ChrisFL

This would be amazing for first gen and spec Cayman people. At least with the 2.5L, the engines were relatively cheap. The 3.4L are getting harder and harder to find. Great work, hope to see it on the market soon.

Cory M

Why is the pressure so low in the Cayman? Your plot has a range of only about 3.1-.5 bar. Your Boxster plots range from about 4.25-2.9 with the dry sump system and 4-1.1 without. You probably are taking the data at a different location but it still seems really low on the Cayman. At what pressure does the oil pressure warning light come on?

krombacher

I'm guessing because 0w40 was being run. Why not 5w40, or a step thicker? Isn't lighter base weight oils a poor choose from oil pressure fluctuation perspective on a race track?

Plavan

You need the second number higher, the first is meaningless on the track. W is for "Winter".

CTS

It was running 0W-40, as stated in the post. Mobil 1 0w-40 gives the lowest oil pressure readings of any oil I tested, and this particular engine is on the low side of normal. It probably has slightly large main bearing clearance.

The Cayman oil pressure was taken at the valve cover, from the normal oil pressure sender location. On my Boxsters, I measure the pressure at the oil cooler, which typically reads about 1 bar higher. When I post a data screenshot, I specify which one, if it is relevant. I think each location provides useful and conclusive data.

The idiot light comes on at a very low pressure. I am not sure of the exact number but it is under .5 bar. Since the oil pump creates this much or more pressure pumping pure air (at least at rpm > 4000) the idiot light is never going to alert anybody to oil pressure fluctuations.

My long experience with various engines leads me to conclude that most of the time, the brand of oil matters very little, and the weight of that oil matters even less. Engines that receive an uninterrupted supply of oil, even at a very low pressure, seem to last forever. Engines that do not, fail regardless of oil brand, weight, or temperature.

That said, everything in racing takes place in that last 1% of performance, so very small things can matter. I use Mobil 1 (the weight depends on expected oil temp) in my dry sump engines, but I don't recommend it for wet sump M96 engines that are used on track.

Chris Cervelli
Cervelli Technical Service

hf1

Chris, what oil do you recommend for a SPB (wet sump + 2QT deep sump) racing during North-East summers? Thx!

jandackson

Subscribed.

Gary R.

Rather than post "Subscribed", you can just click on the "Thread Tools" up on top right and click "subscribe to this thread", saves a lot of wasted subscription notifications..

FFaust

Watching this with great interest. Thanks for pointing me here Chris.

Got the SPC ready, and promptly blew the engine on the second day of the first event, sheesh.

This has been a very informative thread so far; dispelled a lot of myths. Even learned about Occam's Razor.

CTS

Please see boxsterdrysump.wordpress.com for further information.

PorscheDoc

Very cool Chris, always interesting seeing how you are developing these endurance cars further. Always making it faster!

For those that haven't been to a WRL endurance race, typically the given is that you run the car as fast as you can but trying to take it a little easy to make the car last. The Cervelli boys run 11/10ths 100% of the time. There aren't any boxsters out there taking more abuse in probably any race series than what they put on their cars. Both of his cars are currently leading (1/2) the points race this year again.

See you are the 24hr in 10 days!

jscott82

Has anyone petitioned PCA about getting this approved for Spec Cayman?

Once I find a car, I'm starting an SPC build over the winter. Seems like this is a no-brainer, if approved.

GTgears

Exciting times...

Coloradoheel

We have 2 Boxsters running WRL against Chris. One of our cars is currently getting a new engine - the dry sump is being installed as well. We're convinced.

PorscheDoc

Nice! Clock is ticking boys, get to wrenching! Heading to MAM tomorrow to shake down 02, then off to HPR we go!