Great job man! loving the build I think headers will definitely make it much louder like in the original video. Good luck!

 

I have to agree, it doesn't sound nearly as much different from my biturbo with the cutouts as I would have expected. My ignition system issues have deteriorated to the point I'm stuck to about 3/8 throttle max now though so I can't really take the videos at this point. Hoping to do some more diagnostics this weekend.

 

Dear Lord... I need that exhaust

 

Sorry to hear that.
My friend was finally able to send the side by side riding video. Will be putting it up shortly. In those you can hear the sweet spot of the high pitch of the engine.
Unfortunately, still haven't been able to get the tunnel flyby.

I'm planning on going back to the exhaust shop either end of this week or next week to convert it to true dual exhaust. Also going to experiment with some resonators and possibly an x-pipe.

Fine tuning an exhaust note is like tuning the strings of a violin or string instrument. Keep trying till you get the right note.

 

Here are two clips from the side by side riding video:



Talking the car tomorrow morning to convert it to straight duals.

 

Sounds nasty. Are you going to swap tips while you're at it?

 

I was looking around for some tips but didn't wanna pull the trigger not knowing exactly the quality/look it would give. So for now, I'll leave the ones I have and tuck them in more properly.

I'll keep looking. Maybe if I stumble on an AMG dual tips or something I'll get it.

 

This project made me go research and learn about sound acoustics. Here is what I learned so far and thought I'd share. Maybe some know this already.

But in car exhaust, we are talking about sound travelling through pipes which are similar to the acoustics in wind instruments. Led me to search about what affects pitch in wind instrument.

Those of you who took music classes in your early years may remember(I totally ignored it and don't remember a thing) that pitch in wind instruments change based on:
1. the length the sound has to travel
2. the size of the chamber

To apply this on an exhaust system, I can do two things(besides the equal length headers of course ).
1. To shorten the length the exhaust pulses have to travel, I can terminate the exhaust pipe right after the primary cats OR do as ZephtheChef did and put cutouts as close to the engine as possible and let it terminate there while keeping the regular straight pipes all the way back.
2. Reduce the size of the pipe and take it as close to the maximum airflow that would keep the power efficient. (According to this exhaust pipe chart, a 2 1/4" pipe is good for 371HP)

Doing number one might be the least challenging. The only challenge in number one is to find the right spot to fit the cutouts. I am not sure about just terminating the pipes right after the cats. Just going to seem like open headers in a way.

For doing number two, I am thinking of maybe starting with 3" pipes after the primary cats or leaving the current 2.5", then reducing it to 2 1/4" just at the end of the piping right before the tips. Maybe the last 2ft of pipes is 2 1/4". The only problem I see with that is back pressure.

All this rules out my earlier theory of putting different mufflers/resonators. Because most mufflers and resonators just design different chambers for sound to vibrate off of, and that won't change the pitch. Unless there is a muffler/resonators that has a wide to narrow chamber which would affect pitch, then it's not worth trying any.

The custom header option is still there for me but I still have to figure a way to do it. Haven't gotten there yet.

 

They sell turbo blowoff exhaust emulators on eBay
Item 130972238802

These will add a high pitch , don't know if that's the sound you are striving for

 

LoL! I was reading about these way back. There was this town in Oakland, California I think where everyone was getting those for their cars and drove the rest of the town insane. I think the city had to step in and stop it.

Actually better than that would be this:

http://www.soundracer.se/?p=98

 

For the love of God and all that is holy, DO NOT EVER get one of those.

They make baby Jesus cry.

 

I can't agree more. It's one of the few things that makes me grind my teeth more than stick on vents. You get your gearhead card cut up if you get one, and get issued a poser card in it's place. The car is already quite nice, and while I'm perfectly happy with tunes and exhaust and wheels, there's no need to try to fool people into thinking it's something it's not.

 

If you want a turbo blow off sound, get an 03+ and put aftermarket blow off valves on it.

 

Changing to true duals was a failure. Had to convert it back to the way I had it before. True duals took away the high pitched F1 sound for some reason. Like it was totally gone. I assume that, by the time the exhaust pulses reach to the end of the exhaust, it somehow changed. That is probably due to how sound, especially the pitch changes when it has to travel a longer distance and curved path.

When the pipes were first cut and ended right before the rear cats which was literally under the drivers seat, it kept the high pitched F1 sound. Again, due to the nature of how sound(in this case the pitch) stays high when it travels a shorter distance. So by the time they reach the end tip, it died out.

So, merging the two into one, as ZephtheChef originally suggested(and how TG Sasaki had it set up as well) then splitting it back into dual pipes retained that sound.

While at it, I also tucked the exhaust tip inside a bit more. It looks better than before.

I found some single oval tip just like the OEM tips on eBay stamped with an AMG logo. I think it would fit nicely. BUT the only problem with those tips are that they are made in China. Not trusting Chinese metals anymore even if they say they are '304 Stainless Steel' because I know they will rust out easily. So looks like I'll keep the dual tips for now.

Next step is headers. I'm going to reach out to the guys over at stainless headers or this other company I found that also has the same style mockup kit and talk to them and see what they can offer me.

 

If you do go with the China tips, it may be effective to spray them with a clearcoat like you would for rims to ensure they can't corrode. You'd have to keep them clean to prevent damage from carbon, though. Those do look better tucked in a little more, I'm sorry the true duel setup didn't work.

 

A larger exhaust will give a throatier growl. I don't think bends have as much to do with it as you think.... A thinner diameter, and no mufflers, that's how we got quite a raspy tone from our v10 truck. I would assume the same concept would apply here.

 

My stock valves actually make a good bit of noise with the higher boost. I also shimmed the springs a bit when I changed the diaphragms. Granted, it doesn't sound anywhere near as loud as an atmospheric BOV, lol.

 

You've got me dreaming and scheming. Now I really want to build a 2-1 merge-pipe right off of my cutouts and see how it changes the sound with all the cylinders coming out of one pipe. It would be super easy to remove if it didn't work out since I would just be bolting it onto my cutouts and not actually changing the existing exhaust any. It will probably screw my ground clearance, but if sounded really nice, I could probably redesign it to work better later.

 

Yep, I'm definitely doing it. Cuz custom exhaust is obviously more important than fixing my WOT misfire. Ordering flanges now.

 

I'm glad you're so enterprising. Keep us updated!

 

That is interesting. Wasn't the true duals higher pitched than the y pipe the first time you did it? That's weird how it wasn't the case the second time. I also find it highly impressive that you continue to go for that true F1 sound after you have come so close to it. If I get as close to the sound as you have gotten I would be fine with it, but you have incredible determination to get that sound, even going as far as getting the custom headers actually made! I hope you end up having what you're looking for, and it would be an interesting journey to the rest of us like myself keeping up with this post. I wish you good luck!

 

That would be interesting for the TT crowd.

For any of the N/A guys following this thread, If I were to redo the exhaust, I would go with 2 1/4" pipe.
Also I'd try an x-pipe and see the result of that as well. But the key here was to merge both sides of the exhaust pipe into one so as to retain the high pitch all the way to the end of the exhaust.

If anyone wanted best of both worlds, then they could 'in theory' add low profile cutouts right after the primary cats, and have it terminate there. If they can fit the cutouts somehow there, then they can retain the rest of the stock setup and switch to the higher pitched tone when they wanted.

 

The biggest problem with this platform is it doesn't rev high enough to really get that nice high pitch sound. If we could turn the engine to 7-8k it would sound like a ferrari with the exhaust setup you had.

 

Agreed . Shoofs car sounds like it's shifting early , way before redline - making the scream impossible

Maybe contact eurocharged or speedriven and see if one of their ecu or tcu tunes will hold the transmission in gear instead of up shifting .

The TG sasaki car sounds to be holding a higher rpm

 

Does the S600 not have the shiftable transmission like the S430 and S500?