I want to go a little quicker

Do anyone see anything wrong here, except my shift points that is

my 60 ft could be better, actually the whole first half could be better, I m pleased with the MPH but something isn t right here

A little more info about the combo would be helpful. What type/style of transmission? clutch set up? It Looks like you could loosen the rear extension on the shocks a touch for smoother downtrack operation. The first 2 seconds or so looks bad. Less clutch in it would help and tighten the compression on the rear shocks. More info please... I run the RPM data logger also and I am familiar with what you are showing us on Moparts.

Looks like it was spinning the tires to me. at the hit or shorty afterward.

Trans is a liberty 4 speed, 2.19 first gear and a 7300 stall converter.
I m way to lazy to use a clutch

I have tried to eliminate the wheel spin by lowering start rpm but I still end up with that same 1.29 -1-31 60 ft

If you look at the engine rpm at 1 sec, do anyone see anything weird?
since my laptop died I don t have all data here but I remember about the same time the lambda sensors shows a rich condition one one side only
( da vinci dominators on CFE sheet metal tunnelram)


the small peak just before 4th is a bump in the track, shocks may very well be a little stiff

more info here, converter and first gear changed since

https://board.moparts.org/ubbthreads/show...part=1&vc=1

Well I do not see any significant wheelspeed in that graph at all. Would like to see your AFR line however. My guess is if you have the ability to overlay the AFR's and Fuel pressure to that graph you may find a trend there. Also acceleration G's will show if you are seeing any excess wheelspin. That graph you show does not really show anything more than a tad bit more wheelspeed, not really spin. Seems to be pulling motor down and then lazily accelerating in first. My guess is there is a fuel issue causing it.

I don t have a G meter, but I have to dig up the rest of the data I know I have backups somewhere

I experimented with the acc pumps even made my own cams and it got better but seems like there still is something thats not right

I have a pair of holley 1050 s I could try, maybe it would change one way or the other

Is this set up currently a single carb or duals now? You will find with a dual carb set up that carb tuning is even more critical especially down low. Float settings, fuel pressure tend to be the two things I see people have to much of in these faster NA cars for sure. Those things can cause WIDE fluctuations in AFR's especially down low. An AFR meter would quickly become your friend, as I say I do not see any excessive spin just laziness in first. But more info would be helpful.

Dual da vinci dominator, dont really know what mr da vinci has done to them but there is a lot of epoxy and drilled holes in the metering plates , on a CFE sheet metal intake

I think I have the basics covered but I have made stupid mistakes
before and probably will in the future...

Well since it is a two carb tunnel ram deal my first observation based on that data log is you have WAY to much fuel pressure. It shows well over 7 PSI. With a t ram and dual carbs you need to be around 5-5.2 psi. Most guys run WAY to much fuel pressure anyway. I would assume the floats are set close if Davinci was given the info on set up but once again AFR will tell the tale. A few thousandths change in the floats will also show down low in a set up like this. My guess is that you are pig fat down low, this is what is causing what you see on the RPM graph. It will amaze you how much AFR's can change with fuel pressure, and float levels especially down low and dual carb set ups are more sensitive to these changes.

There is nothing in that driveshaft graph to show excessive wheelspeed. The laziness is likely coming form being way rich down low. Dropping carb pressure and likely playing with the float levels will show a marked improvement in those short incremental times. Once again with AFR's it is a guess but from what I see IMO it is a good one.

Seems logical, I think we have already lowered the fuel pressure but as I said, need to dig up my data files

I found another, this is our best so far
you can see on the purple afr graph that something is not right, kinda hard to read and I don t use the lambda sensors for tuning, don t really trust them...
this is still with 7 psi but lower fuel level, a lot better engine rpm graph

As I assumed you are dead fat down low. That is likely what is causing some of what you see. If you can overlay acceleration G's that will help ad to it.

My suggestion is drop the fuel pressure to 5.5 and readjust floats. DO NOT use the window method of setting them, that is HIGHLY inaccurate. Rather use the float drop method. Remove the bowls flip them upside down and measure from the inside of the bowl to the middle or parting line of the float. Start at say .730" and make a lap. Pay attention to the AFR graph and G meter, they will tell you what you need to know.

The excess fuel pressure causes the needle to bounce on the seat, this will aerate the fuel as it tries to fill the bowl. The newer float setting will not allow the float to get as empty, the lower pressure will allow them to fill better without aerating and you should be able to begin to smooth out that AFR line. Once you do that the accel G meter will also climb and the car will go quicker. Then you can work on jetting and bleeds as needed to bring it where it wants to be. Honestly you should not need many jet changes get used to working with the bleeds, HIgh speed rather than the jets. Use the main jets to get you close and bleeds to dial it in or make changes for air, unless they are drastic changes in air.

You may also need to work with a good converter company as well. Leaving with that much RPM may not be the best way to go. Try something lower and allow the converter to flash at the hit. If it is a good converter that will help as well. If not you may need to look at the converter. FWIW my converter stalls at 8400ish and we leave at 3800. That has led to our best results anyway.

Then again I was called out by a junior dragster so my advice might not be any good either

Your advice is best so far

we have tried lower start rpm but not much difference there
and I have tried my share of converters, this one is a swap meet find 8" and the best one so far
I have two 8000 rpm 7" converters ,slightly different,both made by very well known manufacturers, but both slips so much down track that the car was 2 tenths slower and even slower in the late rounds, we even tried a external cooler( leaf blower )

seems like I need to invest in a G meter

Just trying to share my experience over the years. The converter thing is definitely a tough one. I have been through a number of them myself in both cars. We are happy where we are for now with my junk but once we get the motor back from freshen up I am sure we will be out in left field again.

I agree the AFR and G meter will tell ya a lot. Data is good for sure but learning how to use it takes some time for sure. Seems like we learn something everytime we go out with the HS car.