has any Has anyone tried? Probably not. I think Ferrari people generally think a $50 bypass valve can't be any good. So what. At $50 you can replace one every year for 28 years before you break even compared to a Carpisto. Probably easier to adapt on a 2.7 car like mine since it has a 1" or so space in there already. Image Unavailable, Please Login
I agree that $1,400 for this valve is absurd. Virtually every sports car on the market these days has one from the factory. It's not a rare item. Of course, anything produced in low volumes for 355's is going to be expensive, but shouldn't be $1,400 expensive.
I have the Goth valve on mine. Anyone know if he is still selling them? I've had mine for 4-5 years with no problem.
Yes it was Goth, I referenced above, who developed his own valve.. at the time, I did not buy one.. but seemed to be very good. glad you have not had any issues, but I did hear at the time, a few had some minor issues. to my understanding they are no longer available, and Goth seems to be MIA in recent years.. his was the only realistic alternative.. although I don't recall the price point at the time..
Goth's exhaust valves were somewhat cheaper than the OEM ones, but still expensive. They look good, but as mentioned, the quality varied. Some jammed (even after they were updated).
I picked up one of the ebay actuators & butterfly. It didn't fit. It wasn't worth turning down one of the lips. It's now in my parts drawer. So I picked up a Porsche actuator (no valve). Worked like a champ after I managed to get the original knuckle off the OEM valve. though inflation has caught up with that part too. There's an older thread with the part link on it. the only down side was the vacuum nipple. it was slightly different meaning a vacuum line would rub on the muffler shield. I put some fuel hose over the vacuum and let that take the rubbing. Every so often, I still have to adjust the actuator lock nuts to accommodate age and some vibration.
I saw this in one of my Porsche magazines. It looks very close to the F355’s but have not seen it in person. Image Unavailable, Please Login
I decided to fit a good quality third party Porsche valve, supplied by 911 Design in the UK. In order to dial out the rattle, I wanted easy control of the rod length and actuator height, so I cut the old valve off leaving some stem attached to the ball joint, then used a 5mm shaft coupling to join it to the shaft of the new valve. I also placed some nuts above the bracket so that the actuator height could be changed when the rod length was changed. It worked really well and I was able to get enough spring pressure to stop the rattle while having enough movement in the rod to fully open the valve: Image Unavailable, Please Login Image Unavailable, Please Login
