[avi8tir]

As a result of my AFE intake experiment this weekend, I found out my car is not putting down the power that it should be. Baseline was about 380 rwhp with RPI scoops, bmc filters, SS Xpipe & Dinan exhaust. I have heard of certain combinations of mods that actually reduce power instead of making more power. Could the SS X-pipe and Dinan exhaust be a bad combo that is actually making me lose rwhp? One thing that worries me about the SS X-pipe is that it makes no performance improvement claims. Usually there is at least a claim of a couple of hp. Is it a flawed design??

unfortunately I dont have a dyno of my car when it was stock. thinking about switching to the Dinan mid-pipes to see what happens.

 

[keang24]

I can feel your pain and frustration:sad2:. I think i already post the same comment on your 3 diff threads, but sure why not again...

If I were you, I would start by checking for exhaust leak on this current setup, then put back stock resonator, then dyno again.

 

[///Marshall]

We had the discussion about the possibilities of bad results when
mixing different exhaust components. From collective experience I think
we can agree that the section 3 doesn't really add or subtract significant
power. The scoops/bmc/cf filter combo definitely adds power. From the dyno numbers it looks like your car is down a significant amount compared
to other cars.

Unfortunately it seems like the only way to really know is to swap the
x-pipe back to the stock resonator-xpipe. Either that or a thorough check
to ensure you have no leaks or other problems...or maybe even a
second "opinion" on a different dyno? The last being the easiest thing
to do...the others being a pain in the @ss.

I'd love to see and hear what the Dinan midsection sounds like with the
Dinan section 3. I would go this combo but it's not available for the M6
and I'm a little disappointed with the pricing. Offered without high-flow
cats the price point feels about 1k too high. But I suppose you have to
pay to play. :dunno:

 

[tjav8b]

Different dyno first, then replace x-pipe with stock. I am curious to see a hp difference but I don't think it is the x-pipe.

 

[keang24]

Different dyno first, then replace x-pipe with stock. I am curious to see a hp difference but I don't think it is the x-pipe.

Initially we thought something wrong with the Dyno machine, then we dyno another M5 about 30minutes later with scoop and section3 exhaust, and he pulled 412whp. But yes, it would be nice to try to different dyno like DynoJet which many people have an idea on what baseline number expected.

 

[tjav8b]

Initially we thought something wrong with the Dyno machine, then we dyno another M5 about 30minutes later with scoop and section3 exhaust, and he pulled 412whp. But yes, it would be nice to try to different dyno like DynoJet which many people have an idea on what baseline number expected.

I would not even bother with another dyno, this is enough proof. It would be very interesting to see if the x-pipe could cause a hp loss like this.

 

[ThisFlyGuy]

put back on stock airbox first.....then dyno.

then put back on stock xpipe and then dyno....

 

[carlsturm]

Thanks for posting this. I've been modding cars for years and I've got to say that the exhaust mod options for the E60/M5 are tricky.

Firstly, OEM exhaust as a complete end-to-end unit is already very good. If you're gonna swap out exhaust sections then I'd stick with a single vendor who has tested their products in the exact configuration you're seeking.

There are lots of good aftermarket options but mixing vendors is risky.

 

[M5Ranger]

Please stop belaboring the exhaust issue. It is insignificant and of no relevance.
The AFE intakes are useless period end. Move on.
If you want to buy the Dinan intakes be my guess, no comments.

You all know where I stand and it works!
Please excuse me but I am just an "f'en idiot" who deals in the truth.

Cheers gentlemen,

Ranger

 

[///Marshall]

It is relevant as the apparent power loss has nothing to do with the
AFE intake. If you have information about why it cannot be the
exhaust combo then please share this with us.

The intake was brought up as the reason for dynoing but it's the
baseline dyno that is in question and not the subsequent AFE dynos.
That's the subject of a different thread.

Please stop belaboring the exhaust issue. It is insignificant and of no relevance.
The AFE intakes are useless period end. Move on.
If you want to buy the Dinan intakes be my guess, no comments.

You all know where I stand and it works!
Please excuse me but I am just an "f'en idiot" who deals in the truth.

Cheers gentlemen,

Ranger

 

[grune34m5]

e39 m5

I know it is a simple thing but, have the air flow meters been changed recently? WHat about crank sensors. :dunno:

 

[keang24]

Please stop belaboring the exhaust issue. It is insignificant and of no relevance.
The AFE intakes are useless period end. Move on.
If you want to buy the Dinan intakes be my guess, no comments.

You all know where I stand and it works!
Please excuse me but I am just an "f'en idiot" who deals in the truth.

Cheers gentlemen,

Ranger

AFe definitely was an issue for power loss. But even baseline dyno on Avi8tir which has OEm airbox, scoop, x-pipe, and dinan exhaust, I believed he pulled 380ish which is ways too low for that setup.

 

[NobleM400]

The only real way to know is to test.

In terms of the M5/M6 exhaust, it's tricky to pick up power. The stock exhaust is designed remarkably well, considering sound volume, sound quality, and power, within the constraints of price.

Looking at the 3 exhaust "sections" of the exhaust, the easiest place to lose power is section 2. This engine seems pretty sensitive to changes in how the exhaust crossover is done.

It's also possible to lose power in the section 3, though it's not as common. Mufflers that seem to lose the most power are the "vortex" type (internal vanes spin or contour the airflow), followed by chambered.

Section 1 doesn't seem to make a huge amount of difference, plus or minus. You'll gain a bit more power from straight through than a good high flow cat, but the difference is small.

These are not "hard and fast" rules, but merely observations we've seen from testing (and testing and testing and testing). Testing is really intensely boring and time consuming, but sometimes there's no substitute.

 

[ThisFlyGuy]

The only real way to know is to test.

In terms of the M5/M6 exhaust, it's tricky to pick up power. The stock exhaust is designed remarkably well, considering sound volume, sound quality, and power, within the constraints of price.

Looking at the 3 exhaust "sections" of the exhaust, the easiest place to lose power is section 2. This engine seems pretty sensitive to changes in how the exhaust crossover is done.

It's also possible to lose power in the section 3, though it's not as common. Mufflers that seem to lose the most power are the "vortex" type (internal vanes spin or contour the airflow), followed by chambered.

Section 1 doesn't seem to make a huge amount of difference, plus or minus. You'll gain a bit more power from straight through than a good high flow cat, but the difference is small.

These are not "hard and fast" rules, but merely observations we've seen from testing (and testing and testing and testing). Testing is really intensely boring and time consuming, but sometimes there's no substitute.

do RPI xpipe's improve any HP? or just sound?

 

[NobleM400]

do RPI xpipe's improve any HP? or just sound?

It does produce a small gain (2-3hp or so on a conservative dyno) by itself. However, this can change, up or down, with what other exhaust parts are installed.

Not a simple issue, eh?

 

[Myke951]

First dyno with stock exhaust after a week of driving around with it and a couple of hard pulls...

 

[hbpetrides]

Avi8tir, any news regarding going back to the standard x pipes?
Reason I am asking, is because I have the SS Xpipes too, on a standard system and although the sound is beefier, I think I might be a little down on power.
Is it just me beeing over paranoid now, I heard your story?

 

[extassy]

I thought I'd chime in...

I had Meisterschaft section 1 & 2 plus Dinan Exhaust and Evosport Headers.

I lost about 30lbs/ft of torque between ~4500 to ~6000rpm.

Welded the stock cat into the section 1 and I gained the torque back...

All of these findings are based on the Dyno Jet reading a day apart (before and after the cat installed)

 

[keang24]

Avi8tir, any news regarding going back to the standard x pipes?
Reason I am asking, is because I have the SS Xpipes too, on a standard system and although the sound is beefier, I think I might be a little down on power.
Is it just me beeing over paranoid now, I heard your story?

I believe he gained all the power back (i don't have the exact number) after swapped SS x-pipe with Dinan x-pipe along with Dinan CAI. But still inconclusive to determine whether dinan x-pipe or Dinan CAI that brought his power back.

 

[hbpetrides]

Can we just make clear, are we talking about resonted x pipes or just straight throught?
Mine are straight through pipes.