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Discussion Starter · #1 ·
Can everyone with an aftermarket exhaust comment on what performance benefits they've gotten.

What are the performance differences between axel-back, cat-back, and turbo-back?

Difference between 2 cats, 1 cat and 0 cats.... Anything.

I'm just trying to gauge what is worth doing and what isn't. The sound isn't really a deciding factor other than I don't want to sound like a rice-mobile with a fart pipe on the back.
 

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The first component aft of the turbo is the downpipe. The stock one is HORRIBLE. The wastegate gases meet a flat wall and generate large amounts of heat. Without a doubt, after the uppipe, the downpipe will give you the most benefit. In fact, TurboXS found that using a large enough tapered DP, you could run any muffler you want (including stock) and not lose any performance (<1-2HP).

-Jim
 

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Picked up 3/10ths of a second and 1.25mph from a TurboXS stealth (stock muffler) turboback... I love it!
 

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Once the turbo reaches full boost, the boost controller sends a vacuum signal to open the wastegate. This diverts the exhaust gases around the turbine so no more boost is made. The stock DP has a pipe for the turbine outlet welded to a flat flange that covers the wastegate outlet on the back of the turbo. Clear?

-Jim
 

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Discussion Starter · #7 ·
Got it. Thanks. So basically, anything turboback is the best bet (makes sense i guess).

is2scooby, I've been looking at the Turboxs stealth. Made more sense to me to spend the money on the important elements of the exhaust system then pay almost the same for a cat back and get the muffler section, which i really don't care about as long as it performs as well.
 

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re: Not losing too much performance with a stock muffler - this is an e-mail reply I received from the AWESOME guys at TurboXS after asking how much performance I'm leaving on the table by running the stock muffler with their TurboXS stealth turboback exhaust system. They are a real class outfit!

"You will lose about 7-10 HP by running the stock muffler on our Stage 2
kit and about a 10 hp to the wheels gain on an otherwise stock car.

Thanks,
Phil
TurboXS..."
 

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is2scooby said:
re: Not losing too much performance with a stock muffler - this is an e-mail reply I received from the AWESOME guys at TurboXS after asking how much performance I'm leaving on the table by running the stock muffler with their TurboXS stealth turboback exhaust system. They are a real class outfit!

"You will lose about 7-10 HP by running the stock muffler on our Stage 2
kit and about a 10 hp to the wheels gain on an otherwise stock car.

Thanks,
Phil
TurboXS..."
Stage 2 does not include a turboback exhaust. It is a catback only. If you use the Stealth exhaust, you eliminate two cats and replace them with one high flow. I am almost certain that the stock muffler vs. the TXS muffler is only a 1-2Hp difference.

-Jim
 

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Stage 2 Kit (approx 303 HP vs 269 HP Stage1): $1799

Pre-programmed Unichip Piggyback Computer

TXS Plug & Play Harness

4" Stainless Steel Downpipe

3" Stainless Steel High Flow Cat

3" Stainless Steel Midpipe

2.5" Stainless Steel Muffler Assy

Resonator Box Removed

Taken from www.turboxs.com
 

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TurboXS Stage 2 includes the piping that replaces the stock piping normally called the downpipe and the pipe with the 3d cat.

From http://www.turboxs.com/ :

"Stage 2 Kit (approx 303 HP vs 269 HP Stage1): $1799
Pre-programmed Unichip Piggyback Computer
TXS Plug & Play Harness
4" Stainless Steel Downpipe
3" Stainless Steel High Flow Cat
3" Stainless Steel Midpipe
2.5" Stainless Steel Muffler Assy
Resonator Box Removed"



Edit: Darn! Took to long to search, cut, paste and post!
 

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:D

Seems like Phil @ TurboXS is convinced I'm leaving at least a couple of ponies untapped with the stock exhaust - but the cost and my lack of enthusiasm for the single tip keeps me from picking up the TurboXS muffler. I have heard the sound is great though!

If I decide to go for an exhaust (I'm still undecided) - I'm leaning towards the Prodrive muffler. I'd love to just be able to change the sound (slightly) of the car while retaining the stock look though...

Look at the claimed power gains of the Stage 2 TurboXS system and it seems UNREAL that it's basically a full exhaust and a chip that get you that kind of power! Approximately 303 hp from full exhaust, a Unichip, and a K&N.

I've got as much of the exhaust as I plan on changing (at least at this point), and a K&N and the resonator hack. I wonder if I purchase a Unichip if I'm going to be close to that 303 hp claim. I know I'm ~10 horses down according to Phil, but hey ~290hp is fine for me! :D

I'll just see if I can make up the difference with a MBC tuned to 15.5psi. :D

Aloha,
Richard...
 

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is2scooby said:
:D

Seems like Phil @ TurboXS is convinced I'm leaving at least a couple of ponies untapped with the stock exhaust - but the cost and my lack of enthusiasm for the single tip keeps me from picking up the TurboXS muffler. I have heard the sound is great though!

If I decide to go for an exhaust (I'm still undecided) - I'm leaning towards the Prodrive muffler. I'd love to just be able to change the sound (slightly) of the car while retaining the stock look though...

Look at the claimed power gains of the Stage 2 TurboXS system and it seems UNREAL that it's basically a full exhaust and a chip that get you that kind of power! Approximately 303 hp from full exhaust, a Unichip, and a K&N.

I've got as much of the exhaust as I plan on changing (at least at this point), and a K&N and the resonator hack. I wonder if I purchase a Unichip if I'm going to be close to that 303 hp claim. I know I'm ~10 horses down according to Phil, but hey ~290hp is fine for me! :D

I'll just see if I can make up the difference with a MBC tuned to 15.5psi. :D

Aloha,
Richard...
I'd recommend ignoring the extrapolated crank HP numbers put forth by any tuning shop. The @wheel dyno numbers are somewhat more meaningful, but still not gospel.

Frankly put, most experts consider 300HP+ on the stock turbo to be optimistic at best.

-Pace
 

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bedabi said:
Personally, I'm waiting for the release of the Vishnu downpipe.

C'mon Shiv, hurry it up!
Nothing against Shiv, and I understand his motivations for the extensive testing; but man that guy has lost a lot of business due to the delays in the release of his products. It just doesn't make sense for most people to wait an extra year for a Vishnu product when TurboXS and others have just as good items readily available NOW.

Just an observation.

-Pace
 

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Well, I have a custom uppipe/downpipe....0 cat...with a HKS Carbon/Titanium on the end, its LOUD as hell but nice performance gains...im debating the Maxim manifold....it seems like the only place to go now....no nos.
 
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