More Boost Please 850R

[Georgey dee]

Cheers Don,
I'm glad you raised the point about the dump valve. I thought the spring only comes into play when pressure is sensed at the throttle body or is there another part that works on boost pressure? I need re-educating here! LOL. I just slapped the valve in and assumed it was going to work. Oops!

I didn't realise boost could leak through if the spring was too weak with the throttle open. Makes sense though because i get a spike then the pressure seems to bleed off.

Can someone give a quick explanation of how the dump valve works?

Can i get a selection of springs and try it out? are they cheap enough?

So how does the R get the extra power over the T5R, does it just boost full all the time?

[Engineer]

Dump the BOV, let the compressor bypass valve (CBV) do its job and if you want to check your turbo wastegate use a pressure pump with gauge, plumb directly to the gate and pump slowly, the actuator rod should move between 4 – 5 psi if its below this then replace or adjust, saves all the guess work and knuckles if its ok. Hope this helps lol

[STE-MAL]

I have used a cooling system pressure tester for this job, and it works a treat.
My T-5 was down on power. I checked the waste gate actuator and it was very slack. Don't guess this though, use a gauge, and don't go silly!

If you want I can email you the settings and procedure. Just PM me.

[Georgey dee]

Unfortunatly my CBV was jiggered so i replaced it with a blanking plate and fitted a BOV. Can I blank off the BOV for fault finding purposes or will this knacker my turbo?

[Georgey dee]

I've just noticed the thread on the modified section about BOV/DV/Re-Cerc valves. I'm gonna give it a go to see if the boost creeps up! Here Goes!

[Georgey dee]

I'm gonna remove the BOV and see if it helps. will post my results.

[bobcat]

Originally Posted by don kalmar union

The simplest way to explain the right rod adjustment is that when you have removed the split pin and taken the end of the rod off the post you should just be able to pull the rod against the spring to get it to drop on the post. By that I mean the width of a fag paper....no more.
.

I dont think volvo would use that method don!

i think you will find that volvo adjust the wastegate by applying a very specific pressure to the actuator with the correct tools and not fag paper.

here are some static applied pressure values, which as you can see are engine code specific.

Engine Adjustment pressure:

B5204T 12.5 kPa
B5204T2 12.5 kPa
B5204T3 15 kPa
B5204T3 18 kPa
B5204T4 12.5 kPa
B5204T5 12.5 kPa
B5234T 12.5 kPa
B5234T2 30 kPa
B5234T3 30 kPa
B5234T4 12.5 kPa
B5234T4 R-line 28 kPa
B5234T5 12.5 kPa
B5234T6 30 kPa
B5234T7 12.5 kPa
B5234T8 30 kPa
B5244T2 30 kPa
B5244T3 12.5 kPa
B5254T 12.5 kPa

please note don, these figures are for the t5 engine's. if you need them for the t4 let me know.