Gothspeed bypass valve

I always wonder about these threads. Things like the goth valve, Capristo valve, were made because the Ferrari valve was some how deemed unreliable. BUT, mt car, 25 yrs old, 30k miles has the original valve and it works fine, doesn't rattle. Most other, all other 355s I've seen also have the original valve. Is this just another case of Ferrari Chat mania? The one does it so they all must do it. Hence you drink the cool aid and replace your working OEM valve because you read about the failures on FChat?

 

I have tangential experience with bypass valves in my day-job (engineer for a turbocharger manufacturer) and can attest that the design of a high temperature exhaust bypass valve is WAY harder than it might seem. It is not just a case of using “better” materials, there is tons of trial and error and durability testing to get it to not to stick or prematurely wear out.

 

Seems like there are legitimate cases of rattling valves out there, have seen 2 cars myself with the issue, but I’m like you, 46k miles on the original valve and no rattles on mine.

 

Think it depends on year of manufacture, driving style, luck. I’ve seen three cars with rattle including mine.

 

I always assumed some cars developed a rattle (probably a small number) for what ever reason and OEM was too expensive to replace with so aftermarket was put on and so there it begins followed by others replacing their good OEM aftermarket one due to aftermarket'itis etc.

 

I’ve often wondered if the aftermarket mufflers (which a large number of cars have) has any impact on the bypass valve durability. Seems strange that some fail and some don’t. Not sure that it depends on year though, the part number never changed throughout the production run. Driving style could very well be a factor. FWIW - I have a personal rule that every time I drive my car the bypass valve has to be “exercised” . Nearly 10k miles in my ownership and no issues.

 

Just a lot of ain't broke, fix it anyway around here. At least one person admits to taking off the goth unit and putting back the (working) OEM one.

 

This is very sound advice. For many years I owned a 930 Porsche and there was a sentence in the owners manual maintenance section that stated you should periodically after reaching proper operating temperature to engage first gear and bring engine to full boost to "blow out the wastegate". I never forgot that and even though I only own two turbo powered vehicles I periodically will bring any of my cars to "full boost".

 

And deal with the rattles...

 

Still better than not working, no?

But I have no rattles.

There has been at least one thread where someone addressed fixing the rattles.

 

Yeah, I know. But at the time when I was addressing the issue, the gothspeed valve seemed to be the best solution because it was really close to an OEM look and finish. And really, I think the workmanship is really top notch it just needs to have the correct size bushings made from better material. As mentioned in post # 52 it will take some trial and error, I'm just not ready to throw it in the dumpster just yet.

 

I hope you work it out . One way or the other you have work to do: fix the OEM rattle , or fix whatever the Goth valve needs.

But too nice in New England this time of year to be working on cars. Time to be out driving.

 

Yes, exactly. That is why I just put the oem unit back in. I will be able to take my time and experiment with different repairs before finally reinstalling the gothspeed valve.

 

Unfortunately I’m unable to switch to OEM as my was jammed to non-repairable

 

Is the OEM one NLA these days?

 

Yes. At least at european dealer network.

 

Mine is a twin valve and the operation is different so it may last longer. Mine has and no no rattle