[alexandertg4]

So I had some GSC S2 cams installed and noticed that when the car is cold, the car shudders when trying to go over 2k rpms. Is this normal of cars with cams or is something wrong with either the install or tune? The car doesn't throw any lights and the AFRs seem to be within tolerance but the car is definitely not happy. When the car is warmed up, it runs perfectly fine and made 380whp on a mustang. I have no idea what's going on and my tuner says there is nothing he can do to improve it. The car runs perfectly normal when warmed up and makes great power. The problem only occurs when the car is trying to warm up (ie. the idle is higher than normal).

 

[HappyMint]

I don't know what your tune looks like, but there are Mivec and other various maps that are for when the car is below "Normal Coolant Temp" and when it is actually the correct temperature. Perhaps those maps need to be adjusted if they haven't already so the car runs correctly while it is still warming up.

 

[alexandertg4]

Thanks for the reply, I talked to a couple of other tuners and they said with ECUflash, its normal with big injectors and big cam.