[squidtone]

I've got a 67 GTO and I've saved up the dough to buy the exhaust system. I'm restoring the car to be essentially stock and it's got stock exhaust manifolds.
I've already purchased the long case Dynomax Super turbo mufflers. (p/n 17749 I think)

I've decided to go for a Pypes system, but I can't decide on X pipe or Non-X pipe system.

I like the idea of the Non-X system because it can be tucked up closer to the floors, and I HATE low hanging exhaust systems.

But I also want a pretty quiet exhaust. I've read here and there that the X pipe system is quieter. So How much quieter is it? I listened to the pypes sound file of the NON-X pypes with Dynomax super turbos on the 68 GTO, and frankly I think I'd prefer a quieter system. I couldn't find a sound sample of a X-pipe system with Dynomax SuperTurbos.

If the X-system is significantly quieter, I'll give up the clearance and go for the X.

If anyone has some experience with the differences, please let me know.

Thanks!
Dave

[PontGuy]

I've got a mild-built 462 with RA manifolds feeding into a 2-1/2" Pypes system with the Dynomax mufflers. Listened to it going down the road for the first time this past weekend when my wife took the car off for a drive. It really is quiet- probably no louder than the stock exhaust on my 06 GTO. The X really does reduce the individual pulses a bunch.

If you are careful with the installation there is not that much loss in ground clearance. My X system is not really visible without looking up under the car. And if you have good springs so your ride height is stock or a bit higher then there are no concerns with speed bumps etc.

I don't have a sound clip but might make one if nobody else already has one.

Walt

[CROS34]

I installed the Pypes X- system on my ’70 TA a few months back and it was significantly different. So much so that I cut the x-pipe apart and welded in a blank to create standard duals. I just wanted to hear the difference between two identical systems, so the type of muffler or the size of pipes was not factors. The system with the X-cross over was much quieter and with little to no resonation. Without the X-cross over, (straight duals) it was much louder, but now with the significant resonation at 2300 to 2600 rpm. Personally I like the sound of the straight duals, but I can do without so much resonation. In the future I may try allowing some cross over to see if I can lose some of the resonation and still keep the sound that I want. BTW I cut the X cross over out altogether after my experiment and welded in clean 2-1/2” SS pipe to get full flow. Hope this helps.
John

[PontGuy]

What CROS34 is saying sounds exactly right. If you are looking for a real performance sound then the X is probably not what you want. But its really nice to be able to cruise and talk without having to carry over the exhaust note. Even with the X, I do have a bit of a drone around 2000 RPM but its just enough to let you know the exhaust is there. And once over 2200 RPM or so the drone is gone.

Walt

[bonneville Joe]

I heard Walt's car a few weeks back. Sounded really good. Not loud, the idle sounded like that classic GTO tone but when you gave it throttle you could hear the rasp of the X pipe behind the car. I liked it.

[squidtone]

Thanks guys for the responses. I think I will go for the X then. I suppose the worst case I will just eliminate the X if it hangs down too low. My car will ride low, that's the way I like it.

CROS34, Interesting that you cut the X apart and welded it shut. Maybe Pypes should make a "limited edition" X-valve....a butterfly valve in the center of the X that you can open or close to change the sound of the exhaust.
Imagine the possiblities: A VOE on the mufflers, pypes electric dumps on the each leg of the X, and the butterfly valve on the X itself.......maybe not.

Thanks again.
Dave

[ta man]

A few years ago I had a non X system with ultraflos sounded good but at full throttle it was super loud.I installed a X crossover it had a slightly louder idle,quieter at cruise and much quieter but still noticeable full throttle.It picked up almost a tenth at the track with an X.I currently have a three inch X crossover on it now Zero ground clearance issues.Properly installed they tuck up nice and high.

[imposter]

i would go with torque tech with walker super turbos i have a 3" with x-pipe sounds great and QUIET

http://www.torquetechexh.com/default.htm

http://www.youtube.com/watch?v=vGMeI8Y9zuo

http://www.youtube.com/watch?v=ECzRh...eature=related

[goatman55]

My lowered 67 has the 2 1/2 pipes x-pipe system. The x tucks up really nice and you can't see it from the side of the car. Believe me, the headpipes will hit the ground before the x. Last summer, I flattened my headpipes in a dip in the road that I couldn't see. It was disappointing to look under and see that. At least it wasn't the oil pan.

Dave