msindi

I know that many of you here on the forum have tried several exhasts on your 996TTs!!
Some have even tried 2-3 systems until finding one they really liked.
Has anyone tried the above 2 exhausts (tubi and europipe)??
If so, what were your reactions?? I am more interested in the sound quality than the HP gain. I do not mind an exhaust being lous as long as it is a nice sporty throaty sound and not just NOISE!
I have a Tubi on order but do not like the non-removable huge oval tips it comes with and I am looking for something that will allow me to keep my stock dual tips (I know the Europipe offers that!!).
thanx for any input on this.

nyturbo

what about fabspeed quiet version?

Oak

I love the sound of the Cargraphic medium, you can also use the X54 tips. Some resonance around 2k-2,5k.

msindi

how much is the cragraphic?? Im not spending more than say $4200 on an exhaust!!

msindi

Oak,
What exhaust are you currently using?? I thought you got rid of the Cargraphic??

Oak

msindi, I am on my second Ruf exhaust it's the one that JackLA originally had on his turbo. I had traded with Steve-Indiana from funcars who had purchased originally from Jack but was abit too loud for him. I had a slightly quieter Ruf that he wanted, so we made a trade.

Oak

The Ruf made more noticeble torque. <img border="0" title="" alt="[Wink]" src="wink.gif" />

KPV

This is a copy of a post I made the other day. I brought it to the top of the list so you can read it. Its link is also below.

<a href="http://forums.rennlist.com/cgi-bin/rennforums/ultimatebb.cgi?ubb=get_topic&f=6&t=001793#000006" target="_blank">http://forums.rennlist.com/cgi-bin/rennforums/ultimatebb.cgi?ubb=get_topic&f=6&t=001793#000006</a>

If you are considering the EP exhaust system, get the Stage 2 Loud. During acceleration, it sounds fantastic! At idle it is only a marginal amount louder than the factory system. I did the install myself and it took me about 2 1/2 hours. I took my time and enjoyed the wrenching. Speaking of wrenching, EP even provides a selection of various wrenches to facilitate the entire installation. This manufacturer is absolutely top shelf as far as I am concerned. The product is a work of art, Stef's customer service is stellar (Stef is one of the owners), the provided tools are a bonus and the sound is simply fantastic.
I will be dynoing the car in two weeks and wanted to do a before and after but I couldn't wait to install it. Boys and their toys!!
my factory system is for sale if anyone is interested.
<img border="0" alt="[burnout]" title="" src="graemlins/burnout.gif" />

KPV

This is also a copy from a previous post of mine. I thought it would apply here as well.

Just some food for thought..........

The stock exhaust has expansion bellows between the two resonator canisters.

The Europipe has expansion bellows between the two resonator canisters.

The Fabspeed and Tubi does not have expansion bellows.

As we probably all know, engines expand and contract with heat and cold, respectively. They do this in accordance with a predetermined engineering principle utilizing the coefficient of thermal expansion. For steel it is .00065, for aluminum it is .00128. For a 200 degree temperature differential, and assuming a 911 boxer engine is approximately 3 feet wide (from turbo to turbo), this translates to approximately 1/16 inch of expansion for for steel and 1/8 inch of expansion for aluminum. A 996 TT exhaust system must be capable of undergoing this cyclic stretching and relaxing since it is tied to the turbos at each side across the opposing banks of cylinders. The bellows in the factory system and the EP system take up this expansion/contraction. The Fabspeed and Tubi, unless I missed something, must take up this e/c in the tubes, resonator chambers, cats and welds as a unit.

Back in 1986, the first model year 944 Turbo had a factory recall wherein they replaced the original exhaust manifold with a version with a bellows in it. This was to account for the inability of the original manifold to sustain the cyclic expansion/contraction stresses and the resulting broken welds.

Again, just some engineering observations or my $0.02 if you will.

msindi

KPV - out of curiosity what did you study or waht do you specialize in (work-wise)?? I ask because you see mto know a lot of engineering stuff (I myself have a Chemical Engineering degree from MIT)
Engineering is awesome! <img border="0" alt="[thumbsup]" title="" src="graemlins/bigok.gif" />

KPV

Msindi,
I hold a Masters of Structural Engineering Degree from Stevens Institute of Technology. I also own and operate my own engineering company designing buildings and structures. I also have a great amount of hands on experience with cars, building projects, electronics, etc. Couple it together and it makes me either really knowledgable or really dangerous. <img border="0" title="" alt="[Wink]" src="wink.gif" />
Seriously though, my structural engineering experience, with my background in mechanics of materials and all of the other courses I took over the years gives me some good insight with certain things. I treasure my engineering education and I find it a shame that there is not as much interest in it by today's college bound masses. We need engineers!!

fish5225

KPV
Does the Ruf have this same expansion capability? Seems essential for longevity. Fish

KPV

Fish,
The RUF is remanufactured from a factory unit, so yes, it does.

viperbob

Just as further proof of what KPV is stating, has anyone had an older 911 with a B&B header exhaust?? Will not exactly like the 996TT, similar configuration. The pipes coming off the collectors were slip fit into the muffler (allowing for this expansion) and then the screw up of all screw ups was the mounting bands around the muffler. While they took the expansion of the exhaust into account, the muffler guy did not causing everyone to carry two or three extras to the track as they break under the expansion of the muffler. Porsche on the 993TT uses a similar band to strap the muffler to a mounting bracket, but the band has waves / bellows structure built in to allow for this expansion.

KPV

Chad,
Question, how tight should the EP hanger clamp allen bolts be? Viperbob's comments regarding what I interpret as a temperature induced diameter change of the resonator canisters will increase the tension on the straps and bolts. I originally really torqued them but then loosened them a bit.