bypass valve doesn't open in 2nd gear

I'm in the same boat as you. It's frustrating since I want to hear the scream!

Does anyone have a conclusion here? It's either:

1/ Functioning as intended by the factory

2/ It's broken for many of us and unclear why that's the case.

My guess is it's 1/, but I'm sure there's someone who's much more educated than I to answer this.

Side question: It's also strange that many report that it's 2nd gear that doesn't open for them til at least 4000 rpm (or maybe even up to 6500rpm), but why does the manual say 3rd gear then?

 

I'd like to hear from more 95 owners as well. I installed a Capristo bypass valve thinking it was my valve, well the Capristo opens exactly the same! Nice thing about the Capristo is that if you want to leave it open all the time you just pop the vacuum tube off and it stays open.. I am wondering if bypass opening can be tuned on the ECU to open sooner

 

Aaron, your car is an even earlier car than mine (believed to be the 15th to come to NA, yours might be #1 or 2 ) I've not driven mine since fall but I seem to recall it functioning properly. I'll have it on the road again in about a week and I will check again. I seem to recall around 4K RPM's being the magic number when all hell breaks loose

 

I have a 2.7 car and it opens in second, even if rolling into it from a lower rpm. (either way, 2nd gear opening is 4k instead of 2800 if I remember correctly)

 

Interesting, my car is actually a October of 95 build so I don't think its that early, chassis number is 0055X I believe. My owners manual states that the valve opens at 2800 in 1,2,4,5,6 and 4000 RPM in 3rd (which it does).

 

Now you have me second guessing myself as to what gear opens at a higher rpm.

Either way, it will open in every gear from a lower rpm, not just at high rpm shifts.

I'll check as soon as I have wheels again

 

Hey Aaron, it can't be October 95 with that VIN. My VIN is higher and the build date is July 94

EDIT: If your is 10055X it's later - I was thinking you had no leading 1

 

I have a 95 and my valve doesn't seem to work well in 2nd, or if it does it is at a much higher rpm. Next time I have it out I will pay attention and see specifically if I can trigger it in 2nd. Like someone else mentioned, sometimes it does seem to work in 2nd if I have floored it through 1st, but from a cruising roll it doesn't seem to want to open....maybe it is at a really high rpm but hard for me to tell from sound. I've thought about hooking a vacuum gauge into the system to watch as I try different throttle positions.

Question: Am I correct in assuming the solenoid is either 100% open or closed? It doesn't have partial openings to open the bypass say halfway does it?

 

Correct.

 

It works like this ^^^^^ At least it should.

 

This is how it works for me, however, why do you think the owner's manual states 3rd gear at 4000rpm?

 

From the OM and WSM.

Take notice to the "full power" statement...
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Thanks Dave -- I'm assuming full throttle in each of these gears. Still a mystery to me as to why so many '95 owners are reporting 2nd gear opening at 4000rpm (or even higher).

I look forward to hearing your findings once your '95 is on the road!

 

Will do, Chris. Truth be told, when I drive my cars, I'm pretty aggressive and don't spent much time below 5k RPM's

 

As it should be. 355s do not do well if not driven with enthusiasm. When I open a motor I can tell if it's one that hasn't been given revs regularly. You'd think some owners believe it'll break if above 5k. Low revs in a 355 may constitute abuse!

 

Dave, ever get a chance to test your '95?

 

Does a Tubi separate the mix and ok to drive with the bypass wired open? Or can someone point me in direction to link to a replacement (aftermarket) bypass solenoid (mine is no longer operating and just buzzing ). Thanks!

 

The tubis i have seen do not separate. Both the exhaust paths run into the muffler.

Only the capristo twin pipe or factory challenge separates from what i have seen. Even the regular capristo keeps them together.

 

Here is a challenge poc I think
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Capristo twin valve
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I have this on my car. No mixing of exhaust gases in the exhaust because, well, there isn't an exhaust
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I guess if that is a tubi then your correct? Have not seen that one advertised before.

 

Briefly. I only drove it a few hundred miles before I sold it.

In second, it really only seemed to open if hammering it as the WSM states but when hammering in 2nd, you are not there very long so it's hard to get a good sense. For other gears, 4K RPM (ish) seemed to be the norm (contrary to the 2800 published)

 

That's the Topspeed Pro Challenge-type exhaust. This is a Challenge exhaust...

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Ok looks like they kinda copied the challenge then?