[KC_skyrider]

Well I'm sure someone has done something like this with an N54 but I haven't heard about it. So after my DIY success with the KL Racing intercooler I decided to bite the bullet and see how these will work for the community.



I have CP-e ********* which have a great 2.5" diameter straight path back to the mid-*****. I'm going to cut into them at this point and dump the exhaust before the resonators 2nd set of cats and muffler. Of course this will be loud but I'm skeptical on how loud it can be after the exhaust is squeezed through the snails. I'm in germany so the shipping will take a couple weeks so in the mean time feel free to add suggestions to help me get the best possible set up. If all works out I'll get a DIY posted.. and if not I get to do some welding!

This is not a mod for everyone. It's a $369.00 DIY kit that should allow better performance than aftermarket exhaust options at the sacrifice of audio comfort and reliablity due to the added moving parts. This shouldn't be used on public roads.

[SlicktopTTZ]

It WILL be loud, but awesome sounding! Not nearly as bad as an unmuffled NA or Supercharged car.

Be sure to post videos!

[VictorFranko]

From experience, not worth the hassle or expense, particularly if you need two. $400 for the hardware, plus $100 to weld/wire/install, so $500 total. And they tend to leak over time. If you already have ******* ********* and resonators in place of the main cats, you'll be lucky to pick up 10hp for the additional effort and a BMW that sounds like a racecar DSM.

[KC_skyrider]

$369.00 out the door. No welding. Purchased from Summit Racing so I should have a decent garantee against leakage and if I do leak then it's a short weld I can do myself to reverse. I only have ******* ********* the rest of the exhaust is stock. Now that I have found a dyno a couple of hours from home this is an easy enough mod to do a before and after. I think this car has spoiled alot of us. I remember buying a $500 diablo sport tuner to gain maybe 10hp from an SVT Focus. If it works I'll be sure to let everyone on the forums know. And if it doesn't well... I'll be sure to let everyone on the forums know. We're quickly reaching the max on stock fuel system and turbos. I'm a little hesitant to go Nitrous so let's see where else we can squeeze the last few HP out of a stock N54. And who knows this could only increase the numbers if I went with a set of RB turbos.

[temperamental]

Look forward to your experience and write up.

[j x k]

I ran open ********* for a day, good luck.

[KC_skyrider]

Originally Posted by j x k

I ran open ********* for a day, good luck.

What was your experience with this? Any fumes in the cabin? How loud can I expect it to get? Was there a noticable performance difference?

[Qmax03]

Im looking to do the Boost Activated Cut-outs on my car Very soon.... They will benefit you on the top end.. And the sound will be nuts !

[onefastman]

I ran open dp's for a day


VERY loud and it sounds like a un-muffled disel truck below 2500rpm but at wot it sounds pretty cool. Also the butt dyno told me I lost major hp.

[BZ335i]

I had these on my Vette and Camaro. No fumes just a lot more noise and some extra HP. I'd open them at the track and very rarely on the street. Mine were by QTP and the newest models have better motors that dont stick like the older ones used too.

[j x k]

Originally Posted by KC_skyrider

What was your experience with this? Any fumes in the cabin? How loud can I expect it to get? Was there a noticable performance difference?

sounds like an open ******** turbo honda, except theres TWO *********.. so.. be creative lol

[KC_skyrider]

(Im looking to do the Boost Activated Cut-outs on my car Very soon.... They will benefit you on the top end.. And the sound will be nuts !)

Sounds great but IMHO that would cause too many duty cycles and cause the cutouts to leak very quickly. Also try taking off from a red light up a incline with a cop next to you..

(VERY loud and it sounds like a un-muffled disel truck below 2500rpm but at wot it sounds pretty cool. Also the butt dyno told me I lost major hp.)

Seems odd. I've often argued with my friend till we are blue in the face because he insist my car needs the back pressure and I keep reminding him it's turbo and the pressure behind the turbo is all it needs and if I dumped from the turbo it would be the optimal exhaust path for power. Any ideas why you precieved less HP?

[onefastman]

Not a clue, theoretically you should not lose a single hp but I felt significant loss.

[j x k]

Originally Posted by onefastman

Not a clue, theoretically you should not lose a single hp but I felt significant loss.

I felt the same way.

[DBFIU]

Finally someone is doing this.

I would love to see back to back dynos of open/close.

You are right theoretically a dump right after the turbo will yield the largest gains. No, turbo motors do not need backpressure

I cant wait for the results.

[KC_skyrider]

Well the interest is definatly there. If the gains do happen I might fabricate a sidepipe dump around the passenger side wheel well. I'm still a little concerned about venting exhaust directly underneath a car. I know it's only an issue after long periods of sitting idle, but I have no desire of sucking in CO.

[m1bjr]

Okay.
True that reduced BP after the snails is good, but you dont need pressure before them either.
What is useful is smaller (than NA) diameter headers to accelerate the gasses towards the turbo...
After that its all about getting rid as quickly as possible.

The reason you guys lose power on an open pipe is probbaly because you havent mapped to allow for it.

So by definition, the flap valves wont help unless you can map switch at the same time to reap the benefits.

[KC_skyrider]

Originally Posted by m1bjr

Okay.
True that reduced BP after the snails is good, but you dont need pressure before them either.
What is useful is smaller (than NA) diameter headers to accelerate the gasses towards the turbo...
After that its all about getting rid as quickly as possible.

The reason you guys lose power on an open pipe is probbaly because you havent mapped to allow for it.

So by definition, the flap valves wont help unless you can map switch at the same time to reap the benefits.

I'm sorry which map is the exhaust dump map? I think it's like 22-23. I've never accounted for an exhaust in a tune, save using DP to upgrade one map with burger, but even on stock map you can feel the power gain from the DP. The point of this is to eliminate post turbo back pressure allowing immediate spool time and possibly reduce load on the exhaust turbine.

So by definition it should work regardless of a tune IMHO.

If there is a loss of power what I would expect to be the cause is density is being decrease too much with the decrease in pressure, and the loss of density means more air must pass through the turbine to maintain the same speed. Of course this should be so negligible that the waste gates could easily account for it.

[m1bjr]

You cant get energy from nothing, simple pyhsics

So, if you're making gains from no exhaust - then you must be adding more air+fuel.
That's about it.

Add a freeflow to a N/A and it leans out, badly.
The same will be true on the turbo engine to a degree.

At WOT (open loop fuelling) you have the EMU map deciding the AFR.

[KC_skyrider]

Originally Posted by m1bjr

You cant get energy from nothing, simple pyhsics

So, if you're making gains from no exhaust - then you must be adding more air+fuel.
That's about it.

So when I go from an Auto to a Manual I don't gain WHP slightly. There's more than fuel and air. There's friction, resistance, and drag. Reducing back pressure means the engine isn't working to eject the exhaust gas. Meaning when other pistons are on a combustion stroke less of their energy is wasted. And these cars aren't exactly 1st gen EFI. I don't have to change the map to get more fuel if needed. In fact the DME is so capable many members run a dry shot of Nitrous without changing the map and the DME maintains great AFR's

Back to the original dispute.

Can the car gain from being tuned specifically for it's exact configuration/mods ie open exhaust... Yes

Should it be necessary to manually manipulate AFR's to prevent this car from losing power... Absolutely not.

You could be completely right, IMHO it's not how our cars work. But this is why I'm trying this mod. Remove Opinions + Create Fact/Experience = produce a better N54

[PHANTOM666]

I've been thinking about doing this for months now. Looking forward to your results.

[KC_skyrider]

Originally Posted by PHANTOM666

I've been thinking about doing this for months now. Looking forward to your results.

Problem is it will probably take a month to arrive, I'll be sure to let you know. I posted a link on that OCC. Just goes to prove we're paying through the nose. The Big Tom IC has got me thinking. And the overpriced aftermarket isn't going to like what I'm thinking about.

[PHANTOM666]

Originally Posted by KC_skyrider

Problem is it will probably take a month to arrive, I'll be sure to let you know. I posted a link on that OCC. Just goes to prove we're paying through the nose. The Big Tom IC has got me thinking. And the overpriced aftermarket isn't going to like what I'm thinking about.

I know, since Sleepy did the intercooler and posted logs I've been seriously considering it also. I often surf Jegs and Summit for universal parts so I'm also trying to think outside the box...

[KC_skyrider]

Originally Posted by PHANTOM666

I know, since Sleepy did the intercooler and posted logs I've been seriously considering it also. I often surf Jegs and Summit for universal parts so I'm also trying to think outside the box...

Good Deal. That's my DIY that sleepy used, I'm a little worried it took him so long (but I think he didn't have a lift) If you do this (and you will because it's an awesome mod) please let me know if I left anything out or could simplify things.

[JPSlick]

Curious of the results and pictures of the install.

I notice a couple guys say they felt nothing, that sounds a little odd to me. (Not calling you guys liars or anything). However I have hard some guys claiming they FELT like they lost some power with *********..... and that doesnt add up either.

Anyway, curious on the results.