I did some quick and dirty data comparison after installing a 0.035" oil restrictor on my gen2 PTE 6266 ball bearing turbo. I went with a restrictor because after double checking the drain and PCV setup, the turbo still burned oil with occasional smoke on hard pulls when hitting high rpms. On the dyno it burned 1/2 a quart in 2 hours over 20+ pulls which was very unexpected.
Purpose of these tests was to verify the restrictor wasn't too small - starving the turbo of oil.
Test 1: Spin time after hot shutdown at idle
For this test I let the engine idle for ~30 seconds prior to shutting it off with the oil warm. I love that ball bearing turbos keep spinning for a while after hot shutdown.
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[/TBODY]Test 2: Boost response
I compiled some logs where I started a WOT pull in 3rd gear around 3000 rpm, and graphed the rate at which boost built up. Since they were done in different maps the boost target was different. I had to check the response during spool up instead of rpm where target was met.
w/ restrictor: 0.0299 psi/RPM
No restrictor: 0.0272 psi/RPM (average of 3)
Based on the slopes of each trend line I'd say no difference to a marginal improvement in boost response. Ideally there would be 2 more pulls with the restrictor so I could do an average, like with the "no restrictor" data.
In conclusion: I think it's safe to say a 0.035 restrictor is not starving the turbo. Time will tell if it fixes my oil consumption problem, I have a hunch it will.
Input / thoughts / comments welcome
Purpose of these tests was to verify the restrictor wasn't too small - starving the turbo of oil.
Test 1: Spin time after hot shutdown at idle
For this test I let the engine idle for ~30 seconds prior to shutting it off with the oil warm. I love that ball bearing turbos keep spinning for a while after hot shutdown.
Restrictor | Oil Temp (F) | Spin Time (s) |
NO | 220 | 55 |
NO | 172 | 43 |
YES | 220 | 52 |
YES | 216 | 52 |
YES | 208 | ~51 |
YES | 172 | 41 |
I compiled some logs where I started a WOT pull in 3rd gear around 3000 rpm, and graphed the rate at which boost built up. Since they were done in different maps the boost target was different. I had to check the response during spool up instead of rpm where target was met.
w/ restrictor: 0.0299 psi/RPM
No restrictor: 0.0272 psi/RPM (average of 3)
Based on the slopes of each trend line I'd say no difference to a marginal improvement in boost response. Ideally there would be 2 more pulls with the restrictor so I could do an average, like with the "no restrictor" data.
In conclusion: I think it's safe to say a 0.035 restrictor is not starving the turbo. Time will tell if it fixes my oil consumption problem, I have a hunch it will.
Input / thoughts / comments welcome