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5" exhaust = loss of power?

5K views 21 replies 15 participants last post by  stinnett25 
#1 ·
I have an 06 2500 4x4 with the edge juice w attitude, magnaflow 5 inch turbo back exhaust, afe cold air intake stage 2 w pro af. When I first replaced the exhaust, it felt like the truck lost a little low end throttle response. Is this typical of this large of an exhaust? Is there a way to fix this? I have the edge set of 5 and went all the way to 5 on the low fueling to try and overcome the lack of initial throttle response, but it did not feel like it made a difference..........any help any one can offer would be appreciated..........Greg
 
#3 ·
Some people claim to experience some loss in low end power with a 5" exhaust. When I bumped up to a five inch exhaust I did not notice any loss in power but I have a pressure box helping on the bottom end, so maybe that is something you could consider.
 
#5 ·
Our combos are very similar. The addition of a pressure module will definately pick up your bottom end. I have a Striker 2 stacked with my Juice and low end response is excellent. The turbo lights very quickly even at part throttle. The Edge Attitude w/Juice and Striker 2 is an excellent stack. Price is right on the Striker 2 as well!
 
#6 ·
Yea, i would say if you add a pressure box to your set up, (be careful of your tranny) it should bring you back up to where you want to be. Im going to be adding a 5" to my truck but im sure with my Smarty and 3:73 gears im thinking i wont see a low end power drop. (Shouldnt anyway)
 
#7 ·
I did notice a slight low end powerr loss also when I added my 5" system. It does't bother me, truck still screams. I may consider the striker stack setup as mentioned.
 
#8 ·
Well my 5" is on and i actually did notice a bit of a low end power drop. Take in mind i just got my converter, valvebody put in and my Smarty is on #3 with mild TQ management. I going to bump it up to #5 and see what happens. My mid to high range is crazy though.
 
#10 ·
My EGT's went down a bit. And i love the sound which is why i went from the 4 to 5. Over all im pleased.
 
#11 ·
is this a measured loss of low-end power?
because all of the speculation from just seat of the pants feelings really doesnt mean squat except that:
_compared to what your used to feeling_
the addition of the bigger exhaust _feels_ different and the difference is easily speculated away as low end power loss.

A little lesson in biology will remind us that the human body is most adaptable to accomodate a wide range of different living conditions. The entire act of driving exerts g-forces on us from intertia and lateral accel. and decel that we eventually get so used to our minds phase them out as we drive and subconsciously holds are body's still even though we are being tossed about.

holy this is getting long.

the whole point of my story is this: if, with the four inch exhaust, acceleration happened like this
GAS PEDAL - TORQUE CONVERTER STALL - SPOOL TURBO - TAKEOFF
where each moment had its own frame in time so to speak,

your body would than interpret the 5 " exhaust as slower, because it reacts
GAS PEDAL/ TORQUE CONVERTER STALL/ SPOOL/ = TAKEOFF
causing your body to feel the truck reach full acceleration , quicker; with no extra oomph when the turbo comes on because it's already spooled, happening in unison with the fuel being applied and etc.

I learned how not to trust the seat of the pants when fooling around with carbs on my 360 dart.
the edelbrock carb would blow the tires away at 30 mph and slammed you back in the seat when you stepped on it.
my 750 holley with vac secondaries would barely ignite the tires unless you were stopped and seemed like it had 'less' low end grunt
but track times proved the holley was 6 tenths faster just the way they sat.
the reason the dart would blow the tires away with the edel carb was because my foot would go to the floor, the carb would flood the motor and than the motor would catch up, light all the fuel and boom blow the tires away. same reason the holley was faster, the power came on smoothly and cleanly and progressively. felt slower, but our asses are not a dyno
 
#13 ·
OOOOOOOOk........................:thud:
 
#15 ·
Oh, dont get me wrong. I knew this would happen and ive said it before to others. Unless your planning on running high amounts of horse power then you dont need 5" exhaust.

I simply bought mine cause im infatuated with the sound that 5 inches puts out. My power loss can be made up in other ways. Its not hurting me a bit loosing a bit of low end. If it does my REVO can take care of that.:lol3:
 
#16 ·
Until someone puts up a dyno sheet to prove this, I'm not going to believe it. What I did notice is that the truck has a louder engine through the exhaust and the whistle is heard later in the RPM range because it is drowned out. This can cause the brain to think that it is not going as quick because you listen for that turbo to whistle, and associate it with going fast. There is no reason at all for a 5" exhaust to be slower than a 4", the only difference is EGTs and noise. The brain can do more than you think, I deal with it everyday in Olympic Shooting --- it can be very deceiving.

Zach
 
#18 ·
The brain doesn't control 1/4 mile times. You loose between 2 and 3 1/10ths in the 1/4 if you go from 4 inch to 5 inch without making any other changes. You will see the time difference in the small end of the track. I put 5 inch on my 05 and went right back to 4 inch and got my times back.
 
#19 ·
5" is definately ideal for running higher horse power.
 
#20 ·
what would you consider "higher horse power"
 
#22 ·
Higher horse power like maybe in the range of 200+. Its not an exact science and im not a professional but thats just my opinion. You get into bigger turbos and such then they will like the bigger exhaust to breath out of. Im sure they will do just fine on 4" though.
 
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