Exhaust and CAI system slowed car down?

[Hemi Challenger]

Here is a quick question, I bought a New 09 Challenger RT Auto. With it "STOCK" my 0-60 times on the on board computer always showed 5.32 to 5.36 out of a dozen passes. Now I installed a 3" full exhaust and a AFE Stage 11 CAI system, Now my 0-60 times are all 5.86 to 5.89 on 10 passes and that is WITHOUT TIRE SPIN in case someone asks. I don't have the Tune in it yet, waiting on that. Anyone run into this problem? I hate losing 1/2 a second on my 0-60 times. Any info would help.

[1SYCRYD]

My only guess is that the computer has not retuned yet. The exhaust is bigger and if you have better scavenge effect it could be running slightly lean untill it relearns how to run. Reset the computer and try again. This may be solved with a diablo programmer. Also 3" pipes on a 5.7 is not needed, That is just too big, It slows down the exhaust pulses (FLOW/PRESSURE WAVES). Which in turn slows down the engine speed, It helps on the top end but not on the low end, Thats why exhaust size is a trade off on a street car.. Remember we do not have race cars that leave the line at 4000 rpm or higher so you need to keep that in mind when you tinker with FI tuned cars..

[Hemi Challenger]

Reset the computer and try again. This may be solved with a diablo programmer.

I am now waiting for the Diablo programmer, Johan at Diablo told me a few more weeks before they get it up and going for these new 5.7 Challengers Automatics. In the mean time, how do I re set my computer? Thanks again.

[Sublimeon24s]

You probably lost back pressure by putting 3" piping on, which as stated, means you lost low end torque..........I looked into that and was told by 9 out of 10 sources I checked with NOT to go to 3" piping because ill be loosing back pressure and experiencing exactly what you mentioned

[wheelife]

You probably lost back pressure by putting 3" piping on, which as stated, means you lost low end torque..........I looked into that and was told by 9 out of 10 sources I checked with NOT to go to 3" piping because ill be loosing back pressure and experiencing exactly what you mentioned

Yep, I would agree, maybe its time to do heads and a cam to take advantage of the new exhaust..lol

[RT NOMAD]

Another forum dyno'd a Challenger R/T after 3" exhaust and got increased horsepower and torque across all rpm's. They posted curves.

I was doubtful (still have my doubts)

I'm thinking 2.5" might the max exhaust diameter.

[stevesrt8]

This is exactly what happened to my friend with a Charger SRT8. He put on big pipes and an intake, lost time.

You gave up a ton of low end torque. Study Lingenfelter's ideas. That man knew torque personally.

If it's louder it's got to be faster!

[BlackRT313]

Which exhaust catbacks are the best as far as increasing performance and not decreasing it?

[scatpackmopar]

I had a question posed on a different site about my exhaust and the only replys I fot were peoples beliefs instead of facts. So I called the experts [the local muffler shop] They have done several Chargers with the 3.5 and he recommended exactly what I should do and what I should expect. Sounds like you guys are speaking from experience and not just giving your opinion. I like that. [By the way, I wanted an upgrade in exhaust to help improve milage and sound quality from my 3.5L powered 06 Charger]