Based on those comments I am gonna guess the converter is made by A1 And yes out of first sooner is generally always a good idea and the faster way down the track.

I was thinking the converter needed to drop back more after shifts but the mfg told me that these days they don't focus much on drop back rpm. He said they have some very fast cars that run with very small drop backs after gear changes. Keeping the engine right at max power all the way down the track is what they are trying to do. So that makes sense, I guess the issue is having the converter slip enough to move the drop back point higher into the power band without having it slip too much. The stall point on the existing converter is only a few hundred RPM less than peak power.

One of THE biggest issues I find when helping folks with their combos is the converter fall back. Most guys think 15-1600 is fine, WRONG! Thats outdated antiquated thinking on the subject. All that is going to do is slow you down. Every combo is different for sure but anything with 4 digits of fallback is going to be to much. In my experience "loose inefficient" converters tend to be fast. If you are looking for an ultimate low ET then thats they way one should lean. Companies have gotten much better at making loose converters more efficient in high gear for sure. We even have a lock up option now. In the heads up car we like to see 5-600 on drop back. But alot of factors play into getting there, weather, gearing, tune up etc.

I've had several 9.5" converters in mine. From 1300 fall back to 600 fall back. The 600 was pretty good. The current one drops about 800-900 depending on shift point rpm. But it is consistently better on R/T than the other two.
Doug

I help tune an 8 second car with a PG. That car only falls back 50 rpm on the 1-2 shift. Kind of crazy and I'm not sure that is the fastest way down the track but that is how it is set up. You can't even really hear the shift and the data log only shows a small blip when it shifts.

I was originally taught that the engine should fall back from peak power to peak torque on the shift which is about 1500 rpm for most engines. But I think that is now considered "old school". It does make more sense to keep the engine right around peak power as much as possible.

My S/P car with a Mikes Monster glide with a 1.80 low gear set drops between 1400 and 1500 RPM depending on the shifting it out of low gear, shifting it at 7000 RPM would drop it back to 5600 RPM, shifting it at 7300 RPM would drop back to 5800 RPM in the 1/4 mile
All the incremental times except the 1/4 MPH were identical, it ran 8.862 ET at 148.? MPH (the last two MPH digits are in the logbook in the trailer) shifting it at 7000 RPM, shifting it at 7300 RPM 45 minutes later in the other lane made it run 8.864 ET at 150.?:? MPH The 60 ft, 330, 660 and 1000 FT times were identical to each other

You would probably go quicker with less RPM drop but it can be a hassle to test converters, especially at the track. Need a couple of strong, limber helpers to dive under the car and change the converter. I'm not interested in doing it at the track anymore that is for sure.

Awe come on we have been known to have the transin and out three times in a day, and trust me in the Vette NOTHING is easy.

IF you have decent data to provide......i have been told you will keep going faster, every time you change the converter

Wish that was true..Being lowly NA racers we have to change stators, or trans gear rations sometimes way to frequently chasing weather conditons. Part of the joy of racing across the country

But we only have 42 data channels we monitor, maybe we dont have the right one

Here is an OLD screen capture from 2016 when we only monitored a few things and were still learning how and what the car wanted. Also way less RPM then. Looks a LOT different these days but dont have a picture of any. Maybe ill take one this weekend and high lite all the channels just for confusion

i really doubt the owner is going to be making a bunch of convertor changes, when he plans on switching to a Glide anyways. The only thing that matters at this point, is the customer happy with the results?

I would agree but always fun to speculate. In a glide the converter is the make or break piece.....Even more so than a three speed.

“Engine RPM” = 9777

That was back when the engine was a "big" smallblock. It was 440" a fair bit smaller now and the RPM is a fair bit higher these days. We now shift 2/3 at 9900ish go through the top end at 10,2-10,400

We have been racing 1/8 mile out west of late. We don't change the car from our NMCA trim for it, we run legal weight and our normal trans ratios, rear gear and converter and go through the 1/8 stripe still on the converter, which stalls at 9200-9300 if we got the stuff right.

Al, looking at your data, is that where you like your A/F at or did you correct it?

First off I really didn't intend to muddle up Anyds thread so bad, so I apologize. Since this is not a Mopar figured no one would care to know.

Every combo is different and every fuel, racefuels vary widely, has a different ideal stoich number(I see racepaks all the time where people don't use the correct stoich for their fuel, lambda really is the better way but I like stoich). Bottom line is we run the car where it is fastest, we don't have a number in mind and shoot for that on the track. We pay attention to the timeslip and when we are happy with what we see there we then will come up with our own target AFR number. Again all combos are different but don't ASSUME stoich is where you get the optimal performance. I know some folks think that number is a be all end all and I'm here to tell you in the heads up world that it just isn't that simple. Dont chase a "magic" number chase the slip......

That screen capture was early on with the smaller engine and we were not 100% on it for sure. Carb was to small(2.300" throttle blade)and we were struggling with the new changes to the manifold, first time we had the BIG intake on the car. Having said that for the fuel we ran back then the car was always happiest at 11.6-7-1 for a target AFR. These days we are at a higher stoich number on the tune, and a different fuel. Its always a balancing act with a single 4 carb and intake to get all 8 holes happy. We are still chasing some distribution" issues" but the car keeps getting faster. Carb is bigger, fuel is different and we run a fair amount more RPM these days. The car just went 4.98 140 last time out so we are getting closer to the fast guys in NMCA NA10.5. We dont make a ton of power we try to be really efficient down low. We have a coupe timeslips that show sub 1.10 60' but we don't 100% believe that number yet, but either way aint bad for a small block at 2770lbs. I don't worry near as much about the "ideal" afr as I do the wheelspeed at .5 into the run If AFR is in the ballpark we are ok, if wheelspeed is not in the target zone we just are not fast.

Just to muddle it up some more here is a screen capture of a run a last year. Driver short shifted(refuses to use an air shifter) but just to get an idea of distribution on all 8

The green line, and red line are supposed to match in high gear. LOL.

They get much closer in a 1/4 mile than the 1/8, maybe even more odd looking for a clutch guy Beenmy experience looser is better in our world...Remember we don't set the car up to run 1/8. However you do know with a lock up that green line actually goes above that red one right