When does the exhaust valve activate on a 360?

Hi,
does anoybody know the answers to that questions?
I would like to know this, too. My 360 still has a Tubistyle with no valves so I cannot "test" it.
Thanks.

 

I think the stock exhaust opens the valves at 4000rpms

 

ECU's control the exhaust flaps based on a map that uses engine revs and throttle position. See below the stock exhaust flap map for normal and sport taken from a Euro 360:

Normal mode:
No. | 0 1 2 3 4 5 6 7 8 9
PHY| 800.00 1520.00 2520.00 3000.00 4000.00 5000.00 5800.00 6000.00 6200.00 9000.00
--------------+------------------------------------------------------------------------------------------
0 PHY| 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
54 PHY| 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
64 PHY| 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
69 PHY| 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.0 1.0 1.0
81 PHY| 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.0 2.0 2.0
90 PHY| 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.0 2.0 2.0

SPORT MODE:
No. | 0 1 2 3 4 5 6 7 8 9
PHY| 800.00 1520.00 2520.00 3000.00 4000.00 5000.00 5800.00 6000.00 6200.00 9000.00
--------------+------------------------------------------------------------------------------------------
0 PHY| 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.0 2.0 2.0
54 PHY| 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.0 2.0 2.0
64 PHY| 0.0 0.0 0.0 0.0 0.0 1.0 1.0 1.0 2.0 2.0
69 PHY| 0.0 0.0 0.0 0.0 0.0 1.0 1.0 2.0 2.0 2.0
81 PHY| 0.0 0.0 0.0 0.0 0.0 1.0 2.0 2.0 2.0 2.0
90 PHY| 0.0 0.0 0.0 0.0 0.0 1.0 2.0 2.0 2.0 2.0

 

Interesting. The F355 had a number of factors, too, including gear selected.

If 0.0 is closed, what is 1.0 and 2.0?

 

I believe that indicates 1 valve open and both valves open.

Kevin

 

Thanks, Kevin. So, exhaust coming out of 3 muffler tips at 1.0 and 4 tips at 2.0?

I had a look at the AldousVoice website, but despite the muffler being cut open, it's still hard to visualise the gas flow

https://aldousvoice.com/2013/11/18/ferrari-360-exhaust-silencer/

 

No way one exhaust bypass valve opens and the other stays closed since they are both controlled by the same solenoid and vacuum source. What the 1.0 likely indicates is hysteresis, where the valve is in the process of opening or closing and 2.0 indicates fully open. The engine loads are on the left of the chart. The WSM says 2920 rpm, 70% load and 20 degree closing delay (hysteresis) for Euro models. Section 3.05.

See the F430 schedule below for an example.



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The parts catalogue shows two solenoids, Taz. Item 28.

https://www.eurospares.co.uk/parts/ferrari/360-modena/bodywork-lighting/pneumatics-actuator-system-40643

Also, the Spider wiring diagrams you gave us show two components called "exhaust manifold balancing valves". I'm pretty sure these are the bypass valve solenoid valves. The Left ECU controls the Left valve, the Right ECU controls the Right valve. The F430 wiring diagrams do label the valves Left and Right exhaust bypass solenoid valves.

That's not to say that they don't open and close at the same time. I assume the ECUs have the same part number, so unless the ECUs are programmed by, say, shorting out pins (on one bank), they may very well open at the same time.

 

Both valves open and close at the same time.
0, 1 and 2 are definitively there to manage an hysteresis in the valve operation. You don't want to have the "close-to-open" and "open-to-close" thresholds at the same RPM or the same engine load, otherwise the valves would oscillate between positions because of small variations when you are close to the thresholds.
The 1 is there to manage a guard-band (RPM or load). ie. both valves open (RPM or load increase) when map reaches 2, and both valves close (RPM or load decrease) when map reaches 0. When map is at 1, the valves stay in their previous configuration.
This is a simple way to manage "close-to-open" and "open-to-close" transistions, at different thresholds, with a single map.

 

I stand corrected. Apologize for the misinformation. Learn something new every day. Thanks, guys!!

Kevin

 

Eric, can you send me a PM about an ECU for my 2000 360. Want to go 2003+ with CS or CS TCU. Sorry I am new and couldnt find a way to PM you.

Chris

 

Ian- Thanks, did not realize there were two solenoids since the V12s only have one. Should have looked.

 

I want to weigh in here ...

The thresholds for opening / closing the exhaust bypass valves are a combination of engine RPM and throttle position. There may also be additional parameters of vehicle speed and what gear the car is in. I am not sure exactly how many thresholds there are or what the values may be, but suffice it to say that there are more than just a simple engine RPM thresholds.

As the vacuum is applied through a simple pair of solenoid valves, the vacuum is either applied (valves closed) or the vacuum is vented to atmosphere (valves open). Nothing in between. They are either open or closed. It is possible that if insufficient vacuum is available when applying vacuum that there might not be enough vacuum to fully overcome the spring in the actuators on the flapper valves which could result in a partially closed valve, but this would not be by design as the car has a vacuum accumulation tank.

it is not likely that the valves will close at exactly the same point as they open due to the many variables.

Bottom line, just get an exhaust valve controller or disconnect the electrical connector on solenoids (360 only) and stop stressing.

 

I'm trying to understand how the solenoid valves work. The F355 has the same solenoid valve as the 360, but operates in the opposite sense (vacuum = open). I was under the impression that the 355 energised the solenoid to get vacuum to the exhaust valve. If this is the case, does this mean the solenoid is usually activated on the 360 at low rpms or is the "opposite sense" achieved via the exhaust valve mechanism?

I found this picture of a typical solenoid valve, but it may be too blurry to make any sense of.

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It looks like the solenoid is compressing the spring, venting the line going to the exhaust valve to atmosphere (not the vacuum source venting to atmosphere), but that wouldn't make sense on the 355.

 

Ian, the main difference between 355 and 360 is that the vacuum operated valves (not the solenoid valve) are working the opposite :
- on the 360, with no vacuum, the valves are opened
- on the 355, with no vacuum, the valve is closed

So, indeed, on the 360, the electrovalves are energised to close the valves (low RPM and load) while, on the 355, it is energised to open the valve (high RPM or load).

 

Thanks, Eric. It makes sense that the exhaust valves default to open when electrical power or vacuum is lost on the F360, but this means the solenoid valves must get pretty warm (being mostly activated) and perhaps fail earlier than the ones on the F355?

All I have to do now is figure out how that pictured solenoid valve works. It definitely looks as though the vacuum is shut off with the solenoid energised. Perhaps the internals are different on the Ferrari version. Or that spring is in tension, not compression, and the solenoid pulls the plunger up?

 

This is how it works on 360 :
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With no power on electrovalve, the exhaust valve is vented to atmosphere (open port in grey) and vacuum port is blocked
With power on electrovalve, the exhaust valve is connected to vacuum tank.

 

Not 100% certain, but believe the solenoid valve is same on the F355 as the 360. Might be different part numbers, but for all practical purposes the same.

What is different is the exhaust bypass valve. On the F355, 550, and 575M the exhaust bypass valves revert to closed at the loss of vacuum. Whereas on all other cars with vacuum actuated valves, they open at loss of vacuum.

On the F355, 550, and 575M the bypass valves are closed when the engine is off and there is no vacuum present. After starting the engine, the valves remain closed until the threshold point is reached and then car’s ECU activates the solenoid valve to pass vacuum to the bypass valves and they open.

On other cars, the bypass valves are open when the engine is off and there is no vacuum. After starting the engine, the cars ECU activates the solenoid valves to pass vacuum to the bypass valves and they close. When the threshold points are reached, the ECU deactivates the solenoid valve which vents the bypass valves to atmosphere and they open.

By the way, those solenoid valves are robust little critters and rarely fail. If they do fail, they are inexpensive and can be found for around $20 or so. But when purchased as “genuine” Ferrari part number will cost 3x to 6x.

 

Ferrari changed the way they did bypass valves around the time the 360 and its fail open valves came out. On the 550 and follow-on 575M, vacuum opens the valves so they are fail closed, but later V12 Ferraris went to fail open, which is the most logical way to do it. We fudged the valves open on our Maranellos by bypassing the solenoid so vacuum was present all the time. Much easier to plug the lines in later cars so the valves are open all the time.

Best solution is one of Steve Bisel's remote valve controls, which offer either a remote control or control via a switch.

 

One other strange thing Ferrari did on the F355 was to use a single exhaust bypass valve on a Y-pipe.
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Why is anyone’s guess. That Y-pipe has a small catalytic converter as part of it, but the catalyst action is not monitored by any O2 sensors. And over time that bypass valve gets loose and rattles and many people would tie it up permanently open. But doing so would route gas thru the Y-pipe at all times and the catalytic material would overheat and trigger the temp sensor in that area and the car would throw a Slow Down indicator cuz that Y-pipe could be red hot. As the catalytic converter in the Y-pipe is not monitored, one can remove it from the car without any consequences. Fabspeed sells the Y-pipe replacement (without catalyst material) for around $1000. But one can easily remove the catalytic stuff by punching it out, which eliminates any worries about overheating. To address the rattling bypass valve, Capristo sells a replacement bypass valve which defaults to open instead of default to closed for around $1500.

 

Not strange... just one less thing to break down

With the Capristo setup on the F355, you also have to replace the solenoid valve.

https://capristoexhaust.com/product/ferrari-355-by-pass-exhaust-valve-kit/

I assume this is because the (single) ECU only powers the solenoid valve at high rpms/loads.

 

This is very interesting,

on mine the valves are open on start up for about 30-60 seconds, which is pretty loud, then they close, do you happen to know the details on this?

 

I cut and welded my stock valves back into the tubi tips and it works pretty good.

 

Possible the engine is not generating much vacuum at cold start or the vacuum accumulator has bled down and needs to be "filled". Emptied, actually.