8.603 run, data chart, please critique

Here is the data log for my last run on Aug 27, Sunday.
30 inch ladderbar at 120 ,,% anti rise, 10.5 x 33 Hoosiers, 4.56 rear, 2.45 low TF trans. Car weight after run with driver, 2905 on BIR scale.
I am looking for input on shock settings,etc. The high rpm in low gear, up against the rev limiter for .4 seconds must have been caused by a too narrow throttle stop setting I use to limit the shifts. I use it to only provide a ground for a certain window so it never gets to shift a third time

Is that a RPM flair on the 2-3 shift?

I don't see any shock data there so you'll have to explain the different lines. What I assume is the RPM line shows you in the rev limiter on the 1-2 shift and then shows some sort of RPM flare on the 2-3 shift. Not sure if there is wheel spin on the driveshaft or if that is a transmission slipping problem.

Yes, I will call Chuck and ask about that

Andy, top line is engine rpm, the other blue line is driveshaft rpm, red is fuel pressure from constant flow methanol injection
Downward sloping is acceleration in G force.

I don't see much wheelspin, so my uneducated guess is the acceleration spikes are partly from a short wheel stand? The delayed 1/2 shift, which hit the rev limiter, is I believe due to a setting in my deadenbear cc1. Maybe a lockout affecting the rpm switch that fires the air shifter?

A good thing to do is blow up the DS RPM scale a LOT more. Then look at it in the time period of converter flash (say from 0 to 1 second). You'll be able to see wheel speed vs. g force really well there.

You can see the g-force spiked and then dipped slightly about 0.2 seconds. I can see a slight move in the DS RPM at that time too, but blowing it up will help see what happened.

If you overlay the wheel speed... you MIGHT see the wheel speed go up while the g-force goes down. That would indicate spin.

If the DS RPM didn't rise, but the g-force dropped, it was dead hooked, slight carb bog, etc...


There is no doubt there are gains to be made from that RPM limit hit. You can see the g-force dropped like a rock and went nuts in that area while it was on the limiter. Not sure what it's worth in ET, but there is some for sure.

Converter is WAY to tight, just curiius what the drive shaft RPM is at .5 into the run?

I agree that the converter is too tight since you are dropping well over 1000 rpm on the shift. Talk to a converter mfg and show them the graph and see what they say. They'll most likely want to loosen things up so you're only dropping a few hundred rpm on the shift.

You shift at 7600 or 8000? And trap at 7600?

I’ve never run up on the converter that much….. is that a big tire thing? Forgive me for loading your question post with more questions

Assuming that you're asking me about the spread between shift point and recovery? I'm not a converter expert by any means but based on what I see on the cars I tune the mfgs have been narrowing the RPM drop down to something in the 500 to 600 rpm range. The explanation is that they are trying to keep the engine near peak power all the way down the track. In the old days the rule of thumb was to drop the RPM from power peak back to torque peak but now it seems to be to loosen up the converter so the RPM stays almost flat going down the track. I've seen some data logs where the engine RPM is very flat. That is typically with a glide rather than a three speed.

I don't know the answer on this car which is why I suggested he talk to a converter mfg. I'm pretty sure they'll tell him that looser will be faster.

If I’m reading the graph correctly........looks like the DS is at about 1000rpm at .5 into the run.

0

Would just further confirm the converter is WAY to tight

Yep......

thanks guys. I assume a looser converter would actually mean a softer initial hit, as in the first five feet or so? Then is up in the higher part of the power and making the car faster overall?

The 1/2 shift was delayed due to a wrong setting. 7600 will be about where I want to set it.
And all questions welcome hear that shed light on making a car faster.

all questions are good. I may return to 15x33 tires

I like the idea of going back to the 15/33 tire and looser converter. As Al Aguirre has stated in the past. Loose is fast, facts.

Also, Greg have you ever considered a 2.28 1st gear?

I was actually wondering about what appears to be the 2000’ish two step rpm launching from with a 6300 stall. Our converters have similar stalls, I’d just always left at a much higher rpm.

I think RPM is the other line. Looks to me like the RPM is at 1500 then he takes it up to 4000 just before launch.

You may be on to something….. I can’t scroll left and change the data color configuration

Yeah, it is hard to see but I'm pretty sure the line you selected is the G meter line. It stays at zero until the RPM goes way up and then it starts to go. I'm not sure how Greg did his staging. It honestly doesn't look like he was using a two step, looks more like a foot brake launch but he'll have to describe how he launches. What I see is something around 1500 rpm (could be fast idle) and then at the last moment the RPM steps up to around 4000 rpm and then goes up to 6300. But it never holds at 4000 rpm like it would on a two step.

I run a two stage throttle controller that collapses the throttle to about 1/10th throttle opening to allow only 3800 rpm when staged. So when I let go of the trans brake button on the top bulb, I floor the throttle, but it only can move that 1/10th of travel. When the delay box time runs out, the throttle goes full open along with trans brake release. This allows a very soft hit at launch, and required my reducing delay time from 1.10 seconds down to 1.04 seconds because it takes time for that throttle control to fully extend to wide open throttle .
The end result is back to back 60 fts of 1.225 and 1.224. I could drop 60 ft times but with a ladderbar I risk that a harder hit will hurt consistency. Watching the car leave on FB video, and seeing the graphs helped me to understand a lot about how this car works in the first twenty feet. Sometimes less is more.

Okay, I get it. I had not seen that type of throttle controller on graph before so I didn't recognize it. Looks like it could help with the launch but you might need a torque converter that is built for it since it acts different than a normal two step.

Well, into every life a little rain must fall. I went to fire up the Dart and no oil pressure. No prime, again! This is a big Milodon five vane 1.1 inch tall pump, dual NEW lines. It ran long enough before I spotted it (40 seconds?) i think i need to pull the pan and look at bearings. On another note, I looked closer at the graph, and it takes .100 seconds for the throttle to fully open when the transbrake releases. Add in the time it takes for air to push to the cylinders and it is probably .15 seconds before air gets to the cylinders? No wonder I am still slow on the lights even though I pulled .04 out of the delay. I found the problem with late 1/2 shift. The CC1 has a lockout on the rpm switch, and it was set at 2.00 seconds. My car hits 7500 rpm in low by 1.50 seconds. so,,maybe with a little better air and the right shift rpm I will see 8.40s, maybe hit 130 mph in the 1/8th!

Greg,
Have you got a good pic of the oil line routing?

What I would try at this point, before any disassembly happens, is to try and prime the oil system and see how long it takes to build pressure(if it’ll even build pressure).

Honestly, with no load on the engine, and plenty of oil before; I don't think any damage occurred. Like Al said, try fixing the prime. If you do get the oil pressure working, and if you feel worried, cut open the filter after running a few minutes with oil pressure.

The lower "x" at 2,000 is actually the idle speed just before staging. I think the line you are looking at is the G force graph

I use a 3 qt accumulate to pre oil, but that wasn't enough to help it prime. I have to use a high speed drill to re prime it, and it can take 30 seconds to get it to pull oil. I may pull the pump and check clearances. However it is a new Moroso hi volume pump and should be good. I will post a picture of the lines. Thanks for the input. I may have to use a longer hose to create more rise above the pump.

Sounds like you have something plumbed wrong if you can't build prime with an Accusump. The 2 or 3 qts from the Accusump should fill everything with oil including the pump. I've never seen a setup that wouldn't prime with an Accusump.

Welcome to my world, Andy. I took pictures of oil filter junk. Looks like when I have time I will have to see what that black junk is that looks like very course pepper. Lots of ground up iron on the little magnet in the aluminum bodied screen oil filter.

Dwayne, my oil routing. Front hose goes to the unblock port, the rear hose to back of the pump.

That isn't a good sign. Can you pull the pump off to look at it? I guess I'd also pull the valve covers to see what it looks like in there.

I agree, Andy. Something is going away. A full check of the valvetrain, pull the oil pump and look for scratches and measure clearance, and I plan to pull the pan as well. This deal was very hard to prime from day one. At the very least, pushrod tip and adjuster wear are on my mind. When I opened the valve on the accusump it built pressure and held oil pressure long enough to tell me there are no big leaks on the pressure side of the oil system. The thought occured to me there could be a leak in the swinging pickup in the pan. Maybe the rubber "O" ring needs a look. I am not happy to find this, but greatfull I decided to not run it more the last time out.

After you get done checking things over and making whatever changes you deem necessary.........
“What I would do” is prime the system with a drill prior to fire up.
Run the motor for as long as necessary to make there are no leaks, etc.
After you shut it down.......let it sit at least a day.
Then re-prime with a drill and see how long it takes to build pressure. It should be almost instantly.
After you get it to where it passes that test, I’d fire it up again, run for a few minutes....shut down let sit for a day again.

Now, prime with accusump...........then re-test with the drill.
This test is to insure using the accusump doesn’t back feed the pump prime back thru the hoses/filter and into the pan.
You’re looking to see that after using the accusump that there is zero delay in building pressure when running the drill.

Thanks Dwayne for the pattern to try. I plan on first looking at the roller lifter on # 6 cylinder, as the lash has opened up .002 or .003. All others were within .0005, and number six rocker assembly checked out good along with the pushrods and adjusters.
So my to do list now is check #6 intake roller lifter, pull the oil pump and inspect, and pull the pan and clean that up as well as check the swinging pickup, and check bearings. I need to track down where all that junk in the oil came from .If I am missing anything, let me know, folks!

Greg . PM sent.

Have not read other comments yet, my first thought was: Man, thats a LOT of rpm drop on shifts. I think my first conversation would be sending that file to my converter guy . IMHO, 1100 TO 1500 is too much .
Just my initial reaction. Looks like you hit rev limiter once, late shift setting perhaps ( assuming your programming shifts) .
I think thats what i would address first- converter doesn't seem happy.

I have been tied up elsewhere, but did get the lifter on #6 intake out for inspection. Smooth as glass. Not sure why lash was 002 loose, maybe my fault. All others spot on. The oil pump looks good, only very minor scratches, .004 end clearance. Pan is off, will start looking at bearings when I get time.
On the priming issue, once primed, it would be ok for a week or more, as long as I used the accusump to push oil into the rotors . That 20w50 in the pan is pretty thick when temps drop below 70 degrees. Maybe that is part of the problem? Thinner oil is a gamble because I have loose clearances, and run the motor at 185 degrees at the starting line.

I am done for this year. I had a minor heart incident, in hospital since sat midnight, they put in a stint yesterday. But rehab and letting the incision heal will take a week plus, so I won't be able to go Sept 29/30 at BIR. I a bit bummed, but now know why I was so low on energy
I had a 90 percent blockage in one artery. My advice to anyone feeling a little "off" or easily tired is, if you think you may have issues, take the ride. Do not drive to the hospital or ride. Call an ambulance. Nobody can help someone in a car miles from the ER.

glad to hear you got your health incident under control !
having dealt with health issues of my own for years, i know [somewhat] how you feel.
it does bum one out because you can't, or are not allowed to do what you want, but as long as the interest is there, at least it keeps one's spirits alive.

Good you caught it. Prayers to heal up.
Doug

Glad to hear you’re doing okay.
Sounds like things could have turned out way worse.

Hang in there…… that track will still be there next year.

Hope you heal up quickly!

Good to hear you were able to get this minor health issue handled, take it easy for a bit to recover...then get out there and live! Prayers for a speedy recovery.

Holy cow, good to hear the heart problems got fixed.....

We tend to give the racecars a lot of attention, but sometimes our bodies need it too. And racecars are a LOT easier to fix....

Heal up and get after it next year!

Thankyou everybody. Since I know there is more damage with the 549 crank and bearings, I have decided to go ahead and put the 580 cube crank in it. It will be a better match for the converter, it is ready to go with bearings, sitting on the shelf. All I need is a pair of .060 head gaskets to keep compression at 15.5 or less, warm. I will probably Dyno it as well, when ready. It may make sense, since the 580 motor won't need to spin so high, and the converter should stall maybe 6500, which should be closer to ideal.

I am glad you got fixed up Greg! Health issues suck so I say we all should spend the rest of our time left having fun and enjoying the time we have left!

my best buddy preaches this to me every time we talk or are together !

Glad to hear you got yourself checked out and repaired. There's always next year for racing.