Oil Pressure: Weights etc
 

Right now I run 15w40 cause its cheap and I have it laying around from truck oil changes.

That being said, it basically pegs the gauge when cruising and its just wasting power/generating heat. I would like to try 5w40 but AFAIK, that will just affect cold start pressures right?

I would need to switch to a 5w30 area to see a lower pressure?

you are right

Yes, you should see lower pressure.

I don't know enough about oil weight requirements to give any useful info but I think there's information out there that can help you figure out what to run based on bearing clearances and such.

From what I know about oil, you want to stay away from large-weight-range stuff when you have a tough environment for it to live in. A turbo'd LT1 qualifies. I'd try 10-30. It'll be more 'shear stable' than a 5-30, the oil pressure difference on startup between 5 weight and 10 weight would be negligible.

What's your hot oil pressure? Pinning the gauge? If so, I'd definitely try a 30 weight.

Hot idle is prob round 35-40psi, again too much, but it makes me feel fuzzy inside.

Hot idle for mine with 5w40 is in the 35-40 range which I'm fine with.

Do you have the same pressure while cruising? (you and I have similar clearances I think) [I have a HV pump though]

While cruising, I am in the mid 40's or so when hot. I am 60-70 when cold but not pegging the gauge. Keep in mind my cruising RPM may be significantly different from yours.

75mph is 2500rpm for me, 65mph is 2200rpm.

I'm below all of that in 6th. 1800 is around 65, 2000 at about 80. Prob lower since my tach is off by a couple hundred RPM.

Hmn ok, I will toss some 30wt in and see how she does.

Lil scurred :lol:

You should get a real gauge instead of trusting the factory stuff.

Wait, this is with the factory gauge? Yikes.

Its a lot of pressure, vs, no pressure, so wanna try for mid range pressure, vs, no pressure. :rofl:

Synthetic blend?
http://www.walmart.com/ip/Shell-Rote...-gal./20573564

So much fancy

That should work, rotella is good stuff.

Also: High roller turbo build? Put a gauge on it!

I have no where to place an oil gauge nor do I really want that hassle. Like I said gauge is a yes or no kinda indicator.

A manual gauge in the cowl would tell you a whole lot about how great your factory gauge isn't.

Its a potential option, but not directly related to this topic.

But it is. You are assuming you have too high oil pressure. You need to verify your cold and hot pressures with a gauge. You don't need a $300 gauge. A parts store mechanical gauge would be a viable option to verify your actual pressures. You are also chasing loss of power....you haven't even got the car to go down the track 100%. I'm all for doing things for longevity etc. I just don't want you to waste lots of time here when other things need more immediate attention.

Adam, aren't some of the factory gauges off by a large margin? Like 10+ psi?

All of the gauges are significantly off. Everyone knows the fuel level gauge is a joke. M6 guys know the tachs are off. It is what it is. Stick a real gauge on there and see what it is actually doing.

A basic mechanical gauge is a good idea. Can't identify if there is an issue without good information.

I am very very apprehensive about a cheapo mechanical gauge, as its a plastic hose in an engine bay filled with things anxious to melt it and burn my car down.

If you think we can make a nice gauge under the cowl, and use SS braided to the port, I am all for it. And what makes you think I am chasing power? Just don't wanna use molasses if I don't have to.

No recommendation of cheap, plastic line of course but I'm guessing Adam meant you don't need a big $$ electronic gauge with all the fancy things.

You can run a full sweep electronic gauge or go with a mechanical gauge with braided hose (that's what I did). If its mechanical just make sure you bleed it.

Either way it will be better than stock.