Disconnecting bypass muffler valves?

Which car? 360? 430? I invite you to make a search as this subject has been covered so so many times on both models

 

Search will reveal a number of threads with comments and "how to" detail but yes, lots of people do it, you can either pull the vacuum pipe off (and plug it) or pull the electrical connector off the valve control solenoid or you can interrupt the wire controlling the solenoid and wire a switch from the cockpit to turn on and off factory setting at will.

Yes they stay open.

Adverse effect? They don't sound great at tick over with valves open (in my opinion) but once you're rolling they're fine. Perhaps a very marginal loss in low torque. Downshift heel and toe a little more satisfying. No adverse effects, no CEL, no louder above 3k than standard.

 

I just unplugged the electrical connection to the valves on my 360 yesterday. Sounds great. No issues. Wish I would have done it sooner.

 

I had the dealer do it. They just plugged the tubes with a large bolt. It did nothing to the drivability or the emissions. It just sounds louder at low RPM's and no longer is schizophrenic (soft.... LOUD!..... soft.... LOUD!).

The biggest disadvantage is your neighbors may object when you start up and roll out past them.

 

No problem . The best solution I can advise you is to install the Capristo Remote Control so that you can decide yourself when you want to have the exhaust valves open. it's a good solution also for your neighbors and when the engine is still not entirely warmed up, it's much smoother to drive the car with the valves closed. Then when the car is at the right temp, a simple press on the remote control button, and there you go.

Here is the DIY guide which may help : http://www.ferrarichat.com/forum/showthread.php?t=310472&highlight=DIY+remote+control

Stef

 

What tubes? Your are only disconnecting the electrical connection. What am I missing?

 

Yes and No. It depends on the type of muffler you have.

If you have the factory sport CS muffler on the 360 or the factory F430 muffler and you disconnect the vacuum line to the muffler bypass valves you will have a louder exhaust sound during idle and at lower rpm but you will lose some noticeable power at lower RPM's. This is documented by the factory per my service advisor and I even was able to notice the negative effect on my 360.
But if you want to try, you can. The way to avoid the CEL is to simply plug the vacuum lines with small pins.

I can not say about the effect on power with the standard factory muffler on the 360.

 

Vacuum tubes. See other posts. Mine has screws inserted into the two (now disconnected) vacuum hoses.

 

I just ordered two small shut off ball valves, hose barb to hose barb to insert inline with the vacuum line to the diverters. This way I should be able to quickly change without having to plug or unplug anything. I'll take pics when done.

Ed

 

Guess you meant 4K right? That's when the valves open. I can tell you it drones like crazy from 3 to 4K, so this mod is an acquired taste. Valves were removed when car was bought (FabSpeed pipes and tips), so don't have an easy way to try both modes. Have stock pipes, but tips are just awful, so will stay off. Need to attend a large F430 gathering to personally listen to different options.

 

I am (or the seat of my pants is) reasonably certain unplugging hose causes slight loss in low end torque. Worse, it causes constant over-run on lift throttle. Some may like that added rawness. Me, I think that makes the drive "unflowing."

Now am content to leave things as factory intended it.

 

ELP- It varies where they open, and 4000 rpm is actually less correct than 3000 rpm. Here is a plot from Stef from the factory data.

So he meant 3K rpm.

Taz
Terry Phillips
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Do yo have a pic?

 

This is what I did, I assume it is the same effect.

http://www.ferrarichat.com/forum/attachment.php?attachmentid=352533&stc=1&d=1152169628

 

Well, 4K is A LOT more correct for me . In fact, it's well above 4K if you're not on the throttle, like when cruising. At 3K you have to basically be at WOT. Interesting find; learned something new today. But what the heck 'hysteresis' means in this case???

 

I was referring to a 360 as it happens and unless you're on a very light throttle the valves open up pretty much on 3k rpm.

 

Disconnected and plugged on my 430 two years ago. Sounds better. Great deep growl at low RPM. No noticeable loss of power. Frankly, it cost zero and I haven't heard anything better.

 

I did mine a while ago. It's super easy and should you ever want to keep things quiet, it's easy to simply plug the tubes back on the valves.

Takes 1 minute per side.

 

JC, the hysteresis range of my table are the areas where the valves are in "transistion" from closed to open. As the exhaust solenoid and valves are very slow to react compared to a computer or even the engine response time, it represents the delay they need time to open. Hysteresis is very usefull here as it prevents also having the exhaust valves opening and closing when you're close to the decision points where the valves must open (hunting).

Hysteresis is a lot used in electronics as many components have this natural property.
Cheers,
Stef