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As far as I know you cant stick a dump valve on a diesel engine, although I'm sure someone more techy minded than me can confirm the reason why not[:)]
 

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As far as i am aware a "proper" dump valve cannot be fitted to a diesel as they do not run in vacuum so cannot operate your normal diaphram DV's that are available for petrol engines. There are some kits about but use a micro sitch and a few other bits, but sounds the same when it dumps at any rpm, unlike petrol ones which are more noticeable with a heavy right foot.

My PD150 has a standard one i think...you can hear it every now and again.
 

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AFAIK TDis don't have a dump valve - simply because they don't have a throttle. So there's absolutely no performance gain to be had from fitting one only that whooshing noise.
Forge and some others make them and when asked why they said something along the lines of 'because people want the noise....'
 

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Richard W has hit the nail on the head. (again, you swine, leave some of these for me...)

http://tdiclub.com/TDIFAQ/TDiFAQ-6.html#e8

11. Blow-off valves or BOV or similar

Since people insist upon asking about these devices, they need to be discussed ... The purpose of a "blow-off valve" or "diverter valve" on a gasoline engine is to give boost pressure someplace to go when the throttle plate is abruptly closed, to prevent operating the compressor in the "surge" regime. Since a diesel engine doesn't have a throttle plate, a gadget like this serves absolutely no purpose and has no business anywhere on a diesel engine. "But I like the cool noise ..." Too bad, this discussion is focused on things that WORK. Even if you manage to find some way to make such a device work, the noise of people "in the know" laughing at you because they realize that it has absolutely no place on your engine will drown out the noise that the device itself makes.

Installation: Impossible. Cannot be made to work even if you insist upon it.

Advantages: None.

Disadvantages: Won't work. People who actually know how a diesel engine works will laugh at you for even considering it. You are your own warranty.

Cost factor: Too much, all things considered.

Cautions specific to this modification: Won't accomplish anything.

Suggested modifications in parallel: Irrelevant.

"Bang for the Buck": One hundred percent total waste of time and money.

What if I want more? Do something that actually accomplishes something ...
 

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AFAIK TDis don't have a dump valve - simply because they don't have a throttle. So there's absolutely no performance gain to be had from fitting one only that whooshing noise.
Forge and some others make them and when asked why they said something along the lines of 'because people want the noise....'
Am I being totally thick(probably am!) but how does it accelerate if it has no throttle? I thought all engines had them [:$]
 

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Richard W has hit the nail on the head. (again, you swine, leave some of these for me...)
[:$][;)]

Am I being totally thick(probably am!) but how does it accelerate if it has no throttle? I thought all engines had them [:$]
No you're not, a petrol engine has a throttle which allows more air into the engine, which when combined with the extra fuel then demanded (ECU/carb etc all work on the air flow first then add fuel principle). The diesel engine simply adds more fuel which simply sucks more air in.
There's no physical thottle body or valve on a diesel engine. Remeber the very old trucks have governers(you probably don't, but as I'm an old f*rt I do[:$]) this was not to keep the vehilce to a specific top speed but to stop then engine 'running away' as the mechanical pumps would simply add more fuel as the revs increased and the engine would simply blow up!
 

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I was pondering about this too heres a clip of a guy who has fitted an HKS Blow off Valve to his

diesel VW Caddy it sounds good to me

 

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FFS. You CAN fit a dump valve to a TDI. Correct, it won't make a blind bit of difference in terms of BHP, or anything else for that matter, it just lets everyone know that you have a Turbo under the lid.

However, after all that's said and done, you can't just fit and dump valve - Call Derv Doctor for more information.
 

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i have a carbonio fitted and the noise it makes when releasing the throttle under heavy acceleration sounds like a DV
i always get asked what DV have you got!!
 

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Correct. They just release the pressure so the Turbo spins-down more slowly, thus giving more boost, earlier after changing gear.
 

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Hi

Forge do the dump valves for the whole of the VW range

I must admit , Gav at the Derv Doctor do these and does a good job of them too

So as has been said , give hime a call

AFAIK it is electical and will definately not give any gains , just a big grin on the face of the owner

The best thing about modding is the fact that anything you do to your car is not wrong , as it is what you like , not others!

Sarah
 

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i had one of these fitted to my pug 306 td.didnt make it quicker but sounded mint and looked good when i had the bonnet open.i will get 1 for my bora i think.
 

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Yeah, my mate had one on his 306DT. It was pretty amazing the sound that came out of it - completely masked the knock-knock-knock of the old Diesel.

Needless to say, he blew the engine up with too much boost, so rebuilt it. Then blew it up again.

He then realised turning the boost up on a crappy French engine just wasn't going to work - So he stuck a 2.0 Turbo Xantia engine (petrol) into it with a diesel gearbox. - Topped out at 105mph, but spat flames in every gear, and sounded like it had V-Tec from 2krpm right through to 7krpm. Mean machine that thing. Yes, he changed all the fuel rails, pump, fuel tank etc.. crazy amount of work IMO! lol
 

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you have to cut into a boost pipe and then insert the t piece with the dump valve attached,

Then you will need to tap into a vacuum source and you will need a microswitch
 
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