Do these stop numbers sound right?
 

582 in a Davis Roadster, All out runs 850's
Dedenbear Delay Box, APD Max Speed carb
Launch 5200
Timer A1 - .125
A2 - 3.050
Shift (Timer) B1 - .200
B2 - .300

4100 RPM while on Stop

MPH was 152 and car ran a 10.56

Changed Timer A2 - 2.050 and car ran 10.19


I just got this car turn key and im kinda new to all this. Just wanted to see if these numbers looked correct or if there is something that looks incorrect. The 582 is nothing fancy, Id say a mid range 582 with the weakest link being BB2X Xtra Heads.

Re: Do these stop numbers sound right?
 

Is the Davis 57 model or a C5? I have a 57 Davis that has a 582 Head Hunter engine that makes around 1060 H/P. # 1 timer .007 # 2 3.500
Shift .020-off .040 I leave at 5,200 to 5,600 Rpm. All these numbers are depending on the Density Alt.

Re: Do these stop numbers sound right?
 

Its the C5 Davis
DA was 1803 Ft

Re: Do these stop numbers sound right?
 

The C5 model Davis is a good 100 lbs lighter than the 57 model and has better aerodynamics!

Re: Do these stop numbers sound right?
 

It was those numbers that had me guessing. I figured a engine that size running 8.50s would have carried more in the timers or at least close to where they were set, but unfortunately that ended in a 10.56 and 10.19, So it looks like this set up may only carry a second or so on stop.

Re: Do these stop numbers sound right?
 

If it were mine, I'd make the 'Stop On' time later and/or increase the RPM on the stop some so you can carry a little more time on the stop.

It is best if you can always be on the stop through the 60' timer so you have something that should stay constant run-to-run.

Re: Do these stop numbers sound right?
 

What would you recommend Lenny? Throw me some numbers and ill try them this weekend if i get to test.

Re: Do these stop numbers sound right?
 

I totally agree with this
was going to mention this. i like a min of 2 sec duration on stop. ratio will be better and should be more consistent.

Re: Do these stop numbers sound right?
 

just bring the rpm up somewhere around 44-4600, see where you are, then if more needed bring the first (on) time out to maybe .5-1 sec

Re: Do these stop numbers sound right?
 

Ok Ill give this a try next time out with upping the RPMs to 4400. Would 300 RPM make a big difference?


Also Ill change Timer A1- to 1.000, would this be too much ?

Re: Do these stop numbers sound right?
 

Maybe try 0.300 first. I don't know that I'd go over 0.500. Of course you'll need to move your shift later as well. I come off the stop in Low in both of my cars, so I don't have a feel for how to time the shift relative to the throttle stop coming on.

Re: Do these stop numbers sound right?
 

Have you seen the car run 8.50's or run it? Just curious if it did or you were told it did. 152 seems a tad low on MPH for a car capable of 8.50, especially a car set up for super class stuff.

Re: Do these stop numbers sound right?
 

Actually the car has run 8.40 and an 8.37, this has been done with me at the end of last year in good air. This past weekend while running an 1/8 mile race it was dialed 5.45 all weekend long in the heat of Texas.

Re: Do these stop numbers sound right?
 

I am surprised you are loosing that much MPH then. Was just curious I know most of the S/G built deals don't usually ET well off the stop but have good MPH. I would think running 8.30/40 you should be running mid 160's all out. I lost a TON of speed with mine but the car was also capable of going 3 seconds under the index. Also I would think you would be on the stop longer to kill 1.5ish seconds.

My only advice is this. Kill it as soon as you can as hard as you can. Get it on the stop as soon as you possibly can to be able to hit the tree. Shift it on time as soon as possible, use the shift time to get to an "ideal" 60' time. Id be looking to keep shift to .5-.75. Stop RPM between 4-4400 seems to be where everyone wants to be. IMO it is combination dependent to be repeatable. Your converter will be your friend here and make take some tweaking to make it happy and as fast as can be. If its to tight it will come off the stop and just lay there for to long costing MPH. MPH is the name of the game, try to get all you can out of your combo. Of course while being repeatable and predictable. Give it time you will find a sweet spot

Re: Do these stop numbers sound right?
 

One thing that I believe was an issue is the tight converter. While running an all out 1/8 mile race and launching at 4200 the converter was flat and seemed lazy. We upped the launch to 4600 and 4800 and the date looked much much better as far as the curve. So I am thinking with the RPM of 4100 on the stop it may be slightly below where I need to be while on the stop. Maybe an increase to 4400 will be where I need to be.

Re: Do these stop numbers sound right?
 

How did the car handle running all out? I also have a C5 Davis car, but it's the full size heavier body and I've been wanting to try some bracket racing off the stop. I heard with these cars you have to make some suspension/4 link adjustments to calm the launch.

Re: Do these stop numbers sound right?
 

Well when it comes off the stop and its completely open you will have your answer. It will hit the stall speed and you can see how long it hands there. If you have some sort of logging ability, playback tach, Biondo 450 or similar or grid. Its certainly a big part of making things happy and getting the most you can.

Re: Do these stop numbers sound right?
 

The car handled good running all out but yes we did have to go up to holes on top bar of 4 link and calm the launch down.

Was able to make 2 test hits in the car and here are the times
Timer 1 on at .125 and off at 3.050
Timer 2 (shift) at .200
RPM while on Stop 4090 - 4100
Launch 5200
Converter Flashes 6200, Spragless 9inch

60ft - 1.760
330ft - 5.081
1/8 - 7.278
1/8 MPH - 116.79
1/4 - 10.561
1/4 MPH - 151.72

Second pass only change was to timer 1, on a .125 and off at 2.050

60ft - 1.755
330ft - 4.792
1/8 - 6.936
1/8 MPH - 121.72
1/4 - 10.193
1/4 MPH - 152.75