The 996 is a poor track car
09-06-2007, 04:06 PM
#46
Racer
Thread Starter
also check out the mantis sump extension; its design is different from the BK version. instead of a different pan w/ internal baffle, they use a sump extension w/ windage tray. you can see it here: http://www.mantissport.ca/
I think BK's design is pretty much just an extention only. Whereas Mantis' approach also has a windage tray. They both use the stock oil pan (although BK has some instructions for modifying the baffle). Both seem to have virtually the same approach to the issue. Given that, I guess, the deciding factor for me would be price. The Mantis is about twice the price of the BK product (~$564 vs. ~$230). Good to know about the options though.
09-06-2007, 08:16 PM
#48
Addict
Rennlist Member
Rennlist Member
It looks like the X51 will still be a prepared option. A 996 X51 will do fine in the classes as they are proposed though.
Jim
09-07-2007, 02:09 PM
#49
09-07-2007, 03:12 PM
#50
Burning Brakes
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I bought the Porsche version of the baffled pan, very similar. A lot of good it does me sitting here instead of on the car.
996.107.310 8R
FWIW -- the '02 and later cars are a bit stiffer, if I were looking for a car I'd want to understand what exactly changed. The HP difference is also bigger than it seems, I think its the whole area-under-the-curve thing.
09-07-2007, 04:01 PM
#51
Burning Brakes
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Cool. Thanks!
I think BK's design is pretty much just an extention only. Whereas Mantis' approach also has a windage tray. They both use the stock oil pan (although BK has some instructions for modifying the baffle). Both seem to have virtually the same approach to the issue. Given that, I guess, the deciding factor for me would be price. The Mantis is about twice the price of the BK product (~$564 vs. ~$230). Good to know about the options though.
I think BK's design is pretty much just an extention only. Whereas Mantis' approach also has a windage tray. They both use the stock oil pan (although BK has some instructions for modifying the baffle). Both seem to have virtually the same approach to the issue. Given that, I guess, the deciding factor for me would be price. The Mantis is about twice the price of the BK product (~$564 vs. ~$230). Good to know about the options though.
09-07-2007, 04:08 PM
#52
Three Wheelin'
Not sure if there is any data out there on these motors, but I can provide a little bit of information, but nothing directly related to these engines. My experience comes from small displacement four cylinder bike motors and other than the exact numbers should still be applicable.
For the stock wet sumped motor with stock oil pan and no baffling we found that after about a second of sustaining 1g cornering that was definitely oil starvation for the remainder of the corner. Now by adding a flat baffle plate with 1/2 in holes cut throughout (about 50% of the area gone) the minimum load for oil starvation was 1.4g. A pretty serious improvement, but there were still issues as we can easily sustain 1.6g+. Several other baffle plates were made with differing amounts of material removed with the intent of keeping the oil pickup supplied. Our best effort yielded oil starvation at around 1.5g. The last four motors we've used have been in cars more than capable of sustaining 1.6g cornering forces. Now, the earlier two cars we know are capable and do starve oil whilst cornering, but neither have blown motors or spun rods bearings and have been run for several years without issue. But due to some recent improvements from Goodyear in tire technology the last two cars have been near the range of 1.8g. Both have had motors failures. One developed a severe knock and within laps grenaded. The last one spun a rod bearing early in testing. We have since come to the conclusion that for our application we must start dry sumping our motors or anticipate more failures.
Now, how does this apply to the 996. I have not been able to inspect the setup on a 996, but will speculate that there is a definite threshold at when the stock setup will begin to starve oil. An educated guess would say somewhere in the range of 1.5g. It is possible that the current racers are having oil pressure decreases or possibly complete starvation, but it is obviously in a range in which duration and/or severity are not great enough to commonly blow motors. Baffling will indeed decrease the chances, but will not solve the issue. The only true solution is a dry sump.
One another note, one I've found quite interesting, is that there seems to be a connection with driving style to the severity/duration of oil starvation. If you guys would like I could post some comparison data of similar lap times and cornering loads to the degree of oil starvation. It is nothing conclusive at this time, but something that appears to be true the more that I comb thru the data.
For the stock wet sumped motor with stock oil pan and no baffling we found that after about a second of sustaining 1g cornering that was definitely oil starvation for the remainder of the corner. Now by adding a flat baffle plate with 1/2 in holes cut throughout (about 50% of the area gone) the minimum load for oil starvation was 1.4g. A pretty serious improvement, but there were still issues as we can easily sustain 1.6g+. Several other baffle plates were made with differing amounts of material removed with the intent of keeping the oil pickup supplied. Our best effort yielded oil starvation at around 1.5g. The last four motors we've used have been in cars more than capable of sustaining 1.6g cornering forces. Now, the earlier two cars we know are capable and do starve oil whilst cornering, but neither have blown motors or spun rods bearings and have been run for several years without issue. But due to some recent improvements from Goodyear in tire technology the last two cars have been near the range of 1.8g. Both have had motors failures. One developed a severe knock and within laps grenaded. The last one spun a rod bearing early in testing. We have since come to the conclusion that for our application we must start dry sumping our motors or anticipate more failures.
Now, how does this apply to the 996. I have not been able to inspect the setup on a 996, but will speculate that there is a definite threshold at when the stock setup will begin to starve oil. An educated guess would say somewhere in the range of 1.5g. It is possible that the current racers are having oil pressure decreases or possibly complete starvation, but it is obviously in a range in which duration and/or severity are not great enough to commonly blow motors. Baffling will indeed decrease the chances, but will not solve the issue. The only true solution is a dry sump.
One another note, one I've found quite interesting, is that there seems to be a connection with driving style to the severity/duration of oil starvation. If you guys would like I could post some comparison data of similar lap times and cornering loads to the degree of oil starvation. It is nothing conclusive at this time, but something that appears to be true the more that I comb thru the data.
09-07-2007, 04:34 PM
#53
Racer
Thread Starter
One another note, one I've found quite interesting, is that there seems to be a connection with driving style to the severity/duration of oil starvation. If you guys would like I could post some comparison data of similar lap times and cornering loads to the degree of oil starvation. It is nothing conclusive at this time, but something that appears to be true the more that I comb thru the data.
