Constantly Open Exhaust

Great info, and love reading your posts. A little off topic, but can you explain why some Gallardo's shoot flames? Is this bad, bad meaning, can it hurt anything? I think it's wild.

 

You mean like mine??

 

.........The electrically operated solenoid valve is normally closed. During normal driving, the solenoid valve is energized (12 volts) by the engine computer to open it up and allow manifold vacuum to reach the exhaust valves. When RPMs exceed the magic number the computer removes power from the solenoid, causing it to close. The vacuum is then cut off from the exhaust valves, which open and the car gets loud.

 

So, to make the car loud, you can either disconnect the vacuum line or unplug the electrical connector from the solenoid valve. the solenoid valve to keep dirt and dust out of the system.

Does anyone know where this solenoid/electrical connector is on an 06 Spyder, can it be reached with the engine cover up? Did a search but nothing to indicate location

Does anyone know where this solenoid/electrical connector is on an 06 Spyder, can it be reached with the engine cover up? Did a search but nothing to indicate location

Have you looked for it where it's located on the coupe? You need to remove the large honeycomb grill (Torx T15 required), then look up behind the "Lamborghini" logo.

 

If you find it, the plug looks something like this. I believe you have to push in on the retainer wire so it releases its grip on the mating receptacle.

Have you looked for it where it's located on the coupe? You need to remove the large honeycomb grill (Torx T15 required), then look up behind the "Lamborghini" logo.

 

If you find it, the plug looks something like this. I believe you have to push in on the retainer wire so it releases its grip on the mating receptacle.

Actually I had read somewhere it was not the same as the coupe. As it turns out, I followed your directions & found it with no problems.

I'll test it tomorrow...THX!

 

PS, car was built in June of 06, any idea if this mod might trigger a check engine light?

Correct.

I have an '06 and have unplugged the electrical connector with no ill effects whatsoever. ('cept perhaps mild ear damage from the V10 music)

 

About your ears: lol!!!

 

/Per

Hi guys. Any updates ?

Just bought an 06 Spyder and thinking bout this mod. Wondering if lights come on should be fully reversible correct.

 

Cheers guys.

I've done it to my 06 coupe but instead of disconnecting the electrical connector I disconnected the vacuum line and just capped both remaining empty connections. No check engine lights and just a louder exhaust all the time. Can't tell any power difference of course. Total mod took about 10 minutes. There are a ton of torx screws holding the honeycomb piece in, jeez.

I didn't read all the post in here but to make this work without setting off a code is to pull the vacuum tube at the "T" junction and plug up the vacuum tube. Your exhaust will be constantly open and you will not throw a code. I have a 2007 Gallardo Nera and it works.

I didn't read all the post in here but to make this work without setting off a code is to pull the vacuum tube at the "T" junction and plug up the vacuum tube. Your exhaust will be constantly open and you will not throw a code. I have a 2007 Gallardo Nera and it works.

 

This sounds interesting. I have an 2008 Superleggera and it'd be nice to get it a bit louder before I get new exhaust.

 

Where exactly is this "T" junction that you're talking about? Any pictures or general location info?

 

Thanks!

Where exactly is this "T" junction that you're talking about? Any pictures or general location info?

The "T" I believe we're talking about is directly behind the rear bumper, directly below the "Lamborghini" logo and is vertically somewhere between the bottom of the central honeycomb grill and the top of the diffuser. I've circled it in RED on the image below. You can probably get to it by removing the honeycomb grill and reaching down. Earlier in this thread you can see where the solenoid valve (item #29) is behind the logo. There is a rubber tube (item #30) about 6-8 inches long that drops down from it and connects to a metal hard-line "T" (item #16). This splits the vacuum left and right to feed the individual actuators on the muffler outlets.

 

 

I don't see where you break the vacuum line makes any difference in whether or not your engine throws CELs. Pulling the rubber vacuum hose off the bottom of the solenoid should have exactly the same effect as pulling the same hose off the inlet of the "T". It certainly is a lot easier to get to. Just make sure you plug the open ends of the line - on the engine side to prevent a massive vacuum leak and on the muffler side to keep junk out of the line.

 

Thanks SO much, doltmo! I unscrewed the rear honeycomb grille and immediately found the vacuum line in plain sight towards the bottom of the grille, right above the license plate. I undid the clamp, capped off both lines and had the whole job done in 5 minutes flat. What an amazing difference! It's a great alternative until I can get a new exhaust on her - the exhaust note is WAY deeper and it's MUCH louder.. sounds more like a Lamborghini than a Toyota Prius now. Words can't describe how much the exhaust note changed from a simple little tube. It's been 2 days and I have not tripped any Check Engine Lights at all - for reference for those who find this post in the future, I have a 2008 Gallardo Superleggera.

 

-R

This has been a great post for me and highly suggest all do this modification.

 

I have an 08 Spyder and I did the mod using Kinsella's suggestion, ie a switch.

 

I spliced two wires into the ground (black) wire going to the connector and then ran the wires to a switch in my console box (cig lighter box).

 

I had an 06 Coupe with Tubi exhaust and loved the sound/feel. When I went to the 08 I was disappointed as the exhaust note on the 08 was more tame than the 06 Tubi. This mod has now completely blown me away. The note is raw and much better than my previous Tubi.

 

One problem I have is a live in the city and leave early in the morning with many neighbors I want to keep as friends. That was one nice thing about the more quiet 08 exhaust. Now I switch it on or off when I like, ie I slink out with the exhaust tuned down and then when I hit the main streets I hit the switch and it explodes.

 

When you are driving on the freeway at higher RPM's and the exhaust valves are off you hear the exhaust but its drowned out by all the other sounds, ie revs, wind, etc. Now when at cruising speed you can get the full effect of the exhaust. And no CEL's (yet)!!!!

 

I would HIGHLY recommend the mod to everyone.

Can this be done to a Murcielago?

Can this be done to a Murcielago?

It looks like the LP640 has a similar arrangement of bypass valves on the exhaust system. Not sure about the earlier cars. They appear to be under the muffler box. You'd probably have to get under the car to find them. If you do, just unhook the vacuum line (item #14) from the splitter tube (item #34) and securely plug each open end.

 

 

Another observation after driving most of today in it.

 

The exhaust is much louder EVEN in higher gears at higher RPM's. Not just under 3,200.......it seems it's affected across the band.

 

Why is that?????

 

Still can't tell if it robs HP or adds to it......any theories on that??

 

 

Another observation after driving most of today in it.

 

The exhaust is much louder EVEN in higher gears at higher RPM's. Not just under 3,200.......it seems it's affected across the band.

 

Why is that?????

 

Still can't tell if it robs HP or adds to it......any theories on that??

Your ears are playing tricks on you. Open valves are open valves.

 

You'd have to dyno the car to really tell if this changes anything on the low- and mid-range. Maybe you could do some 50-80 times in 6th gear and see it the difference was measurable.

 

One "theory" is that reducing "back pressure" will hurt the mid-range. This is a gross oversimplification of a very complex process that takes place in the exhaust pipe. It doesn't lend itself to common analogies like water flowing through a pipe. It does involve the dynamic interaction of the exhaust pulses and their reflections from the various components - cats, mufflers, and the lengths of pipe between them. It's possible that bypassing the muffler removes an important reflection of the exhaust pulse that is needed for best performance at a certain rpm. But since the cats are the first restriction seen by the exhaust pulses they probably generate the primary reflection back to the engine. So I would bet that as long as the cats were in place, you'd still have much of the original pressure wave environment as the original factory system. (Translation - I don't think you'd lose much in the mid-range)

 

I look at it this way - when I want performance, I press down hard with my right foot and keep the revs up. When the revs are below 4K, I don't care about performance.

 

Agree Doltmo......but I'm telling you there is a distinct difference in the sound when I hit the switch even at the higher RPM's.

 

Having the switch allows me to turn it on and off instantly. Even in 5th at 5k RPM when I hit the button the exhaust not changes. This is what I do not understand.

 

Is it possible there is a "partial" engagement of the valves modulating the exhaust at various RPM's and not just on/off. I just don't get it. I thought it kicked off a 3,200 RPM and then it was open?!?! WTF??!?

 

 

 

nikojo, you may have a point there. I always considered the bypass valve as a binary device - it was either open or closed. But since it is activated by manifold vacuum I could see where it could operate in some linear region where the degree to which it was closed would be proportional to the vacuum. 5K RPM in 5th gear at a constant speed (partial throttle, some manifold vacuum) is different from 5K RPM in 5th gear with the throttle mashed to the floor (full throttle, no vacuum). I would still bet that 5K RPM full throttle sounds the same. If at 5K RPM and partial throttle there is a difference in the sound, then the proportional theory may be true.

That's exactly what it does........

 

FULL throttle = no difference with solenoid on/off

 

PARTIAL throttle = definite difference with solendoid on/off

 

(across RPM's and gears not just under 3,200 RPM)

 

 

Is there a "purpose" to this beyond controlling the "noise"??

......Is there a "purpose" to this beyond controlling the "noise"??

Probably not. I suspect that the partially open condition is just a byproduct of the actuator design. Now that I've thought about it, it would be difficult to design an actuator that would instantly change from "closed" to "open" given that there are times when the vacuum may change slowly. The engineers were trying to meet noise requirements at one end of the performance spectrum while not constraining the upper end. What happens in the middle is probably a "don't care".

I have been thinking about doing this mod on my 06, and since I am not mechanically inclined and dont know what a torx screw even is, doing this myself is too intimidating on something so important to me. I got a quote from aida at lambo beverly hills service, and it looks like they will install a custom switch to do this- switch goes on steering wheel console by right knee- and they are saying it will cost around $500...is that a good deal for this?

...is that a good deal for this?

The hard part is running the wires and mounting the switch in a good position. This takes quite a while and it helps to have some knowledge of the interior - like how to remove the panels and hide the wires. $500 is not a bad deal, given the amount of work involved.

 

Just make sure you are happy with where they mount the switch. They'll probably put in the place where it's easiest to mount. It might not be where you want it.

 

When I wired my car, I used one of the "dummy" push buttons on the gear shift surround. It was a major engineering effort and I don't think anyone else would go this route.

I routed the switch to the empty button next to the "lift" button. Installed a "micro" flip switch. The hard part was routing the wire otherwise its very simple as you are splicing the switch into the two wires to the solenoid. This is all accessible. In my Spyder I had to remove a few panels with torx screws and put the wire under them. It was easy to fish the wire into the cabin and into the center console under the brake lever.

 

I think $500 is a bargain as it took me a good 3 hours -- but I like torturing myself with these types of projects.....I learn more about the car.

Can I do this on my 05 G? If so, how?

Ok guys...I'm going to try this again...disconnecting the valves via the solenoid switch...I'll simply bag the connector to keep moisture out....Hopefully, I won't get the bank light again after about 200 miles.