How do I check my exact model year? Which Fuse to pull?

[Bobajobbob]

Strange question I know but I’m struggling to figure out which fuse looks after the exhaust valves and I think my car sits on the transition. I had always assumed it was a 12.25 car as it was registered in June 13 and has all the new aero upgrade parts etc however looking in the handbook yesterday in the maintenance section it clearly states that it is F22 which I though was per 12.25 cars?

Due to the uncertainty above I have installed the switch on both Fuses but neither seems to make any difference so I am now wondering if the valves have jammed.

I have just removed the secondary cats so car now sounds like a beast but i can’t figure out if the valves are operating as normal or permenantly open currently. I’d love to have the switch installed if it can replicate the way it worked on my previous 4.3 for then occasional quiet getaway.

Any advice very welcome.

[F355GTS]

My 2011 V8S is a Fuse 15 car yet the manual show Fuse 22, only found out as taking out F22 made no difference. I assume the manual was never updated and in any event it's fairly useless with zero references to the 3rd Fuse box I the passenger footwell.

[bignoise]

Hi yes fuse 15 in the boot fuse box

Although as you have noticed not much difference

Im also looking at secondary decat did Bristol do yours?

[bogie]

I had the same confusion when I went from a 2006 to a 2012 car. The manual is wrong, its fuse 15 in the boot on left side (at least on my Roadster)

It is hard to tell a difference just at idle/low revs with otherwise std car. You really need the secondary cat delete, then it really wakes it up. I have the remote switch, works great and very noticeable.

The other thing that may confuse you a little is the cold start cycle revs, so its better doing your on/off testing once its warmed up a bit.

You can buy the secondary cat pipes from a few places, although dealers are not too expensive. I have the Quicksilver pipes here, and cost an hours labour at local exhaust fit garage.

https://quicksilverexhausts.store/collections/asto...

Edited by bogie on Saturday 29th September 15:04

[Bobajobbob]

I spent the morning pulling fuses and can only conclude that either my valves are permanently jammed open or that the valves really make no difference at all on a 4.7 car. I've run with all the fuses in, pulled 22 only, then 15 and then installed the switch in both positions and there is no discernable difference at all. On my old 4.3 it was night and day so I think I know what I am listening for.

Can anyone confirm on a post 2012 4.7 car that they have an exhaust switch fitted and that there is a noticeable difference between open and closed?

I had the dec pipes fitted at the Sevenoaks dealer. They sound great and as I hoped in "Valve open" mode but I was hoping to have the choice to tone them down a bit at low revs.

[Bobajobbob]

bogie said:

I had the same confusion when I went from a 2006 to a 2012 car. The manual is wrong, its fuse 15 in the boot on left side (at least on my Roadster)

It is hard to tell a difference just at idle/low revs with otherwise std car. You really need the secondary cat delete, then it really wakes it up. I have the remote switch, works great and very noticeable.

The other thing that may confuse you a little is the cold start cycle revs, so its better doing your on/off testing once its warmed up a bit.

You can buy the secondary cat pipes from a few places, although dealers are not too expensive. I have the Quicksilver pipes here, and cost an hours labour at local exhaust fit garage.

https://quicksilverexhausts.store/collections/asto...

Edited by bogie on Saturday 29th September 15:04

Thanks Bogie, I had the 2nd cats removed last week. It sounds awesome as I would like it in "Loud" mode however I'm beginning to think that the valves are currently stuck open as no matter which fuse I pull or replace there is absolutely no difference at all.

[bogie]

I had similar issues when I changed to a 2012 4.7, spent ages trying different fuses and checking fitment of my "old" remote kit I had since 2007.

In the end I tried a different remote kit - I got a new one from Chedzec on ebay and it worked right away. It is nice to have it on quiet by default, for 5am getaways to the airport

When you go out for a drive on warm engine with window open (or roof down) and it should be a really noticeable change below and over 4k revs - just as it was before on your 4.3

I guess there is a chance the exhaust valve actuators could be jammed open.

check this thread for a pic of the valve actuators - maybe a spray with some penetrating fluid and wiggle around will help .......

https://www.pistonheads.com/gassing/topic.asp?h=0&...

[Bobajobbob]

bogie said:

I had similar issues when I changed to a 2012 4.7, spent ages trying different fuses and checking fitment of my "old" remote kit I had since 2007.

In the end I tried a different remote kit - I got a new one from Chedzec on ebay and it worked right away. It is nice to have it on quiet by default, for 5am getaways to the airport

When you go out for a drive on warm engine with window open (or roof down) and it should be a really noticeable change below and over 4k revs - just as it was before on your 4.3

I guess there is a chance the exhaust valve actuators could be jammed open.

check this thread for a pic of the valve actuators - maybe a spray with some penetrating fluid and wiggle around will help .......

https://www.pistonheads.com/gassing/topic.asp?h=0&...

Aha so your old remote kit didn't work on the newer car? I spoke to Clive and he said that it should but I wonder if it could be that. If you stand behind the car with the engine idling can you hear the change immediately if you hit the button as was the case with the 4.3 or is it only noticeable at higher revs?

I'll take a closer look at the actuators to see if they are stuck.

[Bobajobbob]

Just had a poke under the car and I could just see the left hand actuator. It's behind a cover so tough to reach but I was able to move it albeit it is very tightly sprung. At idle it is in the open position and when manually moving it I can hear the exhaust close up and get quieter. I think I'll have to take it in to the garage to get the pump checked out. The switch definitely was not moving anything.

[bogie]

Yeah, my old remote switch was not one of Clives kits though, it was someone elses handmade prototype from 2007, hence new one from Clive

Does sounds like yours is jammed or maybe fault with vacuum thingy

[bignoise]

as far as im aware I thought the valves are open on idle closing at about 1000rpm before re opening at 4000 (3000 on an S)?

[F355GTS]

bignoise said:

as far as im aware I thought the valves are open on idle closing at about 1000rpm before re opening at 4000 (3000 on an S)?

I think you're right, you'll not notice a change at idle, my std V8S is definitely noisier in the 1k - 4k range wit the valve open

[Bobajobbob]

I don't fancy squeezing my head under the exhaust to look while someone revs the engine Maybe I can jam a gopro under there and do it that way.

[Jon39]

Bobajobbob said:

When you stand behind the car with the engine idling can you hear the change immediately if you hit the button as was the case with the 4.3 or is it only noticeable at higher revs?

You could try this test.
With the ignition on, but engine off, when you press the exhaust remote switch, you should hear a feint click from the rear of the car.
On - click, off - click.
That presumably indicates the vacuum switch is OK. Are there two vacuum switches?

I don't think you should be able to hear any exhaust sound difference at idle speed, because as already mentioned, the valves are open 0 to 1,500 rpm, then closed 1,500 to about 4,000 rpm in the standard configuration.

[Bobajobbob]

I can hear the relay click in the switch but no change to the exhaust tone at all. With the 4.3 you could hear an audible change in the exhaust even at tickover.

[Bobajobbob]

For anyone interested I took the car to AM Sevenoaks today and they confirmed that the valves had been blocked open by the previous owner. They freed them up and I finally have the best of both worlds with the switch installed on Fuse 15. Quiet mode for sunday morning starts and loud mode for everything else.

[bogie]

Thought it must be, glad to hear you are all sorted at last....the secondary decat pipes make all the difference on the 4.7

[Bobajobbob]

Definitely, I can’t wait for a decent road trip now.