Exhaust Whistle from turbo when back off accelerator

[thenevera]

get a muffler and get rid of the cat and id go 2.5" ive had a 2.5" and a 3" 2.5 sounded heaps better as it had no cat and just a mild muffler my current one is 3" cat but no muffler

 

[superiorcruiser]

a custom dump pipe in 3 inch,hi flow cat and straight thru 3 inch pipe and you will hear turbo whistle at IDLE speed.
thats what i have....sounds great..

 

[Navara09]

Is it worth just doing 2.5 inch straight through from the cat back?

 

[maddogrc]

nooooooooooo!!!!!

the cat is built into the dump pipe!

the dump pipe is restrictive as it is, then they put the cat straight after it, so you have double restriction.

must be from turbo back!

 

[the_bluester]

On my ZD30 a 2.5" cat back (Well, flex joint back) pipe made a noticeable difference so there is some benefit there. But if I still had it I would be redoing it from the turbo back by now.

 

[Navara09]

So get a high flow cat then coz i want a cat to keep it legal

 

[superiorcruiser]

So get a high flow cat then coz i want a cat to keep it legal

yes,hi flow cat is not restrictive at all.

 

[thenevera]

i wouldnt even get a highflow cat
just get a new dump and 2.5 and a muffler if you ever get a yellow get them put a cat on

 

[Leprechaun]

i wouldnt even get a highflow cat
just get a new dump and 2.5 and a muffler if you ever get a yellow get them put a cat on

Pretty sure it's a $10,000 fine for not having a CAT.

Seeing as they don't restrict flow, and will help stop us all from getting lung cancer and brain tumours, I would put one back on.

 

[superiorcruiser]

i wouldnt even get a highflow cat
just get a new dump and 2.5 and a muffler if you ever get a yellow get them put a cat on

why settle for 2nd best? why would you put on a muffler?a hi flow cat is far more important,it doesnt restrict flow and u dont need a muffler to dull the sound?
you got it all wrong..

 

[the_bluester]

I was going to post something similar. Why risk an EPA type fine for something that has very little performance advantage compared to a good high flow cat? Even if you did not get a fine, you could easily find yourself having to take time off work to take the car to be tested to prove compliance after you fit a new cat.

 

[Dave]

Change the dump pipe aswell, its the biggest restriction in the system.

Tweake wont agree with me but thats why I found.

My 22 sounds like that Cruiser George posted up.

Just not as loud.

Dave.

 

[tweak'e]

Change the dump pipe aswell, its the biggest restriction in the system.

Tweake wont agree with me but thats why I found.

you know me so well

if you want that noise you will have to change the dump pipe.

 

[the_bluester]

I briefly ran my ZD30 with the exhaust removed right from the turbo back. The turbine noise was so noticeable that you could even pick when it got oil pressure after startup (The turbo drops a few revs when oil pressure comes up) but it did not make enough performance difference compared to a flex joint back system that I could justify the extra money at the time.

 

[Navara09]

I just got told that if you take the cat off the new d22s it puts an engine light on the dash all the time while drivng

 

[maddogrc]

wrong...

the d22 has no sensor in the cat

also theres the whole HEAP of us who have done it without any issues.

the d40 on the other hand with the DPF has a sensor which has to be bypassed/tricked otherwise it gives you the check engine light.

 

[thenevera]

yer oh well wateva yous rekon ive had both and way prefered no cat and single muffler
sounded better more whistle and no drone

 

[charlie strayarc]

So get a high flow cat then coz i want a cat to keep it legal

Why not put on whatever you want and keep all original bits and pieces for the pits.
As maddogrc says its unlikely a cop will pick it on the side of the road and if they did I reckon youd get a warning first offence anyway.
More likely youd get a yellow sticker for some other nice mod and find yourself refitting original cat etc for pits.Hardly a big job.
Ive been thinking along the lines of straight thru from turbo back with an interchangeable bit for cat etc just in case I ever have to reintroduce it into the system.

 

[wilba]

i had a 3inch cat back wile my dump pipe was getting made and i wasnt very inpressed with the noise but when we put the dump pipe on wow now thats wat im talkin about spooling sound on idle no mufflers or cat ftw