seev

hey everyone. i really need your help on this one.
ive got my hands on a M5 exhaust. (not original)
me and my friend started to replace it, but only finished the left side. i wanted to go for a testdrive and i hit 260 km/t in no time
a couple of days later we were going to finish the right side that needed to be modified a bit.
after we were finish i tested the car again, and now its like the turbo lose its breath. i wont go more than 240 km/t. but i can feel that it wants to go faster, but cant.

the car is a 530D. the middle muffler is gone, and only have the cat and to back mufflers. and the car is remapped to 285 HP and 630 NM.

now the million dollar question is.
if i but another middle muffler back on, and remove the 2 back mufflers, (straight pipe it from middle section) will it help ??

my pictures is to big to post here. dont know how to change it.

dj_rzn

Yes , it should help.
On diesel engines, if you get rid of anything from the exhaust circuit (except final muffler\s) your turbo will go crazy, especially if you remapped it.

The turbo pressure needs to stay constant when you are at full throttle but instead it will fluctuate, it can be adjusted with a new custom remap.

You may also consider the fact that it might be a coincidence and your turbo is going down.

seev

i dont think the turbo is going down, because it all happened right after i cut a hole in the pipe, to make the other pipe to the other side.

seev

this is how i want to make it.

dj_rzn

It's obviously that's about the pressure in the exhaust circuit, if you want to leave it this way, i suggest to get the custom remap.
Or at least you can test the car to see if the pressure in the turbo stays constant.

Btw, i want to modify my exhaust too on my 525D, the circuit will look like yours. Is there any sound difference?

PS: I have the same problem with my Mercedes-Benz C220 CDI, i modified the exhaust, straight pipe and final muffler, and i had to get a custom remap because i lost a lot of power. Now i have more than before and the pressure in turbo is constant, also i deactivated my EGR.

seev

no i wanna make it over again. i want it to look like the picture i posted. it looks much better, and there is more room between the batteri box, and the spearewheel box. because now my muffler hits the spearewheel box, and it makes a noise that im tired of listening to :-)

after i make it over, do you think i need to remap it again, or do you think the turbo pressure will be as it should be ?

but if you make it the way i have now, you will get a very nice sound, its deep and not to loud.

dj_rzn

In the picture you posted i can see the middle muffler.

Case #1: If you plan to stay with the middle muffler out, you will need a custom remap and make sure that you don't have any fume\air leak in the circuit, i had this problem on my first exhaust circuit.

Case #2: If you plan to put back the middle muffler, you don't need any remap and the car should act normal, but again, take care on any fume loss, pressure loss on the circuit, these are bad for pressure, sound and exhaust circuit (in time, every little hole, will become bigger).

seev

okay, thank you very much :-)