Not happy with exhaust

[White ls400]

I just had a twin 2 1/4" twin system put on my ls400 and for starters no x pipe was used and secondly the guy who i asked to do it said hed put the mufflers up front resonators at the back but the other dude put the resonators up front and the mufflers at the back would this be the reason the car sounds roughly a cross between a subaru boxer motor and a small truck?
Also when adding an x pipe i know it will make it quieter but would it quiet it enough to be under 90db if i took the mid resonators out and just left the 2 oval mufflers at the back and yes i do know that all mufflers arnt the same but i only need a rough indication

 

[ABDULLAH D AFGHAN]

Hello I feel ur pain. I redid the back half of my exhaust too and Im not too happy. It isnt loud as i wanted it to be plus i have some sort of leak upfront Im not sure if its EGR leak or Exhaust manifold gaskets or who knows. Anyways here is the thread on my exhaust
http://www.lextreme.com/forums/showthread.php?t=8895

 

[JBrady]

I just had a twin 2 1/4" twin system put on my ls400 and for starters no x pipe was used and secondly the guy who i asked to do it said hed put the mufflers up front resonators at the back but the other dude put the resonators up front and the mufflers at the back would this be the reason the car sounds roughly a cross between a subaru boxer motor and a small truck?
Also when adding an x pipe i know it will make it quieter but would it quiet it enough to be under 90db if i took the mid resonators out and just left the 2 oval mufflers at the back and yes i do know that all mufflers arnt the same but i only need a rough indication

The tone of the sound is due to no crossover. Installing a Y pipe, X pipe or H pipe will change the sound dramatically.

As far as the placement of mufflers vs resonators... yes, that will also effect the final sound but it is the crossover that I would address first.

Maybe you did not notice but I have been recommending that most NA applications keep the stock Y pipe. It is dual 2" (actually 1.97", 50mm) mandrel bent stainless tube. The Y is formed as a good merge collector and the single pipe is 2.36"/60mm. Removing the center resonator or cat and replacing with a 2.5" pipe and or resonator is a good choice.

Since yours is probably cut and thrown away you will want to find or build a quality crossover. Search my posts for lots of info on this subject.

 

[JBrady]

Hello I feel ur pain. I redid the back half of my exhaust too and Im not too happy. It isnt loud as i wanted it to be plus i have some sort of leak upfront Im not sure if its EGR leak or Exhaust manifold gaskets or who knows. Anyways here is the thread on my exhaust
http://www.lextreme.com/forums/showthread.php?t=8895

Sound is a tricky thing. Looking at your thread you have a single 2.5" resonator in the single pipe of the Y pipe. You modified the stock Y pipe per my suggestion. Good work there. You had a nice Y made to split the pipes back into dual 2.25" pipe that you had crush bent. The installer put a bunch of bends in the system.

In your thread you state that it is hard to tell a performance change. I take this to mean that you did not loose low end torque. Often when people go with too large of pipe (not you, yours was well chosen) they loose low end. This softer low end makes it feel like it pulls harder on top because of the contrast when in fact they usualy do not gain top end just loose low end.

Now, you stated it was not loud enough and now have a leak. Definitely have the EGR checked out. To make it louder you could remove the second pair of resonators and have straight pipe added. Should be cheap to do, like $50. Still not loud enough? Do the same to the center.

Now, unwanted noise in the cabin is usually harmonics known as drone. This is tougher to deal with as exhaust systems work like wind musical instruments. A small change can make a big difference.

On my LS400 I used to remove the rear mufflers. This left the rest of the mufflers, cats and resonators in place. No power gain to notice but sound was noticable but only under acceleration. No problems with cruising drone.

 

[ABDULLAH D AFGHAN]

JBrady Im gonna need those headers from you. I lost to an Oldsmobile Alero!!!

 

[White ls400]

y pipe was badly damaged thanks too underestimating how low my car is
would it end up way too loud if i delete the resonators after putting a xpipe in or would the xpipe tone it down as much as the resonators do.

 

[JBrady]

Hard to say. Why not just start with the X pipe and see what you think. If you want it louder then yes pull the resonators.