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Evora S1 exhaust valve


mik

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Apologies as I guess this has almost certainly been discussed before, but I couldn't find anything using search..... :X

A mate has just picked up an Aston V8 and he's going to pull a fuse at the weekend which apparently puts the exhaust in Sport (loud) mode the whole time.

Whenever I get in the Evora I prod the "sport" button as soon as the engine is running. Every time. Even then I'd much prefer the valve to be open below 2.4krpm as well. Is there a way to do this easily?

Edited by mik
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  • 2 weeks later...
  • 3 years later...
  • Gold FFM

Does anyone know which fuse is for the exhaust valve in a MY14 S?

The valve doesn’t appear to be responding to the sports button.

I’ve looked at the service notes fuse board diagrams but can’t see one.

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I don't think that there is a fuse that corresponds directly to the valve (it's not an electric part). Although it is controlled by the ECU, the valve is powered by vacuum (from the SC). The first point of call should be to check that the vacuum line is still ok. Next (with an alternative vacuum supply), check that the valve itself is still operational. (It might have seized or failed).

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  • Gold FFM

Thanks Jonny, the valve isn’t moving on either the old OEM exhaust or a new one just installed. I thought it might have been a sticky valve but appears to be a lack of vacuum in the normal mode.

The flexible tube has been changed, and the metal piping looks fine as far as I can see. Probably something for investigation at the next service then. For now it’s stuck in loud mode but I don’t think the novelty will wear off for some time, and it’s not too intrusive 😎

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  • Gold FFM

funny you should say this but so i press the sport button and throttle response instantly different but exhaust note ? now i kinda feel ours is loud in any case (one cat pipe removed) im not complaining i like the noise and actually wonder why ppl complain about the head unit as im thinkin all i wana hear is the exhaust !! but should i hear an instant difference ?  

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  • Gold FFM
On 29/05/2021 at 10:57, Doug Ashley said:

I’ve looked at the service notes fuse board diagrams but can’t see one.

I’ve found an updated set of notes with the following. Will test the vacuum, but it looks like I might need to replace the solenoid valve. It seems to be accessible from underneath. 

B3308DDF-F4E7-42CD-8F19-F589475DA1F2.jpeg

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  • 2 weeks later...
  • Gold FFM

Update: the exhaust valve still isn't working 😡

I've:

- Checked the vacuum hose from the inlet to the solenoid valve holds vacuum

- Checked the hose from the solenoid vale to the exhaust value holds vacuum (and operates the valve correctly)

- Changed the solenoid valve for a new one.

I think it could therefore be the valve which is part 5 on this diagram:

https://www.deroure.com/diagrams.asp?MAK=1&MDL=20&TBL=12711&SMA=0&SMO=0&ST=&SC=0

This is the only part I've not checked/replaced.  Any other thoughts are welcome though before I order one 😎  Not sure if anyone else has had similar issues tracing the problem.

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I've not tried it by hand, but it worked fine when I attached a separate hose (where the solenoid valve links to the metal pipe) and applied a vacuum directly to the exhaust actuator manually.

There just isn't a vacuum getting down to it, but I'm not sure exactly what the valve (part 5 in the diagram above) actually does.

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  • Gold FFM

SOLVED 😁😁😁

The vacuum was being blocked in the air box. I’ve bypassed this with a petrol filter to link the hoses and the valve now closes. I did have a look in the air box, but the vacuum passes through some filter material riveted in place, so I couldn’t see what exactly the problem was.

However, I may have found a new issue. How should the Evora S valve operate? My expectations are:

Normal mode

closed unless over 4700rpm, or revving quickly. It seems to be doing this.

Sport mode

open all the time. However, I pressed sport mode and the valve didn’t open at all. Admittedly I’ve only tried it on the driveway, will be taking it out later to see exactly what it does…

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  • Gold FFM

It should be open at idle. It'll close when the rise a little for quiet cruising but definitely open at idle

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thanks, hmm it didn't do that on the driveway, but will see what happens later.  If sport mode isn't having the correct effects, I guess it can only be some ECU gremlins, or maybe there's a fuse between the switch and the system...

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  • Gold FFM

Done a bit more research, it could be because the part of the airbox I've bypassed acts as a vacuum reservoir - so I either need a new airbox (OEM = £400!) or to fit a separate vacuum reservoir like the link below.   I'm taking option 2, will see what happens.

https://www.boefab.com/collections/intake/products/boe-evora-vacuum-pod-kit

 

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Wow Bravo

Big shout out ! It’s things like this that forum members require and make this forum a godsend 

not being tech minded I would have just paid the price my lotus garage would had charged me or if I was good enough to DIY would had payed £400 for OEM part 

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Thanks @Bravo73 👍

I found one for £11, but then on a YouTube video of an Evora S CAI installation I spotted the hoses were connected the other way around on the original airbox before they started taking it apart.

I swapped the pipes - lo and behold it's now passing vacuum through the OEM airbox. The hose lengths strongly imply this other way round is wrong, but I'll take it.

The sports button is still not opening the valve though, I've some more digging to do...

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