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Discussion Starter #1
392 TA A8 with Nitto 555R 305/45r18's (stock fronts). I can't seem to get out of the 1.8's for 60 ft times. I've had the pressure as low as 18 psi. I leave off idle and still get tire spin and hop. I heat the tires up in 2nd at about 5k rpm for 2-3 seconds (see good smoke from tires). Any suggestions would be appreciated. I'll attach a few time slips from Bradenton a few weeks back. My 60' times at the 1/8th mile in Pinellas are about the same.
 

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One thing to check is to see how others are doing at the track with somewhat similar set ups on that given day. I am often in the 1.8’s with my MT radials and was very frustrated until I started comparing 60ft Times with others running late model street cars and realized by 60ft Times were often really good in comparison (maybe we are all bad drivers) track prep is often the culprit.

However you can go down to as low as 15-16 pounds and start working up
From there. What RPM are you launching at? Are you rolling onto the throttle or hammering it. I believe your first gear is extremely steep.
 

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Last time out I ran 18 psi , a decent burnout after the box and I brake torque up to about 1700 give or take. Getting pretty consistent 1.6x. I haven’t had any wheel spin at all at the two tracks near me(Long Island). If you’re spinning I’d say it’s prep.
Oh, my bad, 2016 charger scat, long tubes ,Lmi,and tune.


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Discussion Starter #4
Flooring it from idle on the 2nd light...afraid to brake torque it or use launch control since I have no traction off idle.
 

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No experience but word is for the A8 a very quick launch technique is to leave in 2nd gear and once underway then move the shift lever over to automatic mode and let the transmission make the up shifts.

Look for a video on which an automatic Hellcat is pitted against a 6-speed manual for some tips on launching the A8 Hellcat.
 

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No experience but word is for the A8 a very quick launch technique is to leave in 2nd gear and once underway then move the shift lever over to automatic mode and let the transmission make the up shifts.

Look for a video on which an automatic Hellcat is pitted against a 6-speed manual for some tips on launching the A8 Hellcat.


There is absolutely no reason to start in second at a prepped track with an a8 and 3.09 on a stock 6.4. I smash it in first with zero wheel spin. I didn’t even start in second when I ran the 3.70. Only reason a went back to 3.09 was bad wheelhop shifting into second


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maybe get a better grip on your tire pressures, each car is different, find a location that you can play with tire pressures and very small burn outs and have air handy to air up tires, you can do just a little power brake with say 10 psi in the tires, you want to confirm cupping of the tire,you will see two dark black marks on the edge of each tire. you want to add air to the tires til the middle darkens up and your getting the same amount of rubber burned off. this would be the best pressure hot. then let the car cool over night and take a cold measurement of the psi and equalize each side to read the same cold psi, you want to make sure there is no sun beating down on your cold pressures. for example a cold pressure of 27 psi would be 31 psi hot.

The other way, air up your tires to say 40 psi do a small burn out and confirm how narrow your black mark is and measure it if you want, then drop down your pressure 5 psi and repeat, then drop down another 5 psi and repeat, I say this to get a person into a rhythm so they know what they are looking at, as you drop the pressure you will notice the width of the black mark is getting wider and pretty soon you will see there is no more width to gain you will reach the edge of your tires, once again once you have the same amount of rubber coming off the tires all away across you have reach your lowest psi hot.

use of a laser temp gun is useful to, it's worth the time to get your hot and cold pressures, so there is no guessing, you know for 100% your getting all the tread down to the ground and doing it evenly. I would venture off to say there might be a handful of folks on this board who put in any time to find the correct air pressure for their tires to launch.

I had my 275 mt drag radials and they gave me everything they could at 18 psi cold on a 9" wheel, that is for my car and weight and set up. I was cutting 1.78 60ft times with zero spin, full throttle launches, my car had nothing more to give, so there was no way to get a faster 60ft than this, unless I changed something like more gear or stall or found more power or lost some weight or one hell of a cold front move thru.

I did some tire pressure adjustment today on my srt, I lowered the pressure on my 275 tires on 9.5" wheels, I let air out till my black marks couldn't get any wider and I could see where the tires was burning out to the edges of the tires, I reach 8 3/4" of tread width and my little piles of rubber was pretty even, so for this set up I want to run at most 31 psi hot. I might take the car out tomorrow and drive it and get the tires heated up and bring it home and do a few burn outs and check the temp across the the tread and make any final adjustments if I can go down any.

This just shows you, two different cars, two different weights, two different wheels and brand of tires have there own psi for max tread width.

Back in the days I ran slicks, i would have about 7 psi in my slicks and do a small burn out ( really dark black marks on the outer edge of the tires) and add air til I had even colored blackness across the concrete. this was my tire pressures which many times would be 9-11 psi in the slicks I ran.

the idea behind coming from low pressure is to establish the maximum width of the tire tread that will contact the ground and only add enough air to fill in the middle without loosing any of the width, this is really easy to see, it can be a little tougher to air down from max pressure because you may not be sure how wide you can go till you get to dark edges, then you know you aired down to far.



hope this helps.
 

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Hitting the gas off idle is your problem. The resulting spin/hop/bog/hook and go is really hurting your e.t.s too no doubt.

You need to build the revs a little while holding the brake, then quickly(but not instantly) press to full throttle as you let off the brake and roll out. You should be able to feel the weight shift which helps with traction. Really quite easy once you get a feel for it...

While the Nitto 555R's are not nearly as good as the Mickey Thompson E/T street SS radials, they still bite pretty good after a burnout.
 

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I would say its the nitto's.
See what they feel like after a burnout. Are they sticky to the touch? If not that might be your problem. The tires will lose their grip after a while.
 

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There is absolutely no reason to start in second at a prepped track with an a8 and 3.09 on a stock 6.4. I smash it in first with zero wheel spin. I didn’t even start in second when I ran the 3.70. Only reason a went back to 3.09 was bad wheelhop shifting into second


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Except the OP reports he's not leaving well on a (presumably prepped) track in 1st gear. Wouldn't hurt him to try the 2nd gear start. If it doesn't work then he knows and can consider other things.
 

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Need launch advice
8spd 2016 challenger 5.7
over 600 Procharged hp
SRT LSD
Nitto G2 275/40 back Stock front 35 psi x 4

Which works best
Traction control on or off?
Auto or manual shift
Launch RPM ?

Car wants to put me in the ditch
Best 0-60 4.7 s
What am I doing wrong?
 

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Need launch advice
8spd 2016 challenger 5.7
over 600 Procharged hp
SRT LSD
Nitto G2 275/40 back Stock front 35 psi x 4

Which works best
Traction control on or off?
Auto or manual shift
Launch RPM ?

Car wants to put me in the ditch
Best 0-60 4.7 s
What am I doing wrong?
IMO too much power for the nittos. Go to M/T "R" or straight out drag slick.
 

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Discussion Starter #13 (Edited)
I run the Nittos (555r's) at 20 psi at the track. Traction control off, sport mode on, let it shift for itself. Getting better with the launch but I do plan to try the Mickeys next. They've been prepping the track much better and I've been able to foot brake it to about 2k rpms for launch a few times without losing traction.
 

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Need launch advice
8spd 2016 challenger 5.7
over 600 Procharged hp
SRT LSD
Nitto G2 275/40 back Stock front 35 psi x 4

Which works best
Traction control on or off?
Auto or manual shift
Launch RPM ?

Car wants to put me in the ditch
Best 0-60 4.7 s
What am I doing wrong?


You really need M/T drag radials to have any chance of putting 600hp to the ground. Full street tires suck on most cars with 400+hp. Why spend 8-10k on a blower build only to get beat by much lesser cars at the track because you are woefully under tire’d. Hell my heads cam stalled c6 vette only had 460rwhp(my ls2 only put own 332 bonestock) and drag radials made a huge difference. I could only imagine if I had another 140hp!

Even nitto drags make a pretty good difference over street tires and they are decent in the rain, just not deep standing water. I daily drove nitto and Toyo tq drag radials on my vette through four summers. Torrential downpours and standing water was a bit nerve racking to drive in/on though.


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You really need M/T drag radials to have any chance of putting 600hp to the ground. Full street tires suck on most cars with 400+hp. Why spend 8-10k on a blower build only to get beat by much lesser cars at the track because you are woefully under tire’d. Hell my heads cam stalled c6 vette only had 460rwhp(my ls2 only put own 332 bonestock) and drag radials made a huge difference. I could only imagine if I had another 140hp!

Even nitto drags make a pretty good difference over street tires and they are decent in the rain, just not deep standing water. I daily drove nitto and Toyo tq drag radials on my vette through four summers. Torrential downpours and standing water was a bit nerve racking to drive in/on though.


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How many miles were you getting out of the DRs on the street?
 

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I’ll second the MT’s (SS or R). I run the SS but will try the R’s next.

Case in point, last week a Hellcat and I lined up, my 60 was 1.769, his was 1.840… Im on MT SS and he was on the Nitto’s. Another buddy who's PB was 10.7 with a 1.603 60ft runs the MT R’s and swears by them.
 

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Need launch advice
8spd 2016 challenger 5.7
over 600 Procharged hp
SRT LSD
Nitto G2 275/40 back Stock front 35 psi x 4

Which works best
Traction control on or off?
Auto or manual shift
Launch RPM ?

Car wants to put me in the ditch
Best 0-60 4.7 s
What am I doing wrong?
There seems to be a problem here..."Nitto G2 275/40 back Stock front 35 psi x 4"

1) You're running 35 PSI in the rear???

2) Those Nitto are not Drag Radials, there street tires.
3) With that power a little more tire width on a wider wheel, would help, along with the proper tires and pressure.
 

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I ran a few weeks ago in my 17 A8 392 stock with just the 18" bravados/MT ET street Rs in the rear. The 305 ones. No matter how I launched, 1.80 was the sixty.

I tried off idle matting it, same. I tired 1500RPM then matting it, same. Even at the limit of the converter to where the car was starting to creep, and still pulled the same 1.80 sixty. Not sure what else I can try.

The MTs were at 20 PSI. They stuck like glue, not a hint of wheel spin off the line or in any gear. Me thinks that 1.80 might be what they all do give or take a 10th, in the stock setup with a tire. See my videos attached. The first one I brought it up off idle a bit. The second one I was at the limit of the converter.


 

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Some folks have done better than 1.8s "stock".


<- tells some things he did.

I think Lonnie is on here as Evil87GN or something like that.

And I think cdahl383 has done better than 1.8 too.
 
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