DB9 exhaust valve questions
Discussion
https://aston1936.com/2015/10/25/uncorking-your-db...
You may have seen this already but it explains the normal behaviour of exhaust valve as well as post removal of fuse.
When you say you don't notice any difference after pulling the fuse, at what RPMs is the engine?
You may have seen this already but it explains the normal behaviour of exhaust valve as well as post removal of fuse.
When you say you don't notice any difference after pulling the fuse, at what RPMs is the engine?
vet652000 said:
Hoofy said:
Valve rusted close? Does the valve actually move?
I can move actuator easily, so not frozen. Car is a one owner and is from Silicon Valley CA, zero rust or corrosion.Underside is like new. When key is turned on should valves move or not until it reaches 1500 rpm?
Normally when you switch the engine on, the valves close, and then open when you press on. With the valves locked open, you get a louder sound all the time.
I'm surprised you can't tell the difference. (Not saying that there is a difference, mind - you may have some kind of fault with the exhaust box.) What about when you rev the engine?
I don't notice any difference at any rpm, but I was using the remote switch when engine is running vs when engine was off, if that matters. Obviously when you increase rpm you hear more engine sound, but not anything close to loud. When engine is off, are valves open or baffled? Will the valves move if just revved up in park to 1500 rpm or 3000 rpm, or only when driven?
vet652000 said:
I don't notice any difference at any rpm, but I was using the remote switch when engine is running vs when engine was off, if that matters. Obviously when you increase rpm you hear more engine sound, but not anything close to loud. When engine is off, are valves open or baffled? Will the valves move if just revved up in park to 1500 rpm or 3000 rpm, or only when driven?
As I say, it closes when you switch the engine on due to the pressure in the hoses (as I understand it), so it's open when off and stays open when you pull the fuse.Sounds ('scuse the pun) like something's broken. I thought you were physically squeezing a valve to confirm that the valves were working.
Hang on - you said you moved the actuator easily. What did you physically do then?
Hoofy said:
As I say, it closes when you switch the engine on due to the pressure in the hoses (as I understand it), so it's open when off and stays open when you pull the fuse.
Sounds ('scuse the pun) like something's broken. I thought you were physically squeezing a valve to confirm that the valves were working.
Hang on - you said you moved the actuator easily. What did you physically do then?
My bad I just read link you provided, I need to move the Actuator and check the opposite exhaust outlet as that is where the exhaust flows. When mine is idling or engine off the actuator rod is all the way out/down, which I assume is bypassing the Baffles in muffler, so when I push the actuator rod up it should causing the exhaust to quiet down?Sounds ('scuse the pun) like something's broken. I thought you were physically squeezing a valve to confirm that the valves were working.
Hang on - you said you moved the actuator easily. What did you physically do then?
My son is coming over tomorrow to help me with a couple things, so I'll be able to run/rev engine and have him check what the actuators are doing with fuse in and with fuse out. It may be that previous owner has plugged the vac hoses and they are open all the time, so I don't hear a change in sound level. I just expected a big difference the way people were describing bothering the neighbors in the morning, which is exactly what I want to do
vet652000 said:
Hoofy said:
As I say, it closes when you switch the engine on due to the pressure in the hoses (as I understand it), so it's open when off and stays open when you pull the fuse.
Sounds ('scuse the pun) like something's broken. I thought you were physically squeezing a valve to confirm that the valves were working.
Hang on - you said you moved the actuator easily. What did you physically do then?
My bad I just read link you provided, I need to move the Actuator and check the opposite exhaust outlet as that is where the exhaust flows. When mine is idling or engine off the actuator rod is all the way out/down, which I assume is bypassing the Baffles in muffler, so when I push the actuator rod up it should causing the exhaust to quiet down?Sounds ('scuse the pun) like something's broken. I thought you were physically squeezing a valve to confirm that the valves were working.
Hang on - you said you moved the actuator easily. What did you physically do then?
My son is coming over tomorrow to help me with a couple things, so I'll be able to run/rev engine and have him check what the actuators are doing with fuse in and with fuse out. It may be that previous owner has plugged the vac hoses and they are open all the time, so I don't hear a change in sound level. I just expected a big difference the way people were describing bothering the neighbors in the morning, which is exactly what I want to do
Yeah - it's possible they did something else so the fuse makes no difference.
There are quite a few videos on YT - search "fuse 22 DB9".
vet652000 said:
Thanks Hoofy for your input/help!
No probs. I suppose one thing to consider - does the exhaust sound quite loud? I think DB9s are generally quite quiet. The exhaust bypass valve doesn't turn it into a straight pipe and you have two cats down the line (do you also have a resonator box, I can't remember?). The exhaust gasses still go into the silencer but exit via a less convoluted path hence it's louder.My son came up last night and the valves does not move at any rpm. It is open/not thru muffler all the time, which is why I never noticed any difference, now I need to determine if the valves are not getting vacuum/hose plugged or the is no vac from the source. I must say I don't think it is overly loud even with muffler bypassed 100% of the times, in fact, I'd say some more volume could be good!
vet652000 said:
My son came up last night and the valves does not move at any rpm. It is open/not thru muffler all the time, which is why I never noticed any difference, now I need to determine if the valves are not getting vacuum/hose plugged or the is no vac from the source. I must say I don't think it is overly loud even with muffler bypassed 100% of the times, in fact, I'd say some more volume could be good!
It's still using the silencer box, so it's going to be louder but not racecar loud. If you do go down the custom route, investigate bigger downpipes, X-pipe and no exhaust box or a smaller exhaust box. Search on YT for "DB9 X-pipe". Gassing Station | Aston Martin | Top of Page | What's New | My Stuff