I get a little bit with my x-pipe setup, but not bad. In fact I'm glad I get some noise since before the car was so quiet at any speed I would catch myself driving too fast. Now it's easy to tell based on noise.

 

I asked this question on corvette forum:

On a V8 engine that has a catalytic converter on each side of the engine and a muffler on each side of the car what would be the better plumbing setup?

1. Manifold to catalytic converter, to muffler for each side of the engine or

2. Manifold to catalytic converter to an X pipe then to each muffler?

Exactly what is the benefit of an X pipe?
===================================

The answer that came back was the message that I posted. When I read that the tone would be lower and less loud I decided that I'm going to leave my exhaust the way it is. It's not that loud to start with and I do like the growel when you step on the go peddle.

All I know about exhaust systems is they cost! I've been driving my Vette this week for the first time in 9 months. Its plumbing is manifold to high flow cat using a Y pipe then a Y pipe to two flowmaster mufflers. It's loud! A drone at 14 to 1500 rpms which is 60 mph. It's much better at 2000 rpms but that's 80 mph and too fast for Oregon! Would you believe most of our freeways are still 55 mph! Sounds great at WOT but it's not a car for a long trip without ear plugs.

I'm not going there with the Jag. It's our long distance road trip machine and can stay at the growel level.

 

Matt - why the h-pipe vs. the x pipe? daleD

 

I think the x-pipe quieted it too much Dale. The H-pipe should be perfect instead. The tone will be identical, low and growly, but you'll be able to hear it just a bit more. Only time I can really hear mine now is when the windows or down, or better yet, when the top is down. Then I can hear the low rumble.

Remember, I'm a very conservative person, I don't like loud (except my stereo), I don't like annoying things, rattles, clunks, etc...so the sound of the exhaust to me would be perfect if the volume was what I had without the x-pipe. An H-pipe would get me closer, with all the benefits of balancing out the exhaust pressure into both tail pipes...no puffing like my first video w/ the muffler removed.

 

Sound reasoning Matt. Will we now be able to compare all three setups on the same car - vid and sound clips?

I'd like to do one of the modifications, but if we could actually hear what you hear, we could make a better first decision. Thanks for all you do - DaleD

 

So.. all you are doing is removing the center muffler??? Is that good for the car? Environment? I noticed that it has a 2 more "mufflers" on both sides... is that enough for the XK8 to not sound too loud? I love the engine roar when i get on it.. would like to hear a little more out of the back-end!

 

turbo, without going a full aftermarket or custom exhaust with larger pipe diameters, removing the mufflers (one, or two) is all we can do to get some more volume. If you look at my links for before and after vids, you'll hear the difference. It does not hurt the environment at all. Its not like we're removing the CATS.

Dale, I think I'm going to keep the exhaust as-is, I've fiddled with it enough, and it is noticeable now. I've got other car issues to address, like my rear bumper is rattling! Sorry, can't do the H-pipe right now.

I will try a take-off from standstill video with sound so its relevant to background noise and such.

 

I took the ol' cat into Exhaust Pros yesterday to get a quote on a custom setup, and the quote I got was less than expected, so I'm probably going to be getting a full custom setup within the next month. The plan is 2.5" pipe the whole way, H-pipe, under axle, dual Flowmaster 40 Series mufflers. The other option that was recommended is a Magnaflow Dual in Dual out muffler in the same place the center muffler is that you guys are removing and then just pipe the rest of the way. I might save a little $$ that way, but I'm not sure I like the sound of Magnaflow's mufflers as well. If the weather is decent next week (I'm sick of these extremely cold rain, it's suppose to be summer!) I'll take a baseline video for a later comparison.

The quote I got was ~$450 for a full system (but I didn't think to add some nice tips, so that will probably add around $100 more)

 

Nice! Should sound pretty mean.

If you like my tips K.W, I edited my earlier posts with the manufacturer and model number.

 

Has anyone observed any noticeable performance changes from the X or H pipe modification (actual power incr/decr aside from change in sound)?

 

Hi Bob,
I have the McLeod X-Pipes I System. I was hoping to get better MPG, but sadly, I found no difference. I don't utilize the horses that I have, so I wouldn't know if there are any more now under the hood. What I do know, is that the McLeod system sounds and looks awesome, and that it greatly enhances my driving pleasure. I am thrilled with my setup!
Brian

 

Matt, the tips you have a nice and I plan on going with something similar, but not exactly the same. I will have 2.5" pipe with a 3" straight cut tip with rolled edges in chrome. I think they will look quite nice. I'm getting a little ahead of myself though because I need an alignment first.

 

I have the Flowmaster Force II cat-back y pipe and 2 mufflers on my Vette and they are NOT a "MILD" sound as Flowmaster states. They sound great but there's a drone that's NOT mild.

Have you heard what a set of 40's sound like?

 

More sound clips please. In car with top down on the freeway? all three set up's, if possible. Maybe from the outside with the car going by? I want more of a growl just on the freeway with the top down while cruising I want it to be quiet. I was thinking of straight pipes from the center muffler back maybe?. I believe they put on the center muffler to get rid of the droning effect.

 

Brian, will try the in-car video with sound too. There may be wind though.

Burg, you're missing the two pre-axle mufflers! Could this be the reason you have a little drone at highway speed?

 

I don't know which mufflers are in your kit, but I know 40s are considered "aggressive.". I've got some friends with Mustangs that have them and they are loud, but not overly so. After driving my Cougar for years most exhaust systems seem a bit quiet.

 

Well the drone isn't that bad, but as to what there is, I'm not sure if it is because of the lack of the small pre-axle mufflers or the design of the Flowmaster mufflers. I've heard Flowmasters tend to have a certain sound to them regardless of the vehicle.

Anther option could have been to put some kind of glass packs (straight-thru, tube design) muffler in place of the Flowmasters. On an old Impala I had many years ago, I put two glass packs next to each other in the center of the car and there was no noticeable drone inside.

I have yet to see a glass pack setup like that on an XK8, probably because it would be significantly louder out the tailpipe and the small V8 could sound more raspy than most of us would like. That and there would be no crossover to get the balance effect for the engine.

 

I think they are a 50 series. When on Flowmaster's site they are listed as Force II. They sound great for a mussel car if you want the noise/sound like it loud. The labels that Flowmaster has on their site as far as how loud or mild the sound of the muffler puts out is pretty conservative. Mild to me is on the loud side which is fine with me but someone else might get upset thinking they'll have a mellow sound and end up with a dragsters sound.

 

"They ain't trippin 'bout the flows! It's just for decoration!" Best video ever! lol

 

Sorry folks; There is no such thing as a nice throaty exhaust without some drone at speed, especially when under load. It just don't work that way. Only way I can see it happening would be with a cut out system or tailpipes sticking 10 ft out the back of your car. Thomasso