rs10

And to that end ...

I came across something interesting in the original review of the C4S in Excellence (April 2002):

"Andreas Schneider, in charge of engine development on the Carrera 4S ... feels the quasi-dry-sumped motor of the new Carrera 4S in indeed suitable for track events.

'That's why we have oil pumps in the cylinder heads,' he explains. 'This car is good for 1.4g. I wouldn't do it for 10 consecutive laps (80+ minutes) at the Nurburgring, but certainly spikes to that figure are okay."

First the weird thing: "in charge of engine development on the C4S". Why? It has the same engine as the C2. Maybe his title was reported incorrectly. There isn't anything different about the C4S engine. Or is there?

Then what mainly interests me. The 10 lap thing suggests that it matters not only how hard you drive, but how often/long you do it. Why would this be? The second time oil is pulled away from one side of the engine, that side starts hotter and with less oil than the first time?

This goes back to one of my earlier questions: will the engine be OK if I just do a few (hard) laps before letting the car cool down? Or would this be enough combined with some other precautions? And if so, how often should one cool down, for how long?

Sneaky Pete

RS....you are thinking and over analyzing this to the N'th degree. As a 996 stands stock it can track all day long on street tires. With track tires you are playing Russian roulette...you may be ok or you may not. Doesn't matter what bumper, 3rd rad or any other things. Street tires forgive and track tires don't when it comes to oil starvation. It may not bite you right away but eventually it will.

alpine003

+996. Some come on here looking for guarantees on the 996 alone but when you combine 996 + track time, everything is thrown out and you run at your own risk. Everything you needed to know was on the first page. We can take this to 50+ pages and outcome will be the same. As they say if you can't stand the heat...

Now put down the keyboard and get out there. Worrying about aero, top speed, cooling should be last after driver improvement has eclipsed to the levels that those additional components are needed.

WynnS123

What kills engines that aren't prepped for track use is long sustained high G loads. Top end MPH has nothing to do with it unless you are topped out in the middle of a corner (never). This is not isolated to the 996. It is any vehicle made that isn't factory prepped with dry sumps, baffles, coolers, etc. Very few vehicles meet this criteria. 99% of everyone in here will be fine taking any car that is not track prepped to an HPDE. Go to any track event and look at all the street cars in the HPDE groups. They aren't prepped either but still running on track. If you are new to the track, you are not fast enough to harm the engine especially on street tires. Can you lose an engine? Sure, but you can also lose one driving to work. It generally takes a long time to build your skills and speed enough on track to get to where you really need all the prep.

JayG

YUP!

ejdoherty911

+996 +996 +996 on street tires.

WynnS123

Even on race tires, most novice drivers will not be able to hold the slip angle enough to harm the car. However if you are a novice, you should be learning on street tires anyway.

To the OP if you are really that concerned about it, I suggest buying a cheap Miata to learn on the track. You will learn more quickly and have much less at stake if anything does happen. These 996's have fairly high limits even on street tires that it makes it harder to learn. If you aren't reaching and slightly exceeding the limit of the tires and your setup, you can't truly learn how to control and balance the car at the limit. Besides, it is more fun to drive a slow car fast than a fast car slow. There is nothing wrong with taking the 996 to the track though.

rs10

Thanks all for the as always helpful advice! Maybe it's helpful to clarify a bit. I'm certainly not the best driver out there. However, for many reasons, ranging from what my data logger tells me to enough experience driving on track, rightly or wrongly, I'm worried that I'm one of the people who will pull enough g's to be at risk. (Unless it turns out that cooling down every few laps is enough.)

So rightly or wrongly, I, and undoubtedly a lot of other forum members, will want to better understand what we can do to reduce risks. There are simply too many people who say don't take a stock 996 on track - not just on this forum but also several people I know who tell me of bad experiences their clients have had - for any number of assurances to the contrary to make me - and probably lots of other forum members - not worry.

I've certainly learned a lot here recently - thanks again to everyone! I think I know what are the first things to investigate further about protecting my car against oil starvation: A baffled and possibly deep sump, better oil, and possibly an accusump. Not sure whether a better sump is enough without an accusump and vice-versa.

I'm a bit fuzzy about heat. Maybe I need to review the earlier posts, though I suspect that even if I do, I'll be left wondering how high this risk is independant of any impact of heat on oil starvation, and not sure whether either a 3rd radiator, Evans coolant, or a low temperature thermostat (whatever that does) alone is enough, not two or all three of them.

And I'm definitely fuzzy whether regular cool down laps or similar precautions make a big difference ... . Logically they must for pure heat concerns, but for oil starvation?

Schnell Gelb

"I'm a bit fuzzy about heat"
A few ideas to research:
1. The engine oil acts as a coolant and having a deep sump adds more oil so that helps the heat issue.
2. Lots of discussion about "thermal stability" and "shear" of different brands/grades of engine oil .
3. An accurate reading of engine oil temperature would help you cool off before you caused engine damage.
http://www.pedrosgarage.com/Site_2/TechnoGauges.html

garrett376

My 02 996 club race car with over 100K miles on the clock, running various DOT-R compound tires (RA1, V710, NT01) has run Cal Speedway's banking or WSIR's sweeping turn 2 and 8/9 an unknown number of times over the years with no oiling mods, running 0w-40 mobil1 with a stock filter, with no cool down: just pull in to post-race impound and shut the car off... that must make the internet 996-masters cringe...

vandersmith

Once you start on the Rcomps you're opening your wallet to much, much more. You saw my shopping list on turning my C4S into a suitable DD/Track machine. I've built multiple SCCA/NASA cars and wouldn't do anything less than what I have there taking everything into consideration.

My build is here and I've already completed 80% of that list.

Otherwise, your $ per fun meter is highest keeping it mostly stock and maybe adding some coilovers on great street tires (Pilot Sports). The car will handle any track you throw at it for multiple lap sessions. If what you actually mean about HPDEs is that you care about lap times and want to run in Group A- then I'd still tell you the same thing and to run as many events with instruction using a more basic setup until you are able to show consistent lap times on the line.

KrazyK

Then your one of the lucky ones. I would imagine you have caused engine damage that you have not seen yet. Maybe its time to tear down the engine before its too late.

KNS

Outstanding..!!

rs10

Interesting. What temperature is too high?

rs10

And more generally about heat, is this just about preventing the oil from foaming to help avoid oil starvation? (And in that case, might a good sump and/or an accusump and good oil be enough?) Or does one need to worry about heat because of some other, heat related problem that affects our cars, and which is not related to oil starvation?