mark kibort

How I would love to get 2 other top drivers to run my car with data and video. If I wasnt so scared that someone else might blow it up, and that it wouldnt cost a lot to have someone besides just Anderson do it, I might just do that!

I have done a lot of side by side comparison videos of Mark As old 420rwhp version and my car now on DOTs. there doesnt seem to be a lot of differnce in lap time or sterring input, but as we know, it doesnt take much difference to make a big difference on the G meter.

Back to the subject. I have a real hard time seeing the oil go through that screen in all instances, fast enough to keep up with oil flow. in fact, it seems like a trade off betwen windage and oil level. maybe the answer is always having the oil overfilled by a quart when using one of these things? or is it a problem that can outpace oil flow and you always have a problem if the rpm is high enough.

out of my leaque for sure here, but just posting my own intuitive thoughts, as way off base as they could be. All I do know, is what I have now, has been working. If it wasnt for beating the car up at Road America too, I would have thought it was thunderhill, Laguna, and sears dependant.

justaguy

Mark K
We all drove the lemons Race. None of us broke it. I think we were all pretty coservative as it was Brians car and not a whole lot of competion on the track. That being said it stands that your car and the lemons race and my street car have a lot of track time on basically stock engines.

This proves to me that a stock 928 can be tracked successfully but requires carefull management of the RPMs and of course Snake Oil, sorry I mean Amsoil.

My personality is such that I would prefer not to have to manage or drive around the problem but would rather fix it. Then not have to worry about over reving or blowing a shift in the heat of battle.

I am quite sure if I drove your car or any other 928 ( notwitstanding dry sumpers) the way I drove my race engine it would have a very short life.

All that being said I will be running a stock engine with an OB pan and pan spacer in my next race
So would you mind sharing the Mark Kibort magic formula for track 928 motor eternal life with your fellow rennlisters ?

Do you have an RPM to G ratio ? Or do you just keep the RPMs below 5,500 or a specific number in long sweepers or do you just go by the seat of your pants becasue what ever it is you do obviously works very well for you, And I would like to try it ,And share the results with the group. I will have data from the next race and will try and get the RPM and oil pressure function working on the traquemate then we will have some good data to argue, I mean discuss.

Oh yeah forgot to mention my warm up routine for the street engine is drive 200 miles to the track at 90-100 MPH ( mostly 5th and 4th gear for passing) then do 4 hours of 20 minutes on 20 minutes off Then drive 200 miles back home at 75 MPH to cool down. So I have the warm up cool down procedure covered.

Thanks
Sean

justaguy

Mark
I'll drive yorr car and you can drive mine, with all the data loggin you want,No Problem.
That would be very interesting and a lot of fun.

justaguy

I promise I wont break it

dr bob

Am a Tour look at that GB sump screen says that the intention is for oil falling down the walls of the block to pass around the screens not through them. The screens keep the oil that's below in the sump from sloshing up into the spinning bits where it would get frothed. A layer of oil on top of those screens, even an aerated layer, obscuring the openings, actually does a better job holding the oil underneath from splashing up through than a dry screen would.

mark kibort

http://www.youtube.com/watch?v=lq2aJ...layer_embedded

listen to the revs and let me know if you think I am taking it easy.

one thing I do is that i dont go for excesive revs in sweepers, because its not the fastest way. generally, you dont accelerate around turns, so why be in a rpm range that requires a shift, very soon after the exit. this does too things. it makes you faster out of the turn and you dont have 5500rpm to 6500rpm sustained through the turn, which could burn up a bearing.

watch the video and tell me if you would do anything different that might cause my engine to blow.

mk

justaguy

Mark
Great video! We definetley have different driving styles and you are not doubt more experienced, smoother and faster than me .That is why I ask.

This is very subjective and like Freud said it is impossible to analyze your self. But this is what I see
And I know you will correct me if I'm mistaken. From listining to the sound track and Rpm's I dont hear the engine wind up until way well past the apex of nearly all corners. It appears as if you trail break or at leat coast and use engine breaking until way past the apex.

I prefer to get on the throttle before the apex to try and balance the car( because that is what I have been taught) and as a result may be over breaking in to the corners and tend to drift through the apex and as as a result carry less speed and more RPM's through the corner which makes for a good thrill but is obivously slower and could be all it would take to kill the motor . That's the way I see it any way.

The first time I drove laguna I drove quite simalarly to what I saw in your video, abeit much more slowly and recieved a stern lecture from my instructor for coasting through the corners,
I watched the video 4 times and the engine is very quite at every apex or if you prefer quite when the the higest G loads are present.
Very interseting!
Thanks
Sean

svp928

The screen Greg uses is stamped so it has "directional" walls like louvers. All the walls point toward the crank's direction of rotation, so when the crank is spinning, the oil coming off is directed away and into the pan. Conversely, "bounceback" from the bottom is coming almost directly at the flat wall, and is deflected back into the pan again. So, it isn't really just a screen, in the traditional sense, its directional, and nearly transparent to oil fling off the crank. Plus, its flying off at such a velocity that it will never just sit on the screen, everything gets blasted through there at whatever the tip speed the rods and crank are traveling at.
So, it is not an impediment to oil drainback, it actually is scraping oil off as the assembly rotates, and helping to keep it from bouncing off the floor and back into the crank.
I am also fairly certain that Greg, Mike, and Kevin (I_J) all channel the head drains away from the crank and into the floor along the sides of pan, as well as blocking direct access to the drain ports so oil doesn't get blown back UP into the heads....
I don't believe any of these things will contribute to bearing failure- every racing engine I've ever seen has some form of this oil control in the pan, dry sump or not.
Mark K's success says you may be able get away without it, but I really don't see how having it can hurt.

hacker-pschorr

I almost forgot about this.

This is not my work, sent to me from a fellow 928 junkie. Never got past the test fitment stage since it would not fit without a pan spacer, this pic was taken long before anyone was making spacers..

-

Ducman82

thats a nice looks Windage tray... real nice.

GregBBRD

Good eyes. The mounting area of my screen is designed to not restrict the oil returns from the heads, but to gently redirect the oil towards the edges of the block and pan, away from the crank.

GregBBRD

There you go. That's the beginning of functional. Yes, it would take a gigantic think pan spacer and the unsupported screen would break pretty quickly, but the basic idea is there. Let the oil pass through the directional screen and fall below.

Rick Carter

This makes sense, thanks for putting it simply for me.

hacker-pschorr

So Greg,

What is the availability of those screens you have on the web site?

mark kibort

good observatios. yes, i do a lot of trail braking for most turns, exept fot the turn 6, where I do get on the throttle early, and do a little drift though there because the car can, but most other turns at laguna with the exception of turn 4 and 9, are very similar. Yes, you are right, over breaking and a power drift on the exit is generally slower, as I prefer to late and trail brake, find the maximum grip and use the throttle to steer and find the limit of adheasion. If there is no push back, i keep on applying throttle until I get wheel spin. the reason is that generally, there is no real acceleration during the apex area of the turns, so, you are really hanging on and waiting to be able to slingshot out, rocker the weight to the rear on exit and get a jump on the next straight. (kind of like a water or snow ski turn)

This all does two things. It alows you to be in the right gear for the exit to apply the max hp for the longest time, without being interupted by a shift, and it saves the engine from experiencing RPM levels that could hurt it when the g's are at their highest.

If you notice, i have also done soemthing that works for me, where i make my last shift of a multiple down shift, in the "dead" zone, where there is a true coast, and scrubbing of speed just before the apex. Its an area that doesnt require braking or acceleration , so i found it advantageous to put a last shift there. It alows me to focus on using the real brakes of the car, and tire scrub braking, rather than compresssion, for which at that point effectively just basically becomes rear wheel brake bias, which I dont want then and there anyway.