Dodge Challenger Forum banner

1 - 18 of 18 Posts

·
Premium Member
Joined
·
382 Posts
Discussion Starter #1 (Edited)
A little background first: Mine is a 2019 G/T Plus RWD. Prior to the gear install I had installed Flowmaster 3 chamber mufflers and ended up settling on a Mopar Performance cold air kit, aside from those 2 things the car is all stock but did have a 3.08 open rear end. In cold air one night I was able to get a 6.0 0-60 and 14.6 @ 97 1/4 going by the performance pages but was never able to repeat that. In current air temps (about 60-65 degrees) I was getting 6.3 to 6.4 0-60 times.

I found a 3.90 diff with axles on e-bay from a totaled 2016 Shaker for $789 with free shipping, so I bought it and not wanting to do this on my back in the driveway paid to have the install done - it took the shop about 4 hours on a lift. No computer mods or other work was required beyond the install of those parts. Apparently the computer now gets vehicle speed from the wheel sensors, so there was nothing to do regarding the speedo - speeds are still correct.

My best 0-60 so far in equal temps (it was 61 that evening) is 5.8 seconds - .5 to .6 seconds quicker. I haven't been able to check 1/4 mile times yet. Mileage did drop a little bit, but it's still averaging 30-31 cruising @ 65 and that's not on flat ground. At 55 it will get 36-37. Climbing rolling hills is MUCH easier. Before on rolling hills at a 65-68 mph cruise, the instant mileage would drop to low teens but it's now high teens to 20 mpg instead. I credit the extra toque multiplication of the gears for this. Climbing steeper hills or bridges is also greatly improved and it no longer drops down a gear or two to maintain speed. Punching it at 65 on level road and counting one thousand one, one thousand two gets me to 83-84 mph - passing on the highway is certainly no issue :)

The only problem I've found is that hammering the throttle at low speed - say under 15 mph - gets a drop down to first gear which pegs the tach (not sure but it might be breaking the tires loose), the rev limiter kicks in and it falls on its face, then it upshifts and goes as expected. I think this is a programming problem that can be fixed with a tune. Later down the road I'll do that and also make sure to include tuning for the other mods.

My goal was to get sub 6 second 0-60 times, run at least 100 in the 1/4 and if possible break 13.99. Just going by what I have so far I think this will do that and a tune should certainly put me at or better than my goals.

Oh, and yes, it will now light BOTH tires - time for stickier, wider rubber than the stock 20" Goodyears.

PS, one thing I forgot to mention: When driving like a "normal" car, it goes into 2nd at 5 mph, 3rd at 10, 4th at 15, 5th at 20 and into 6th just past 25. It's pretty funny how many shifts it does at such low mph.
 

·
Registered
Joined
·
1,470 Posts
Hot Rodding at it's finest. That is a great mod and money well spent for the gains. If you are spinning traction might be all you need to get those times you are after.Put some 315/35/20 on the back and try again for the 13 second times.
 

·
Registered
Joined
·
440 Posts
Interesting..this is the first confirmed installation of a 230mm LSD ZF differential in a 6 cyl car that I've seen . I installed a 3.90 LSD in my A8 Scat 3 years ago and it was a blast on the street. FI now so 3.90 came out and back to 3.09
 

·
Registered
Joined
·
13,727 Posts
Nice write-up!


Does your car have 18s or 20s?
All GT RWD come with 20's.



Interesting..this is the first confirmed installation of a 230mm LSD ZF differential in a 6 cyl car that I've seen .
You can get it factory installed by ordering a GT with the Performance Handling Group. It will have a 3.09 not a 3.90 but will be LSD and the same 230mm from the Scat Pack.




Sent from my SM-N960U using Tapatalk
 

·
Premium Member
Joined
·
382 Posts
Discussion Starter #6
OP, hows the acceleration when driving regular? i.e. not flooring it?

Does your car have 18s or 20s?
I have the light 20x9 wheels. Regular driving is a blast, especially in sport mode. The closest I can compare is acceleration is close to (but still better than) 1 gear lower than the gear you're in - keeping in mind I already had 3.08's. So, my acceleration in 3rd feels a little better than it did before in 2nd, etc.
 

·
Premium Member
Joined
·
382 Posts
Discussion Starter #7
981637
Nice write-up!



All GT RWD come with 20's.




You can get it factory installed by ordering a GT with the Performance Handling Group. It will have a 3.09 not a 3.90 but will be LSD and the same 230mm from the Scat Pack.




Sent from my SM-N960U using Tapatalk
They had other GT's on the lot that DID NOT have 20's
Mine DOES have the Performance Handling Group, but had the 195mm ring gear.
 

·
Super Moderator
2016 SXT Plus Blacktop
Joined
·
13,576 Posts
Were they RWD GT's?

A Guy
 

·
Registered
Joined
·
13,727 Posts
View attachment 981637
They had other GT's on the lot that DID NOT have 20's
Mine DOES have the Performance Handling Group, but had the 195mm ring gear.
Yes you are right, no 230mm or LSD on GT even with PHG, that would have been cool to have. So guess still no LSD with a V6. But all RWD GTs should have 20's, the AWD GT will have 19's. Only RWD SXT should have 18's now.




Sent from my SM-N960U using Tapatalk
 

·
Super Moderator
2016 SXT Plus Blacktop
Joined
·
13,576 Posts
I was replying to mcm95403 saying there were GTs on the lot without 20" wheels ;)

A Guy
 

·
Premium Member
Joined
·
382 Posts
Discussion Starter #15
Yes you are right, I should have looked at the guide a little closer.



Sent from my SM-N960U using Tapatalk
Yeah, pretty crazy that mine has Performance Pages and launch control but no LSD from the factory.
 

·
Registered
2016 Jazz Blue A8 Scat
Joined
·
603 Posts
Following for 1/4 mile timeslips.

I rented a Charger GT recently and was impressed eventhough it only had the 2.62 gears. 3.90 or 3.70 gears would be the first thing I would do to a 3.6 car!
 

·
Premium Member
Joined
·
382 Posts
Discussion Starter #17
Following for 1/4 mile timeslips.

I rented a Charger GT recently and was impressed eventhough it only had the 2.62 gears. 3.90 or 3.70 gears would be the first thing I would do to a 3.6 car!
I had a chance last night to pull over on the freeway and make a run. I only got a 5.9 0-60 and 14.4 @ 97 1/4 mile. I hate to say it but I really am starting to think that it needs a tune to deal with the intake and muffler changes.
 

·
Registered
17 Challenger SXT
Joined
·
4 Posts
Follow the build on ....
instagram : @Project_slow_six and YouTube: Project Slow Six

I never had a chance to test mine N/A. I swapped in a 3.70 manual hellcat diff and 230mm axles Dec 2018 after I was boosted though. Went from a 2.62 open diff....ran a 12.3 in the 1/4 mile with the 2.62 open diff. on the stock 17" Michelin's peddling it off the line.
 
1 - 18 of 18 Posts
Top