Just got my headers installed catless with the H-Power pipe. The tune was updated by OETuning and I'll be going back for a Dyno Tune next Friday....

Love the sound. I don't know why people say it's too loud - it's not. Sounds awesome. When I get on it and then get off the gas, I notice a sound as if there's some turbulence in the exhaust system.... maybe due to the H-pipe...
- is that what rasp is?

Not fond of the tune yet...I think it needs the Dyno because it feels like it's revving with a delayed response or something....not sure.

At idle, I can smell the fumes....not terrible and not enough for me to put the cats back on.

Considering removing the H for an X to get rid of what I think is the minor annoyance.... the in cabin occasional rasp / turbulent exhaust sound. Not sure if it's the H or if it's from the headers.

Would a 3" X be better than an H or should I go with a 2.5" X instead? My H pipe is from the Power Pipe group buy so I'm not sure what size it is. I was also thinking of modifying the H and just making it 2 straight pipes..... the X is to even out the exhaust flow but I'm pretty sure that the Tri-Y design accomplishes that. Not sure if the X is really needed....

Thoughts?

 

I have 200 cel cats and I still get fumes

 

I strongly suspect that the turbulence noise are collectors from headers

 

Hey Jason,

Post vid of your sound if possible. So you kept the H-pipe at the same location or did you move it in place of the resonator?
As well do you have some drone in the cabin?
Mike's power pipe is a 2.5' so maybe the reason why the sound is not as loud as a full 3' exhaust, my guess

 

3 inch xpipe is way better than a silly h pipe.

 

Yes the h is at the same location. X is for scavenging but a tri-y does that.

Benzworks says a 3" x is too big and will lose power.

No drone at all just occasional turbulence sound when at higher rpms and coming down....

 

You kept your resonator too?

 

Yes

 

So my guess is the H pipe and resonator are not helping you get the full potential of the headers, meaning the full exhaust flow. You start with 3' then enter the H at 2.5 then finally the resonator at 2.1/4'.
Hence your sound is not as loud as others with catless headers + xpipe.

 

well it's pretty loud. not sure if it would be smart to go any louder. i wanted the headers for a louder sound and more performance.

 

it sounds sick - just wondering if it's better to put an x instead of an h with tri-y headers.....or just leave it, tune it, and go.

 

You might be the first with headers and h-pipe IMO. Optimize that tune and get a dyno to see your numbers. Then we'll be able to compare.
I'm actually in that boat whether having headers or not. I want increased performance but at the same time I want the noise to be bearable for a daily driver. Your setting might help me decide

 

Need a video of it , curious about the sound!

 

If you drive it in C or S normally, it's almost not noticeable.

You really notice it when you get on it - and it's fun. The only issue I can tell so far is the sound it makes in the cabin after heavy acceleration on decal / coasting.... that's when i hear a bit of a turbulence sound / rasp. not the normal downshift sound..... but a sound of air flowing and maybe bouncing? it's not bad. i was curious if it had to do with the h-pipe or if there could be a leak in the exhaust. just looking from the engine bay - the MBH headers are a really tight fit.

didn't come with gaskets so Benzworks had to get some.

I'll get a few clips tomorrow.

 

Mine sounds just like this:

http://www.youtube.com/watch?v=VuGQQ..._embedded#t=82

He has the same setup as mine in the video. MBH tri-y with h-pipe in stock diameter @ 2.5/2.75.

 

Hey Jason! Congrats on the new add ons! Car looks fantastic btw. Modded with absolute class! How you liking the sound when you get on it? It sounds AMAZING imho.

Hope you get the tune dialed in.

 

looks much nicer than my avatar - i added the boca carbon pieces to the front bumper and the revosport carbon pieces to complete the sides on the rear.

sound is awesome. i want to get it on the dyno soon.

 

Simple curiosity: how much and how long was the install?
Do you have to pull out the engine to install headers?

 

not very much. Dropped it off Wednesday, picked it up Friday.

 

487 HP 425 Torque

Tuned today. Last time I was at 417. Since then I added SLS Plugs, ROW Airboxes, MBH Headers, 20" HRE P44SC wheels.

 

Sls plugs?? What do they do where did u get them

 

Weistec 1 step colder plugs

 

I'm also now getting 19-20mpg. Before the headers I was at 12-14mpg.

 

I thought they were for a super charged application

 

No. Increasing 100hp over stock calls for it