Dodge Challenger Forum banner

Dazed & confused on MPH

2K views 9 replies 8 participants last post by  EricG 
#1 ·
Hey people, I am an old school drag racer from the 90's. Had a Fox Body with carbs and a Jerico crash box that ran 8.90's. Currently I own a '16 SRT 392 A8 Challenger.
Been to ATCO twice so far. Best pass was a 12.11 @ 113.80 mph. I feel the mph is down for the ET. Using Nitto DR's 315/35 20 with 27lbs of air. My 60's have all been in the 1.7 range. Best being a 1.739,but that didnt come with the best ET of 12.11.
My question is this.....I have found that if I turn of all traction control including stability control,it is prohibiting the launch control from activating. Am I missing something here? I need the SC off to do my burn out.
My best 60' was with SC off, but I had to flat foot it out of the gate. That netted a 12.15 @ 113.62 with the
1.739 60'. I made another pass same pressure in tires power braked it to 1000rpm and it gave me the 12.11 with a 1.788 60' at 113.80
All ET's were in the 12.1 range 12.15 being the slowest. All mph's have been in 113 area.
My '11 Vette went 12.09 @ 117.00 mph. My '15 C63 AMG 507 went 12.16 @ 117.5. This is why I am confused with the SRT's mph.
I looked at the posted ET's for the 12 second club and I am off quite a bit. Only mod is a Hellcat CAI.
Anyone have some input on the mph issue?

Thanks, John
 
See less See more
#2 · (Edited)
2015 Scat pack A8. I have the same problem. My best 60 foot was not my best ET and vice versa. My best 60 foot and ET was on the foot brake. My times and mph is exact as yours with the same mods and same issues with launch control. But I have the 305/35/18 Mickey Thompson street SS's which are 26 tall so I thought that was the problem but then I looked at everyone else's mile an hour and seen it's pretty close to being on point. My guess would be the aerodynamics of the car.
 
#4 ·
What did those other cars 60 foot? Are you comparing those?
I had a 2015 SRT 392 and I probably put 300 passes on it in 11 months. My best 60 foot ever was a 1.675. I had lots of 1.69's and 1.70's . But in the summer when the DA sucked they could easily be in the high 1.70's. I will tell you that the 8 speed auto is why this car ET's so good for the MPH it runs. Plus aerodynamics might be part of it.

I would think you would know if your car is spinning or not.....but I would be running 18-20 PSI in those tires. MAYBE 22 if I was at Englishtown or Atco or somewhere where the prep is exceptional.

Launch Control cannot be used at the track because you will not be able to get it set up in time. If you get on it at the pre stage you cannot bump the car in to final stage. So forget it once and for all. I NEVER used it.

You want to run in SPORT mode. It will let you burnout but will not change your ET one bit. Set your custom setup as follows in the SRT pages.

Traction : SPORT.
Suspension : STREET.
Paddles : ON.
Transmission : TRACK
Steering : Your Choice

Start car, Put trans in MANUAL using the shifter, Quickly Double tap the SRT hard switch (puts you in custom mode), roll out to the bleach box and stop, pull the right paddle, verify 2nd gear and 2 warning lights on in dash, do a good smokey burnout when motioned to by track officials, PUT TRANS BACK IN DRIVE, Stage, Race (sorry Camaro).

Also you will 60 foot better flashing the converter. BARELY power brake it up to about 900 RPM (just enough to take the slack out of the drivetrain), STOMP the throttle when you hit your spot on the Tree.

ALSO, do NOT put a bigger throttle body on your car. It will kill your 60 foot and trade that for a little MPH. But your car will ET the same.

Easy, no?

.
 
#5 ·
Mph=hp

MPH = HP. If you are getting the MPH then you have the HP to run. My last time in Vegas (Hot) I was running 12.5's and 135 MPH. My best 1/4 mile time 10.92 at about 128 MPH in Billings Montana with less HP. You may have trouble getting out of the hole for what ever reason, but if you have the HP and Torque you will get the MPH at the end of you 1/4 mile..
 
  • Like
Reactions: RNashCPA
#8 ·
My MPH varies from 114 to 118 and I really dont know why since my times are mostly low 12's. I do know since I went to 17" slicks that my MPH should drop a bit but I still really dont know where the 4 mph went?? Im with you on this OP.

My guess is temperatures as I ran higher trap speeds in cooler weather and they have gradually started to drop with the warmer temps now.
 
#9 ·
Sounds to me like you are doing everything right; my absolute best in my 2015 Stock SRT is 11.936 with a trap speed of 115.02: 60' was 1.713 on a cool January afternoon.


113 is pretty avg for the trap speed; not too shabby for 4,500 lbs of steel and flubber ((including driver)) lumbering down the straight a way.
 
#10 ·
You're seeing the overall effect of weight versus horsepower, and our low end torque is also on display. Our cars really do pull well from 0-100, we can keep up with a lot of high-power cars around town...makes it fun :). Our torque and 8-speed autos feel similar to a high-power turbo diesel truck, you gotta love that forward surge at all times - plus we have that high-rpm pull and sound!
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top