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I use similar design from fabspeed -installed it may be in 2010 or so.
Expect some minor cutting of pipes and be careful with cat bolts connecting to headers. Be careful where you get cats from. Bad cheap cats may desintegrate and get sucked back into motor and then you will have to shell out for a new one. So I would not buy such things from eBay, ever.
Can you help me understand at which point of the combustion cycle does the engine suction air back into the cylinder thru the exhaust path ?
I believe that there is a secondary air injection system (known as SAI or SAS) that helps the cats get up to temp as well as burn off any un-combusted fuel so that it does not go out into the atmosphere.
In other words, some exhaust gases get re-routed back into the engine to be re-burned for emissions purposes. This technology has been used for years.
.....there is a secondary air injection system (known as SAI or SAS) that helps the cats get up to temp....
This is also my understanding.
Originally Posted by 82_930
...... some exhaust gases get re-routed back into the engine to be re-burned for emissions purposes......
This is different than my understanding. The exhaust gases DOES NOT get re-routed back into the engine, the additional [fresh] air is injected by the SAS (secondary air-pump) into the intake manifold during cold start to create a lean condition so the exhaust gas is hotter to get the CAT up to temp faster.
Can you help me understand at which point of the combustion cycle does the engine suction air back into the cylinder thru the exhaust path ?
Throttle closed, engine decelerating or being driven by the drive wheels. Severity is highly dependent on camshaft characteristics.
Not sure if our 997 camshafts have this characteristic where this would be a concern (overlap, intake valve and exhaust valve open at the same time)
Can you help me understand at which point of the combustion cycle does the engine suction air back into the cylinder thru the exhaust path ?
it had happen more than once when those cars were new and people were experimenting with back then new 100cell and 200cell cats in custom made exhausts and were blowing up their motors on the track.
then list of companies supplying those modded cats and headers has dropped dramatically and prices somewhat stabilized.
Be very careful when purchasing catalytic converters. The factory cats are notorious for failure, not just in setting a CEL but in breaking apart and/or separating from the outer shell causing rattling and chunks of cat core making its way down the rest of the exhaust system. The last thing I would want as Porsche owner is to put myself in the same boat as before, and i'm sure you would agree.
Taking this into consideration, we import the highest quality cat cores available on the market from HJS in Germany, and utilize them in the fabrication of our Sport Cat X-Pipe. In addition, we use the highest quality T304L we can get our hands on from the same US supplier we've been using for over 15 years, and we get their best batch. We also use an investment cast X, to maximize the consistency of exhaust flow at the merge between products and eliminate welds in the center of the system for more reliable structural support of the exhaust system. We are here to maximize the quality and longevity of our products, with the goal to outlast the life of your car
I emailed Phoenix directly a few days ago, but no response. Perhaps I will try the Top Gear site.
So I exchanged a few emails with Phoenix about a group buy, but haven't heard back since I asked them for more details on pricing and cat manufacturer. They did tell me their products are UK made.
I also inquired with Top Gear about a groupbuy, but no response either. Unfortunate. However, they have good reviews on 911uk.com as a 'price conscious' brand, shall we say, but with good fitment.
I have heard back from Phoenix. They actually carry the Top Gear systems, with a focus to marketing to the North American market (with Top Gear's blessing).
I'm awaiting a bit more information, and then should be able to announce a group buy!
I have heard back from Phoenix. They actually carry the Top Gear systems, with a focus to marketing to the North American market (with Top Gear's blessing).
I'm awaiting a bit more information, and then should be able to announce a group buy!
Sorry if I missed it, but was there ever a definitive conclusion as to whether these cats are HJS or not?
Also, can anyone speak to the sound difference after installing the top gear catted x-pipe? I'm looking for a slightly higher pitched, GT3ish sound. SpeedTech claims to accomplish this with their x-pipe, but of course I like the top gear price
01-29-2017, 05:11 PM
