SLC Build Thread-Chassis #53

[Ricardo Montalvo]

So are you looking at or incorporating tuning tubes/adjustable? Will you have space after the muffler to incorporate? I've seen some pretty impressive home brood resonate chambers that completely change the quality and db of the exhaust. Very good at eliminating the American V8 rumble that some fret over with the LSx engines and the DRONE that no one wants.

Yes, I'm looking at using adjustable j pipes (2 or 2.5" od) to tame any weird harmonics or outright drone. I do have room but they wouldn't be an exact "j" shape. I won't know what/if I need until it's running again and on the dyno. I'll use a spectrum analyzer if it sounds funky and go from there.

My hope is that the cats, x-pipe, multicore mufflers, etc will provide the sound I'm looking for and I won't need any j pipes.

I've had 3 different H-pipe setups. One didn't work properly flow/performance-wise. The other 2 did. They all quieted down the exhaust a lot and gave a smooth deep tone even at short pipe lengths. I liked the sound of the h-pipe, but I wanted to "exhaust" all the possibilities of the SLC with the street tail.

Do you have links to the videos of the exhausts you mentioned?

 

[Howard Jones]

Ricardo, Do you have pictures of the three types of "H" pipes you tried. I would love to have some examples of what worked, and like wise, didn't. This sort of information really is what this Forum is for and saved the rest of us a lot of lost time and wasted money.

Thanks in adavance.

 

[Luke S]

Cruise Loud or Quiet - Exhaust Cutouts Installed on Resonator Tubes - YouTube

Here is a guy from our Mustang forum that has put in electric cut outs that are doing nothing more than opening and closing the resonance chambers. He states the difference is even larger inside the car. I'm not suggesting either sound is what your looking for in the SLC, but thought it was interesting in the qualitative and quantitative difference these chambers make.

Here are just some purely objective muffler flow numbers disregarding quality:
broaderperformance.com/muffler_flow_tests.htm

Cfm flows of the more popular mufflers, glasspacks and resonators @ 15” wc:
2 ½” diameter straight pipe 521
2 ¼” diameter straight pipe 365
2” diameter straight pipe 283
2 ¼” diameter tailpipe 268
2 ¼” round glasspack- no louvers 274
2 ¼” round glasspack- with inward punched louvers 133
2 ¼” round glasspack- inward punched louvers/installed backwards 141
2 ½” inlet/outlet Dynomax SuperTurbo 268
2 1/4” inlet/outlet Thrush CVX 260
2 ½” inlet/outlet Flowmaster 2-chamber 249
2 ¼” inlet/2 ½”outlet Cherry Bomb turbo 249
2 ¼” inlet/outlet Flowmaster 3-chamber 229
2 ¼” inlet/2 ½”outlet Maremount Super C (OEM Replacement) 149
2 ¼” inlet/2” dual outlet Maremount 183
2 ¼” inlet/outlet California Turbo 229
2 ½” inlet/outlet Hooker Aerochamber 324
2 ½” inlet/outlet Hooker MaxFlow 521
2 ¼” inlet/outlet Maremount Cherrybomb Vortex 298
2 ½” inlet center/outlet offset Borla Turbo 373

 

[Ricardo Montalvo]

Ricardo, Do you have pictures of the three types of "H" pipes you tried. I would love to have some examples of what worked, and like wise, didn't. This sort of information really is what this Forum is for and saved the rest of us a lot of lost time and wasted money.

Thanks in adavance.

I've taken a lot of pictures, but I didn't take pictures of every variation in it's fully welded state. Here is a pic of one that worked and sounded great. The crossover tube is fabbed laying on the horizontal roll bar support. It's 3". I drilled 1.5" holes on the apex of the bends after the cats and it cleared the Ricardo and shift linkages and went underneath the body. This would work for most street tail installs even if they used the plastic LS intake manifold and intake tract directly above the transaxle like most builders use.

One of my more ambitious contraptions...this one worked, sounded wicked, and was quieter than it looks. The problem was that the Pagani inspired center exit location would have required fiberglass work on the tail to look good. I decided to go back to the drawing board. I'll save this for my next SLC:

This one didn't work how I wanted. There were people who warned me it wouldn't, and some who thought it would. In the end, the passenger side cat was a consistent 60 degrees or so hotter than driver side. It was quiet for a cam with over 40 degrees of overlap though:

 

[Ricardo Montalvo]

Hmmmmm...

 

[Ricardo Montalvo]

Dry sump belt came in (Mandrel washer is at the powdercoater):

 

[Ricardo Montalvo]

More progress on the exhaust:

 

[Ricardo Montalvo]

I'm experimenting with different exit locations.

 

[Doc Kaler]

Nice Work! I haven't seen a front Gilmer drive pulley attached to the ATI balancer.

 

[Ricardo Montalvo]

Cruise Loud or Quiet - Exhaust Cutouts Installed on Resonator Tubes - YouTube

Here is a guy from our Mustang forum that has put in electric cut outs that are doing nothing more than opening and closing the resonance chambers. He states the difference is even larger inside the car. I'm not suggesting either sound is what your looking for in the SLC, but thought it was interesting in the qualitative and quantitative difference these chambers make.

Thanks for the link Luke. That's a nice illustration of how much of a difference it makes.

Nice Work! I haven't seen a front Gilmer drive pulley attached to the ATI balancer.

Thanks Doc. That's a HTD pulley, but I get your point. It was not a shelf item. It took a lot of research and work just for the damper mandrel solution.

 

[Troy Truglio]

Ricardo- amazing work and lots of variations. It makes me feel like I need to learn a lot how the sound works with the different options you have there. When I see 4 exits for the exaust it just makes my mind go, hmmmm, whattttt, howwww, whyyyyyy. There are always things to learn for sure.

 

[Ricardo Montalvo]

Thanks Troy. I wish I could give you a clear scientific/performance reason for the triple exit, but it that one was primarily an aesthetic-driven experiment. Just trying different things to see how it worked out. I'm not sure which exit ended up dictating the ultimate exhaust length the engine was recognizing.

 

[Troy Truglio]

So are you just guessing and doing what might look good and work or is there a method to the madness.

I was going to copy the Honda hsv-010 exhaust as close as I can thinking they did the hard work.

 

[Ricardo Montalvo]

There is a method to the madness. I use software to determine the optimal spec ranges for my headers, collector length, and full exhaust length. Then I do my best to match a design within the optimal ranges that can fit within the install constraints of the SLC, and my desire to have a smooth/quiet exhaust.

Even the triple exit design had both exits to atmosphere within the optimal ranges for best/torque power. However they had different total lengths. Logic may say the shorter exit had the dominant pulse signal to the engine, but I have no idea what the engine actually saw and used.

I'm not even sure how I could know, except to experiment on the dyno with it. In the end I would think the differences were small, and I wasn't going to go through the effort or expense. Neither length was near the "worst" ranges the software said to avoid. I scrapped it in the end anyway.

The latest/final version is geared towards sound quality and attenuation while staying within the optimal hp/tq range in total length.

 

[Troy Truglio]

Cool. I have a program that gives me different length based on engine parameters and exhaust type. 4-2-1 header or 4-1 header, ect. Should be interesting when done. Too bad you did not do a YouTube compilation of the different sounds.

 

[Ricardo Montalvo]

I look forward to see what you come up with. You've done some wild things with your other builds. Cool stuff.

I should have taken pictures of my 4-2-1 setup I did in inconel. It took up too much space and didn't allow me the room for the muffler setup I wanted at the time. Looking back I could have made it work if I was starting over.

If I do anything again, it will be a TT setup with 1500hp for mile events. I just have too much invested in my current motor/trans setup to start over unless someone bought it.

It's not the right base for a TT build, but it's about as mean a pump gas NA setup as possible.

 

[Ricardo Montalvo]

I'm happy to report that the exhaust is quieter than my engine (injectors, intake noise, etc).



The dry sump is working well. Great oil pressure, plenty of crankcase vacuum--I had to regulate it down. The next test is WOT to make sure the dry sump belt works well at high rpm.

 

[Bill]

Wow, that is amazingly quiet!

Do have PICs of your exhaust from other angles?

 

[Ricardo Montalvo]

I posted pictures of it in the page before this one.

 

[Alex]

I'm happy to report that the exhaust is quieter than my engine (injectors, intake noise, etc).

you're dong it wrong