[nate82]

I just picked up an '11 335d. A few of my friends have diesel trucks and have deleted the mufflers on them and have measurable hp and torque gains. Has anyone done this on a 335d or X5d and with any gains? What do you think?

[MisterSkiMask]

ohferchrissakes

[Bakeme521]

Try it and get back to us

[DieselDiner]

Originally Posted by nate82

I just picked up an '11 335d. A few of my friends have diesel trucks and have deleted the mufflers on them and have measurable hp and torque gains. Has anyone done this on a 335d or X5d and with any gains? What do you think?

Most of the back pressure on the d is further upstream around the DPF. You cannot remove the DPF. So - if you remove the mufflers, you might succeed in making your car noisier, but probably won't succeed in gaining much power.

[nate82]

Originally Posted by DieselDiner

Most of the back pressure on the d is further upstream around the DPF. You cannot remove the DPF. So - if you remove the mufflers, you might succeed in making your car noisier, but probably won't succeed in gaining much power.

Thank you. That's more the answer I was looking for.

[rizzo2008]

Actually you could remove the DPF and Urea injection if someone figures out an engine coding or external tuner that could remove the error codes associated with removing those items (of course that will void your warranty but I imagine some people don't care). It is very common with new diesel trucks (albeit illegal but impossible to enforce) where owners will take out the DPF and/or eliminate urea injection with a new engine coding. So far I haven't heard of a similar coding for the 335d US spec car though. Perhaps I'm wrong have any tuners managed to do any of the following on US spec diesel cars or SUVs?

1. delete the DPF with a straight pipe
2. eliminate/disable urea injection
3. bypass/delete the egr system
4. replace the swirl flaps with fixed plates
5. do any of the above and code to eliminate errors/check engine lights?

[Forcefed3]

F-335i

[rizzo2008]

Originally Posted by gbreeE90

F-335i

Is that a company?

[N55 Power]

Originally Posted by rizzo2008

Is that a company?

JFK, f-350? see how that could be slighlty modified to sound like 335i?

I own a f-250 with a dpf/cat delete and i have a h

[rizzo2008]

Well has anyone heard of this? Seeing as nobody's warranty on a 2009 car has run out maybe these mods will become more common as the first warranties expire in 2013.

[DieselDiner]

It's been done now across the pond: http://www.e90post.com/forums/showthread.php?t=535271

[rizzo2008]

Originally Posted by DieselDiner

It's been done now across the pond: http://www.e90post.com/forums/showthread.php?t=535271

So the programming is there for the DPF delete but they don't have the urea/adblue system in European cars do they?

[Quasimodem]

Originally Posted by rizzo2008

So the programming is there for the DPF delete but they don't have the urea/adblue system in European cars do they?

I dont lurk in the UK forum much, but I just saw a discussion where they were discussing a 335d with DPF failure and forcing a "regen". I may be mistaken, but that seems to imply a DEF system. Is there a regen for DPF systems without DEF? Maybe they have some other way of purging the DPF of soot besides using DEF.

[maswastage]

Quasi, I think you may be a bit confused. The DPF regeneration is separate and independent from the DEF injection. The DPF physically catches particulate matter, which is periodically burned off. The DEF is injected into the exhaust to react with and neutralize nitrogen emissions.

The European cars must still undergo he DPF regeneration process even though they don't have DEF systems.

[Quasimodem]

Originally Posted by maswastage

Quasi, I think you may be a bit confused. The DPF regeneration is separate and independent from the DEF injection. The DPF physically catches particulate matter, which is periodically burned off. The DEF is injected into the exhaust to react with and neutralize nitrogen emissions.

The European cars must still undergo he DPF regeneration process even though they don't have DEF systems.

Not confused, just ignorant. So then the regen is something accomplished by the engine system without any DEF injection. Interesting. The thread I was reading had all kinds of advice about driving certain speeds and whatnot to allow the vehicle to do a proper "regen". I wonder if US 335ds could be reprogrammed as European 335ds so that they can do the non-DEF regen. But from the problems being discussed on the UK forum, it appeared that tne non-DEF regens were not that reliable since some apparently had their DPF plugged up. Possibly caused by driving the car short distances or in a type of driving which did not allow it to accomplish the required regens. So maybe the DEF system is best as well as being cleaner.

[Hotcoupe]

Originally Posted by nate82

I just picked up an '11 335d. A few of my friends have diesel trucks and have deleted the mufflers on them and have measurable hp and torque gains. Has anyone done this on a 335d or X5d and with any gains? What do you think?

I've been running a straight through exhaust on my 335D's since 2008, all three mufflers (centre & two rear boxes) have been removed.

In terms of performance gains you can expect approx 18-20bhp increase with little to no gain in the torque figure.

My car is currently running at 363bhp and 500lbs torque measured on a Dyno Dynamics rolling road.
My previous 335D running the same map and the stock exhaust system ran at 345bhp with the same 500lbs torque.

Note: UK 335D's stock figures are 286BHP and 425lbs torque.

[itsbrokeagain]

Holy crap thats a lot of torque...