Has anyone done catless Midpipe and DP?

[mpbruin108]

Hey guys,

In a bid to make my car slightly louder and hopefully more sporty sounding, I was contemplating changing my midpipe to catless. However, I already have a catless DP and my worry was that it would be bone shaking loud. I loved the sound of my old E92 M with just an catless X pipe and wanted to duplicate it as close as possible.

So just wondering if anyone has done both midpipe and DP catless and how loud did they perceive it became. Bearable? Drone? etc?

Thanks

[javol]

Originally Posted by mpbruin108

Hey guys,

In a bid to make my car slightly louder and hopefully more sporty sounding, I was contemplating changing my midpipe to catless. However, I already have a catless DP and my worry was that it would be bone shaking loud. I loved the sound of my old E92 M with just an catless X pipe and wanted to duplicate it as close as possible.

So just wondering if anyone has done both midpipe and DP catless and how loud did they perceive it became. Bearable? Drone? etc?

Thanks

I did it and it sounded raspy (with OEM rear mufflers). I should add 2 "mid pipes resonators" to achieve a good compromise.

[mpbruin108]

Is it pretty loud? Like Eisennman sport loud?

[javol]

Originally Posted by mpbruin108

Is it pretty loud? Like Eisennman sport loud?

Loud but RASPY. Something like a GREEEEEKKKKKK!

It doesn't sound good completely decatted + OEM mufflers.

[Toink]

OK good to know. I just received my Milltek catreplacements so I won't swap the DP in that case.

[jannisa]

Originally Posted by javol

Loud but RASPY. Something like a GREEEEEKKKKKK!

It doesn't sound good completely decatted + OEM mufflers.

What exactly do you mean by that?

[ManiacGT]

We need a video to see/hear the result!

[mpbruin108]

Originally Posted by javol

Loud but RASPY. Something like a GREEEEEKKKKKK!

It doesn't sound good completely decatted + OEM mufflers.

lol I'll take your word for it. Probably just get some Eisennman then.

[javol]

Originally Posted by jannisa

What exactly do you mean by that?

Ops! It was just a sound, I didn't realize the posible interpretation of the word, sorry buddy!... Better if change it to a GRAAAAAAACCCKKK

[Asbjorn]

Originally Posted by javol

Ops! It was just a sound, I didn't realize the posible interpretation of the word, sorry buddy!... Better if change it to a GRAAAAAAACCCKKK

btw, is it really safe to change the flow resistance right after the turbos (ie alter the back pressure at the DPs)? Or can they re-adjust the boost to the desired level by themselves?

[jannisa]

Originally Posted by javol

Ops! It was just a sound, I didn't realize the posible interpretation of the word, sorry buddy!... Better if change it to a GRAAAAAAACCCKKK

Grack is what my hometown is called, mate you're doing it all wrong.



(Kidding, thanks for your explanation )

[VailM3]

Originally Posted by ManiacGT

We need a video to see/hear the result!

We need a video compilation of all exhaust options...

[javol]

Originally Posted by Asbjørn

btw, is it really safe to change the flow resistance right after the turbos (ie alter the back pressure at the DPs)? Or can they re-adjust the boost to the desired level by themselves?

DPs are a really nice mod, the car feels smarter since the throttle response is improved (less turbo lag). No bad effects on the low-end torque. I could feel the DPs performance benefits with and without the JB4.

For what concern the engine health... the oil temps seems to be lower with the decatted DPs installed...

[Asbjorn]

Originally Posted by javol

DPs are a really nice mod, the car feels smarter since the throttle response is improved (less turbo lag). No bad effects on the low-end torque. I could feel the DPs performance benefits with and without the JB4.

Again, perhaps a stupid question, but are you sure that is not because the turbo boost has increased as the exhaust flow is less restricted?

Or is it somehow controlled by the ECU? And if so, is the explanation that target boost is reached faster due to lower flow resistance?

[javol]

Originally Posted by Asbjørn

Again, perhaps a stupid question, but are you sure that is not because the turbo boost has increased as the exhaust flow is less restricted?

Or is it somehow controlled by the ECU? And if so, is the explanation that target boost is reached faster due to lower flow resistance?

The turbo boost is controlled by the ECU: with stock map it is aprox. 8 psi and as you say, with decatted DPs, this target is reached faster due to the lower flow resistance. With JB4 map 2 (my case) the boost grown up to 15 psi due to the input signal of the modified ECU and, once again, those psi are reached faster due to the lower flow resistance of the decatted DPs.

[Vintage]

well, I have Eisenmann Race and AR race cat DPs; it is a great combination. I had the race cats in the DPs since Eisenmann eliminates the secondary cats; I did not want what would have been essentially a straight through system has we not included cats in the DPs

[mpbruin108]

My main concern with the Eisennman is that I have the catless AR DP so the elimination of the secondary cats in he Eisennman worries me in terms of loudness and sound. But talking to Tom @ EAS, it seems that the turbo cars are quieter overall than the M cars in terms of exhaust systems...so I'm still considering it...I should have gotten the Race Cat AR DPs.

[AsiaKid]

I have the catted dps from ar and cal2nd cat delete. Sds good but a bit raspy.

[mpbruin108]

drone?

[al1]

Originally Posted by AsiaKid

I have the catted dps from ar and cal2nd cat delete. Sds good but a bit raspy.

would love to hear it

[Yeggman]

Originally Posted by mpbruin108

My main concern with the Eisennman is that I have the catless AR DP so the elimination of the secondary cats in he Eisennman worries me in terms of loudness and sound.

Living in LA, isn't there a concern about Enforcement authorities, and periodic inspections?

[mpbruin108]

inspections? enforcement? loud cars are so common these days in LA...i can't remember the last time I got even a talk about having a loud car. It's mostly the folks who show off obnoxiously that get the attention.