Capristo exhaust bypass valve owners

If you are speaking of the oem type replacement valve made by Capristo, the opening is not adjustable. It opens differently than the stock one, but is still triggered in the same manner, via a signal from the Motronic to a eletrovalve. It does seem to open a bit more willingly to me, but that just maybe my perception, rather than reality.

Have you attempted to adjust your oem one? You can remove it, and adjust the pre-tension. A couple turns out should do it. PM me and we can talk on the phone, it would be easier than writing a lengthy explanation....

 

Can you please provide a link regarding adjusting the pre-tension on the valve, calling you is an option, if you don't mind and depending on the time difference between New Zealand and where you are.

 

To adjust you first need to remove it. This requires removal of the air boxes and heat shield. I just remove the air boxes as a single assembly. So unhook the air ducts to each air box, remove the hose to the MAF and then take off the various nuts holding the air boxes down and take the whole thing out. (remember to take off the MAF connector plug, and the vacuum line to the exhaust valve) Then I remove the nuts to the heat shield and remove it.

Now I remove the two bolt, nut, spring assemblies holding the exhaust valve in. Once those are removed, you will need to pry the muffler a bit to create a gap to slip the exhaust valve out (I used a wooden broom stick). Once it is out, you can see that there is a nut that acts as a "lock nut" to hold the adjustment rod in place. Loosen it, and turn the rod about two turns out (to turn it "out" you will need to remove the three small nuts holding the pneumatic thingy (technical term) and turn it out). You probably can turn it out a maximum of three or four turns, then the thing is "undone" and no longer threaded into the ball socket. Start with two turns. It has been experienced by one other f-chatter that if you put too much pre-tension on it, it can prevent it from opening. I have not experienced this, and had mine out the max it would allow, and it no longer rattled, and worked normally. It is easily adjusted, so no biggie, you can always back it off if needed. Obviously this spring looses some tension with time and heat, and adding some pre-tension brings it back into spec.

Attached is a side by side of the Capristo valve and the oem Pierburg valve so you can see the threaded rod and ball socket that you are adjusting.

BTW, I give credit to JH355 for teaching me this.

Good luck.
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I thought the Capristo valve had some sort of electronic activation via remote that could be adjusted for different opening times...

 

My understanding is they offer that option when you buy the entire exhaust system. AND, my understanding was the opening was not adjustable, it was either working via the Motronic, like stock, or you could activate the electrovalve, and force the valve to always be open. (this is by taking away the vacuum to the valve). I would imagine with a little study of the operation, they are perhaps interrupting power to the eletrovalve, causing it to no longer direct vacuum to the exhaust valve to keep it closed. I am not an expert on how this thing works, but I bet you could wire up your own switch to the electrovalve. Unlike the stock valve, which requires vacuum to open it, this one works in reverse, and requires vacuum to close it. So it includes a different electrovalve and you "re-plumb" it to work this way. The simple way to open the valve constantly would be to simply yank the vacuum line to it, and stick a golf tee in it. The valve's normal at rest position with engine off (no vacuum) is open. If I shut off my engine and pop the lid to watch it...about 15 to 20 seconds after shut down it looses vacuum, and I can see the valve open.

 

Thank you for the reply. I will get into this soon. Am I winding the shaft out or in to the diaphragm above it? I guess that will become clear when the valve is in my hands and I can see the butterfly, essentially my aim is to put more pressure on that butterfly. Correct?

Thank you again for your help, very informative.

 

The latest capristo solution requires a drilled hole in the exhaust pipe to install a sensor there.
The sensor pulls backpressure values and sends it to the capristo box which triggers the valve to open (and to close again).
Important to understand: The OEM brain is no longer attached and the revs are no longer read to operate the valve - it's backpressure now.

3 modi:

- sport (opens very early)
- travelling (almost stock)
- always open (well ... If you need that)

You can programm the first 2 modi by yourself by RC unit.
I think it's a reasonable approach.

For further questions you should visit Tony's site too, because I can't explain from my own experience; my stock pierburg is still fine.

cinque

 

Hi,

My name is Martin and I have recently joined the Capristo team. I have noticed that there are different queries and I wish to give some explanations on this subject.

1) 355 Bypass valve
The original bypass valve is closed when without vacuum. But the problem is that the vacuum must be generated before the valve
opens. This means a delayed opening of the valve. If the driver aggressively accelerates, this will impair both the manifold and the
engine. If a vacuum tube is damaged, the vacuum cannot be generated and, as a result, the outlet valves would be damaged. This could
also lead to a damaged manifold or engine. It happens often that the vacuum is only partly existing, the valve opens, but only at a
small portion, not completely, and the driver is of the opinion that it has opened completely, because there is a change in the sound.
Considering the electronic way, both electronic bypass valves are controlled at the same time, that means our valve as well as the
series valve.

2) Capristo Bypass valve
This system works quite the other way round. The opening is effected by means of a spring fixed in the vacuum diaphragm. That's
the reason why it functions faster than the series part. The valve is closed by means of vacuum. This is a proven system, because
the recent Ferrari Models (360 Modena, Enzo), the same principle is applied like our system. It provides the big advantage that the
bypass valve keeps open in case of a damaged tube. In such a case the series valve, however, remains closed and could cause
damages. Moreover, we have a new system of patented exhaust gas valves which do not generate any vibrations at all, because this
was also a well-known problem of every exhaust gas valve-manufacturer. Another big advantage of our valves is that one can buy a
repair kit at a price of Euro 18,-- for overhauling our valves, because they really get hot during operation and they move. Therefore
they are wear parts and we offer the possibility to overhaul them. When we design a new part, we are focussed on the safety of the
engine.This is also applicable to our exhaust system for the 355, which cools down at full load. If the exhaust gas valves open,
fresh air is taken in by means of two endpipes thus cooling the complete exhaust system. If the fresh (cool) air is taken in through the
endpipes, the portion of oxygene is detected by the lambda sensor and additional fuel is injected. That's the reason why the exhaust
fumes are cooler. If you have a look at an old exhaust system supplied by our company, you will notice, that there are no overheating
changes on the stainless steel in the middle of the muffler. Furthermore we use a heat-resistant stainless steel T309 and is comparable
with Inconell.




I would like to seize the opportunity to explain the new control unit for the exhaust gas valves.

The aim of the new control unit is to enable the driver to programme himself each valve-controlled exhaust system, irrespective of the manufacturer, including the original exhaust system.

This control unit provides the opportunity to programme the back pressure preferred by the individual driver. In this way one can achieve the maximum performance provided by the installed exhaust system.

The advantages of the new control towards the previously used control unit are detailed below.

1) The control unit can simply be connected to the battery. If no back pressure is detected for a 10 minutes` period (this period is
freely programmable, can possibly be extended) the control unit changes automatically into the standby modus and does not consume any
power. For this reason there is no danger of discharging the battery
while the car is not used.

2) The control unit has an illuminated display showing all functions in plain text in 3 different languages (German, Italian, English).

3) The control unit is TÜV-suitable (TÜV = Technical Supervisory Board), since the modus "exhaust gas valve open" can be suppressed.

4) The control unit can be installed in a severely accessible location (sight contact required), because all of the functions provided by
the control unit can be programmed via the remote control.

5) The size of the device has been reduced by 2/3 and is splash water-protected.

6) When starting the engine the "Travel modus" is automatically adjusted.
Pushing the right button means changing into the "Sport modus". Keeping the
right button pushed for 3 seconds means opening the exhaust gas valves and they remain open. Every time the left button is pushed, the presently
selected modus changes automatically into the "Travel modus".

7) The exact point of opening the exhaust gas valves is individually programmable in both the "Sport Modus" and the "Travel Modus".

8) The pressure cylinder essential for the old type of control unit is no longer required. This was solved by using an electronic way.


An important question is to ask for the work involved for carrying out a modification on a valve-controlled exhaust system. This work is
specified below.

1) One has to drill a hole in a tube and to weld on a threaded part provided by us and to connect this to our monitoring device by means of
tube made of silicone provided by us.

2) Connect the device to + and - power.

3) Remove the cubic plug of the existing electronic change-over valve and put on the compatible plug of our device.


Ready! That's it! Now the exhaust gas valves are controlled via our back pressure monitoring device dependent on the back pressure.

What' the purpose of such a modification?

It will never happen again that the motor is exposed to too much back pressure, because this could lead to excessive consumption, damage on manifolds, overheating or even to an engine breakdown.

What's the advantage compared with other systems?

There are systems which work dependent on rpm or speed. The problem, however, is that the motor has always a different back pressure at the same speed (e.g. 50 km/h) dependent on the gear chosen by the driver. As a result it may be that the exhaust gas valves remain closed even at an increased back pressure.

The same problem also occurs when dependent on the revolutions (e.g.
5000 rpm). The back pressure at 5000 rpm varies dependent on the gear chosen by the driver. Driving at 5000 rpm in the second gear means less back pressure than using the sixth gear for a possible speed of 200 km/h.

Our control unit is directed to the source of influencing the performanc.
That's solely the back pressure. Irrespective of the revolutions per minute or the speed, only the back pressure is allowed that gives power and does not impair the power.

As soon as the programmed back pressure is reached, the exhaust gas valves are immediately open.

Another big advantage is that the control device recognizes the driver operation characteristics. If the driver aggressively accelerates, this is identified by our device by means of the kind in which the back pressure is generated, and the exhaust gas valves open immediately.
Usual
accelerating results into a later opening of the exhaust gas valves.

I hope that I have given enough explanations on the functions of the new control.

If you have any further questions, please do not hesitate to contact us under [email protected]

Martin
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Thanks for explaining Martin!!! Very nice writeup... I have one of your newer systems that incorporates the dual bypass valves...

 

Thanks Martin,

guess it's also worth to point out that all kind of muffler/cat combos are supported.
Assuming they provide different backpressure, you're always automatically adjusted.

Any example of (re-) programming one of the modes would be nice.

cinque

 

The one I got?

 

Hello 285 Ferrari,
all our 355 Exhaust are so constructed that they remain colder,
Your exhaust is the inferno on earth, where we have the problem of 355 discovered, we have built the racing exhaust
with two valves, we wanted to see whether more power, and it was so! we guarantee 20HP more, we have tested about 15 cars and the majority of the performance of the cars was on hall from 21 to 32 HP more, if you want I can show you diagrams, we have different
Headers tested, and the best results we had with the originals.

apologize for my English but Martin is Monday again in the company.

Antonio

 

So the 355 exhaust with the dual bypass valves is considered the Race exhaust?

 

Yes, the version with two valves is a Recing exhaust, is designed for maximum performance, and to protect the engine and Headers?

 

That is the one I have...

 

285ferrari: Have you felt any difference in power with that exhaust? How is the sound from it? Very "Growly" - screamy, or F1:ish?

K /// Sweden.

 

Capristo race exhaust / Fabspeed headers / Hyperflow cats

 

Do you have a photo of your Headers? can send via e-mail?

 

http://video.google.com/videoplay?docid=-7399112760534170948&q=source:005939121701826182817&hl=en

 

Sounds like a Challenge Stradale ....... !

http://www.youtube.com/watch?v=QUUWMLJR-KQ

 

285ferrari:

Do you still have your original Bypassvalve mounted? And a Capristo level 3 with 2 more "valves"? If im correct, then you have 3 exhaustvalves in your car?

Is this really necessary?

Im a little confused about these Capristo exhaust systems and valves. I now have a Tubi Race-exhaust muffler on my car, and i still think its too "growly", not so F1:ish as i would like at high rpm:s. Also its a little quiet in the whole range. Before i took my engine out a couple of weeks ago, i started my car up without the muffler, just with the cats, and it didnt sound as loud as i thought. Sounded very racey though... So, i will change my exhaust during this major on the engine/car, but im not sure what exhaust to go with. I have looked at Kreissieg, MS-Racing and Capristo. The thing with Kreissieg and MS-Racing, is that they run straight pipes when the bypass opens... No muffler is involved in those cases, at high rpm:s. This is for me very interesting...

Maybe ill just re-weld my Tubi, so it works like KS or MS, straight out when Bypass is open...

Anyone measured the primary-tubes on Fabspeed Headers - Are they using the same length and diameter on these, as Ferrari Original Headers?

K /// Sweden.

 

The original bypass valve is removed. The Capristo race exhaust that I have has 2 bypass valves built onto the exhaust itself....One on the left and one on the right side

 

http://www.allaboutmedia.de/capristo.de/bild.php?aW1hZ2VzL3ByZF9ncnAvem9vbS92ZW50aWwuanBn

Pic of the valve on the exhaust..