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Discussion Starter #1
Bassani and Corsa, and I'm sure a few others, sell crossover pipes. Both claim better exhaust flow, increase in power and a "throatier" exhaust note. Both also say they are not legal for street use.

Questions:
1. If GM tweeked our Z06's for greater HP and torque, why didn't they find "extra" HP and torque by redesigning the X pipe?

2. Do these pipes mellow out the exhaust tone?

3. Since the entire exhaust system remains unchanged(except for this pipe) why is it not street legal?

To those that have installed these WITHOUT any other exhaust mods...your opinion and comments please.

Thanks

Charlie
 

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The off-road x-pipe eliminates the cats completely, thus the off road designation. The on-road version which keeps the cats intact really doesn't add any power but elimintes the burbling sound on decelleration and cuts back on some of the resonance inside the car. I don't know this first hand but I've tracked other posts on this subject.
 

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The x-pipe is also supposed to provide a "balancing" of the flow and burn as well.
 

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I had a Bassani xpipe on my 99A4 with corsa indy's. The xpipe cut down the burble on decel, cut the resonance out and smoothed the flow of the exhaust. When I had it on the dyno, it sounded awesome at an indicated 163 mph!!
 

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Discussion Starter #5
Thanks for the responses...however...

...Aren't there more of you out there with crossover pipes installed? I can't believe only 3 responses to my questions:(

C'mon now, I'm really looking for some feedback.

Thanks

Charlie
 

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I have the Corsa X-pipe, there's nothing that I can see that would make it illegal for the street. It requires cutting the exhaust pipe after the cats, but no welding; bolts into place. As mentioned, it balances the exhaust flow between the 2 sides, and in doing so also quiets the exhaust note down a little.

As far as why GM didn't do it themselves, I'd probably guess just for some extra cost-cutting (You could say that about pretty much any bolt-on that replaces a stock piece for better performance). The H-pipe that is currently on there is probably much cheaper to make than bending pipes to form the X.
 

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I spoke with my custom exhaust guy the other day (he sees alot of different cars from everyone, very popular/great work) about what he saw other people doing and if he heard any negative/positive responses. He said he put the Magna-flow unit on for an engineer customer who tests EVERYTHING! (sound familar), anyway, that paticular manufacturer's design LOST 5hp. :( DR. Gas say's it was poor placement for fluid dynamics. Dr.'s set-up won't be ready for a few months (arg!), so I will hopefully be testing the Breathless unit. Ernie claims it really works and that he already dynoed the 2002 with it and verifyed it, "qoute unqoute". I should know within a week or two. I do have to admit I will be trying the unit directly behind the 2002 cats and modifying the X-unit with sensor bungs, since the sensors will need to be located in the X-unit for proper placement. This is where the Dr. says the best results will be found, as always, closest to the motor. Not just where it's convienant! ;)
 

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Another thing to consider is the fact that using a bolt on pipe that requires cutting and slipping on a new unit using ehxhaust clamps takes away from the smoothness of the inside of the pipe. I got up close and personal with my exhaust yesterday when I gutted my pups and GM did a pretty good job on the stock exhaust where quality is concerned. All of the bends look very clean with no flat spots and there are no unnecessary welds or breaks in the pipe. An x-pipe may have some benefits but if I were to put one on my car I would want it welded with no slip joints.
 

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I had a Bassani put on my 02 along with the header installation. It's a legal mod because the cats are not touched. I don't have data about the horsepower gain. I can tell you that the headers/X-pipe mod on the 02 made a much bigger difference than the headers alone on my 01 Z06. Hot Rod Magazine did a comparison several months ago; they tested a car with open headers, an X-pipe through the mufflers and an H-pipe through the mufflers. The X-pipe made almost as much power as open headers.
 

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EBZ06,

Could you see where they actually placed the X in the article.
 

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Ernie at Breathless is installing on road x-pipe and his long tube step headers today on my '02 Z06, will pick it up tomorrow morning. I also have the complete Halltech T-1 package. Will be checking out the Reflections Vette show Saturday in Coconut Creek then heading over to Bradenton for the Vette/Viper Shootout. Hope to get a few runs in on the strip & get some indication what the new headers & x-pipe will do. I have never raced on a drag strip before, only on the street. It will be interesting.
 

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ZDOG,

Since you're picking up your car, maybe you could ask him also what his X-pipe alone is worth and to maybe see a dyno sheet on the results for the '02. I would really like to see some hard data/print on the claims. If I'm not mistaken, he is one of the ones who says he dyno's everything. And if it don't show, he doesn't sell. How about some upclose and personal help here to verify that. We all know the headers are going to work. :)
 

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MrZ06

Ernie claims the street version X-Pipe shows 9 HP and 8 lbs torque increase, not bad for price of about $116.

I picked my car up today with installation of long tube headers & X-Pipe completed. Changes are quite interesting. The burbling, popping sound is almost completely nonexistant now. When you back off the throttle, it is at least 90% gone.

When the Z is started the initial ignition explosion seems less prominate than before. The overall sound is less rough, almost more civilized, but smoother, deeper and very very sweet. I am quite pleased. It is very authorative at WOT.

Most important, the Z runs very strong. Definitely more power than prior to installation. Traffic is bad here in South Florida on a Friday afternoon and I have had limited opportunity to evaluate. I can say this, on my one and only WOT run in competitive mode I fishtailed almost completely through third gear.

I was most pleased with Ernie and the crew at Breathless Performance Products, a professional, quality installation. I decided to order the Procharger supercharger from them. Breathless will do the installation complete with intercoolers and new software. It should be installed by mid March. Ernie says we should be running around 600 HP at flywheel. I just can't wait!
 

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I am having the headers and x-pipe done at BPP, removing the pre-cats in the process too. I was supposed to have it done this past week but there were complications with the parts, at least that is what I was told. I hope to be down there soon and have the work done. Thanks for the feedback. Did you do any pre & post dyno runs?

Don
 

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So, everyone I see who has tried the X-pipe has either installed it with headers or deleted the cats.

I tried the BPP X-pipe and it felt like a banana in the tail pipes. :puke: And sounded like a single exhaust LS1. :puke:

You cut two (2) 2 3/4" pipes to install a piece that is pinched to maybe one (1) 2 3/4" size in the middle.

My exhaust guy said "It'll never work"

I looked at it and said "It must be a velocity vs. volume thing, even though its NOT a Dr. Gas Product." :-?

"It's supposed to make 9 hp." :p :lol: :lol:

I had him take it out and it was back to that Z06 open, hollow, growl sound and back to rev'ing freely. :)

He asked me, "So where's the 9hp" I told him "They forgot the MINUS (-) sign in front of it!" :eek:

So owning a muffler shop I asked him how much the retailer had in this thing? He said "Since there's no mandrel bends, $1.25+$1.25, about $2.50-$3.00" :eek:

If anybody, but the retailer's cash register, has seen this thing work by itself on the plus (+) side, I'd like to see it!
 

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Did you dyno it before and after the x-pipe or just listen to it?
 

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Drove it for two days and a total of 50 miles at up to 80 degrees in the day and down to 48 degrees at night to make sure it wasn't a warmer day effect or something.

In and out of the car, cool downs, multiple test drives, scaner on, every test drive the same thing. :puke:
 

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No quantitative metrics then, just your impression... Thanks.
 

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It FELT SO BAD I was afraid to waste the dyno session I had the 2nd day. :puke:

So I stopped and had it removed first thing in the morning before the dyno run.

It still scares me to think how low the numbers might have been!

It really felt that BAD.

Still looking for somebody, besides the retailer, who has actually had any INDEPENDENT success with it by itself.

2001Z06, Have you by any chance?
 
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