Join Date: Feb 2014
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I just installed the comp cam 274 with all supporting mods: pushrods, Springs, retainers, brand new gaskets on everything that was touched, and new lifters. However after getting a start up tune from Johan, my challenger was surging and idling rough and if I revved it up it would stall once the RPMs went down. After a few revisions from Johan, I was able to get it idling better and more consistent, I could even hear the cam lope. I took it for a ride to data log and I was very disappointed; when accelerating through all the RPM ranges it almost felt like it wasn't getting enough fuel from about 1k to 4.5k RPM. I knew I wouldn't gain much torque in the lower RPMS with this cam, but it seemed like it was getting less power than before the install. I believe this has a lot more to do with the tune than the cam, but it is concerning. I talked with the mechanic who installed it and he assured me that he made sure everything was installed correctly. I want to dyno tune eventually, but I was hoping that Johan's tune would at least hold me over. What are y'alls thoughts? My only other mod is catless midpipes. Also, what mods can you do to the 5.7 to increase low end torque? I know about the 392 intake manifold active runners mod but what else?
1. Ditch Johan's tune. Since he left Diablo, he isn't the same tuner. Get with Mike @ OST.
2. In all honesty, the 274 is much too large for the 5.7L. Your already there though, so lets make the best of it. You really need long tubes with that cam. That cam has some overlap and the long tubes will help scavenge and bring back some low rpm torque.
3. Is your car an automatic? If so, then I'd look at 3.90 gears or a stall. The active power for that cam starts at 2,400 rpm.
A better tune will absolutely help for the time being.
2015 Phantom Black Scat Pack A8
Hotchkis Springs, Petty Front Strut Brace, Solo X-Pipe Street Race Exhaust, JLT Intake,Katzkin Leather, Hurst / Racing Brake 2-Piece Rotors, Spohn Rear Swar Bar links, Spohn Rear Trailing Arms, Bob's Catch Can, Diablo Tune and PCM, Jet 180* Thermostat, Peak Speed Ported Manifold / API 88mm TB, Kooks Long Tubes w/ Green cats
11.693 @ 120.11 - 1.727 60 ft (before headers)
Coming soon: Comp 270 w/ springs, HHP/BES Heads and DTP tune