Topgear center muffler bypass for 997.2
#16
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Join Date: Oct 2015
Location: Lakewood, OH--Sedona, AZ
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i was one of the first to buy thier Boxster muffler. Nice sound, very good build quality. Extremely good value at the time. It was quite a long time ago though, i think it was back in ‘07 or ‘08
#18
I can tell you that these guys have a great reputation here in the UK, as do Hayward and Scott. I was all set to pull the pin on an H&S pipe but came across a full Tubi system hidden 40 pages down in eBay.
I wouldn't have an issue with either of these guys products.
There are many 911uk.com members that run either of the above and I've never heard a bad word about either.
Hope that helps in some way
I wouldn't have an issue with either of these guys products.
There are many 911uk.com members that run either of the above and I've never heard a bad word about either.
Hope that helps in some way
#19
Drifting
#20
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https://rennlist.com/forums/997-foru...l#post15373145
As Iceter noted, the Billy Boat seems to have a high probability of clearance issues with PSE cars
Karl.
Last edited by wjk_glynn; 11-06-2018 at 08:36 PM.
#21
Nordschleife Master
Yup, that was me.
https://rennlist.com/forums/997-foru...l#post15373145
As Iceter noted, the Billy Boat seems to have a high probability of clearance issues with PSE cars
Karl.
https://rennlist.com/forums/997-foru...l#post15373145
As Iceter noted, the Billy Boat seems to have a high probability of clearance issues with PSE cars
Karl.
Ok, so good fitment of BB on non-PSE cars but not so much on PSE cars.
#22
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My Topgear bypass arrived today here in CA safe and sound (3 business days after ordering from the UK). This is what you get (the X-pipe itself with gaskets and 6x bolts/nuts/washers):
Will update after I get it installed.
Karl.
Will update after I get it installed.
Karl.
#23
looks great. Waiting on the feedback as I have a 997.2 c2s with pse, pdk and I’m considering this vs the Hayward smith option.
#24
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I installed it yesterday myself without a hitch. And if I can do it, believe me anyone can
I also captured some clips comparing the in-cabin sound of the Billy Boat vs. TopGear pipes:
My personal conclusions are:
So whether you'd like one type over another really depends on your own personal preferences.
Karl.
I also captured some clips comparing the in-cabin sound of the Billy Boat vs. TopGear pipes:
My personal conclusions are:
- 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.
Karl.
#25
I installed it yesterday myself without a hitch. And if I can do it, believe me anyone can
I also captured some clips comparing the in-cabin sound of the Billy Boat vs. TopGear pipes:
https://www.youtube.com/watch?v=UkOwoBR5Ksw
My personal conclusions are:
So whether you'd like one type over another really depends on your own personal preferences.
Karl.
I also captured some clips comparing the in-cabin sound of the Billy Boat vs. TopGear pipes:
https://www.youtube.com/watch?v=UkOwoBR5Ksw
My personal conclusions are:
- 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.
Karl.
About the video, with headphones on I could not notice difference in sound with pse on/off on either bypass pipes. Maybe its harder to capture on video.
I know for certain there is a difference between fabspeed vs sharkwerks bypass pipes. Former is more v8 American sound and latter more euroish
#26
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Personally I’ve found that when in the cabin, PSE-on results in only a modestly louder sound, especially with the windows closed. But if you’re outside and behind the car, the difference between PSE on/off is a lot more noticeable.
Karl.
#27
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You’re dead right, the (iPhone 6) video doesn’t capture the in-person reality.
Personally I’ve found that when in the cabin, PSE-on results in only a modestly louder sound, especially with the windows closed. But if you’re outside and behind the car, the difference between PSE on/off is a lot more noticeable.
Karl.
#28
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Do you mean the photo in post #24? Then ‘nope’, no crossover is installed in that photo (you can see the side cans sagging down a bit in that shot). In fact both the BB and TG pipes are on the ground in that same photo.
My car came with some type of aftermarket tips (which are a bit larger in diameter than the PSE tips). They’re 4x individual polished tips, individually welded to the 4x PSE exit pipes.
Karl.
My car came with some type of aftermarket tips (which are a bit larger in diameter than the PSE tips). They’re 4x individual polished tips, individually welded to the 4x PSE exit pipes.
Karl.
#29
Rennlist Member
Yes post #24. The tips look really low and misaligned so I was wondering if it was the BB pipes causing that as they did before. Is the fit/alignment good with the Topgear pipe? Do you have a pic of that?
#30
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1) Sorry, don't have a pic to hand.
2) Yup, the TopGear went in without a hitch, everything lined up. Now at the end of the day, even if you were just taking out and putting back in the stock central muffler, there'll be some degree of grunting/swearing as it's a tight space - but it's not the TopGear part's fault. In fact, because the TopGear bypass overall is less bulky than the stock muffler, it's probably a easier to put in than the stock muffler part.
3) Tip alignment is actually registered to the exit pipe from the side-can. In turn, the side-cans are partially registered to the cats, which are bolted to the headers/engine. That explains why you see sagging tips if your engine mount if failing.
In the diagram below, bracket #9 is connect to the 3-bolt flange coming out of the cats. In turn, bracket #9 lifts the side-can up into position (via bracket #17 connecting to a mounting point on the can). When you're removing the center muffler, you disconnect the two 13-mm nuts holding bracket #9 to the flange on the cat, and then bend the bracket back so you can wiggle the muffler off of the studs on that flange (that's where I had most of my grunting/swearing, I used a pry-bar). Installation is the reverse.
So the picture in post #24 showing the sagging tips is due to bracket #9 being disconnected at that time, hence the side cans sagging down. When you put everything back and bolt bracket #9 to the 3-bolt flange coming out of the cats, that pushes the side-cans (and hence the tips) back up into place.
Karl.
PS: The PSE cans have two exit pipes, so that area is more crowded than the normal setup. That's where the Billy Boat got into trouble...