Derv dump valve

Continued from

http://www.diyperformance.net/t205-read-and-post-need-to-know-numbers-asap

Andymac wrote:

Don't wanna burst ur bubble mate but do u realise you'll lose power? Every gear change you're blowin all your boost pressure off which will cause a turbo lag (might not have explained it right but tryin to lol) basically i was gonna fit one to my 1.9tdi passat but was advised not to as I will lose power and boost, was gutted cos i love the sound but decided not to for that exact reason. I'm goin for a mufflerectomy instead as it sounds awesome and if anything increases performance as the turbo spools up quicker, if ur goin with the dump valve thing I'd get an electronic one or one thats made for a diesel

Heres where I've been told different - it blows off EXCESS pressure, not ALL pressure, so the turbo doesn't have to spool fully back up, because there's already boost in the pipes.

If it does reduce power, I doubt I'd notice too much as its only 100BHP as standard anyway.

I've also had a back-box-ectomy so zorst is more free flowing now anyway

The dump valve I've got is a forge one, for diesels AFAIK - it's got wiring, solenoid, DV and piping

fiar play mate seems u have researched properly, might check mine again then I've got a forge one that i havent fitted but not sure what parts i need as i have only got the dv, but then again i love the sound of a mufflerectomy and its much less work lol

Andymac wrote:

fiar play mate seems u have researched properly, might check mine again then I've got a forge one that i havent fitted but not sure what parts i need as i have only got the dv, but then again i love the sound of a mufflerectomy and its much less work lol

As you know, If it's derv, it's electronic so you'll need a control module for it which connects to ECU and also a solenoid which is controlled by the control module so that it can dump properly.

Only real difference I've noticed since removing back box is I can hear turbo a bit more now.
Also, apparently, to feel a difference, it needs to alter power by about 10%

jesus.
diference between derv and petrol engines 101.
since the dawn of time, petrol engines have been based on throttling the air entering the engine then matching the fuel accordingly.
derv engines throttle or control the fuel being injected, then it naturally draws in the air required. theres no throttle body or valve cotrolling the air.

you need a dv on a petrol as when the throttle valve shuts and the turbo is boosting (after a gear change) you'll either get an almightly boost spike that blows the boost pipes off or tremendous turbo stall as the pressure created goes back thru the turbo the wrong way.

fitting a dv to a diesel is a pointless idea as it serves no purpose. kinda like saying im on a roundabout in the playground, its fun going round and round, but i like the swings where i swing back and forth......... how do i make the roundabout swing back and forth???

get on one or the other item in the playground and stop being gay.

Tbf, I know that a dv on a derv servs no direct purpose but if I was running a derv turbo then it'd probably fit one, why?
Well its my car, I'm building it for me, what's stopping me?
I think its 'cool' so I'm doin it,
If we all went for what works on princible then the modified car scene would be very boring,

No offence intended, that's just my thoughts

shrek wrote:

Tbf, I know that a dv on a derv servs no direct purpose but if I was running a derv turbo then it'd probably fit one, why?
Well its my car, I'm building it for me, what's stopping me?
I think its 'cool' so I'm doin it,
If we all went for what works on princible then the modified car scene would be very boring,

No offence intended, that's just my thoughts

My thoughts exactly, if everyone was the same, it'd be a boring place to live and there would only be 1 car

I'm also childish and like the vroooom tshhhh noise

Duey wrote:

shrek wrote:

Tbf, I know that a dv on a derv servs no direct purpose but if I was running a derv turbo then it'd probably fit one, why?
Well its my car, I'm building it for me, what's stopping me?
I think its 'cool' so I'm doin it,
If we all went for what works on princible then the modified car scene would be very boring,

No offence intended, that's just my thoughts

My thoughts exactly, if everyone was the same, it'd be a boring place to live and there would only be 1 car

I'm also childish and like the vroooom tshhhh noise

Hi Duey
If you want a kit come down and see me ive got an exdisplay one you can have for £80

Race_Spec_Performance wrote:

Duey wrote:

shrek wrote:

Tbf, I know that a dv on a derv servs no direct purpose but if I was running a derv turbo then it'd probably fit one, why?
Well its my car, I'm building it for me, what's stopping me?
I think its 'cool' so I'm doin it,
If we all went for what works on princible then the modified car scene would be very boring,

No offence intended, that's just my thoughts

My thoughts exactly, if everyone was the same, it'd be a boring place to live and there would only be 1 car

I'm also childish and like the vroooom tshhhh noise

Hi Duey
If you want a kit come down and see me ive got an exdisplay one you can have for £80

Thanks for the offer. I've already got the DV, but have no idea how to plumb it all in.
How much for fitting?

we must be able to work it out some how, cant be that hard

I'm not doing anything at the weekend if you fancy a challenge :-)

you plum the dv into a boost pipe like normal

you tap into a constant vac line ie brake cylinder line

plum a electronic solenoid into the vac line wired up to a switch behind your pedal or on your throttle cable if you have 1



so basically when the pedal hits the switch it opens the solenoid allowing the vac to open the dv and dump

but on a diesel it will cause loss of power

murran wrote:

jesus.
diference between derv and petrol engines 101.
since the dawn of time, petrol engines have been based on throttling the air entering the engine then matching the fuel accordingly.
derv engines throttle or control the fuel being injected, then it naturally draws in the air required. theres no throttle body or valve cotrolling the air.

you need a dv on a petrol as when the throttle valve shuts and the turbo is boosting (after a gear change) you'll either get an almightly boost spike that blows the boost pipes off or tremendous turbo stall as the pressure created goes back thru the turbo the wrong way.

fitting a dv to a diesel is a pointless idea as it serves no purpose. kinda like saying im on a roundabout in the playground, its fun going round and round, but i like the swings where i swing back and forth......... how do i make the roundabout swing back and forth???

get on one or the other item in the playground and stop being gay.

Surely it makes no difference the boost hitting the closed/slower moving intake valves on a diesel or the closed/partly open tb of a petrol the effect of overboost is still the same
I might be missing the point here
Diesels therfore still must have a boost regulating system of some sort other than just the wastegate

I dont understand the workings of dervs, BUT if the amount of air required is DRAWN in naturally, Why is it FORCED in via a turbo?

Hows that work?

Dervs confuse me