robbonds

mdrume - will i see you at cars and coffee this saturday morning?

NVRANUF

If adding only aftermarket cans gives little or no additional HP over stock cans, how can you deduce putting stock cans downstream from aftermarket headers and sport cats will "clog" the system and give zero gains??? I don't follow your logic..... loud = HP ?

ianwallwork

The internal design of the 997S cans is much freer flowing than older Porsche designs. The outside of the cans look the same as the older and very restrictive 996 muffler but the inside is completely different. There are other threads somewhere with pics where somebody cut away the side of one.

It is because the standard muffler is already quite efficient that even a 'straight through' design shows almost no power gain. If the standard cans flow 355BHP perfectly well, they will not suddenly choke off the power if you add another 10%!

Mike Romano at AWE also confirmed that this setup would only lose 3-5BHP compared to a full system with their cans. If their claims are true then that would still mean a 30+ BHP gain (crank) and a quiet car. Stealth performance!

Ian

PS. I had PSEs on my 3.6 996 and Fabspeeds on my 3.4 so I'm not anti loud exhaust! I just do more highway miles now (and the British police show too much interest in loud cars)!

carmos

i got agency mufflers put in about 3 weeks ago or so...and today revo software loaded up.i like the agency mufflers alot they sound the same to me as the fabspeed mufflers and there 200.00 less ,i have heard a couple of cars with with the fabspeed installed next to my car..i had the fabspeed bypass pipes on,now thats loud...as to the revo software i notice it goes through the rev range above 4000 rpm smoother..i am happy with it.i also have a a k&n drop in filter and the fabspeed "cold air kit" aka the red tube...

synergy

I have the entire AWE setup for my 997S and love it!! AWE are masters in performance, craftsmanship and sound and I recommend them highly.

mdrums

I understand what you are saying but aftermarket mufflers AS PART OF A SYSTEM with headers and free flowing cats will give you the best chance of gaining power. Just adding mufflers or just adding hearders will not do much of anything with stock clogged up mufflers all though the muffler vendors claim free flowing mufflers will net you around 10hp. You can not fell 10hp though.

One thing I feel a lot of people on here confuse is the term exhaust. Exhaust is the by product of the combustion of the engine. Headers, cats, mufflers and the tubing connecting it all together is the exhaust "system"....mufflers on here are often refered to as exhaust and they are not exhaust, they are mufflers.

mdrums

AWE or Fabspeed or Tubi (the mufflers I've heard) are not all that loud. They do not even come close to the volume decibels of open by pass pipes. I have opened the stock 997 muffler and it has a lot of baffles which equal restriction. I have seen the inside of a Fabspeed muffler and it is a simple tube in the shape of a U and a lot less restrictive. What does the inside of an AWE muffler look like?

mdrums

My plane lands very late Friday night and I am over in Apollo Beach so it takes about an hour to get to the meet. I will try my best to get up early and be there by 8am. I've been wanting to check this meet out and bring my camera. See ya there...look for the tall guy with a silver/blue prosthetic left leg...I am easy to spot.

see ya! Mike

ianwallwork

Unfortunately I've not seen the inside of an AWE muffler but I'm assuming they'll be some sort of straight through design like the Fabs. However, the simple truth is that the standard mufflers cannot be restrictive if replacing them with a straight through design nets a negligible (well within dyno margins of error) BHP gain as per AWE's dyno graphs. And remember that the mere presence of baffles doesn't automatically mean a restrictive system. It's all about how the gas flows through the muffler.

Ian

Dave07997S

Exactly...I am going with new mufflers just for the aggressive sound. The power I believe will come form the more free flowing cats and better exhaust manifolds. I am not saying that AWE or Fabspeed are misleading about their products but I feel at best you are going to see with a full exhaust is maybe 10-15rwhp, software and CAI maybe another 5-10rwhp.

Dave

ianwallwork

Agree with you totally, and I think your estimates of power gains are about right too. Aftermarket mufflers on a 997S are about SOUND and (very) small gains; any meaningful extra power from an exhaust system change comes from the headers and cats. This is also different to the 996 where the stock muffler is very restrictive and claimed 8-10 crank BHP gains are realistic from a muffler change alone.

Ian

mdrobc1213

thanks for all the info. Have pulled the trigger and am having an AWE exhaust installed in the AM. Unfortuantely they are in the process of re-designing the tips and they won't be available until mid June according to my shop manager. I have a non-S 997 so the OEM tips will have to do for now since I am toldethat the OEM S tips would rub against my rear valence and possibly burn my paint there at the contact point! Oh well what is 2-3 weeks for the new AWE quad tips? Will post pics and observations soonest. thanks again.

synergy

Re-designing the tips? I have the AWE tips and have been looking at them latley and think they look too thin and the cut is too angled. In fact it reminds me of those cheap Monza tips I had on my mini truck in the 90's. When I first put them on I liked them initially but now I think it is time for a change. Any feedback on the changes they are making to the tips? I should call Mike and see what the deal is....

Anyway here are the current AWE tips:

mdrobc1213

Don't know yet...am at the shop now waiting. It seems that the AWE exhaust will NOT fit my OEM non-s tips so we are in search of a solution until the newly designed tips are released next month as the exhaust is now already on the car. Gotta have tips...

synergy

I know a few people who put back their OEM tips onto the AWE mufflers....they must have changed something as of recently. In fact, I ran OEM tips on my AWE system for quite some time and had no fitment issues....good luck and enjoy the music