Thread: Think I went with too big of a turbo...

Everyone emphasis peak timing, is that really the number one killer of the motors? I would expect midrange timing being at fault too.

Coheed, I'm so tempted to slap on an NA header on the car, just to see how it is supposed to be fully na. I wont know how a NA VE feels, until I get a VE dropped into wife's car. But as it stands right now the VVL switch is very mild at best.

Now I'm loosing some oil, I haven't seen blue smoke though. But I wonder if the pistons are leaking. The motor did do 210psi, which seems healthy.

A stock ve in a p11 is not that fast, decent but not that fast. Its not destroy the tires in 1st and 2nd fast but its decent. How much oil are you losing? Pull the hose off the valve cover vent closest to the intake manifold and see if at idle you have a suction happening there. If so your fine and you might be getting just a bit of blowby. You can check that by pulling the intake pipe off and see if you have oil traces all through there. That means your getting a bit of blowby and oil going back into your intake tube. Thats the point where you need to run that to a catch can if that is happening. Dont want to fill your intercooler and pipes up with oil. That and the suction being created by the turbo doesnt help. Its probably sucking oil slosh right out of the valve cover. I recommend a Catch Can ASAP and vent to atmosphere. Cap the port on the intake pipe.

And what the hell are you still doing up at this hour. You must work nights. haha

Yeah you want to have the timing low at peak torque. Thats where detonation likes to take place more than anything. Right when the boost hits hard usually. Id say 19-20 in the midrange and around 19 through the topend. Should be plenty safe when you go to 15psi as well.

Alright played around with the TP. At a very low speed I put it into the highest gear possible then opened the throttle all the way. The car very slowly picked up the speed, but the boost gauge stayed at 0psi, which is what we wanted.

Looking back at the data logs, I see where the throttle is 100% open, the TP (Engine Load) spikes up to 60 TP, then instantly backs down to 55. My 0 psi is around 55 TP. Thus Nissan TP is proportionate to the airflow. I also do see a spike up in the MAF voltages, by about 1 volt.

You know if a roller rocker can feel fairly decent, I can only imagine how good the VE should do .

I took the car out to the beach last weekend, roughly 500 miles both ways. When I checked the oil yesterday it was at half mark, not good.

There is plenty of suction coming from the PCV valve, actually it's fairly strong/stronger then any of the DE's that I've seen. I didn't have the valve cover breather (turbo piping one) hooked up, but it was blocked off, and the PCV valve vacuum was so strong that the oil cap would get sucked in at idle. Now I do have the VC breather hooked up, to the turbo intake, but there is not a single drop of oil on the turbo or piping.

I need to get under the car and see if any gaskets where leaking, I was suspecting my lower oil pan leaking, because there was oil under it on the ground. But that seems to be from when I had my valve cover breather blocked off and the overpressure caused the oil to escape through the dip stick and valve cover. Maybe that caused my oil pan seals to leak through too and hence I'm loosing oil.

When I did a compression test, it did 210psi on warm engine, when I added oil (which I added too much off), it spiked to 300 psi. Nissan FSM says if the CR increases with oil, you could have worn piston rings.








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I might pull more top end timing to be safe still then. I don't live much at 7k rpm so it doesn't bug me loosing a few ponies.

Yeah you probably broke the seal on your pan from the overpressurizing. I would still recommend you get a catch can and vent to atmosphere and cap off the intake pipe.

As long as your vac at idle is still strong your motor is fine and your rings are fine. With 210 across the board your motor is healthy. As for the adding oil thing. I think you added way too much. It had nowhere to go and thus boosting compression ratio. lol. Only supposed to put like a teaspoon in and thats all. Your motor is fine. Your probably just leaking it from the pan.

btw same compression gauge i have, im on my second one. My first one broke when we compression tested the 2.2L 12.5:1 compression VE build i did on my buddies 200sx. Hit over 300 with a 50 mile breakin period. lol. Broke the gauge and wouldnt function after that. I hope you didnt break yours after that

Well I'm not seeing any oil traces on the ground now, though I did see some oil on the silicon gasket on upper oil pan connected to the block.

In my experience, I highly suggest not removing the much needed suction that the turbo creates. I was playing around with Exhaust Evac system, and it didn't seem to deliver enough vacuum to keep the dip stick from popping out. NA motors might be fine though, since PCV valve will provide suction at WOT, but on a boosted motor that valve closes and the piston blow by has no where to go, and in my cause it found every single hole possible.

I plan on doing a dyno test to see how much power you loose by not having a good vacuum in the crankcase with boost .



I guess I'll test it out again today, this is my second one, first stared bubbling at the tube, and that was on my 120psi DET!

I just use 3 vents on my motor but much higher power levels and boost levels. If you look at all the high hp hondas they all eliminate the pcv and run 3-6 vent lines to a catch can to keep the crankcase from pressurizing under high boost levels. I doubt you loose much not having it in vacuum but you probably lose some if it goes under pressure. On a healthy running motor at low boost levels that your running you shouldnt have any problems with pressurizing the crankcase if you just vent the hose to atmosphere after a catch can on the valve cover breather closest to the intake manifold.

Be a cool test but i doubt you will see much if any difference at all vs open atmosphere vs recirculated back to the intake pipe.

Gah, all these turbo talk makes my brain hurt.

I am going back to the N/A cave....

Go Vadim Go! I know your persistence will pay off.