I have a 71 dodge demon 340 dedicated drag car that I brought to the track this past weekend and did not get the results I was looking for despite lots of tuning time. I wanted to know if the goal of 10.90s seems reasonable given my specs. The car weighs 2900 lbs with driver. It is a 345 cubic inch small block with h beam rods, mopar performance crank, stock stroke, 13.5:1 compression, with 0 deck height, and fully race prepped j heads. .040 off the heads, 2.02 intake, 1.60 exhaust, mechanical full roller crower cam pn 31409 with spec at dur @ .050) lift 268,274 @ 50 with 106 lobe center, and a gross of valve lift with 1.5 rocker with .645/ .623. supposed to be good up to 8250 rpms. It runs an Edelbrock super victor jr with mild porting and a holley 950 double pumper with 80 jets in the primary and 88s in the secondaries. The ignition is an electronic tach drive distributor with tailor pro wires msd digital 6al and a Mallory performance coil. the convertor is an 8 inch 5500 stall unit coupled to a 904a fully race built, with a billet drum, bolt in sprag, manual valve body, rollerized, etc. It was at the time of the track utilizing 456 rear gears. I have since ordered 513 rear gears in hopes of upping my trap rpm and speed. It has a spooled 8.75 Chrysler with ladder bars and super stock springs using only 2 leaves per side. It is running a 30 x 10 inch slick in the rear and leaving off the foot brake. the fuel system is .5 inch from tank to regulator at the carb with a holley black pump. the hedders are 1.75 to 3 inch collectors with an 8 inch extension on them.

the car this past weekend ran a best et of 11.86 at 111.92 mph. it ran a 1.619 at the 60 foot and 4.752 in the 330 foot. it ran a 7.426 in 1/8 mile at 91.9 mph. it ran a best of 9.803 at the 1000 foot mark. these times are the best overall times for each marker. I shifted the car between 72-7500 rpms as well as launching off the foot break between idle-3000 rpms with greater success coming with a higher rpm launch. Again, would a low 11, 10.99 time be an unreasonable goal with some more tuning and weight reduction?

I hate to come straight out and tell you this but something is wrong with your combo and did you try shifting at a lower RPM? Here's my Sons combo. (1970 Duster)
.040 over stock crank 360
set of Edelbrock heads I ported
Victor intake I ported
520 lift Racer Brown solid cam
11.2-1 compression flat-tops
H beem K1 rods
750 alcohol carb
1 7/8 headmen headers
4.10 rear geat 10-28 slicks
shifted at 6400 RPM
727 transmission with 5400 stall
34 degree locked out timing
footbrake car
3150 pounds
10.50-10.60's at Pittsburgh Raceway Park not some east coast SUPER track.
very basic low maintenance combo

My car is lighter but when I ran a stock stroke
with W-2s I ported and a 260/270 .640/.640 on a
105lsa installed at 103 with a 727 and 5600 stall
and 4.88 gear with 14x31 slicks I ran a best of 9.90
but I had to keep it at 10.0 or slower.. my headers
I built were 1 7/8 with a 3.5 collector 18" long..
I was turning 8100 rpm... what are your heads like
do you know what they flow

I had almost the same combo in my street car.My 72 Demon had a .030 over 360 with Hughes Engines stage 2 ported J heads (flowed 265 cfm) 13.5 comp. a Hughes Engines solid cam with 1.6 rockers (265/270 @ .050, 642/656 lift cam). It was a stock interior bench seat all steel except hood with no roll bar (3450 lbs). 750 carb , 5000 stall 8 in PTC convertor, 486 gears driven to track (130 miles round trip). My best ET on motor was 6.99 @ 96 mph. On 100 shot NOS (47/53 jets) spinning it ran a 6.47 @ 106 mph.

At 112 mph you are running an ET for that MPH...something wrong...

check timing..is the carb opening all the way?

dont think 5.13 are going to do you any good...

how tall are the rear tires?

It runs almost the numbers my 10.5 to 1 318 runs with a hydraulic cam( except I am 500 pounds heavier)

To run like that, must be the heads aren't any good, can't think of anything else for a car that runs the right number for the ET.

I would agree that its down on power. My old 340 Dart that I ran back in the 70's and early 80's ran about as good. It was a 66 Dart I put a 340 in that was a stock bore and piston 340 as a matter of fact it was a stock shortblock that I just rebuilt. The heads were stock 340 heads that I ported some and I milled .030 to raise the comp as I used the factory stock pistons rated at 10.5 but I never actually cc'd everything. I ran a Crower solid flat tappet of .500 and .510 lift and 284 & 300 advertised duration. Stock 273 rockers with lock nut adjusters. Used the Holley Strip Dominator intake and a 700 DP. JR headers and it was a stock 4-speed with 4.56's and a 28.5 x 9 slicks. Car was all metal and all there so I guessed it weighed about 3000 to 3400 lbs. It ran a best of 11.94 @ 113 mph in 1981 as I rolled the car in early 1982. I would think your car would make more power and more mph then mine did. It seems something has your eng down on power some. Ron

Get it warmed up and drip some water on header tubes as close to the heads as possible. Water should disappear immediately. My guess is you are running on 6 cylinders. I had an 8 to 1 CR 318 in my Demon with 360 heads with 1.88 stock valves and went 11.60s. Have built several 10.5 to 340s in darts and dusters that run high 10s and similar stock stroke 10.5 to 1-360s in my Demon and run below 10.50 at 3100lbs. Something not right with yours, your high 10 second goal should be easy to obtain. Put a 4" stroke crank it in and high 9s are easy.

thanks for all the response. the slick is a 30"x10.5 set of hooisers. I set the timing at 38* degrees total at 2500 the dizzy only has mechanical advance its a direct connection electronic with tach drive. I was shifting the car @ between 72-7500 rpms and it was going through the traps @ 5700 rpm hence my thought on the gears. I will pull the plugs today and check them throw a new set of plus in it and check the headers with a temp gun once it gets to temp and go from there.

I don't know any flow rate on the heads. All I know is they are ported very heavily for cast iron j heads with a ton of bowl work

thanks, I have the timing set at 38* and I am running a 30" slick going through the traps @ 5700 rpm

Take some timing out of it. Shift closer to 7,000 rpm. You had one 1,000 ft mark of 9.80. Good numbers. Shouldn't have taken 2 more seconds to go another 300 ft. Try and duplicate your driving sequence for that run. Are you running a power valve in the carb? Large spread on jetting. As already mentioned, check for full throttle opening.

I think I will knock the timing back to 36*. the 950 has on the primary's 80 and a 6.5 power valve and on the secondary's no power valve and 88 (reason for the difference.) I will have to be more consistent with a 7000 rpm shifts I do agree there is know reason for 2 seconds to cover 320 feet I am most likely over revving with no performance gain

are your valve springs new whats the specs on them ???????????

The springs and motor, actually the whole set up is new the motor has 6 pass on it with probably 45 minutes of run time total. The motor is consistent it is only a 3 hundredths difference from fastest to slowest pass. I do not know the spring spec of the top of my head but I could find out in a little bit I have to call the machinist.

There are lots of reasons why it could be down on power but I think I would start with a basic compression test followed by a leak down test. I would also check the springs. Maybe the cam is in wrong? Your combo should go at least 11.0's but I'm sure faster so your missing a bunch. This is why running the engine on a dyno is a good idea. If you dyno'd and the engine made good power and didn't act stupid then you'd know the problem wasn't there and you'd have an idea of what it should run in the car. Then you could start looking at the converter, fuel system or an electrical problem. Start by looking at the basics.

Make sure the wires on 5 and 7 arent backwards
it wont sound like a miss but will be way down
on power... as me how I know.. since they fire
next to each other

Make a pass with a 6,500 shift and see what happens. That will tell you right away if you have been over revving.