1st trip to race track. Rockingham Dragway.
40deg weather overcast. had been raining and now misty. track cold. 1st 4 cars down track get free pass.
pulled #2 fuse to clear transmission shift learn.
turned sport mode on.
left traction control on.
less than 1/8 tank 90 octane non ethanol fuel.
warmed car fully.

1st pass. i was 1st one down the left lane.
cleaned tires off and went around water box. no burn out.
prestaged.
stalled to 1000 rpm and tried to bump in shallow to stage.
left on last amber.
Car was super slow to respond. i had read that cars with fly by wire throttle bodies were slow to react but wow. spun in 1st. then i felt engine management taking power out, big time. spun and 1-2 gear change and again pull timing.
R/T .433
60' 1.695
330 6.922
1/8 10.096
mph 77.43

2nd pass
cleaned tires off and went around water box.
dry hope/spun.
prestaged
1500 rpm and this time i bumped in 3-4 times to stage deeper.
left on last amber.
Left better but still spun, pulled power. on 1-2 shift it did spin as bad and kinda felt a thump. i left and got back on throttle.....not sure why i lifted.

R/T .296
60' 2.596
330 6.655
1/8 9.809
mph 77.68

Not sure whether to try true deep staging/ turn prestage light out or try leaving on second amber. i think both of these will lead me to red light.

Brother in Christ
Walt

 

Sorry about your loss Walt, Rest in Peace Bobby Thrower, God Bless the Thrower Family!

If you are after off the line improvements Walt, the first thing you should do is change out that Open differential to a Limited Slip Differential, it makes all the difference in the world.

That's not a cutting drilling thing, IMO, no Challenger should be running an open differential.

Another brother in Christ Ryan

 

ANY car can be a competitive bracket racer (unless you want to race an index class)! In bracket racing, robot like consistency will make you a winner. I remember there a guy where I grew up who nobody in his class could beat at the track we frequented. Believe it or not, this guy raced a '73 Duster with a 225 slant six 2 barrel with an auto trans.

His times were ridiculously consistent high 19's and his reaction time averaged right at .1 second. His times never varied more than .01 to .02, and he was unbeatable!

Now as for your ride, add some sticky tires to help with the spinning and start working on your reaction and 60' times. Unfortunately, nothing but seat time helps here...you have to learn how your car responds. I usually stage just deep enough to light the staged bulb and no more, but everybody has their own preference and leave as soon as the last amber turns on. This usually keeps my reaction time below .2 ...most of the time.

As far as the doggy launch, you are trying to get a 4000 pound can into motion and it does take some time. There are a couple of things you can try to help the built in delay. Get a tuner, it has a feature where you can eliminate the pre-programed delay and if you want, make it super sensitive. You should always return the setting to about mid scale before driving it on the street again, it's a simple 45 second process once you learn your tuner. The other is called a pedal commander which I am given to understand does pretty much the same thing...only.

Your other problem is that 3.08 open differential. Installing a Getrag with 3.73's and a posi results in a seriously lighter checking account, but is real kick in the pants; but that mod also exacerbates the traction problem. Lastly for that mod, your RPMs at highway speed are getting on up there. My SXT+ has the same auto as yours and my 70 ish MPH RPMs are 2750, so your engine is buzzing.

Unfortunately, there's no free lunch in the performance world, everything's a performance vs driveability trade-off. You just have to determine your level of commitment

 

Like already said you need drag radials and a dif change. Lean on the converter a little more if you can that should pull that rt down. I personally heat soak the car. I have a converter and gears I’m usually .03-.05 on the lights. Pump the front tires up to max and practice. Nice to see another 12 RT with less then 8k miles out there getting after it lol.

 

Hope this is of some help. First, you need to turn the traction control completely off by holding in your traction control button until it beeps twice (I think it’s twice?). It may have to be in park when you do it? You might want to research that some. When your traction control kicks in, it retards the engine timing to reduce the power and limit the spinning. This slows you down. Your 1/8th mile time should be a lot closer to 9.2 or better. If you don’t at least have Summer performance tires and pretty good starting line prep by the track, you will not get good traction no matter what. If you are going to race regularly, get another set of wheels and drag radials to put on it when you go racing. My 2013 Charger R/T has the same 3.06 rear as yours and gets traction with both tires. If you get any 60’ times better than 2.0, that’s really good for a pure stock car with street tires. You won’t be consistent until you get some drag radials and practice your hole shot. To regularly win races, your reaction time needs to be more like .05 or better and for a 5.7, you need consistent 60’ times around 1.9 or better. I found my best times were just leaving it in automatic shifting in drive and not in Sport mode. You need to power brake it to about 1200-1500 rpm’s and leave when you see the last yellow light. Here’s an example of my best run with a pure stock 5.7 Charger with Goodyear F1 Summer performance tires (around 24 psi rear and 45 psi front) and no modifications. Again, this has the same motor, trans and rear as your car. I think it’s great that you want to race. Have fun and be safe!

 

I don't know if this applies here but with the older cars it's best after a fuse pull to drive some miles and do some spirited driving before heading to the track.

 

I assume the first run 60' was actually a 2.695....and since you have plenty of bracket racing, only you can figure out your staging (deep, shallow, what light to leave on, you already have a handle on that). Saying that, the first thing you have to do on these cars for consistency (and as a result better times) is 17" drag radials. 17s will launch better and more predictable, pretty much eliminate any wheel hop and you wont have to lift on the 1-2 shift because of more hop. Simplest and least expensive single thing to do. If you dont want to change the rear out, halfway through the life of the tires remount them so you can swap what side they go on. They take very little heat for a good bite. But then again I see you trailer your car so you could go for a slick if they are allowed in the class you are running. On a 2012, I would definitely get a tuner if for nothing else than to change the throttle response but also a bonus of picking up a little ET. 2012 tuning is very easy, just a plug in (no PCM swap required like the '15+ cars) Another deeper dive for an auto (I assume you have the NAG 1), is to swap in Mercedes blue top solenoids. The car with shift harder (but not crazy hard for the street) and the shift points will also be more consistent. Not knowing your mechanical ability, which I am assuming is pretty decent with all the racing you have done, to swap those solenoids is little more effort than changing the fluid and filter in the transmission. You just drop the vale body and on the top side swap the solenoids, bolt it back together. Those would be my top 3 for consistency and not bank breakers. Also, if you ever did swap the rear for limited slip and different gears you need a tuner to tell the computer the new ratio, which you would already have. And lastly, keep having fun and welcome aboard.

 

Another deeper dive for an auto (I assume you have the NAG 1), is to swap in Mercedes blue top solenoids. The car with shift harder (but not crazy hard for the street) and the shift points will also be more consistent.

A cheaper option, and almost as good, is a Tranzformer by Z Automotive. It firms up the shifts on the street and you can set it for neck snapping shifts (within the limits of the stock pump's pressure limits) on the track and adjust the shift points too when in autostick mode. Good for about a tenth if you're hitting the rev-limiter at the shift point.

 

Thank you for all the suggestions. As far as spending money on upgrades, i want to go to the 17" wheels and drag radials asap. that's going to have to wait for the time being because of money. lots of good info for future upgrades. thank you.
Might go this Saturday, not sure yet. next trip, Lord willing will be on good prepped track. plan is to try deep staging to try and get RT into the .09 or better. i need to figure out where to stage to get .03-.05 lights. if deep staging doesn't work i'll probable get a pedal commander and try that.

As far as mech ability. i'm ASE certified master tech and run my own shop from home.
His garage LLC. But i don't have much experience with modifying the new cars. really only thing I've done is a PPE programmer on my diesel and that's pretty simple. i worked at chevy dealer about 12 years and did most f the drivabilty and electrical.
Thanks again. updates asap.
Brother in Christ
walt

 

Went to Fayetteville Dragway yesterday. Ran car in drive and left track on and sport mode off. Basically i put in drive and ran it. I did try deep staging (turned prestage light out). this is the way to run a fly by wire car and get a light. at least for me.

1st 2 1R 2R 3R
RT' .2234 .0631 .0105 .0374 .1518
60' 2.6749 2.5885 2.2095 2.5215 2.2891
330' 7.0091 7.1182 5.9489 6.4626 6.0634
1/8 10.2257 10.3713 9.1978 9.5946 9.1968
mph 77.51 77.05 69.47 78.63 74.48

Very happy with RT except of course 3 round. haha. not sure what happened there. i have a couple ideas what i might have done. i'm confident with where to stage car now. Just need more seat time on that part of it.
Both time runs and 2nd round u can see car spun bad and engine management kicked in. it's really had to dial a car that runs that much diff. u can see also that on 1st and 3rd round i was off gas at finish line. very rusty on driving finish line also. in my mind i was asking why am i so far out on them. Never thought about hoe car felt/hooked. All in all it was a good day,learned a lot and have fun.

Now what to do about the spinning. Money is the hold up. i'm sure a set of drag radials will take car of it. I know a posi unit is part of the fix also, but just no way right now to spend that kinda money. diff, axles, drive shaft, tune......Nope.

i will be looking at rear wheels and tires. would lobe to go with 17x4 front and 17x9 or 10 on rear with drag radial. hate to have mismatched wheels but may have to.

thanks.

 

Went to GALOT today. got 1 time run and lost 1st round. learned some more and had fun.

time run 1st Round
RT .124 .156
60' 2.013 2.039
330' 5.664 5.710
1/8' 8.699 8.759
MPH 80.60 80.09

so i learned that for some reason i started just barley deep staging. i had been turning top bulb out and bumping in 1 more time. 3RD last week and again today i was not doing that. I also learned how to get it to hook. I cleaned tires off before pulling threw water box. Pulled all the way to front edge of wet spot, stalled to 1500 rpm, left off the brake and floored gas. I don't have any kind of line lock.
I did turn on Sport mode on and turned traction control off using factory buttons.
Had a good day at the track.
God bless.

 

Are you warming the car up each round or going in cold?

 

I don't have tags or insurance on car. I am running car 10 min or so to get engine up to temp. driving around pits to get everything lubed good. basically same thing i did with my race car. So engine id up to around 210 deg.
thanks.

 

Be couple more weeks before i get out again. Thanks.

 

 

Went to GALOT to try figure out RT. just couldn't get my stuff together till the end. 1 pass they turned tree on before i went deep. Another run i got run with NT so had pro tree. got lots of runs. finial got .02 and .04 lights. learned that if i hot lap car it really slows down. started opening hood to let some of that heat out. having fun and still learning. running GALOT Saturday

and Sunday so we'll see.

 

Not last time at GALOT car ran much faster. Track prep alot better.

 

Pretty easy to wire your fans up on a switch also if you want to cool it down

 

IMO you need to work on your 60' times. Doesn't matter what the 60' number is it must be the same every pass. Make sure you stage in the same spot north/south and also east/west. Tracks have crown to let water run off. The closer to the center line the less roll out will be. Changes in your 60' will impact both RT and ET. Is the car spinning or bogging out of the hole? Are you leaving at the same rpm?

I attached a page from my log book. I was having 60' issues for sure. Turned out that my line lock wasn't fully disengaging. Car didn't spin or bog and I couldn't tell the difference between the "good" and "bad" 60's I totally missed the tree in E1 because I glanced down at the tach instead of focusing on the bulb. I was set up for a .020 light so you can see my variance on the tree. I was deep staged foot braking at 2000 rpm. If I need to go harder on the tree I simply leave at 2200-2300 which is the .00x setting. Of course with my variance the red light will come on 20% of the time.

 

IMO you need to work on your 60' times. Doesn't matter what the 60' number is it must be the same every pass. Make sure you stage in the same spot north/south and also east/west. Tracks have crown to let water run off. The closer to the center line the less roll out will be. Changes in your 60' will impact both RT and ET. Is the car spinning or bogging out of the hole? Are you leaving at the same rpm?

I attached a page from my log book. I was having 60' issues for sure. Turned out that my line lock wasn't fully disengaging. Car didn't spin or bog and I couldn't tell the difference between the "good" and "bad" 60's I totally missed the tree in E1 because I glanced down at the tach instead of focusing on the bulb. I was set up for a .020 light so you can see my variance on the tree. I was deep staged foot braking at 2000 rpm. If I need to go harder on the tree I simply leave at 2200-2300 which is the .00x setting. Of course with my variance the red light will come on 20% of the time.

Yes i agree. i've started doing a light burnout. i know i need to change tire/wheels but just not in budget now. check out intake air temp deference.

 

 

I used my Snap-on scanner to watch ambient temp, engine coolant temp and intake air temp. I remembered reading about how much intake air temp affected fuel injected cars. i see a trend that when temp is low car ran much quicker. running on street tires or maybe not enough drive time yet but i could not feel it when leaving line. But i knew it based on log data. As you can see i took a screen shot when i pulled into water box and again after crossing finish line. I'm thinking when i leave line the heat is effecting engine power and once i get moving the heat is being pushed out/cooler air is going into engine. So i want to try and keep it hot/consistent under hood. i talked with guy whose been bracket racing dodge truck and he basically said he runs his all day. Said some times he will just ride around pits. Don't really want to do that but i'll see.
I am going to look into cooling fan mod.
Thanks for suggestions and following along. Have a good time so far.
God bless
walt

 

I agree about heat soaking for consistency. I don’t ride around all day either but I usually have the car around the same temp before each round. Only time I open the hood run the fans or even throw ice on the intake is if im slow in an index heads up run. Im looking to get out on Saturday for a local race if rain holds.

 

Please check if you have insurance on your car while you are racing. Most insurance won't cover damage suffered while participating in a timed event. That includes a car you may be racing. If you're good to go have fun!

 

Those aren’t bad reaction times. I personally just barely load the torque converter so I don’t spin.

 

Throw some drag radials on the back. Street tires suck and are difficult to be consistent with. Leave on the third yellow. Smile entire way down the track.

 

Yes, as a matter of fact, you could say it's my home track.

Been a while since I've been there. I moved to Florida in 2011. Got to love a track with an ice cream stand in the staging lanes. lol. My home track was Maple, but raced at Numedia, Atco, Englishtown, and Island as well as Cecil.