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turbo blown twice, which oil to run?, 800bhp


msupra1

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Hi gents. Looking for some advice and help.

 

Long story short, shortly after my tune early 2015, I had my turbo rebuilt. The rebuild shop was claiming oil starvation was the culprit.

 

The car was tuned for 600whp (high 600's bhp). It was running 10w40.

 

So after I got the Borg Warner S366 rebuilt. I ran it for 6 months last year for about 3500 miles before it started shooting blue smoke again.

I just got around to getting it rebuilt again. They are now saying the inside of the turbo was fried, the bearings, and had dried up oil on it.

 

They rebuilt it to factory spec + beefed the turbo up to tolerate higher heat this time around.

 

 

The car at this moment is just had the whole fuel system redone for E85 fuel.

The other mods remain the same, such as full 4" dp / exhaust, gsc s1 cams with springs/retainers, greddy 3 row, and all other supporting mods.

 

The bottom end is unopened and stock (87k miles).

So i'll see how long the bottom will last me.. but got some other guys here pushing more power then that for years.

 

I'm trying to decide what weight oil is good for around 800bhp.

I was thinking 10w50 because the last 10w40 didn't seem to hold up.

 

My only concern is how thick in oil can I really go for stock bottom.

 

And would an oil cooler be a good idea? For the majority, this car is used driving around town and on cruises.

 

Cheers.

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Would a thicker oil help your situation? I certainly wouldn't be using a 10w50 in Canada during the cold months, I'd be aiming more at a 0w30 to be honest. In our oil FAQ it's recommended for us to drop to 5w40 in the Uk when single turbo. I always assumed that was to have the oil a little thinner to move around the system more freely with less friction.

 

Don't base your choice on what I'm saying here, I just want to give you some food for thought.

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I don't live in the cold part of Canada :) ..The weather now is averaging above 10c daytime, and is anywhere from 20 to 35c in the summer. The car is not driven in winter.

Most start taking their cars out in February and store them in October.

 

I was reading about that too thick of an oil, like 10w60 isn't necessary the best for an unopened stock bottom end.. because it wasn't designed to flow that thick of an oil... but it seems like many are running 40 and 50 weight from my searches.

 

So considering it's not cold but mild and getting warmer... just trying to see if something like a 10w50 would be okay for the bottom end. Or another option may be sticking with 10w40 and get an oil cooler. If I don't have to dish out the money for one, I would prefer not to... but if greatly helps I will probably.

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Do you have the correctly size oil feed nipple? I know that dbb turbos have a reducer , so if you have one of these fitted and running a journal bearing you will suffer oil starvation. Also if your not running one on a dbb turbo you will blow your oil seal due to the larger volume of oil.

Edited by mellonman (see edit history)
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Do you have the correctly size oil feed nipple? I know that dbb turbos have a reducer , so if you have one of these fitted and running a journal bearing you will suffer oil starvation. Also if your not running one on a dbb turbo you will blow your oil seal due to the larger volume of oil.

 

The turbo oil line kit I purchased years ago, I wasn't sure on the sizing.

 

I purchased a proper 4an 1/4 inlet line which is the correct one for a billet S366

 

So there is a few factors why I had these issues.

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Is there a restrictor in the oil feed? Measure the oil pressure in the feed line. Is the drain big enough and unobstructed? You need to measure oil temps in the sump, too.

 

This! And are you allowing the engine to run on after a boosted run so the turbo can cool a little? as this combined with bad flow through the turbo from too small a restriction wont help, is the turbo also water cooled? it wont be the oil grade, a good fully synthetic 10W40 should be up to it as long as your not seeing very high oil temps, I presume you have a cooler fitted?

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They actually specify 5w30 for NA but for TT there's a temperature chart. It's pretty much 10w30 though unless you have temps lower than -18c :blink:

 

The chart in the user manual suggests that 5w30 isn't great if you're stating your car at over 10c which is most of our summer months.

 

 

image

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The 5 in 5W30 just means it will be better at lower starting temps IE better flow, using it instead of 10W30 wont have any impact at higher starting temps at all.

 

So do you think the chart is saying 10w30 is the recommended weight for a GTE engine startup (probably due to the addition of the turbos etc) but you would need to run 5w30 if you're starting the car in a cold environment?

 

Otherwise, surely the chart would be the same as the NA (GE) one which just has one big arrow for 5w30 across the whole range?

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So do you think the chart is saying 10w30 is the recommended weight for a GTE engine startup (probably due to the addition of the turbos etc) but you would need to run 5w30 if you're starting the car in a cold environment?

 

Otherwise, surely the chart would be the same as the NA (GE) one which just has one big arrow for 5w30 across the whole range?

 

It is, I think you may be misinterpreting it.

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Running 800rwhp here and only use 10-60 in mine. Ran 10-40 in my BPU TT and spun a main bearing after around 6 to 9 months. Oil was just too thin when driving it hard, causing oil starvation. Plus the pump was having to work too hard to cope. All this was confirmed on the Syvecs data logs, so I know what I'll be using in future

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No sure just how the oil was too thin when driving hard? and how the pump would have to work harder, thicker oil would put the pump under more stress, it is possible that due to rod loadings the oil was forced from the bearing surface, causing it to spin, but the viscosity shouldn't be the deciding factor, it will be more likely due to the component make up and shear factors, or even a tight or misshaped bearing or even the material, or just plain bad luck.

Edited by Tricky-Ricky (see edit history)
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Oil was way too thin when hot and had the viscosity of water almost! Pump was most likely worn too, which wouldn't have helped, but bottom line was the oil wasn't doing its job when I was pushing the car. Kept getting low oil pressure trips on the syvecs under hard braking even when I changed the threshold to trip at less than 1 bar; this was happening at high speed and high revs. One shell spun and the others were heavily scored. I had a built engine waiting to go in so wasn't bothered about the warnings, stupid I know, but the truth.

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Exactly! which Is why I asked the question, a 10w40 oil should be still w40 at up to 120C or higher if synthetic, so wont go thin unless contaminated with fuel, agreed! the pump or the pressure release valve would be the culprit, or simply worn bearings will reduce oil pressure, the 2JZ oil pump is pretty tough, mine was knacked yet still kept good pressure with no problem.

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