now then im not going to claim to know everythin there is to know about dump valves or on what spec cars they can be used on but all i wanna know is wether it would be worth thinkin about shovin one on my punto JTD?

ive heard of various people that have said you cant put them on a diesel but then ive heard other people say u can only put them on a turbo engine and i was wondering as my engine is both, would one actually work and make a good noise lol

some of my m8s have said it wouldnt sound right because the diesels already have their own waste gate and it wouldnt be worth putting another one on but then some of my other m8s have said that because its diesel it builds up more pressure and would make a good noise when released :S what are your thoughts?

Hi mate,

Can you fit a dump valve on a TD?? YES
Is it worth it?? You will not gain any performance from it (infact you will almost definately loose some), however you will gain the Tschhhh if that floats your boat.
Do they differ from ones on petrol turbos?? YES. When you are on boost in a petrol and then let off the throttle, in essence the butterfly valve in the TB closes, meaning that the excess pressure from the still spooling turbo needs to go somewhere. This is where the dump valve comes in. It opens, releasing the excess air, and giving a Tschhhh (unless it is the Re-circulating type).
On a diesel, there is no "excess build up of pressure" when coming off boost due to the lack of TB set up as on a petrol. As a result, the dump valve that you would need to fit to your JTD would have to be electronically controlled in order for it to release/ divert pressure (this also makes them expensive (around £200 for a not so good one))) So in essence it wont be a "real" dump valve as it wont be dumping excess air, it will be simply dumping air when its told too.

So to sum up, yes you can fit one. However, it is not needed on a diesel and wont gain you any performance. It wont be a "real" dump valve as such ether, but it will make the Tschhhh that you are after.

Think that's everything (started loosing myself in there somewhere! Difficult to explain the principals of dump valves on a TD at this time of the morning!! lol)

If you have some spare money burning a hole in your pocket, spend it on a re-map instead (if you haven't already) It totally transforms the car and will give you around 125BHP and over 200ftlb or torque!

Hope that helps you matey, (from a fellow JTD owner!)
Alan

Dump valves on diesels generally do jack. (A1ant beat me to it This is popular one on the Fabia forum.

In your petrol engine your turbo is spinning at say 100k revs.... suddenly your throttle closes, and turbo is still spinning due to inertia... consequently the air has nowhere to go because the thottle plate is shut... so the dump valve opens and allows this air to escape to the atmosphere(or back into the air box if a recirc is fitted)... this has the benfit of allowing the turbo to keep spinning in a partial vacuum for a longer period of time, and therefore takes less time to get back up to speed after you reapply the throttle..

On a diesel engine it isn't required because there is no throttle body, so the air doesn't get trapped like it does on a petrol engine.... in fact the excess air actually reduces the emmissions output from the engine and also has a mild intercooling effect on the combustion chambers

You can get electronically actuated valves for the JTD but TBH the only thing you will get out of it is a Noise and it might actually adversly effect the performance.


Check this out For the JTD

There is also One of these Evil pieces of equipment

But then you end up with a car that goes like this

It's not a good look, especially if you imagine that with a diesel clatter either side of the PSCHHHHHTTTT....

Get a GSR kit, costs around the same, is a bit of engine bling, it gives a similar sound and actually improves performance

www.gsr-uk.co.uk

tar for that, was just wondering because i do actually like the noise they make, are u saying i wud have to fit one that electronically makes a noise or one that is naturally sounding but operated electronically if that makes sense lol confusin i no but if i got one i wouldnt want one that sounds like it isnt natural! oh and i think im gona get a remap anyway lol

honestly, spend the money on a GSR kit. you then get the DV sound with added performance too

H2DaE said:

honestly, spend the money on a GSR kit. you then get the DV sound with added performance too

Click to expand...

Sounds like I gotta get myself a GSR kit for my JTD then. Will be the first thing I do when I get the car back from the bodyshop...