Dynomax Race Bullets: COMPLETED

[Horse]

Exactly. At max I cut 15-20lbs with my new exhaust. What's even more crazy is that before when I did my 0-60 on OEM mufflers it would chirp the tires on launch with traction control off. Now, tonight when I did my updated run this car fully excitued a burnout with some sideways action before straightening out and chirping into second gear. It is absolutely crazy the apparent gain in power from just a muffler change.

Did you time your 0-60 run while you were having muffler delete? I can not help wondering whether that would give you even more power.

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[zackmd1]

Did you time your 0-60 run while you were having muffler delete? I can not help wondering whether that would give you even more power.

I did not...

So an updated driving report....

Dorne is terrible at 2k.... Very disappointed with this. I am going to try some new clamps this weekend as I have a big leak through the band clamps. This might help some but I am not expecting much. Would anyone here have any suggestions for curing most of the drone without having to change mufflers? I have been contemplating a center resonator delete but I do not think I want to go to this extent yet. If I were to change mufflers I am thinking about going with a 2 chamber muffler. I just don't know if this will help the drone that that resonator is creating...

 

[zackmd1]

Well I just ordered a throttle body spacer from AM on a whim. Read a few reviews that stated that it actually helped with their exhaust drone. Don't know how much of this is true or if it will apply to me but it's cheap with my gift card. We shall see...!

 

[Reaper]

Well I just ordered a throttle body spacer from AM on a whim. Read a few reviews that stated that it actually helped with their exhaust drone. Don't know how much of this is true or if it will apply to me but it's cheap with my gift card. We shall see...!

I used a throttle body spacer on my last mustang after adding a Flowmaster and it did seem to help slightly although it might have been a placebo effect. Certainly let us know if adding it helps with the drone or at least smoothens the RPM climb.

 

[zackmd1]

So I might have discovered a way to curb my drone problem without effecting back pressure or changing mufflers. I am going to create a resonator tube between the muffler and the exhaust tip that tuned to the right length should create a sound wave to cancel out my 2k drone. It's called a 1/4 wave resonator tube or a Helmholtz resonator. Using a few equations from physics II and some assumptions on the speed of sound at operating temp I have determined the length of tubing needed for each muffler. I need to figure out how to fit 33" of tubing perpendicular to my exhaust flow.... This is going to be a fun one!

 

[zackmd1]

Updated OP with new video

 

[zackmd1]

Update on the drone situation....

Throttle body spacer showed up today so I went ahead and got it installed. I did help with the drone in a number of places. Mainly at cruising between 60-70. 2k drone is still there though. It might have actually made it worse but not by much if any. Looks like my resonator idea is next on the list. Hopefully I can get the drone to manageable levels because I love the exterior sound.

 

[Reaper]

Update on the drone situation....

Throttle body spacer showed up today so I went ahead and got it installed. I did help with the drone in a number of places. Mainly at cruising between 60-70. 2k drone is still there though. It might have actually made it worse but not by much if any. Looks like my resonator idea is next on the list. Hopefully I can get the drone to manageable levels because I love the exterior sound.

Great, maybe the drone will also decrease a little overtime after break-in.

I know its hard to quantify any real world gains with a spacer but did it give a feeling of better acceleration and/or power?

 

[zackmd1]

Great, maybe the drone will also decrease a little overtime after break-in.

I know its hard to quantify any real world gains with a spacer but did it give a feeling of better acceleration and/or power?

It is really hard to say at the moment as I need to get a few more miles on it. Initial impressions are that it finally seems to get the automatic transmission in sync with the engine. (ie it finally seems to downshift correctly with throttle input) This I believe has a lot to do with the improved throttle response from the spacer. So based on initial impressions, it is good improvement for many things but not something I would spend $100 on. We shall see if I see any improved milage with the spacer.

 

[zackmd1]

Drone situation update....

No more drone!!! My resonator idea worked! Eliminated drone by about 90-95% without effecting exterior volume. Pics of my setup below!

Ps: no making fun of my welds..! haha first time I have welded stainless.

 

[zackmd1]

Updated with bill of materials and interior video.

 

[Reaper]

Nice job Zack, sounds pretty awesome!

 

[jmstang66]

as a guy with a 12 3.7 I am very impressed! Exhaust for these cars that doesn't sound like a freaking tractor is hard to come by..sounds great Zack!

 

[Runner12]

Good work on all of your videos and pictures, very detailed and sounds great.

 

[iBookmaster]

Great job, sounds nice!

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