XR550 g23

[jsta281]

This may be a little irrelevant but headers are not nearly as big a factor on a forced induction motor as compared to a NA motor.

[Miljack]

most of the $$$ difference will come down to the cost of those custom headers...The engine covers are plastic, and paint is nothing...
So PCM was paying around $1500 for the headers, charging CC 2 x that, CC 2x to the dealers...etc...

[core-rider]

OHHHH YES THEY ARE!!!! You stuff in more air, it has to come out. If anything your point is exactly opposite. It would be like sawpping out an aereator pump for impeller style without up-sizing the hoses and expecting top performance... Yes you would pump more water, but not as much as possible for that pump with larger plumbing.

If the cost is half as much, I see many XR550 orders in the future over ZR450's.

[core-rider]

most of the $$$ difference will come down to the cost of those custom headers...The engine covers are plastic, and paint is nothing...
So PCM was paying around $1500 for the headers, charging CC 2 x that, CC 2x to the dealers...etc...

Not sure who builds headers for PCM, but a friend of mine was just quoted $5500 for a pair of CMI hearders and tails to go on his "go-fast" boat. They look nearly identical to the pair on the XS550.

[Zach@n3]

You guys are one it! The XS stays as standard in the costal edition. The XR is painted black and has exhaust manifolds instead of stainless headers. Its 6k less than the XR and still makes the ponies so I don't see anyone opting for the 550 XS. XS must mean Extra Spensive!

I think they need a Barefoot Nautique 210 with a 550 XR .

Here she is

[Zach@n3]

281 is spot on on the FI motors and headers. Headers clearly have more flow from a standpoint of pure size and mandrel bent tubes buttttt the biggest advantage they have to a standard exhaust manifold is a collector to scavange the exhaust gases from one cylinder or another during camshaft overlap(when the exhaust and intake valve are open on another cylinder when the piston is near TDC in it's rotation). This scavanging effect essentially pulls out all spent exhaust gasses while also replacing that gas with fresh air and fuel mixture(like a 2 stroke) with no help from a downward moving piston untill the exhaust valve closes. Thats why go fast cars have camshaft overlap that makes for a rumpity rump sound. The XS idles smooth and probably doesn't have much over lap in the camshaft. As long as it has nice smooth passages to flow through of proper size the Forced Induction doesn't care that much that is isn't breathing through headers.

[jsta281]

OHHHH YES THEY ARE!!!! You stuff in more air, it has to come out. If anything your point is exactly opposite. It would be like sawpping out an aereator pump for impeller style without up-sizing the hoses and expecting top performance... Yes you would pump more water, but not as much as possible for that pump with larger plumbing.

If the cost is half as much, I see many XR550 orders in the future over ZR450's.

Not true. I run 21 psi on factory log manifolds on my car my car makes 656 hp. Similarly boosted cars with long tube headers make 15-30 hp more.

Where the 550 motor is probably only seeing 8 psi at WOT headers are not going to be worth much hp. Also I have not looked at the design of the manifolds but I suspect volume is not a problem.

Headers are much more a factor when they are "tuned" to have scavenging effect helping to "suck" the exhaust out.

Unless the manifolds are so small that the exhaust can't get out I don't see it as much of a factor especially on a low boost application.

[jsta281]

Zach beat me to it :-)

[Zach@n3]

Resident go fast guys

[Laketexoma]

I wish they would have had this motor a few months ago!! LOL Oh well..

[jrz1]

I thought the XS was $17.1K upgrade on the G25.

[ironj32]

Can anyone 100% confirm that the XR is only $6100k more than the 450? Kind of a kick in the nuts for those of us who have the XS being delivered next week, if true. Maybe post up the new MSRP pricing sheet?

[wakeslasher69]

Just heard from dealer it is a $10k option instead of the $16K option. "...and only difference is no ss headers and things painted black instead of red , and a different cooling system setup"

[robertsmcfarland]

option over what? is the 409 standard now? it used to go like this.343 standard. 409 $6,526.......450 $10,873......550 $23,092.....

[Casey@NautiqueMN]

XR also loses the full Fresh Water Cooling System, and goes to the thermostatically controled 1/2 Fresh Water Cooling.