Accusump Installed this weekend...

[insite]

Originally Posted by jaykay

Okay thanks for this comprehensive response. I don't know how the oil system is arranged but from what you are saying oil pooling the opposing head initiates the problem and not sump sloshing. If this correct, a deep sump won't help if oil is trapped in the head. Is this correct?

exactly. the issue is that the sump can run out of oil. sloshing probably exacerbates this. the deep sump kits w/ an extended pickup tube can help to an extent (as can modified baffles), but the problem can still occur.

[Mike_Yi]

Originally Posted by jaykay

Ouch, are we saying that long sweeping rights will develop high enough g loading on ps2s (as in without slicks)? What sustained g loading threshold are we talking about? I might just put my i-phone up on my dash and set an alarm

It happened to my engine at Road America on Goodyear Eagle F1 Asymmetrics (which are rated slightly better than PS2s, but probably not enough to make a difference). I had done several track days on other tracks before with no problem. However, RA has so many really high speed corners that it imposes much more G than tighter tracks with slower speed corners. Add to that the Carousel....

[Jake Raby]

Track related M96 engine failures are not entirely dependent upon high speed cornering and the associated G forces.

Oil that cannot take exceptionally high temperatures without losing its ability to maintain pressure is the single biggest element that we have seen. Oil temperatures of m96 engines can exceed 250F and at that point off the shelf oils lose their ability to maintain pressure. In this scenario the G forces further aggrevate the pressure issues and appear to be the culprint, when they are really just a part of it.

All the issues we have experienced with the M96 failing on the track due to oil pressure issues have been experienced at the end of sessions when the oil is heated exceptionally. I haven't talked to a single person who experienced a failure in the early laps of a DE or track event, only after the oil is heat soaked and thin. In my personal 996 equipped with an accusump I noted this with my data acquisition system on track at Road Atlanta where turn 1 and turn 7 were the worst for oil pressure, but only after the oil temps were eleveated and the session was 3/4 over. That was with coilovers all around and sticky tires.

Just something to consider.. The accu-sump does help a lot. We do not have on- track issues these days, even without an X 51 pan and other measures that are commonly applied to overcome what appears to be the root of the issue.

[ChrisZang]

Originally Posted by Jake Raby

Track related M96 engine failures are not entirely dependent upon high speed cornering and the associated G forces.

Oil that cannot take exceptionally high temperatures without losing its ability to maintain pressure is the single biggest element that we have seen. Oil temperatures of m96 engines can exceed 250F and at that point off the shelf oils lose their ability to maintain pressure. In this scenario the G forces further aggrevate the pressure issues and appear to be the culprint, when they are really just a part of it.

All the issues we have experienced with the M96 failing on the track due to oil pressure issues have been experienced at the end of sessions when the oil is heated exceptionally. I haven't talked to a single person who experienced a failure in the early laps of a DE or track event, only after the oil is heat soaked and thin. In my personal 996 equipped with an accusump I noted this with my data acquisition system on track at Road Atlanta where turn 1 and turn 7 were the worst for oil pressure, but only after the oil temps were eleveated and the session was 3/4 over. That was with coilovers all around and sticky tires.

Just something to consider.. The accu-sump does help a lot. We do not have on- track issues these days, even without an X 51 pan and other measures that are commonly applied to overcome what appears to be the root of the issue.

Thank you VERY MUCH for this explanation
So for people like me who track their cars regularly what oil and probably more important what oil weight would you reccomend
Especially for people who live in hot climates in the summer and don't have to worry about cold temperatures (I am happy to put in a different oil during the off-track (cold) season)

[Jake Raby]

The only oil we have experienced that will stay alive at these temperatures has an additive package thats depleted after only 750 miles of service.. It has to be changed every 750 miles, or generally after just one track weekend.

Thats the problem.. True race oils are exactly that, they have no lifespan.

[ChrisZang]

Originally Posted by Jake Raby

The only oil we have experienced that will stay alive at these temperatures has an additive package thats depleted after only 750 miles of service.. It has to be changed every 750 miles, or generally after just one track weekend.

Thats the problem.. True race oils are exactly that, they have no lifespan.

OK, so I'll add an oil change to the list of things (bleed brakes, change pads, install rollbar, etc.) to the list of things before a track day - I can live with that
What oil is it?

[jaykay]

Originally Posted by Jake Raby

The only oil we have experienced that will stay alive at these temperatures has an additive package thats depleted after only 750 miles of service.. It has to be changed every 750 miles, or generally after just one track weekend.

Thats the problem.. True race oils are exactly that, they have no lifespan.

Jake. Very interseting stuff. Is there a theory as to what exact mechanism is causing the loss of oil pressure at elevated temperatures? It is not entirely clear me unless it has to do with oil pump efficiencies/effectiveness under less viscous conditions. Would your transducer placement potentially play a role in the trends you see ?'

[insite]

quick update:

byron blew his motor at barber yesterday.......three laps in.

[jmatta]

Guess the accusump didn't help much...

Sorry to hear another died.

[ChrisZang]

Originally Posted by insite

quick update:

byron blew his motor at barber yesterday.......three laps in.

SERIOUSLY?

[AndyA6]

Originally Posted by ChrisZang

SERIOUSLY?

Say WHAT??!!

[insite]

seriously. it still turns over & will run, but it bangs & clatters. weird that it happened right off the bat.

[ekam]

Just got the X51 oil pan and deep sump spacer installed this morning. Accusump is too much for what I need since I don't foresee putting R-comps on and I am not that skillful to push the car to its full cornering limit yet.

[Mike_Yi]

Originally Posted by ekam

Just got the X51 oil pan and deep sump spacer installed this morning. Accusump is too much for what I need since I don't foresee putting R-comps on and I am not that skillful to push the car to its full cornering limit yet.

I have street tires on my car and destroyed my engine. I had always heard that you'll only have an issue if you have slick. I think Jake's explanation seems most likely. If I ever track by Boxster again (which is unlikely at this point), I will be putting in some race oil before I head to the track.

[jaykay]

Originally Posted by Mike_Yi

I have street tires on my car and destroyed my engine. I had always heard that you'll only have an issue if you have slick. I think Jake's explanation seems most likely. If I ever track by Boxster again (which is unlikely at this point), I will be putting in some race oil before I head to the track.

What grade of oil were you using when things went wrong?

[Cloudsurfer]

I've thought about an Accusump for my 3.8 since I stuffed the thing in the car, but what comes up in my mind, is rather than running a super stubby oil filter ON the sandwich plate (that needs to be changed extremely frequently), why not just run an in-line filter (available from several sources, including the folks who make the Accusump- Canton Racing), which could be plumbed in and mounted in the rear trunk, next to the Accusump. It's only one more oil line, and a few more fittings.

[jaykay]

Originally Posted by Cloudsurfer

I've thought about an Accusump for my 3.8 since I stuffed the thing in the car, but what comes up in my mind, is rather than running a super stubby oil filter ON the sandwich plate (that needs to be changed extremely frequently), why not just run an in-line filter (available from several sources, including the folks who make the Accusump- Canton Racing), which could be plumbed in and mounted in the rear trunk, next to the Accusump. It's only one more oil line, and a few more fittings.

Surfer you are thinking man! Changing the filter all the time is why I would want to avoid the accusump...maybe you have something here! What filter and hardware were you thinking about?

[Cloudsurfer]

Originally Posted by jaykay

Surfer you are thinking man! Changing the filter all the time is why I would want to avoid the accusump...maybe you have something here! What filter and hardware were you thinking about?

Take your pick....

http://www.cmfilters.com/oil_filters.html

http://cantonracingproducts.com/store/oil_adapters.html

[ekam]

Just an FYI to those who just want to get the deep sump spacer, X51 oil pan is much better designed than the stock pan, check the photos on this rennlist post below.

http://forums.rennlist.com/rennforums/6663161-post10.html