kdurg

Excellence claims the package also consists of different cams. Would make sense given the other enhancements to the head and springs but I've read posts that say otherwise.

What's the word on this Danny Boy ?

Aside from the heads ( cams ? ) everything else is a bolt on swap....for a heck of a lot less than the factory $16k upcharge.

alexb76

Anyone's got a detailed list of all X51 upgrade parts?

I know there's also a 3rd radiator upfront, a different oil pan, and obiously the expensive CF intake!

Edgy01

The heads, 3rd cooler, cams, headers, air filter--all a part of the complete X51 package (w/applicable software ECU flash). PSE is also a part of it.

I just happen to like the sound mine makes with th X51 headers, PSE, etc. I wouldn't say there is any HP gain.

If you look at the kit price broken down the heads are where they get you.

Bruce R

Here is a picture of my car, C2, on the lift yesterday. I guess you are saying my headers look X51 ish? Bonus!

alexb76

Interesting, I guess they maxed out what they can take out of 3.6, but, since they knew there's a market for X51 with C2S/C4S, they left some room for improvement to sell that Powerkit for $18K!

Amazing marketing/engineering/sales cooperation.

Edgy01

Th 3.6 headers look much like the X51 but only in a casual way. The 3.8 X51 headers are physically larger in diameter. I just didn't care for the 3.8 stock ones. (See)

utkinpol

It`s other way around. Somebody decided to cut corners when C2S was designed. So X51 headers simply put back what it was supposed to be, adjusted to 3.8L required intake diameter.

alexb76

So, they can sell it back for more $$ in X51!

Dave07997S

No cams for the 997.1S X51 package they reuse the OEM cams. Even the heads are OEM units with a stiffer exhaust valve spring and some bowl work..that's it. The heads at best are making 5-8rwhp. The majority of the gains are coming from the intake tract due to the intake manifolds larger cross section and larger throttle body. The dual intake setup is there to feed the intake more air going in the engine. What I find interesting is the 997.2S has the dual snorkle setup along with the larger throttle body as the X51 package for the 997.1S and very similar ouput.

With the 996 X51 package cams were part of the package..not with the 997.1S.

Dave

alexb76

So, if the heads contribute to 5 HP, the next 20+ HP is due to Intake? What about the headers and ECU flash?

Dave07997S

Its the whole package..the intake along with the flash and headers all add up. There are several tuners who have done what I call a X51 lite by just adding the intake manifolds, throttle body, X51 intake along with a flash and full exhaust (to include 100-200cpi cats) that have put down close to 390hp. Remember the OEM heads on the 997S already flow good enough to make 93hp/litre while under 7krpm.

I don't know what the intake by itself would add, but I feel at this point you will probably peg out max voltage on the mass air and you will need a flash to keep A/F ratios in line. This can all be done for under $4k with labor. The big part of the expense of the X51 kit is the heads and PSE (which doesn't contribute any hp), these 2 together are over $12k in parts.

Dave

alexb76

Thanks Dave. I am seriously thinking of just doing X51 headers and PSE, to see how it does. I might do a dyno before/after to see...

Intake cost is quite high and as far as I know it's not plug and play and you need to do some modifications to fit it (can't remember what exactly it was). Wish it was, as I would have done it for sure.

utkinpol

PSE is quite heavy and really if you are after power you need 200 cell cats, not a mufflers change. But it is a matter of taste, of course.

alexb76

It's the best exauhst I've seen, the sound is sweet. I also don't believe it doesn't add ANY HP, whatever it adds would be fairly small nonetheless. I might do 200 CAL, but not sure if I'd then pass emissions, and I like to keep things as OEM as possible as I am CPO and don't wanna give PCNA any excuse!

utkinpol

It depends on how you have emissions test done in your area - sport 200 cell cats do work normally when they get hot, so if car is not left to completely cool down at test station you should be OK with emissions.

Common knowledge says best aggressive sounding mufflers out there are Borlas. To me they all sound pretty much alike and Fabspeed is no worse than AWE or Borlas. It is all hype, well, mostly.

Do not overrate role of exhaust mods BTW - I just got my water pump replaced on warranty, I have fabspeed x-pipe cats plus whole caboozle of other stuff and no one really cares about this at dealership.

There was only one documented case on forums where cats did lead to engine destruction - but it happened because it was a prototype version on a supercharged car where catalyst element got melted and sucked in back into engine. No one of major cats brands will do such a trick so it is all quite safe and dealers know that.
Just go with major brands - AWE, Fabspeed, FVD, what else big is out there.

Plus what I was saying before - warranty issues may be originated mostly by aftermarket headers, as most important exhaust parameter for any engine is a diameter on receiving pipe in headers as it controls pressure at engine exit and then less but still important thing is cats as it also affects pressure before catalyst.
Mufflers (which PSE is) is pretty much an irrelevant element and essentially it is just a dead weight we carry to preserve our ears , so, if you want to invest - I would look at lightest one.
Sound wise all aftermarket ones are quite loud, so, put 200 cell cats and headers first and then run car with stock mufflers, then take `em off and run car again. With sport mufflers that roar will be reduced appx 2-3 times and will be 5-6 times louder than with stock mufflers. Then decide what is it you really want.