smitty2919

After my wife drove my car in a parking lot and hearing the TERRIBLE exhaust note caused by the stock H pipe, I knew it was time to correct this. Both videos are stock manifolds, stock cats and OBX style catback. The only thing I did was cut out the stock h pipe section and weld in a Cherry Bomb 2.5" x pipe.

H pipe...note the motor boat/flutter to the exhaust tone:

X pipe...much smoother tone:

X pipe used...this was no bolt in...since the stock H pipe is roughly 4.75" on center between the main pipes, nothing remade would fit. So I cut the legs at the proper angles, flipped the ends 180* to create parallel inlet/outlet legs and welded it in. The welds and internal transition is very well made:
https://www.summitracing.com/parts/IMM-429835CB

Thought I would post this for anyone curious. Oh and my 03 (if this is truly a late model mid pipe) still only had a 1/2" hole for a crossover.

Mike98SilVert

Big improvement. The X-pipe sound so much better.

smitty2919

It's crazy how much better it sounds. I was horrified being outside the car when my wife drove it. I instantly hated the sound lol.

Total investment:
Week worth of x pipe selection research and planning
$30 x pipe
couple hours of actual wrenching/welding

I'm happy vs the alternative of $200+ premade Borla/Corsa x pipes. But realize not everyone has the tools/knowledge to fabricate this.

Vetteman Jack

An x-pipe can make a big difference in the sound of the exhaust. Not much power gain, but a much better tone can be had.

grantv

The H pipe sound bothered me as well. Switched to an X when I installed my TSP headers. Much better!
It really surprised me to find that nobody had a simple X to match the C-C dimensions of the C5 exhaust. I bought a Magnaflow unit and had my fabricator widen it to suit.

mstromquist

Wow, much better sound. I may have to pay more attention to mine now since I still have that H pipe installed. Thanks for videos.

redzg

I honestly don't hear enough of a difference to matter. Must be the age of my ears, I guess.

smitty2919

I agree. The issue is when you cut the stock h pipe out, there are many ways you can get the rear flanges misaligned. Since there are no hangers supporting/holding the over axle pipes of the catback in place, you lose spacial relationship to the midpipe.

Once the h pipe is cut out, you need to be sure to have the proper rotation/angle/front to back distance correct for the catback flanges to line up again. The Corsa/Borla x pipes do all of this for you so people only need to make 2 cuts on the stock midpipe...the slip fit at the front of those x pipes takes care of the front to back variation.

ArmchairArchitect

Thanks for sharing. This seems way more affordable than the big brand X pipes and a viable option. I'm guessing it leaves the factory cats in place?

How much do you think an ordinary muffler shop would charge to do this? And with the possible alignment issues would it be risky to go this route, or since they're experienced there's less a chance of that happening?

knewblewkorvette

I guess I'm the minority, I like the sound of the h-pipe over the x-pipe. That's the one mod I regret on my 02, I replaced the h-pipe with a Magnaflow x-pipe. I have the Billy Boat Bullet exhaust. I'm immature as I love the gurgling during the deceleration and the x-pipe took that away.

redzg

You're not the only one...
That said, I'd like to hear a true H-pipe, with more than a 1/2" hole for the cross pipe.

smitty2919

I wouldn't suggest a muffler shop use the x pipe I bought since it requires them to cut then ends at a 9* angle (x pipe uses 18* bends) AND at a point that when the ends are rotated they are 4.75" on center...By the time they do all this, I bet you are nearing the price of the Borla/Corsa units. Used ones are around $200-$250 and can be done in your garage with renting an autozone tool for $50 and some jackstands.

But if someone offered one of those stamped X's which already have parallel ends with proper centerline distance, absolutely use a muffler shop. Which may be $150 or so?