I've had a little think about dump valves myself...

**nutron** · 8th March 2007, 22:18

Now I don't like the idea of an electrically operated one for a multitude of reasons. I would like a diesel dump valve that works based on pressures but without a throttle plate that's not straight forward.

At this point I got myself a pen and alot of paper and started thinking in picture form. The result (apart from a getting through alot of paper and ink) was a focus on the air box. Now I'm not possitive but I recon there may be enough of a change in pressure in the air box to operate a valve.

The only way I can see to check this is to get myself another boost gauge and plug it into the air box. So that is what I am planing to do...

**chrisgettings** · 8th March 2007, 22:48

i like the way your thinking
maybe after the airflow meter there may be more of a presure drop there

you prob know a lot more about it than me,,,but any idea's for a dump valve may give you a idea of how you could do it

**nutron** · 8th March 2007, 23:05

I already have a boost gauge just before the inlet manifold which should be the highest pressure point. A gauge on the air box will tell me what is happening before the turbo as well and if the air is backing up and creating positive pressure there, I might be able to use it to open a valve.

**chrisgettings** · 8th March 2007, 23:13

please please please

i want to do a diesel dump valve to

**plasma** · 8th March 2007, 23:22

You want to drop the kids off at the pool?

**nutron** · 9th March 2007, 17:45

Success and failure...

I fitted the gauge to the box but there was no apparent change in pressure at all, which I find strange. It might just be my box due to the massive increase in available air but so far the needle hasn't budged. I've tried two different boost gauges on the line and they are the same.

I'll try reving the t*ts off it tonight and see what happens...

**The Doc** · 9th March 2007, 19:36

Struggling to see if you want one on the CDTi engine why you don't just have an offtake off the intercooler pipework with a dump valve in it and a electronically controlled solenoid to turn it on as and when you want it? Switched off it works as a normal CDTi, on it has your chav valve? Just make sure you have a strong enough spring in your dump valve so that it doesn't leak boost.

Then you trigger it with a PTM switch on your accelerator.

Not too hard really.

You ain't gonna get performance gains anyway.

And the airbox idea isn't gonna work either, not enough pressure differential.