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FARTBREF wrote:
[quote]damn right…what was up with #8???
Al[/quote]
#8 had oil pressure problems at VIR once the oil got hot. Might have been a problem with the oil pressure relief valve. Bearings were damaged by the low oil pressure tho so it’s going to be rebuilt into #9.
I tried running special “race” oil that someone gave me “for performance” - but it showed low oil pressure as well. I went back to my tried and true Rotella T 15W-40 and have never had a problem - in either the E30 or my 550 hp AIX 'Stang.
wildhorsesracing wrote:
This makes me remember reading about Joe Gibbs race oils last year. They spec their oils for specific bearing clearances. The oil they spec’d for us (0.0018 to 0.0020" is ideal I think) was scary thin.
Ranger wrote:
[quote]wildhorsesracing wrote:
This makes me remember reading about Joe Gibbs race oils last year. They spec their oils for specific bearing clearances. The oil they spec’d for us (0.0018 to 0.0020" is ideal I think) was scary thin.[/quote]
Got the hot ticket: 0w20 mixed with the Shell synthetic that Jim mentioned. Special brew=great straightaway talent?
Really, how much power is in the thinner lubes? Anyone know?
Thread hijack.
Ranger see you soon.
RP
Patton wrote:
Based on my data* at Road Atlanta, the effect on lap times is due to a combination of factors:
minus 0.4 sec - more power by using 0/30 rather than 20/50
plus 0.3 sec - messed up turn 7 and got a bad run down the straight because I thought the OP light flickered in turn 6
plus 0.6 sec - had to use 12-heat-cycle RA1s instead of stickers because I spent all my money rebuilding a motor instead of waiting for the sucker to air condition the block all by itself
equals
plus 0.5 second (slower) lap time due to thinner oil
*data, meaning hypothetical, imagined results for a problem that has not been double-blind tested. Your mileage may vary.
IMO hp tricks are somewhat of a black art. Not much written down, and not that many folks that have really done the testing that separates results from theories. That makes it really hard to get good info. Chuck Baader lives near a NASCAR engine guy. That’s the kinda guy that would really know.
What I do know, however, is that it’s not just about visc.
Visc’s run in ranges. That is to say that each visc rating like xW50 has min/max 0deg visc and min/max 100deg Visc value that it has to hit. Race oils do all run on the thin side of the their weight band, which for an xW50 is ~17@100deg C (I don’t remember the units) IRRC.
That being said, some thick oils have dyno tested better then some thin oils. There are, for example, additives that make an oil more slippery. Both Redline and Royal Purple use Moly, for example. But others say bad things about Moly. Oil’s complicated and there’s arguements for and against.
I’m not saying that Moly is the answer. I’m just saying that it’s not all about visc and I don’t know what the secrets are.
Me personally, I’d be tempted to use oil pressure as my guide. If the ambient temp and my oil cooler was keeping an xW40 cool enough that my OP was ok, I’d be tempted to use the 40W. But if my OP was <50psi, I’d go with a thicker oil. But I’d use real 100deg visc values and not use a clumsy measure like it’s xW50 “weight”. In the end, reliability is vastly more important then an extra pony or two.
Ranger wrote:
[quote]IMO hp tricks are somewhat of a black art. Not much written down, and not that many folks that have really done the testing that separates results from theories. That makes it really hard to get good info. Chuck Baader lives near a NASCAR engine guy. That’s the kinda guy that would really know.
What I do know, however, is that it’s not just about visc.
Visc’s run in ranges. That is to say that each visc rating like xW50 has min/max 0deg visc and min/max 100deg Visc value that it has to hit. Race oils do all run on the thin side of the their weight band, which for an xW50 is ~17@100deg C (I don’t remember the units) IRRC.
That being said, some thick oils have dyno tested better then some thin oils. There are, for example, additives that make an oil more slippery. Both Redline and Royal Purple use Moly, for example. But others say bad things about Moly. Oil’s complicated and there’s arguements for and against.
I’m not saying that Moly is the answer. I’m just saying that it’s not all about visc and I don’t know what the secrets are.
Me personally, I’d be tempted to use oil pressure as my guide. If the ambient temp and my oil cooler was keeping an xW40 cool enough that my OP was ok, I’d be tempted to use the 40W. But if my OP was <50psi, I’d go with a thicker oil. But I’d use real 100deg visc values and not use a clumsy measure like it’s xW50 “weight”. In the end, reliability is vastly more important then an extra pony or two.[/quote]
:laugh:
NOTICE…both Levie and Gress got dynoed today and both make in excess of 160/155 in 100 degree weather. It only took 8 ECUs and about 18 pulls each to finally get the F/A close to right.
Be advised they are lock and loaded/ready to rumble:woohoo: Chuck
cwbaader wrote:
[quote]NOTICE…both Levie and Gress got dynoed today and both make in excess of 160/155 in 100 degree weather. It only took 8 ECUs and about 18 pulls each to finally get the F/A close to right.
Be advised they are lock and loaded/ready to rumble:woohoo: Chuck[/quote]
And the best thing is that Scott’s engine had great oil pressure the entire time!
I went thru 3 DME’s and it was my third one that really did the trick. The one I’ve been using for the last year, and the DME that I used the 2 yrs previous, created really lean mixtures. It was the DME that I bought just a couple days ago that did pretty well.
I don’t understand enough about how different DME’s can cause such different behavior, but I was pretty darn surprised at just how much difference it made.
Me and my 100psi of oil pressure will see you girls at Road Atlanta.
Ranger wrote:
[quote]
Me and my 100psi of oil pressure will see you girls at Road Atlanta.[/quote]
What color warning light comes on when you have 100 psi? 
Ranger wrote:
[quote]
Me and my 100psi of oil pressure will see you girls at Road Atlanta.[/quote]
Just wait 'till you see my aux oil pump. Since oil pans are free, I “integrated” a secondary oil pump in my pan.
I can’t wait to see this setup. I hope you will post detailed instructions and pictures on gress.org haha.
Never let it be said that Scott will make things more complicated than necessary:woohoo: Chuck
Where are you guys getting your box full of computers to take to the dyno with you? It seems odd that this is the way the rules require that we deal with lean engine killing mixtures…
100 psi oil pressure? Scott, you’ve gone mad.
BigKeyserSoze wrote:
[quote]Where are you guys getting your box full of computers to take to the dyno with you? It seems odd that this is the way the rules require that we deal with lean engine killing mixtures…
100 psi oil pressure? Scott, you’ve gone mad.[/quote]
The DME’s come from a junkyard, or you buy them over time on Bimmerforums.
Not mad. Piezo pumps. http://www.newscaletech.com/doc_downloads/Positive_Displacement_Microfluidic_Pump.pdf
Ranger wrote:
I thought we were talking about you engine, not your… 
nevermind! :laugh:
