dump valve on 2.1td

[Will406td]

just wandered if it was possible to fit a dump valve on a turbodiesel.

ive always had a soft spot for the sound of a dump valve amd ive had on my petrol turbo cars
(series 2 rs and sapphire cossie).

also i have a d8 406 and i like the rear lights off a d9 will they fit?.

[lozz]

Hi mate,

D9 lights on a d8 wont fit,
differnt shape bootlids and bumper


dump valve on a 2.1 is possible but you wouid to need a switch,
simalar to the one in this pic

[CalamityJames]

That's really tempting to do, my mate has 3 dump valves spare so it could be worth a crack. Easy to wire up?

I'm not a chav, honest!

[lozz]

That's really tempting to do, my mate has 3 dump valves spare so it could be worth a crack. Easy to wire up?

I'm not a chav, honest!

Im not 100% on this but ithink you use t peice conectors and tap in to the turbo pipe,
theres a Thread on this over on the Turbodeisel forum showing how its done .

iwas going to have a bash at fitting one on mine but couidnt find the right dump valve

[FarmPug]

Why would you want to fit a dump valve on a diesel anyway? You will actually be SLOWER as you have dumped useful boost for NO GAIN.

A turbocharged petrol engine will suffer from "lag" because the turbocharger takes a certain amount of time to heat up and "spool up" to its final steady state. This is felt as a delay or lag from when the driver puts his/her foot down to the eventual steady state power. To reduce this (and it is reduce - it can never be gone completely ) manufacturers use a throttle by pass system or Blow Off Valve. As far as I know this is universally used now & I think Porsche were the first.
A petrol engine has a throttle valve (connected to the pedal) which controls the amount of air entering the engine. When the throttle is closed (ie your foot is off the pedal) there is very little air flow through the engine and this will slow the turbocharger significantly. When the throttle is opened the turbocharger is going quite slowly and will take a while to accellerate to speed and boost. This is felt by the driver as lag. If the throttle is bypassed by a blow off valve this will allow the turbocharger to continue to spin and recirculate air and maintain a higher speed. In this situation, when the throttle is opened the turbocharger is spinning faster and will accellerate to speed in less time hence reducing the lag.

BUT
On a diesel engine (like the 406 HDI mentioned above and all others) there is no throttle valve. There is no restriction to air going through the engine. The speed and power of the engine is controlled by the amount of fuel injected into the cylinder.
So, when the "throttle" (and it is not really a throttle so I will call it a "pedal") so when the pedal is lifted, the turbocharger will still spin quite fast because there is no restriction - there is no throttle plate to stop the air flow. When the pedal is pressed again the turbocharger is already spinning at quite a speed and will accellerate to final steady state quite quickly.

There will be NO ADVANTAGE to fit a BOV to a diesel as there is NO throttle plate to bypass.
In my opinion it would be more usefull to learn how to left foot brake and spool up the turbocharger before you need the power.

Regards,
FarmPug

[CalamityJames]

Yeah I've gone off the idea now lol

Interestingly, when I left foot brake and use the accelerator, my check engine light comes on!