Analyze My Timeslip

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BrianT

BrianT

Here we go again...
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I only got to make one decent pass last night but can we try to analyze where I'm at? Car is a 67 Dart 408/727 497hp/519tq 3.54 gears 325/50 drag radials at 3800# with me in it, 750 ft above sea level.

The Dart ran a 12.64 @100.96 60ft was 1.97 330 was 5.27

I know my 60 foot isn't good. My tires were not heated properly because I was nervous (first time on a track in 30 years), but the temp was 86 degrees and they weren't cold. I feel like my mph should be higher, but I think that is because I lifted early at the big end. What do all think? Can't wait to make some changes and try it again!

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Being you say you lifted, might be better to focus on the 1/8 times? What’s the OD of those rear tires? My first ever run with my stroker deal was an 8.28@86mph in the 1/8. Soon after I got it to 7.92@87mph without much more than tweaking what I had at that time. I’d say you have to get a few more runs in to really know where things are at but obviously there’s more in that nice looking car!:thumbsup:
 
Good idea. I was so hung up on 1/4 mile times I completely missed it. The eighth mile was 8.05 @ 89.23 The drag radials are 28"

I should also say that I had a big cooler, two camp chairs, a tool box and 3/4 tank of gas also. If I emptied the trunk (like earlier in the day) I probably could have taken out another 100 pounds.
 
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Biggest thing I figured out quick was drag radials psi, length of burnout and launching. I leave just off idle, vs anything higher. That works best for the launch, 60’ and so forth. But it took me a few runs to verify that was best for what I have.
 
I wasn't able to air down my tires because I didn't have any way to air them back up. I'll have to pack a mini compressor next time. I know I didn't get the tires hot enough because it was late and I felt rushed to make one last pass. I was already loaded up to go home.
 
Get some more runs and get in a comfortable routine. I run 20 psi 255/60/15 drag radial, quick 1,2 burnout to clean tires. 1/8 to 1/4 mph is off by at least 10 mph. Bring some plugs next time and check to see the burn. If you have an AFR gauge get WOT to 12.8 as a starting point, jet for mph.
 
If it was your first time in 30 years, you just need more seat time. As you get more passes under your belt, the time slips & log book will give you hints as to what needs to be done. Just remember, only make one change at a time so you know what the effects are.
 
There is a bunch left with those hp numbers. Make a bunch more runs until it becomes consistent, but with a 28” tire and 3.55? rear gear you might want more rear gear in the future. What converter is in the car?
 
BrianT said:
Good idea. I was so hung up on 1/4 mile times I completely missed it. The eighth mile was 8.05 @ 89.23 The drag radials are 28"

I should also say that I had a big cooler, two camp chairs and 3/4 tank of gas also. If I emptied the trunk (like earlier in the day) I probably could have taken out another 100 pounds.
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I'm not sure if it's even a "snap shot" for your car. 1/8 mile times are botched by poor traction, and 1/4 mile times because you lifted early. The only thing i see is your 1/8 mile speed at 89 mph suggest you were on your way to about 110 mph 1/4 mile time which is capable of about a 12 flat.
 
furrystump said:
There is a bunch left with those hp numbers. Make a bunch more runs until it becomes consistent, but with a 28” tire and 3.55? rear gear you might want more rear gear in the future. What converter is in the car?
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It's a street car 99% of the time, so the gears will stay. The convertor is custom piece built to our specs by Kris at Continental Convertors. It was one of the last custom convertors he did before he retired. Flashes to about 3 grand.
 
What about the flash stall speed of the torque converter? I would think that would help all these experienced racers help as well.
 
You need seat time as others have suggested. Your 1/8 mph shows 110mph quarter, if you can get it to leave. A two tenth improvement at sixty foot,1.77, can mean five tenths on the other end, and 500 hp should be able to go 1.67, even with 3.55s. The weight and gears are holding you back. If you can't get the drag radials to work, maybe some 26"tall real slicks, to crutch the gear ratio?
(And lifting early has minimal effect on e.t, substantial effect on mph. 60 ft. Improvement has a dramatic effect on e.t., next to nothing on mph.)
 
Can’t really base anything off that one run, other than...... there’s more in it if you put together a better pass.
(Better burn out, don’t lift early, take out the extra 100lbs, etc)

Nice looking Dart though:thumbsup:
 
One thing you can bet on is there will be more seat time. I'm ready to do it again today!!
 
Lower tire pressure and a good bit of heat in the tires will greatly help with 60', which will lower E.T. as others have stated. Lifting early has made a big difference in trap speed, I agree that 110 to 112 mph should have been easy. 100 lbs of weight equals about .01 second in E.T. so the cooler etc wasn't a big factor, but I would never have anything in the trunk when I make a pass except the spare tire, firmly secured in the well, and I normally try to keep close to 3/4 of a tank of fuel for traction. Try 18 to 20 psi tire pressure next time and do a 5 count in your burnout before letting off the brakes. Keep getting more seat time and the improvements will come.
Good luck and beautiful car.
 
33IMP said:
You need seat time as others have suggested. Your 1/8 mph shows 110mph quarter, if you can get it to leave. A two tenth improvement at sixty foot,1.77, can mean five tenths on the other end, and 500 hp should be able to go 1.67, even with 3.55s. The weight and gears are holding you back. If you can't get the drag radials to work, maybe some 26"tall real slicks, to crutch the gear ratio?
(And lifting early has minimal effect on e.t, substantial effect on mph. 60 ft. Improvement has a dramatic effect on e.t., next to nothing on mph.)
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Knowing you want to keep the rear gearing, I would agree about some dieting......of the cars weight and more practice. Very nice looking MoPar.
 
A56 said:
Knowing you want to keep the rear gearing, I would agree about some dieting......of the cars weight and more practice. Very nice looking MoPar.
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Thanks! I don't know how much weight I'll be able to remove? When the floor pans were done, we covered them in sound deadener since it is a streetcar and I HATED all of the heat coming up through the carpet. I'm also running a Dana style rear end which is overkill, but I can empty the trunk and the gas tank. I didn't know how much I needed so I filled it up. Next time, I'll run it low, and bring a five-gallon can with me.
 
I agree that 110 to 112 mph should have been easy. 100 lbs of weight equals about .01 second in E.T.
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Actually....... in the 110mph/3500lb range..... 100lbs is worth about a tenth(.10).
 
I'll be interested to see what you get out of it once you dial it in. I have a similar 408 with a tad more tq and power and anxious to see what it'll run. IF I can ever get out of the rabbit hole...

Keep us all posted...that's a really beautiful car!!
 
Car looks great! I've been watching you build that thing on this site for quite a few years, kudos. I run my drag radials at ~19 psi, I would suggest somewhere near that. Other than that, warm the tires and give it another go. :)
 
Lifting at the end really messes up speed. Get the 60' sorted and I agree with the rest.
My car currently gains almost 25mph from 1/8th to 1/4mile. So 110-112mph wouldn't be out of the question. Get the 60' around 1.7 and you'll be in the business.. and no more lifting.

my drag radials were happy 18-20psi... Usually 18psi is where it would hover. Old engine ran 12.40's@107 @ 6500-7000ft da. 3.55 gears, 255x60x15 ET Street R's... It would hook well and usually get the best pass launching off idle, with super stock springs and CE drag shocks.
 
I, too, have been watching your build. I'm a year or so behind you, but you help motivate me to drive on. Get some more seat time, and you'll get more consistent. You're living real life, and not some keyboard commando. Keep driving her, Brother.
 
Dumb question. How does a 67 dart weigh even remotely close to 3800 pounds.? It appears to not have a cage/ rollbar?
Reason i ask, my all steel 69 Dart with rollbar, Full carpeted interior, etc, etc missing only the back seat, weighs 3310 with a full tank of fuel and my 320 pound butt in it...lol
 
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