James Bailey

Mark next race please focus your camera on the DASH. Then you can talk about pressure drops and RPM with factual evidence rather than subjective recollection. Anyone who says they shift with in 50 rpm of red line or never runs below 4,500 RPM really should welcome the oportunity to prove it.
And PLEASE rather than..." i certainly think that my observation was flawed by the good chance that I had a g force related electrical connection issue. " just admit that you were wrong........You KNOW you had a bad ground, you KNOW the needle jumped up and down, you KNOW it has nothing to do with anything but bad wiring.

IcemanG17

MK
I do think the factory oil pressure gauge is marginal at best......you really can't rely on it for accurate information in a RACE car.....while you have had great success with the stock S4 oiling system....you are the ONLY person to do it...... Everyone else who runs the S4 system blows engines....typically around 10 hours on track.....

I think a large part of your success with the S4 setup is your driving style....you are a very smooth driver who "loads" the car in the corners smoother than many other drivers do.....you "bend" the car into the corner vs other drivers that "throw" it.....

I am 100% sure that other drivers could kill your car very quickly...... I also think that running only short sprint races helps too....since a typical race day is only a qualifying session and race.....thats well under 1 hour track time per race day..... Even with a full season thats around 12 hours PER YEAR....which is still far more than most race 928's get

In my videos you can see the oil pressure gauge and tach pretty easy.....it drops in corners.....but never that bad.....and typically only at lower RPM......at high RPM its always high pressure like it should be.... It also runs for HOURS on end.....at least a couple hours every single day I take it out... A typical race day for me is to run the race group (70 minutes) and the open group (100 minutes)...but I tend to not run the last session in open....

Hard to argue with results...51 hours and counting on my $300 engine...51 hours in just over 1 year...... Only 18 hours lemons racing.....the rest on R comps

Going out Friday August 5th at Thunderhill....open test day......I'm hoping for at least 3 hours track time....I want to test the fuel consumption & oil burn rate at 1 hour intervals.....

mark kibort

I wish i had read this before I went to thunderhill. Ill have two cameras next time on the qual laps. one on the oil guage and one on the temp guage with RPM.

my rpm guage has been seen on multiple videos, plus you can hear audible proof, as well as the rev limiter hit in multiple videos or were you not paying attention Jim???

I was NOT wrong about he electrical connection. I was conceding that it certainly was a possiblity. But, the lose connection was not causing this phenom. after testing it today, at oil temps from 180 to 220F , i could not get the temp to vary, even with constant radius 45mph turns at the limit. Im suspecting that the phenom is real, and i think it has something to do with GB's theory of the oil being pumped up in the head at high rpm. what I need to do next is to run for 30 secs to a min at average RPM levels of 4500 to 6500rpm and no lower. this might duplicae what Im seeing at the track, and also proving that there is still enough oil in the pan, to no cause starvation. further proven by the fact that the oil pressure guage doesnt show any reduction below 4 bar even at the highest of G loading the 928 can see.

YOU know you DONT know what is happening and it is purely conjector on your part to claim you know anything at this point! Its not electrical. Its a factor of oil or hot gasses in contact with the sensor. I will futher prove this as we dig deeper on what is really going on.

mark kibort

I think the gauge is really accurate. Not for level but when it detect a variance, it shows it clearly.

Im not the only one that has shown sucess with the 928 engine. Joe Fan, and several engines with Scot as well. Joe and me are the fastest ever to hit laguna seca, and mine is the fastest ever to hit laguna with as little power as I have. keep in mind, my car has only 370rwhp, and has run 1:36.1 . when anderson ran on DOTs, with 410rwhp, ran 1:40.1, (with new track, more like 1:39). the point here is if im doing it with a lot less hp, the car is seeing more g's in the turns as well.

I dont agree the driving style, but certainly there might be subtle things that might asisit, such as being in differenent RPM ranges around turns that might not require the RPM to exit them sucessfully. remember the engines we know of that have blown have been suspect from the beginning. some have had oiling isues due to scrapers, missing head plugs, screens.
I think the only thing we know of that helps engines from blowing is the drilled crank, but the holbert block had a stock crank, and so did my other 3 928 raced engines, and by the way, i was putting way more time per year than you on them. YOu have to remember, you putting the hours you do on a car with street rubber, and 200rwhp, is like running my car at half throttle. engine wise, you would think it would last a long time, just as my engine vs anderson's engine is like his at half throttle. ceratinly, our engines can take it. with my pulling as many gs as him the main thing is the oiling system working and it seems to give all indication that it does work. as sensitive as it is, using amsoil or redline seems to fight oil pressure drop when the oil is at race temps and that level is 240 to 280F. could also have something to do with those oils anti foaming characteristics.

anyway, we will know more soon.

IcemanG17

MK
I don't think the HP produced effects oil nearly as much as you think...sure my lowly 200whp isn't much but a stock stroke 928 at 6000 rpm is the same stresses as the holbert car was at 6000rpm...granted the stroker has higher stresses due to the higher piston speeds from the longer stroke...

Don't forget how long Jim Bailey's 82 has ran......also a stock stroke engine.....I don't think he EVER has had an engine failure....occasional TB failures...but thats it....

My oil temps (no cooler) vary from 225-260F.....maybe a bit more if its hot & its a long session...I will find out on Friday....but the weather at Thunderhill is forecasted at only 93F...rather cool for T-hill in August..... We did see oil temps of 300F at the Sears Lemons race when the car was overheating....

Also I run only R comps now....unless its raining.....my times from start-finish to T-5 (over the top measured at apex) are within about 1 second of yours....typically 38 seconds.....I think I clocked you at 36 seconds once....as a comparison Spec Miata's are around 37 seconds

I do think quality oil makes a HUGE difference......

James Bailey

I need to start taking video on my oil pressure gauge as well.... Sat and Sunday POC ran the old SCCA track at the Pomona fairgrounds. Little 1.8 miles track fast cars hitting 130 MPH or so. And yes my oil pressure jumps around in a long sweeper at higher RPM and that is using Redline race oil.

mark kibort

130mph i have never seen until i got a stroker on any of the west coast tracks, besides Willow springs. (big track) what is this 1.8mile track like, Lime rock? sounds fun if there is a atraight that is that long!
oil pressure jumping around? mainly on left turn sweepers?

I wasnt refering to oil pressure being effected by HP of the comparison of different engines. just wear and tear. the bearings have MUCH more stress on them, and so do the rings due to combustion pressures being proportioanlly greater. So, my point was that your motor lasting forever, is not a stretch, because its like my motor running at half throttle. with the forces less on the rod bearing and sufficient lubrication, its not surprising that you willl have a motor that will last a long time. heck, my motor will last a long time, because it is still down 200hp to andersons motor!

I get times from start finish at thunderhill of about 1min even to turn 8, I would think if you are running 2:11s and im running 1:59, the split of time of 12 seconds is skewed a littl to the faster part of the track. there is no miata that i wont leave in the dust from start finish to turn 5. It might be only a second or two, but the point is the cornering speeds of my car would be faster and pulling more Gs. go check your times up to turn 6 and see the difference as that is just before the HP is the real factor. I see your point, as you can see how I was able to hold off the 600hp mustang on the goodyear slicks in the same area and he has a lot more grip than i do and would certanly pull more gs in that section, as would anderson too.

This entire thing is about why my success running at the car at its limits, where others have blown. you had oil leaks and low oil levels for sustained periods, suspect engines to start with who knows what was wrong wiith them to start, Kmart oil during the lemons race, etc etc.
You can see from my videos, im reving the car out, never easing up even for a second at any time during all of my races. running 13" slicks, and running tracks with left and right sweepers that are high g loading and long duration. (i.e. thunderhill turn 2 sears carocell, laguna turn 9, etc)
why do I see no fluctuation in oil , cept for the left sweepers where I go from 5 to 4 bar, min. ? I have temps at up to 280F regularly. no ext. oil cooler, no accusump, spacer, screens, breathers, etc. I have no blowby, no smoke, no burning oil, no problems. never had on any of my race cars, no of those Ive supported.
Now, take it as luck or investigate why. im tryng to see if all these things we talk about are happening and to what extent they happen on my car. I mean if i was tootling around, it would different , but running near 2-3 seconds off a fully refined version of andersons car at GTGP race at Laguna (1:36.1 v 1:34.xx) while only on DOTs as well, means Im beating on the car pretty hard.

Is it the oil???? I dont know, but when I looked at what anderson and fan were doing early on in my racing career, i did exactly what they did for the most part! superstition or not, I like to follow those that are successful and do my tweaks from there.

mk

James Bailey

Try a 60-70 mph sweeper onto a 1/4 mile long straight

IcemanG17

MK
Clearly more testing is required to answer the success of your car vs the failure of SO MANY running identical setups.....

I just scored a FREE set of sparco race seats...so I will put one in the 928 Estate so I can take passengers....then a passenger can ride along and WATCH the gauges.....then we can do the same test in your car.....both 928's on track on the same day.....


Here is my best lap over the top in the Estate 2:09.8...about 38.5 seconds from start-finish to T5....right at 1:05 to the apex of T8......give the 10 second delta between the cars...about 5 seconds at T8 is about right.....your car will easily pull me an additional 5 seconds on the front-back straight....I lost about 4.5 seconds to a Mustang FR500S in just the back-front straight and your car is more powerful....

mark kibort

nice laps! you can hear, you are near the limit of those tires. was that with the big tires or your normal 245s DOT Rs?
pretty funny. makes me smile to hear the automatic again! it would be interesting to see what a stick would buy you . there are quite a few times where you are just bogging along. also i would be even more interesting to see this car with the euro 5 liter power and big tires and rims.

Im still waiting for you do jump into a NASA race and run the GTS2 group!!

I liked the video with the mustang. just shows you need more power. you were mopping him up in the turns, but even his 400hp but porkey weight, was still enough power to just pull away and crush you on the straights. pretty funny! just about 50 more hp plus the bigger tires and rims, and you would be able to hang with a car 25 years newer, and about $50k more in cost!

mark kibort

like 9 to the straight on the willow big track??

thats what a lot of our tracks are missing. I think i need to get to cal speedway!!

James Bailey

The front straight at big Willow is 1/2 mile long.....so some cars are really hauling as there...The old very brown 1980 I take a nap while I wait for turn one to appear.

mark kibort

makes me want to go back. I remember 90mph through turn 9 and then that long downhill (unusual ) 1/2 mile straight.

jpitman2

This needs some systematic data collection done to make sense of MK's temp observations, and others' thoughts. There are out there some R/C model radio sets now with telemetry capabilities. On one of them, for $150 you can add sensors etc to the airplane to send back to transmitter - battery volts, fuel level, engine rpm (optical sensor), and FOUR temperature readings. There ought to something similar that could be adapted to cheaply collect and store useful data in a race car.....
You could get some useful data by putting the car on a ramp whose angle could be changed lengthways (simulating accelerating and braking) and laterally (simulating cornering forces).
jp 83 Euro S AT 53k

rad_951

Mark,

What gear and what rpm is your car in around turn two at Thunderhill?