[PRAY]

I guess this damn car is never going to go 10's with boltons. If it isn't one stupid thing it is another. I put a converter in it and it didn't go any faster really. It 60ft'd like crazy but lost 2mph in the 1/8th and 4mph in the 1/4. No point in having a good 60ft is all of your mph is gone. (not blaming the converter). DA was around +1,100-1,200 all afternoon. Track was good to begin with but started to fade. I had an 02 sensor go bad on me yesterday and couldn't tune it out with EFI Live so hopefully that is my power issue. Or something seriously broke and the car should be dead. There is a bunch of tuning to be done with the new converter as well. If the weather is close next weekend and I can get back on E with the 02 sensor fixed then I may try again. Other than that, I am done and moving on. 10's bolt on already went down so there is no point any more. No one remembers who does anything second. Here are the two best passes.



The pass on the right was against a Gen5 with H/C/E/CAI/Converter/Drag pack/150shot. He said he put down 500rw before the spray. Awesome race. Just clipped him. My buddies car that has all of my stuff on it with a cam only ran 11.3@122+. I will have to see his new E dyno numbers.

[DiGiam]

What's next on the list. Ported heads, cam, or that LT4 supercharger?

[PRAY]

Originally Posted by DiGiam

What's next on the list. Ported heads, cam, or that LT4 supercharger?

Yep, in that order.

[laynlo15]

HUH, I have been there and the converter always helps out down low but will cost you on the big end. I think I brought this up in a different post. Man what a 60 ft though and that's how it usually works. I remember going from a 4000 to 5000 converter in my drag car, 60ft was killer went a little fast but slowed down on the big end mph. Maybe with more hp in your up coming mods that converter will really shine. That's one of the best 60 ft times on this forum. Sorry to hear the 02 sensor messed with ya. Still really respectable time for your mods.

[PRAY]

Originally Posted by laynlo15

HUH, I have been there and the converter always helps out down low but will cost you on the big end. I think I brought this up in a different post. Man what a 60 ft though and that's how it usually works. I remember going from a 4000 to 5000 converter in my drag car, 60ft was killer went a little fast but slowed down on the big end mph. Maybe with more hp in your up coming mods that converter will really shine. That's one of the best 60 ft times on this forum. Sorry to hear the 02 sensor messed with ya. Still really respectable time for your mods.

I could see losing mph in an old school converter that doesn't lock up. That makes perfect sense. If anything, with a modern lock up converter, I should have gained a bit of mph in the 1/8th from leaving under power and run the same mph up top or a little better locked up.

I was able to get the converter to lock in third sometimes right after the 2/3 shift. Sometimes it would lock up when it wanted to in 3rd. It did lock every time before 80mph. There was nothing I could do to lock it in 2nd. I tried everything. I need this thing to lock right after the 1/2 shift. Sucker was leaving hard though. That is for sure. I would almost bet a paycheck it was lifting the wheels.



If it is the converter that is costing me 4mph then it is coming out as soon as I can get it out. There is absolutely no reason on having a converter to get a cool 60ft with no real gain in the 1/4. I was gaining 27mph on the back half two weeks ago on the stock converter and the exact tune I started with this week. I did drop the 1/2 and 2/3 mph down in anticipation for the converter not being locked. I think it averaged 23-24mph on the back half this week. The converter was definitely locked by then. I really hope the lack of mph has something to do with the bad 02. I guess I will get the 02 fixed and get it back on the dyno to see where it is at.

[PRAY]

I don't want this to turn into a blame game. I have the utmost faith in Chris and the guys at Circle D. I going to go through the logs and tune and check some stuff out. With how hard this thing is leaving I know they did their job.

[PRAY]

SO, I just went back over my logs and slips from last time out and this time today. Almost all of the shift mph/rpm points line up from the stock converter to this converter. The shift mph/rpm line up exactly. The crazy thing is that the car is reading the same MPH at my let off past the traps. I let off at exactly the same point every time. There were a bunch of dudes today complaining about how slow their cars were going. I am starting to wonder if there were some clock errors going on today. Stuff isn't adding up at all. How in the world am I leaving that hard and it now showing out.

[laynlo15]

Did you run both lanes? Speed is measured in the last 66 feet before the traps. Is it a 3000 stall or more? Whats the diameter? 9", 10". I know those guys are good at circle D and if the DA was up and the temps up you could loose some mph in the traps compared to last time out. I know I was down a couple MPH from my prior runs as temps were a few degrees higher and DA was positive and not negative. It could have just been a combination of all the above. Something is wrong as it seems it should have broken into the 10's with almost a .10 pickup in the 60' times. You'll figure it out.

[wbt2012]

60' is great and then starts to peter out from there on.

Is the converter staying locked after the 1-2? Can you post some logs?

On the Coyote side if we lose an upstream o2 it absolutely impacts performance. I have seen a couple of MPH and .2 down. (this is common with e85 and LT's due to the additional moisture generated)

There are a couple of solutions:
1. Dumped exhaust so that moisture doesn't pool in the collector.
2. Wrap the headers to keep temps up inside the tubes to reduce moisture.

Don't give up on this....

Incrementals for comparison:

[bhillakaiceberg]

Something else is going on there Brett. We basically had the same 1/8th at 7.01 but your MPH is hella down. I know you will figure it out for sure. Give it another shot!

Glad to know the Circle D stall is working on those 60fts tho!

[PRAY]

The converter is a Circle D 4C 248mm Triple Disk. It is obviously working like gang busters. I am not really exactly sure what the stall speed really is. I asked for it to be a 3,600ish for my pump gas numbers and on E I make a bit more tq so I am suspecting it is flashing higher on E. As far as I can tell I have the best 60fts on the boards right now. I was foot braking to 3K and letting it ride. I did get it to foot brake to 3,300 or so but I was getting wheel spin at that point. My two best 60fts were with just a hair of wheel spin. I am thinking that if I could have gotten it to hook stalled to 3,300-3,500 I would have seen a 1.45 60ft. But the track just wasn't having that by the afternoon.

So here is what I am thinking. The DA was +1K from my last runs, so lop off 1mph and 1tenth. In same weather last time out I would have run 11.2@124. I dropped .12 off of my 60ft which should have gotten me .24 on the big end with no other benefits. So that should have put me at 10.96 ET wise. I only went 11.04. MPH wise that should have put me in the 123 mph range. My best was 122 after a ton of retuning. The same tune from the stock converter runs barely netted me 121. So there is a tenth and 2mph that need to be accounted for.

Looking at the logs from the stock converter my post 1/2 shift recovery knocks me down from 6,472 to 4,866 the 2/3 shift goes from 6,500 to 4,850. Both of those shift recoveries put me at peak tq and well back into my power band.

On the converter runs from yesterday my 1/2 shift recovery is from 6,459 to 5,700 and the 2/3 recovery is from 6,500 to 4,850 when the converter locked and 6,541 to 5,768 when it didn't lock.

My car makes peak power at 5,700 and falls off pretty hard after that. So on the 1/2 shift I am recovering past peak power where I have nothing to propel the car forward with. When the converter would lock in 3rd I am good on shift recover but when it wouldn't I am past peak hp and well past peak tq again where I have no power. I have to find a way to get this car to lock the converter on the 1/2 shift. I am sure that little bit in the heart of acceleration is killing me.

I have also gone back and looked at the fueling/spark. I was having to run the car at 11.8 and up to 31-32* total timing yesterday just go get it to run and not fuel bang. Normally this car likes 13.0 with 28* total. All I can think is that the bad 02 sensor was flooding the car before the start and adding those fuel trims all the way down. I had the bad sensor in the drivers side and my WB in the pass side. The bad 02 was in the pass side before and could have killed my WB but it reads "correctly" going down the road. I did try leaning it out to where it usually runs but it only slowed down. I have heard that you can't compensate for a bad 02 with leaning out the P.E. cause it doesn't translate to both banks and what not. The jury is still out on all of that so I am not going to put a lot of brain power into it right now. I will replace them both tomorrow and see what happens. This car and computer are tricky. It probably didn't like the way I went about trying to trick it and fought back. Quasi Open Loop never seems to work out.

Where does this leave me? If I can't get this converter to lock on the 1/2 shift back into my power band then I will have to extend my power band. Only two ways to do that, cam or MSD. I can get my hands on a MSD and port it fairly easy so I may just go that route first. Extending my usable rpm band to 6,600 should show a drastic improvement now that I don't need all that tq to get out of the hole. Option two will come eventually and will be tested with both manifolds.

As usual I will keep everyone as updated as possible with every step of this process. We can all only learn from it and in the end I feel my battles will only help the community make the most informed decisions as possible.

[PRAY]

This new computer samples to fast so I can't get the entire pass in one frame. The post 2/3 shifts are identical in both logs.

Here is a log of the stock converter. 11.10@125.07



Here is a log of the Circle D. 11.04@121.7

[PRAY]

So here is some more analysis and some silliness. The tires are obviously effecting the MPH in the logs but the time under power and getting to the same rpm and mph are a constant since tire pressure was the same on the runs. I logged out each gear and the time it took from peak rpm to peak rpm. Another way to say it is how long the car was in each gear. Both runs were from 0-122 mph on the scanner. On the converter run the rpm at 122 was 5,329 and on the stock converter the rpm at 122 was 5,346.

_________1st_______2nd______3rd________4th______5t h_______0-122
Stock C__2.277_____1.639____2.823______3.026____2.045___ ___11.76
Circle D__1.872_____1.607____3.073______3.416____2.183___ ___12.15

What this is showing us in my opinion is that the car was dying in 3rd, 4th, 5th which are gears where the converter is locked and doing it's job. So I am leaning towards a fuel issue. The Circle D is slipping no more than the stock converter once it is locked. Even thought the ET's were almost identical the time to mph shows the real story. The car just wasn't making power. So I have to track that down now.

[wbt2012]

Originally Posted by PRAY

So here is some more analysis and some silliness. The tires are obviously effecting the MPH in the logs but the time under power and getting to the same rpm and mph are a constant since tire pressure was the same on the runs. I logged out each gear and the time it took from peak rpm to peak rpm. Another way to say it is how long the car was in each gear. Both runs were from 0-122 mph on the scanner. On the converter run the rpm at 122 was 5,329 and on the stock converter the rpm at 122 was 5,346.

_________1st_______2nd______3rd________4th______5t h_______0-122
Stock C__2.277_____1.639____2.823______3.026____2.045___ ___11.76
Circle D__1.872_____1.607____3.073______3.416____2.183___ ___12.15

What this is showing us in my opinion is that the car was dying in 3rd, 4th, 5th which are gears where the converter is locked and doing it's job. So I am leaning towards a fuel issue. The Circle D is slipping no more than the stock converter once it is locked. Even thought the ET's were almost identical the time to mph shows the real story. The car just wasn't making power. So I have to track that down now.

IMO I would replace the o2 first, make no other changes, and compare. If the problem still exists work at it based on new logs. If you have a way to look at MAF lbs/min then that will give you an indicator on power.

The screen shots above don't really relay any usable info for me other than at one point IAT's were significantly higher in the second screen shot. Having actual files would be useful but I understand if you don't want to share that publicly.

I also agree locking the converter after the 1-2 shift will be key.