The Lotus Cars Community banner

1 - 11 of 11 Posts

·
Registered
Joined
·
111 Posts
Discussion Starter #1
I've heard of this being done on Aston Martin Vantage's, where you can pull a fuse and leave it permanently on loud mode.
The first thing I do every time I get in the car is press the exhaust or sport button anyways.
I was wondering if this would work on our cars (400's) if you turn the car on, press the exhaust button to open the valve, then pull the fuse out. Do you think this would leave it permanently in the open exhaust mode?
 

·
Happy To Be Here
2013 Lotus Evora IPS - Carbon Gray
Joined
·
856 Posts
I don’t know how the 400 works, but I believe I know how the S1 Evoras work. The S1 muffler system has a valve that is open when in the muffled mode and then closes when in loud mode. On my Larini exhaust it is much more obvious as the bypass “loud” pipe is outside of the muffler. When the car starts, there is no vacuum so the valve is spring loaded to be in the shut position, leaving the car in “loud” mode, then it will open moments after ignition. When open, some exhaust will pass through the muffler and less through the straight pipe, causing the car to be quieter. When the sport button is pressed, the vacuum turns off and the valve closes, causing all exhaust to go through the straight pipe which has less back pressure and no further restrictions. When the car is turned off, the valve has a spring that will return it to the closed position.

TL-DR - the car starts in “loud” mode and if the vacuum line to the valve were simply disconnected and plugged (with something like a golf tee), you will always be in loud mode.

This is how I believe the system works, and if I’m wrong, I would love to be corrected.
 

·
Premium Member
Joined
·
6,784 Posts
They usually operate by vacuum. Whenoff they are open, when started that is why they are loud till vacuum builds to close valve. Do yourself a favor and get rid of that obese stock exhaust if you want sound. There are much better ways to enjoy the noise , be lighter, handle better etc. All you had to do on an S1 was cut the hose and , volia, valve always open if i remember right.
 

·
Registered
Joined
·
288 Posts
I actually built my own valved exhaust to get rid of the 40+lb monster. @brgelise is correct, when the car is off there is no vacuum applied, so the valve is open. You could unplug the connector to the vacuum switching valve on the side of the airbox, which would keep it permanently off and you don't have to go under the car. (I'm all for the laziest approach :grin2: ) While testing my exhaust I ran a golf tee in the vacuum line, since I was already under the car, and that resulted in no degradation to the performance.:
 

·
Premium Member
Joined
·
6,784 Posts
Golf tee is indeed a way to go.
 

·
Registered
Joined
·
111 Posts
Discussion Starter #6
Golf tee...genius would never have thought of that.

You wouldn't happen to have a picture of where it's located on the side of the airbox would you?
 

·
Premium Member
Joined
·
6,784 Posts
orange/red hose
 

·
Registered
Joined
·
288 Posts
Golf tee...genius would never have thought of that.

You wouldn't happen to have a picture of where it's located on the side of the airbox would you?
If you block the orangish hose on the side of the airbox at the airbox, you'll have a vacuum leak when the ECM is trying to keep the valve closed.

The golf tee trick should be done either at the valve itself or where the orangish line meets the hard line mounted to the body. If you don't want to crawl around on the ground just unplug the VSV on the side of the box and it will hang the valve open with no detriment.
 

·
Illegal Alien
Joined
·
5,009 Posts
If you block the orangish hose on the side of the airbox at the airbox, you'll have a vacuum leak when the ECM is trying to keep the valve closed.

The golf tee trick should be done either at the valve itself or where the orangish line meets the hard line mounted to the body. If you don't want to crawl around on the ground just unplug the VSV on the side of the box and it will hang the valve open with no detriment.
if you pull the hose off the muffler valve, the hose must then be plugged. Pipe at muffler valve is left open to atmosphere, however hose feeds back to engine and will be a vacuum leak if not pulled.
 

·
Registered
Joined
·
288 Posts
if you pull the hose off the muffler valve, the hose must then be plugged. Pipe at muffler valve is left open to atmosphere, however hose feeds back to engine and will be a vacuum leak if not pulled.
Ah, I see where my advice could be misconstrued. Plug the orangish line in the engine bay, where it meets the hard line or where the orangish line goes into the valve.
 
1 - 11 of 11 Posts
Top