To re-cap:-
|
|
Mod |
Idle |
Cruise |
Boost
0.7bar |
Comments |
|
1 |
Standard |
0
psi |
0
psi |
0.4
psi vac |
From
cruise to boost, momentary positive pressure of 0.018psi, dropping to 0.4
psi vac |
|
2 |
Tank
connected |
0
psi |
0
psi |
0.325
psi |
From
cruise to boost, momentary positive pressure of 0.144psi, dropping to
0.325 psi vac |
|
3 |
Tank
connected and breather to air box lid aluminium restrictor removed. |
0
psi |
0
psi |
0.4
psi vac |
From
cruise to boost, momentary positive pressure of 0.018psi, dropping to 0.4
psi vac |
|
4 |
Tank
connected and breather to air box lid aluminium restrictor removed.
Restrictor placed in atmosphere exit of green filter in airbox. |
0.036psi
vac |
0.036
psi vac |
0.216
psi vac |
From
cruise to boost, momentary positive pressure of 0.018psi, dropping to
0.216 psi vac |
|
|
Vacuum
pipe connected directly to the breather pipe. |
1.0psi
vac |
n/a |
n/a |
1.0psi
achieved within 4 seconds from connecting the pipes. |
- ******************************************************************************************************************
- Following tests carried out by Dave Kember May 2007
- At last..some pressure measurements using the Magnahelic gauges kindly loaned to me by RB. All readings etc taken
- with a
nice hot engine.
Test 1 With the crankcase venting to atmosphere via the camcover stub, sump pressure was 0 "wg (gauge moving very - slightly
around the 0 mark).
Test 2 With the crankcase venting to atmosphere via the RB catchtank, sump pressure was 0 "wg (gauge moving very - slightly
around the 0 mark). So the catchtank isn't causing a sump pressurisation
problem - good news.
Test 3 After 2 mins idling with sump at 0 "wg, plumes of smoke were emitted from the exhaust when the engine revs - were
taken up to and held at 2700 rpm.
Test 4 After 2 mins idling with sump at 4 "wg vacuum, no smoke emitted from the exhaust when the engine revs were - taken
up to and held at 2700 rpm.
Test 3 and 4 were alternated several times and the same results were seen in each instance. So it seems that negative - crankcase pressure has an effect on the smoke from my turbos. I'd expected this.
*******************************************************************************************************************
- While warming the engine there was a drip of oil from the compressor side of the rear turbo which dropped onto the exhaust
- side of the front turbo, this produced a little puff of smoke. I knew there was oil around this area,
- but had previously not taken much notice. Time to investigate as I now had an idea where this oil originated.
- Removing each of the air box to turbo connector tubes revealed lots of oil at around the turbo intake, and more
- which had accumulated in little pools with the creases of the tubes !!
View of front turbo from underneath engine.
Turbo hose removed.
A small pool had collected at the leading edge of the turbo intake.
- What was quite surprising was the amount of oil that was laying in the creases of the connector
- tubes !! The tube below had the most amount of oil in it. I guessed this might be because this turbo
- (rear) got its air from the side of the air box favoured by the atmosphere exit from the green filter.
I was correct, the left side feeds the rear turbo.
This tube feeds the front turbo.
- Seems that a lot of oil had been getting into the intake stream that was never supposed to !
- With everything cleaned up and put back, I'll see how it goes from here....................lets hope
- tank does it's job.