FormulaOne10

I thought the DL-1 was fairly accurate...

Are the lateral acceleration readings similar in magnitude for both right and left hand turns? If one direction of turns is producing higher average readings than the other than the other then this may indicate an issue. Generally, it is ok if the unit is not perfectly flat but it must be somewhat close. Additionally, it is important to "zero" the system in its relaxed position (i.e. let the system know where 0g is).

Also, the camber of a carousel can definetely give you more lateral accel since there is an additional normal (downward) force component. Keep me posted on what you find.

TD in DC

The lateral distribution was very even. I can tell you that I barely pulled .1 gs acceleration and, IIRC, my braking gs were around .8gs. I didn't "zero" the system but, as I said, the readings were consistent from left to right. I assumed the 1.4s were wrong, but I was surprised to see so many 1.2 and a fair number of 1.3s. Again though, I was so upset about what happened to my motor that I didn't spend more than 5 seconds looking at the data . . .

Z-man

FYI: the Porsche M030 rear sway bar is 19mm, 3-way adjustable. Probably what you have - a 26mm rear bar coupled with a 30mm front would make your car snap oversteer when exiting your driveway at 2mph with only a 2 degree turn on the steering wheel!!

-Z-man.

TD in DC

I haven't actually measured so I don't know. On a sticky track, the car is outstanding. When it was rainy and slick at Summit Point and I was on MPSCs, the rear end was snapping out very quickly all the time. Supposedly, this is the same setup the guy who won the 44 cup a few years ago had.

TD

TD in DC

Ok. I don't have my flashcard handy, so I don't have access to the final day's runs, which were by far the best. What I do have is one run from the middle of the first day. I am still getting my legs under me, and the data is not pretty, but it does show distribution and many 1.2gs and 1.3gs.

As you can see, there are a few 1.6gs. I wonder whether that was karussel? I will have to check.

I promise you the next day's data was even better, many more 1.3gs and a handful of 1.4gs, meaning that there is a bunch of them grouped rather than just a few outliers, (and better distrubtion along the entire edge of the friction circle (well, my acceleration did not get any better )

TD in DC

OK. Not that I plan to change my driving much on account of this, but I just noticed something interesting. Does this data show that I was doing an OK job of accelerating trhough the turns since I have several points near the maximum accerlation gs I can pull in the 44 (i.e., most of the plot points are below 0, including the max lateral gs.)?

It looks like this might show that I was on the go pedal pretty hard most of the time (which I was). It is not my fault that there is not much go to be had

Tim, paging Tim, oooohhhh Tim. I posted a little data (some bad data at that). Come out and play!

kurt M

Yet....

Todd, the motor is out in the shop. When can you bring your stand by?

TD in DC

Kurt,

I had it shipped directly to the Taj. Should be arriving any day now. How does she look? Ready to be abused?

TD

P.S. Should I get a second one since your rack is being used? Would that make the job substantially easier? The H-F stands aren't really that expensive, and I have a feeling I will be collecting motors soon.

TD in DC

Z-Man,

I have spoken with four or five shops now, and they all told me that left-handers are known as 944 killers. Actually, they said that the oil pickup is roughly in the middle of the engine, so both right-handers and left-handers that are both high g and high rpm are problematic, but they said that left-handers are worse than right handers.

TD

kurt M

I will pull my 2.7 off my motor stand and put it on a roller cart while we swap parts over to your replacement motor. I have a fits-all mount that we can used on my stand and will mount this motor to my stand after pulling the flywheel. Each 944 motor will be on a stand for ease of part swaping.

Motor looks like your standard greasy lump. I dod not spend too much time looking it over other than turning the crank some and noting no injectors or fuel rail.
Acording to the seller it ran fine and he drove the car around some prior to pulling the motor. It was pulled from a car that was visualy poor looking, had a bad dif and was parted out for more than it was worth to sell intact.

38D

Remember that the g measurements are instantaneous values. I can't remember the exact resolution of the DL-1, but is probably is taking ~5 measurements per second. So, your 1.6g happened for .2 seconds once. There is no way that caused an oil stavation issue.

On the DAS side of things, it looks like you're average lateral g is more like 1.0. What you probably should do with the data is smooth out the points to determine an average lat g value for a given corner, as the instantaneous values don't mean to much IMHO.

TD in DC

True, but there are several points between 1.2 and 1.6, which could be when I was going through Karussel. Also, my data was much more aggressive on the second day. Too bad I can't get to it right now (I think one of my kids ran off with my 4 meg flashcard that has all the data ).

What is a high enough g value to cause oil starvation? How long at that g value is too long?

TD in DC

I have tried to make it clear that I do not know exactly why I had engine problems when I started this thread. There may or may not be any connection to Shenandoah, and there may or may not be any connection to G-loads. That is why I said "potential caution" etc . . .

I am not claiming that I know what happened, and I am not entirely sure that I ever will.

I only posted the G-Plot data because it surprised me a little, and I wanted to learn as much as I could by asking those who know much more than I do some questions.

Also, as I stated earlier, I really like Shenandoah and do not plan to avoid it in the future.

38D

It takes a bit of time for the oil to slosh away from he pickup, for air to get into the pump, and for stavation to occur. I doubt there is an exact time, but would guess you need a couple of seconds for the issue to cause damage. Of course, this is just a guess.

What you should do is watch you data on the DL1 along with the track map (you can watch virtual laps, which is pretty useful). Setup the lat G as a dial gauge, and then you can see where you are generating these high Gs. Also watch your engine RPMs. Aslo see if high Gs have anything to do with your fastest laps. I suspect you will find that your average G load in a corner is more like 1.0 (just based on looking at the middle of the dark area on the graph).


Understood.

}{arlequin

looks to me like a 6pg argument for a 911.....

Todd, Kurt,
if you guys could use another set of hands let me know, I'll gladly come by to help out
(just not until Monday )

TD, do whatever you have to do to make it run, even if all you can do is go straight.... we'll tiptoe through corners together.