Dump Valve!?!

[M 80NGD]

Hi,does anybody remember dump valves?! They were an after market thing that were sometimes fitted to cars with

turbos and I think they helped to release exhaust gases! They used to make a great hissing noise when changing

gears and were fitted to a lot of RS turbos and Scooby Doos'.

Well my question is,can these be fitted to a turbo diesel and more importantly,to an automatic

turbo diesel? Has anybody with a bongo fitted one,great to know if they have and what it sounds

like.Cheers,Lee (p.s,no toilet jokes please )

[simon_gone_surfing]

My understanding is this....dump valves and blow-off valves for turbo charged engines only work when you lift your foot off the throttle. In an automatic engine you don't do this, so you would get no wooshing noise as the dump valve wouldn't operate. The point of a dump valve is to maintain turbo operating speed (when you take your foot off the throttle the back pressure in the engine slows the turbo down, therefore giving the traditional lag time between re-accelerating and the turbo kicking in - the dump valve releases some of this pressure helping the turbo to remain spinning close to its operating speed). In the Bongo, the turbo is set to kick in at such a low rev speed anyway and stay in operation the whole time, a valve would be redundant.

All this considered, one thing springs to mind - dump valves can sound quite cool when you drive a car that goes vrOOOMMM first! The bongo (mine at least) would go CHUG CHUG CHUG!!! I have pondered this in the wee hours as it would be nice to rock up in a pimped van and ceam the kevs at the local supermarket carpark! Maybe you should consider a flamer exhaust kit instead! http://www.akamoto.co.uk/flaming-exhaust.asp. Just mind the plastic bumpers and tailgate handles!

[M 80NGD]

My understanding is this....dump valves and blow-off valves for turbo charged engines only work when you lift your foot off the throttle. In an automatic engine you don't do this, so you would get no wooshing noise as the dump valve wouldn't operate. The point of a dump valve is to maintain turbo operating speed (when you take your foot off the throttle the back pressure in the engine slows the turbo down, therefore giving the traditional lag time between re-accelerating and the turbo kicking in - the dump valve releases some of this pressure helping the turbo to remain spinning close to its operating speed). In the Bongo, the turbo is set to kick in at such a low rev speed anyway and stay in operation the whole time, a valve would be redundant.

All this considered, one thing springs to mind - dump valves can sound quite cool when you drive a car that goes vrOOOMMM first! The bongo (mine at least) would go CHUG CHUG CHUG!!! I have pondered this in the wee hours as it would be nice to rock up in a pimped van and ceam the kevs at the local supermarket carpark! Maybe you should consider a flamer exhaust kit instead! http://www.akamoto.co.uk/flaming-exhaust.asp. Just mind the plastic bumpers and tailgate handles!

Cheers Simon,you explained that really well I probably couldn't have afforded it anyway! I think I'll

steer away from the flamer kit,knowing my luck,it'll set fire to my chargespeed body kit!! Thanks

again,Lee.

[simon_gone_surfing]

If you want to boost performance, I guess the sensible thing would be to upgrade the turbo and exhaust system. The fact that the Touring Cars are nearly all diesel now says a lot about how good the fuel could be if delivered to the engine in the right way. Some people claim an increase in performance using things like Ultimate Diesel rather than regular, but I'm not so sure. If yours is 4WD you could always remove the front drive system and shed some weight (apparently quite easy to do).

I'm yet to find video footage, but I remember reading about a trackday company that uses a Bongo to tour the track - its suitably lowered and stiffened and can be drifted! Will see what I can find.

[scanner]

My understanding is this....dump valves and blow-off valves for turbo charged engines only work when you lift your foot off the throttle. In an automatic engine you don't do this, so you would get no wooshing noise as the dump valve wouldn't operate. The point of a dump valve is to maintain turbo operating speed (when you take your foot off the throttle the back pressure in the engine slows the turbo down, therefore giving the traditional lag time between re-accelerating and the turbo kicking in - the dump valve releases some of this pressure helping the turbo to remain spinning close to its operating speed). In the Bongo, the turbo is set to kick in at such a low rev speed anyway and stay in operation the whole time, a valve would be redundant.

All this considered, one thing springs to mind - dump valves can sound quite cool when you drive a car that goes vrOOOMMM first! The bongo (mine at least) would go CHUG CHUG CHUG!!! I have pondered this in the wee hours as it would be nice to rock up in a pimped van and ceam the kevs at the local supermarket carpark! Maybe you should consider a flamer exhaust kit instead! http://www.akamoto.co.uk/flaming-exhaust.asp. Just mind the plastic bumpers and tailgate handles!

Cheers Simon,you explained that really well I probably couldn't have afforded it anyway! I think I'll

steer away from the flamer kit,knowing my luck,it'll set fire to my chargespeed body kit!! Thanks

again,Lee.

They are pointless and wasteful on a diesel as a diesel doesn't need one.

All it does is dump excess boost (not exhaust) to stop the turbo stalling when the butterfly valve slams shut on a petrol engine - diesels do not have a butterfly valve.

Big turbo'ed high revving petrols need one to over come the short comings of fitting them to an engine whose inlet tract is continually opening and closing all the time, as diesels do not have that problem they don't need the solution.

If you do fit one to a diesel
1 - It probably won't work as there is little or no excess boost
2 - All it does is mean you have to keep spooling the turbo up to accelerate again giving you turbo-lag.

If you want the noise just record it onto a tape or CD and play it through a speaker fitted under the bonnet.

Or easier still just lean out the window and shout "PSSSSHHHHTTTTT!"

[M 80NGD]

Thanks Simon and Scanner,both explained very well Scanner was right,it was only the noise I liked!!

It loooks like I'll be putting my head out the window making PPPPPSSSSHHHTTTT noises then!!

Cheers,Lee.

[harpo42]

Why dont you get one of these http://cgi.ebay.co.uk/TURBO-Dump-Valve- ... 286.c0.m14

[jaylee]

Why dont you get one of these http://cgi.ebay.co.uk/TURBO-Dump-Valve- ... 286.c0.m14

Looks a bit like something that dropped off the Apollo space mission.

[bigdaddycain]

Why dont you get one of these http://cgi.ebay.co.uk/TURBO-Dump-Valve- ... 286.c0.m14

Good thinking simon, but won't work with an auto...

I bagged a ride with a fella that had an electronic dump valve fitted to his tdci focus a few years back,he had it tuned in excess of 400lb/ft of torque,all work carried out by these chaps....

http://www.dervdoctor.co.uk/ (click on products)

They are gaining a really good reputation, they even tune commercial vehicles!

[scanner]

I bagged a ride with a fella that had an electronic dump valve fitted to his tdci focus a few years back,he had it tuned in excess of 400lb/ft of torque,all work carried out by these chaps....

http://www.dervdoctor.co.uk/ (click on products)

But why?

£200 or more just so you can noisily dump expensively built up boost.

They are meant to cure the failings of petrol engines, not create failings in diesels.....................

[bigdaddycain]

I wouldn't say that a dump valve is a cure for a failing in a petrol engine,it merely helps to vent off excessive boost pressure.

I'd be inclined to agree that a dump valve in a diesel would be unneccesary, but m80 asked the question would it be possible, and the short answer is yes it would.

The chaps at dervdoctor know their stuff,if it was in any way detrimental to the performance or reliability of a diesel engine, i'm sure they wouldn't have developed the product.

My suspicions are that the dump valve is used in conjunction with a potetiometer,which merely senses throttle lift,sends a pulse to the electronic dump valve,which then does its WHOOSH!

I guess if one wants the sporty sound badly enough...then be prepared to shell out a few hundred quid for the privilege....

[M 80NGD]

I wouldn't say that a dump valve is a cure for a failing in a petrol engine,it merely helps to vent off excessive boost pressure.

I'd be inclined to agree that a dump valve in a diesel would be unneccesary, but m80 asked the question would it be possible, and the short answer is yes it would.

The chaps at dervdoctor know their stuff,if it was in any way detrimental to the performance or reliability of a diesel engine, i'm sure they wouldn't have developed the product.

My suspicions are that the dump valve is used in conjunction with a potetiometer,which merely senses throttle lift,sends a pulse to the electronic dump valve,which then does its WHOOSH!

I guess if one wants the sporty sound badly enough...then be prepared to shell out a few hundred quid for the privilege....

Cheers Big D,Your right,I was just wondering if it would work If I had the money I would love some more items

on the bongo But for now,in the financial crisis we are in,I'm quite happy just to be able to put diesel in and

enjoy it But watch this space when my six numbers come up tonight on the lottery

Thanks everybody for great info,cheers,Lee.

[scanner]

I wouldn't say that a dump valve is a cure for a failing in a petrol engine,it merely helps to vent off excessive boost pressure.

I'd be inclined to agree that a dump valve in a diesel would be unneccesary, but m80 asked the question would it be possible, and the short answer is yes it would.

The chaps at dervdoctor know their stuff,if it was in any way detrimental to the performance or reliability of a diesel engine, i'm sure they wouldn't have developed the product.

My suspicions are that the dump valve is used in conjunction with a potetiometer,which merely senses throttle lift,sends a pulse to the electronic dump valve,which then does its WHOOSH!

I guess if one wants the sporty sound badly enough...then be prepared to shell out a few hundred quid for the privilege....

Cheers Big D,Your right,I was just wondering if it would work If I had the money I would love some more items

on the bongo But for now,in the financial crisis we are in,I'm quite happy just to be able to put diesel in and

enjoy it But watch this space when my six numbers come up tonight on the lottery

Thanks everybody for great info,cheers,Lee.

The failing is that petrols have butterflys that slam shut when you lift off and if the turbo is still spinning hard the build up of boost can cause that fast spinning turbo to stall and in extreme circumstances shatter the impeller that is not the case with diesels as there is no butterfly obstructing the inlet tract.

I'm not saying fitting one does any harm to the diesel - it's just a totally illogical thing to do, dump all the boost and then have to build it all up again. It's surely better to keep the turbo spinning smoothly all the time than to keep stopping and starting it.

Also if fitted to an auto it ain't gonna work much anyway, as I can't remember when I last lifted off when changing gear.

You might just get the odd f*rt when you lift off for a roundabout, so I still reckon an MP3 player and a speaker under the bonnet would be a quicker, cheaper and easier solution.

I'll sample my daughter's Cossie blowing off if you want.......might make a good ringtone.