irokdastar

Hello everyone . I recently installed a exhaust cutout and i have done it before on other cars. the issue here is that by mistake i ordered the 2.5 in instead of the 3 inch . i am noticing it not to be too loud like i would expect a v8 to be . Should i swap out the 2.5 to a 3" or would it make no difference ?

gixxerboy

where in the exhaust did you install them? Also how are you going to put 3 in cut outs in with out 3 inch exhaust?

Fatz

I wouldn't think a 3" will make a difference, whether you are referring to the "Y" used to tap into the exhaust or the throat of the cutout valve. The exhaust volume will be dictated by the smaller tube, which is most likely your OE exhaust tubes.

If yours is like the 550, the tubing after the OE "Y" merge pipe is 2.75" OD (outside diameter) but the tubing has very thick walls (I believe they are 14 gage). So the inside diameter is not much more than a 2.5" 18 gage piece of tubing. I would guess your cutout is 18 gage stainless steel.

I think you would normally install the cutout just forward of the OE "Y" merge pipe, which means the cats (primary and secondary) and the resonator is still in the exhaust path and is probably the reason it is not as loud as you expected. My OE muffler was pretty much a straight through design, so much of the noise control happens in the resonators and secondary cats/resonators.

kb24forlife24

Hey irokdastar, listen to Fatz. He's an exhaust genius.

irokdastar

Thank you everyone for helping . I looked at the install again and it was installed after the resonator . but the cutout tub in inserted into the factory tubing . When it was installed they basically cut the OE pipe and inserted the exhaust cutout in the pipe and welded it . I think that is a restriction . I had this done on my infiniti fx35 also after the resonator and the minute you open it up you hear a big difference .

gixxerboy

if thats what you did it only cuts out the muffler so not going to change sound much, and if its a 2 1/2 its smaller than the stock pipe where you put it, its going to be a restriction when closed. I would removed it

Fatz

- Inserting a 2.5" pipe into the main 2.75" pipe is not good and is restrictive, as noted
- both due to the reduced diameter and the bump the exhaust gases encounter
- generally the OE tube goes inside the cutout "Y"
- even then there is restriction when closed - not when the cutout is open
- Your FX probably did most of it's noise suppression in the muffler
- likely used a reflective muffler
- I see your point about having a 2.5" vs. a 3" cutout
- 3" would make it easier to insert the OE tube (but it is not absolutely required)
- the 2.5" ends should have been enlarged to fit over the OE tube
- the diameter of the 2.5" is not such a big deal imo
- ID of OE is ~2.6" ID of cutout is ~2.4" if 18 gage stainless is used
- you would have to be WOT to approach overtaxing your tube flow capacity
- Someone on this forum successful had a cutout installed. I do not recall the vehicle model.

irokdastar

I was going to remove the resonator and just install the cutout instead of it but I don't want the interior to have a drone . IF I remove the resonator would the drone be to loud?

Fatz

I don't have specific info on the drone after resonator delete on a 500. I suspect it will not be too bad (relative) with the secondary cats,the "Y" merge pipe, and the heft of the mid pipe still having influence.

Several members with 500s have deleted the resonator, and some have deleted both the resonator and secondary cats. They can best give an idea of the amount of drone.

Drone is mostly a pain when cruising at highway speeds (65-75) or attempting to have a serious conversation with a passenger (). Check your RPM the next time you're cruising in top gear in that speed range. The farther it is from 1900 the less annoying the drone will be.

kb24forlife24

I have no resonator, muffler or secondary cats on my 500. The drone is most @ 1800-2000 RPM but I'm fine with it.

gixxerboy

kb do you have an x- pipe?

kb24forlife24

Yup! In place of the resonator.

irokdastar

Thank you all for your help . I ordered the 3" and will be installing it soon ...

kb24forlife24

Post videos and pics!