Question about 550 X-pipe exhaust mods

As promised, here are some pictures of the installation of the Burns Stainless X-pipes (321 Stainless Steel) on my 550 at Classic Coach today. There are slip joints on the anterior pipes to insure ideal fitment.
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login

 

Felix Medina trial fitting the X-pipes. Tomorrow, he'll add the hangers and clamps to complete the installation.
Image Unavailable, Please Login
Image Unavailable, Please Login

 

Just received my X-ost Maranello center pipes and no-valve rear silencers in the mail this week. Installing next week. FYI, the website shows the center pipe as being silenced, with a bit of bulge in the middle, but that seems to be a photo of the solution for the 550 rather than the 575. The 575 product was more or less "bespoke", made to order.

The 575 center pipes are two separate units that attach to the underside of the car independently--with no silencing. Craftsmanship looks solid & it will be interesting to hear the difference in sound. Any ideas on what difference the "x-pipe" configuration makes, whether just sound or from a performance standpoint?

Also, the X-Ost people were very professional and responsive, quite happy with the experience.

 

Interesting feedback. Phil's design process was making several sets up for me based on his "theories". On the dyno these theories all proved incorrect and straight pipes (not crossover/kiss or whatever you wish to call them) produce more power at EVERY point of the rev range. The crossover pipe concept is based on an 8 cylinder motor and not a V12, it simply does not work. If you like them for the sound, then great, aside from that they are good for nothing. Your local exhaust shop can fabricate a set of straight pipes, with or without silencers for minimal cost that will produce noticably more power. Having said that, the x pipes are better than the stock pipes/centre muffler, which seem to have intentionally designed resrictions which kill performance.
If anyone cares to check I posted before and after dyno's at the time showing empircal evidence of these findings.

 

Stephen,

Are you referring to the testing you did about 2 years ago (graph below)? My tech will be having Burns Stainless redo the crossover/"Siamese" pipes. As you can see, there was a problem with the rear portion of the unit. If that's the case, we'll just do staight pipes in 321 Stainless Steel.

Barry
Image Unavailable, Please Login

 

Yes, that's the one!

 

Thanks, Stephen. Straight pipes it will be.

Barry

 

The X-Ost is well known for its performance but when you demand the very best, then accept no less than the O-pipe:
http://kalecoauto.com/index.php?main_page=product_info&products_id=3&zenid=e4d4d371498cb62cbd8de8cf888a0d54

"You've heard of the Y pipe.. the X pipe.. the H pipe.. nothing can touch the O pipe!!! It provides 100% back pressure feedback on ALL engines!! Torque increase and kuneutson valve float brings in much lower revs so you don't hurt your motor! Not CARB Legal. Please specify standard or polished finish. Product shown is single input O-Pipe with polished finish."

 

That's funny! This was a nice old thread. I wonder what the dynamics were that made the straightpipes work better than x pipes in Steve's 550?

 

The dynamics are probably quite simple.
With Xpipes the sucking of exhaust gasses out of the combustion room is being disturbed by backpulses from the other cylinderbank.
Less scavenging means less HP.
Exhaust systems can be designed and calculated in advance to quite some degree, based on experience over many thousands of dyno runs.
But the last piece of fine tuning has always to be found out by trial and error.
This is exactly the area where Xpipes happen to prove to be inferior in terms of horsepower to straight pipes. Stephen was the first one who reported this.
My 456 had a remarkable increase in HP, once the mid muffler was replaced with straight pipes. A dyno curve is somewhere in this Forum.

Hans

 

FBB, Hans- Ferrari figured out the same thing when they eliminated the central muffler on late model 575Ms and went to straight through pipes. Probably where part of the increase in quoted HP for Superamericas originated. Plus a new engine ECU for Euro models.

Taz
Terry Phillips
Image Unavailable, Please Login

 

Well all I can say is the straight pipe thing flys in the face of everything you hear about x pipes and H crossovers but I'm not arguing. I weld and bent rollcages so I can do the same with exhaust tubing. It is way easier to make straight pipes and cheap as dirt. So I'll just take everyone's word for it and build straight pipes. Man that makes my life easy. I don't even have to buy anymore pipe. I got stock laying around the garage!

 

FBB- Have to love that. Simple is wonderful.

Taz
Terry Phillips

 

My straight pipes (321 Stainless) were installed today. The technician will dyno the car tomorrow.
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login

 

With pure straight pipes you will not get any of the desired scavenging effect (hence X or H pipes)

 

Whoa...hold on there Billyboy...I need you to make me some too

=b

 

But of course what are friends for?

 

That is 100% wrong.
X or H pipes are disturbing the scavenging effect, for this engine. That is what dyno tests confirm.

Hans

 

You are completely correct, I had inverted in the meaning of the sentence.

 

It's curious to me that Tubi, Larini, X-Ost, Fabspeed, etc. use a design similar to Phil's? I would think that straight pipes must have been evaluated?

 

I'm very curious about this too and would love to see back-to-back dyno tests comparing the styles of center pipes.

Seems like Tubi and all the other major exhaust suppliers would be marketing straight pipes, if they worked better. They are
certainly easier and cheaper to construct than x-pipes.

Are there any exhaust manufacturers lurking on here who can comment?

 

I can say my car felt faster between 1k-5k rpm.

 

hehe...Tubi wants $2500 for straight pipes...way too much money. Happy to pay a friend to make me pipes. I just need to research the whole 'resonator' issue.

 

HOW LOUD do you want your car to be? If you eliminate the cats, you will have re- program the ecu
You mat want to look at an aftermarket cat, yhis will raise the noise level some & avoid the ecu issues
[email protected]