this could be completely normal on these trucks but it sounded funny. I have magnaflow exhaust on my truck and if i punch it and hold it, right when it shifts to second gear it sounds like the exhaust makes a really loud almost fart like noise haha...i dont know if this is just the slip between gears or what but when my girlfriend was in the car she was like did something just break and i was like no i think its just the exhaust...but it kinda scared me haha...my truck is in the sig lmk if you get the same thing

 

I have never noticed anything like you describe. Your going to have to be more discriptive about the noise since there are at least 10 different fart noises ranging from SBD's( Silent but deadly) to screamimg wet paint peelers.[sm=smiley2.gif]

My guess would be that during the shift, perhaps some combustion was still occuring in the exhaust manifold. It would make a popping sound.

Not to be confused with a pooping sound that could involve the previously mentioned fart noise.[sm=smiley4.gif]

 

Your not completely alone, i just got my Dynomax muffler put on, and it to does the same thing. At 5900 rpm on the 1-2 shift, and a small one on the 2-3 shift. I thought it might have been my choice in muffler, but now i read of a complete different brand doing it also. I think it comes from teh slop in the tranny on the shifts.. how many rpm it takes to do a gear change. BUt.. im not certin

 

shoulda gotta 40 series , flowmaster.

 

haha its definitely not the silent but deadly, its not so much of a pop, im pretty sure its just the time between the shift, i didnt want the flowmaster because it resonates and doesnt sound as clean IMO but its all personal preference...anyone notice this with theirs?

 

So your truck fart between gears. LOL That's a great sound, and typical of low back pressure exhaust systems. My Corsa, which is equivalent to a straight pipe behind the cats, does the same thing: Buuaaaaahh-rip-rip-rip-Buuaaaahhh The drop in rpms during shifting causes a decrease in exhaust flow speed which results in an expanding flow in the exhaust sytem.

 

Mine farts. My kid brother thinks its hillarious!!! Does it when i hammer it from a dead stop and hit the 1-2 shift.

 

so does that mean i dont have enough backpressure? Or just that i have a low backpressure system?

 

anyone at all????

 

Exhaust popping in between shifts or upon deceleration merely indicates a low backpressure system. It does not mean you have a problem with too little backpressure. Backpressure is a funny thing, there are some who seem to feel the less the better, and others feel that today's engines need backpressure to operate properly and scavenge. Ultimately the truth is that you dont really have to worry about having too little backpressure unless you run straight pipes with no muffs at all, or duals that are the same size as your single stock pipe was. EG, if your stock piping was 2.5" or 3", and you go with 3"in, dual 3" out, obviously you have more tube diameter going out then you have going in, this will often lead to atmospheric pressure causing air to rush backwards into your pipes. I seem to have rambled off topic, but either way you have nothing to worry about.