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When they break off flush, just use a spacer between the press and the broken stud.
You are right that that it gets tight in there. Sometimes the only thing to do is use a punch and a heavy hammer and don’t be afraid to hit the ever-living crap out of the stud. IMO, many light blows risks damage more than just a few heavy blows. Once the stud starts to move, it pops out fairly easily. The hard part is breaking that years-old friction and rust bond.
When I changed over my exhaust, every bolt I had to deal with was rusted to the shthouse. I was concerned about those studs and snapping them.
Once I found out that they were pressed and not welded, I was happy as Larry. All but one snapped and took a day and a half to rip and replace the exhaust from the cat back with a Tubi system.
I few good whacks with a nail punch and hammer sorted that out and replaced with marine grade stainless steel hardware.
Thanks for posting the video. I had to dremel each one out until I could punch them. The upper ones are the worst, spent an hour on one of them. My advice, preserve your studs if at all possible or just pay someone to do it.
The bolts that came with the Topgear pipe are much too large to fit in the holes in the cat and also too long. Maybe this is something unique to the X51 headers? I bought stainless M8 1.25x30 instead. Also, the nature of the design or any other X pipe style will be a little trickier to install vs individual crossing pipes. The individual pipes would only have to line up on the two ends whereas the X pipe has to line up in 4 different locations at the same time which takes a little maneuvering. It's up to individual choice whether it's worth 2X the price.
...I had to dremel each one out until I could punch them. The upper ones are the worst, spent an hour on one of them. My advice, preserve your studs if at all possible or just pay someone to do it.
But... are you in business?
If so,
Originally Posted by Chris M.
...the nature of the design or any other X pipe style will be a little trickier to install vs individual crossing pipes. The individual pipes would only have to line up on the two ends whereas the X pipe has to line up in 4 different locations at the same time which takes a little maneuvering.
Side note... they used to charge $895, it's now listed at $760 on this Black Friday weekend...
All of the others, whether the crossover style (SW, BB, etc.) or X-pipe (Fabspeed, TG, etc.), have both pipes welded together. So you'll have the "line up in 4 different locations" challenge with all of those as well (AFAIK).
I don't know if it's really a benefit or simply snake-oil. But since the TopGear design is (presumably) based on the same principles, this maybe of interest to some folks...
Side note... they used to charge $895, it's now listed at $760 on this Black Friday weekend...
All of the others, whether the crossover style (SW, BB, etc.) or X-pipe (Fabspeed, TG, etc.), have both pipes welded together. So you'll have the "line up in 4 different locations" challenge with all of those as well (AFAIK).
Karl.
It's all wrapped up now, thanks. I appreciate all the tips. I assume people leave off the muffler strap? There's nothing for it to hold now.
I doubt I could tell the difference between 408hp and 420 (as some state the gains would be from this mod) but sounds a little better and I dropped a few pounds in the process.
I never closely shopped the crossovers because of the price but I thought they were all two separate pipes. In that case the AWE might be a little easier to install. Thanks for the clarification.
That Fabspeed video is particularly unscientific and doesn’t really prove anything other than the way Kleenex flows through pipes when compressed air is blown through them.
Exhaust gases flow in pulses, not continuously like compressed air. It is also a fact that the location and size of an exhaust crossover are important considerations in building HP and torque. It is convenient to put a crossover in that location, but that doesn’t mean that location is the right place for a crossover.
In fact, a crossover or H-pipe may add HP at higher RPMs but reduce torque at lower RPMs, which might not be what some drivers want. Or, that location might be suboptimal for either and not increase performance at all.
The only way way to know is to see dyno sheets with attached and unattached pipes under the same running conditions. The manufacturers of those types of pipes might have those. I’d love to see them, as I am fascinated with the idea of crossover pipes, but am skeptical of their effectiveness in every application.
Of course the best way to remove rusted nuts and bolts is with the hot wrench, the oxyacetylene torch using the small tip. When the nut is red hot, let it cool and you can almost remove it with your fingers. Watch out you don't melt any aluminum of course. A propane torch probably isn't hot enough to do the job. If you use stainless steel fasteners use some type of anti-seize compound. I have had stainless exhaust fasteners fuse together (galling).
Of course the best way to remove rusted nuts and bolts is with the hot wrench, the oxyacetylene torch using the small tip. When the nut is red hot, let it cool and you can almost remove it with your fingers. Watch out you don't melt any aluminum of course. A propane torch probably isn't hot enough to do the job. If you use stainless steel fasteners use some type of anti-seize compound. I have had stainless exhaust fasteners fuse together (galling).
I did go back with stainless so hopefully if I ever remove it I'll have an easier time.
After having it installed for a month or so now I have to say I'm a little underwhelmed at the difference in sound (I don't think this is specific to the Topgear part, could be any bypassing of the center muffler). So much so that I don't know why Porsche even bothered with the center muffler at all as it makes almost no difference. It is great on a cold start but once the car warms up it is barely noticeable. There is nothing different on deceleration which I've always enjoyed on past cars. Maybe when we get to some windows-down driving weather it will be more noticeable and maybe it sounds better from outside the car than I can tell while driving. I am certainly glad I only paid $450 vs at least 2X that from many other manufacturers. The car already has PSE so the only thing left to do would be 200 cell cats but that would involve losing the X51 headers so I doubt I will go that far.
TopGear Exhausts (UK based) is running a group-buy on their 997.2 Carrera/S center muffler bypass - http://911uk.com/viewtopic.php?t=130642. There are links to the product and a demo video in that post.
It's an X-style setup à la Fabspeed, plus it looks like they add an additional a set of Gundo-like bypass tubes as well:
Their normal list price is £266.67 (excluding VAT), plus £70 shipping from UK to CA (YMMV), totaling £336.67 (~$430 at today's exchange rates).
With the group-buy, I got a roughly $60 discount off that price. But again, YMMV (e.g. differences in shipping).
At that price, I said 'what the heck' and have put one on order. I'll update this thread once I receive it and get around to having it installed,.
The differences between the Billy Boat and TopGear bypasses are small, there aren’t dramatic differences between them (at least to my 50+ year old hearing).
The Billy Boat is a bit louder/bellicose than the TopGear, with more sound in the lower ranges. Note that when combined with PSE open valves, it’s close to being too loud or “hey look at me” in a suburban environment for me personally.
The TopGear also sounds great. It comes in at higher ranges and has a smoother, more refined sound than the Billy Boat. Day to day it’s a tad quieter (less “shouty”) than the Billy Boat. But has more of a yowl at the top end…
So whether you'd like one type over another really depends on your own personal preferences.
Price wise this post sort of put these center muffler delete options in perspective.
Namely, current options like Sharkwerks, AWE, Fabspeed and now even Billy Boat are just around the $900 mark. Fortunately I bought my BB pipes three years ago for $510.00 shipped! Now they're just like the others mentioned once they saw what prices the others were getting away with. BTW, even at $510 I still could not understand why two pieces of pipe could possibly cost that much... but I bought them anyway!
So now along comes this British firm that basically offers the Fabspeed pipes for less than half the price INCLUDING shipping from England. And even at those prices I'm sure that they're still making money because that's what you do when you're in business!
Yes, I've read Sharkwerks justification for their prices (R&D, Chinese vs. US manufacture, etc.) but basically it still comes down to two pipes. And the Chinese/US controversy... well even if the Chinese version is not as as good quality and materials as the US, they'll probably last as much as the car. If not and at this rate, there will probably be an even cheaper option when they need replacing.
11-24-2018, 08:12 PM
