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I don't want to start another "best sounding thread." Currently own a EP2, looking into a lighter and better performing system. 3" straight pipes wouldn't bother me but, I do have emissions to pass from time to time. A straight pipe system would have to have the ability to swap a cat pipe for actual cats "when not at the track of course."
Do you have a 997.1 or 997.2? A few of us have the BBI exhaust, which uses the FJS cats as the mufflers relocated from the stock location to where the mufflers ordinarily go. EGTs remained low enough to not cause issues even when running 24psi in the heat of a desert airstrip event. Sound is obviously subjective and "best sounding" like you said is different for everyone...but I can tell you what the BBI exhaust sounds like...it sounds like a combination of a GT2 and a GT3. Basically a higher pitched GT2 and no decel dump truck sound...instead you get gurgles and pops on decel. Its a work of art IMHO.
If given the choice, I would not choose a classic X design where the exhaust gases crash into one another at the merge point. Many have argued that the X creates a bottle neck in these types of exhausts . This may not be a issue for street use but might be under prolonged track use. Several exhaust manufacturers I have talked with have confirmed this also and it seems to make sense when you think about it. A better solution in my opinion is an exhaust that uses pipes that form two "U" bends that have a small cross talk between them where the exhaust gases from the left and right bank just kiss each other instead of crashing into each other.
Here is a great option: SpeedTech 3" X-Pipe, modular design with easily swapped HJS cats and/or cat bypass pipes.
Very lightweight with full 3" flow and fantastic sound, as well. Pictured with dual, full 3" tips, but can be supplied to re-use the OEM tips.
This would definitely give me the flexibility with the Cat issue. In fact, I was looking at this setup last night. What's your thoughts on what Pwdrhound stated below?
Longborder - you make some valid points. What exactly is "best sounding." Your explanation sounds good. I have a 997.1 with EP2. The EP2 has a nice deep sound with no drone, its pretty and also pretty heavy (64lbs.)
pwdrhound - when do you expect delivery on your unit? Nice to see you decided on the TI version. Your explanation on the X design "thermal zone" makes sense. To me, I would think that this area would be hard to control flow. Looking at your photo, the volume where the 4 connect doesn't appear to match the total volume / diameter of 2 pipes.
This would definitely give me the flexibility with the Cat issue. In fact, I was looking at this setup last night. What's your thoughts on what Pwdrhound stated below?
I totally disagree. I can not speak for others, but our systems do not change color in the middle due to heat, even after 10's of thousands of miles and flow extremely well, as they are a straight through design and our "X" is enhanced to allow clean flow. You can clearly hear the turbos spool and whistle, which is a sign of superior flow and no restriction. We have experimented with other "X" designs, specifically the design pwdrhound is describing and found the sound to be of a much lesser quality than we achieve, actually horrible by comparison and the drone level to go through the roof. It is clearly not what our customers are looking for...We have good reason to do it the way we do and with our proprietery "X" and tip design, we achieve a very exotic sound, much like the Italian exotics, great power and complete comfort in the cabin due to the frequency we have developed with our overall design. This combination has been extremely well received in the market.
For example, here is some feedback we received from one of our 997TT 3.0 X-Pipe customers that hangs with some of the Italians:
John, I thought you were being a little optimistic with that statement ("it will compete with any exotic"), as anything is better than a stock or straight pipe sound, but my friend, YOU WERE NOT JOKING!!
I am so giddy to finish work to just drive home, my friend, it is insane - the tone, shriek up top, the friggen turbo whistling everywhere.... it is intoxicating!!!Well done, good job!!!!
If you read our testimonials, you will see many more forum members speaking out like this...so this is why we do it like we do. I use one on my own car and I have to tell you, the experience of driving from inside the car is very similar to the aural experience of operating a Ferrari F430 and it has transformed the Porsche Turbo driving experience to a level that is hard to put into words. It's epic! Other designs are not like this - I have used, tested or heard pretty much every one of them and IMO, we have achieved something very special...and the customer feedback/reinforcement to let us know we are doing things right continues to come in every week.
I had the Speedtech system on my 996T (but it had a muffler), with over 10 000km and other then the WHOLE system having a light amber tone, IT NEVER DID what that system did. My whole Speedtech system, including the "X" was all one color. I only have 1000km on my 997T with this same system (but with out muffler) and it looks brand new.
I understand for turbo cars the bigger the diameter and shorter the distance for the exhaust is better ( I ran a 4" down pipe to a 3.5" QTP electronic cutout right off my down pipe in my Supra days!!). I have been around turbo cars A LONG time, actually all my driving life! If everyone on this forums was looking for a race car 1200hp beast, we would all be driving around with straight pipes as the absolute best solution to peak hp!! I believe a lot of individuals are more like myself (concerning an exhaust) that are driving true STREET car: wants a exotic sound to match the emblem of car we are driving , looks the part, supports 500-800+hp...bottom line something that makes HP and stirs the soul when driving.......what I have does all that and more!!!
I purchased my 997T with straight pipes and NOTHING would make me want to gain a few hp even if I was making 1000+hp and give up the system I have for a true exotic street car!! I can say with the system I have, that switching back over to even straight pipes I am pretty confident I wouldn't be faster. If I didn't sell my straight pipes I would of VBOX the difference (I was going to, but all my other mods came in the same time...63.5mm turbo, ERP triple with LWFW etc)
The system I have is so free flowing and the numbers do not lie. I have a member that lives near by and I have the exact same Proto tune (Todd used it as a base TUNE for my car as we use the SAME 94 Petro Canada Fuel & live in the same area etc), the same Proto 63.5VTG turbos and after talking to each other we test very conservative under the same repeatable conditions (how I do my 60-130 times: https://www.6speedonline.com/forums/...ight-pipe.html) . The other member Vboxes 60-130 7.2 WITH 997.2 INTERCOOLERS (AWE EXHAUST) and I do 7.1 WITH STOCK intercoolers (3"Speedtech Exhaust). Now I do have a 82mm GT3 throttle body, 82mmIPD plenum and EVOMS LW crank pulley, but most would agree those are more for throttle response (which is CRAZY by the way with my ERP Triple LWFW) and would not come close to the performance advantage to me having instead 997.2 intercoolers for 60-130 times. Lets say my extra mods at BEST case scenario equal out compared to his 997.2 intercoolers. Considering exhaust plays such a vital role to turbo performance wouldn't we see a bigger difference in times. So much between the cars that really matter for performance are the same between the cars (exact fuel, climate, exact Proto tune & turbos) and we run almost the same times!
I could of purchased a 1400RWHP supra (almost did BTW) or even a GTR etc..... but I bought my 911 for the whole experience and this exhaust completes that exotic experience period!!
I understand to a point what you are saying about the merge, but for the 95% of the 500-800+hp 911 customer, it does not measurably effect performance, but adds a considerable other joyous experiences that are measured by the smile that extends from ear to ear!!
Cheers and enjoy either which way you like YOUR 911!
Thanks
Bobby Ali
ba
Originally Posted by pwdrhound
If given the choice, I would not choose a classic X design where the exhaust gases crash into one another at the merge point. Many have argued that the X creates a bottle neck in these types of exhausts which appears to be true based on the purple heat discoloration at the "X" of the exhaust pictured below. This may not be a issue for street use but might be under prolonged track use. Several exhaust manufacturers I have talked with have confirmed this also and it seems to make sense when you think about it. A better solution in my opinion is an exhaust that uses pipes that form two "U" bends that have a small cross talk between them where the exhaust gases from the left and right bank just kiss each other instead of crashing into each other.
If given the choice, I would not choose a classic X design where the exhaust gases crash into one another at the merge point. Many have argued that the X creates a bottle neck in these types of exhausts which appears to be true based on the purple heat discoloration at the "X" of the exhaust pictured below. This may not be a issue for street use but might be under prolonged track use. Several exhaust manufacturers I have talked with have confirmed this also and it seems to make sense when you think about it. A better solution in my opinion is an exhaust that uses pipes that form two "U" bends that have a small cross talk between them where the exhaust gases from the left and right bank just kiss each other instead of crashing into each other.
Conversely, if given the choice, which I actually have every day, I would not choose an exhaust with two U-bends that barely "kiss" or have a meaningless amount of cross-talk between them. In effect, you create the sound of two 3 cylinder motors, which IMO leaves a lot to be desired. When you combine this with a straight U-bend pipe and no mufflers...well I have tested it and let's just say that I would never have it on my car. Additionally, the exhaust has to travel all the way around the "U", which hinders flow, whereas with an X-Pipe the way we design it, the exhaust has a choice to go either way after the merge, so it has dual 3" pipes to expel and it will naturally take the path of least resistance. When you look through our 3" X-Pipe, you see a lot of daylight. The exhaust gasses do not have to work very hard to exit with our design. We also create a very large merge point that is the better part of 6" wide x 3" deep. What this all adds up to is superior flow and sound. Fortunately, we have had the ability to test various designs on our test car for sound and performance and after extensive testing, we went with the unanimous choice of our team, all of whom drove, listened and experienced the various system designs first hand. Nobody liked the dual "U" bend style with a small degree of cross-talk. Simply put, it left a lot to be desired and we improved upon it, until we were satisfied with our offering. That is our experience...but if "U" bends makes you feel better, fine, that is why there are alternative products on the market. We have had several customers who purchased a "U" bend style X-Pipe, only to call us within 2 weeks of their initial purchase (unhappy with the sound) to order a SpeedTech X-Pipe and sell the other...then come back and tell us they wished they would have ordered a SpeedTech in the first place. This has happened several times.
In the end, I think Bobby has summed it up perfectly above. Thanks for your feedback, Bobby, I appreciate your insight and contribution to this thread.
12-02-2014, 11:45 PM
