Under Tunnel Exhaust Plans

[NytroMisfit]

Here are some rough sketches I made up for my under tunnel exhaust. I want to do something completely different. My plan is to use the muffler shown below which reverses direction and exits on the same side the exhaust entered the muffler. I planned on mounting the muffler at the back of the tunnel and using oval piping from the header to the muffler for extra clearance. Then just a 45* cut tip turned 45 * so exhaust will exit toward the bottom lip of the tunnel. I'm thinking having the muffler at the back of the tunnel will give it extra snow exposure to keep it cooled down and also hoping with it being mounted that far back that even if it did ice up it wouldn't cause clearance issues with the track and would also be easy to clean off. The muffler I'm using is a Dr. Gas Spinpro. I plan on cutting off the end of the header and repositioning it so it is on a level plane instead of angled. I will use the offset of the nytro header to my advantage so that i can mount the muffler centered but since the inlet and outlet are off centered I am hoping to match them up well. I will also have a plan to have detach points so the system can be removed for alteration or service. These Dr.Gas mufflers are built to last and very durable so I'm looking forward to working with it.

I am open to any ideas or criticism you have on the idea.

 

[thor452]

will you sacrafice power comming back out like that with the ehaust gases having to curn completly around to get out?

 

[nydiver]

It should increase back pressure, which might give it more low end torque if it doesn't squelch scavenging too much. But higher up in the band he'll have too much back pressure and alot less scavenging which is going to kill the higher end power. If where you are could care less about noise (here in NY you either run the stock exhaust or run a 99.9% chance of getting slapped around and legally harassed) then try like a tuned chamber muffler or maybe a tuneable disc muffler. The chambered isn't going to be adjustable on back pressure, but it will free up back pressure while not eliminating it like a resonator (straight thru glass pack style) would, also economical (under $75 for a 316 stainless). You need back pressure off the line then in the higher rpms you don't want it. The tuneable disc like it sounds can be tuned in for back pressure on the low end, and it scavenges well, but its more $, and its kinda loud.

 

[NytroMisfit]

A piece about the muffler from the Dr. Gas website.

This is the same great sounding SpinPro spin trap muffler we're famous for, but in reverse-flow design. Both inlet and outlet tubes are on the same end of the muffler. It's perfect for specialty exhaust systems that take a unique approach to exhaust routing.

This muffler style is commonly used with boom tube tips for a side-exit exhaust where there just isn't room for an inline muffler before the side exit.

These mufflers (like all our SpinPro mufflers) feature excellent flow and a smooth, throaty growl exhaust note that you'll love (with none of that awful rattly/raspy noise you hate).

The muffler measures 12" x 8.5" x 3.75" and is available with 2.5" or 3" inlets / outlets.

 

[NytroMisfit]

Background on the company
ABOUT US
Dr. Gas Exhaust
EMAIL: info@drgas.com
Woods Cross, UT US

Performance. Power. Passion.

At Dr. Gas we know that to you, your car is more than just an object. It's a labor of love. We understand that to own a high performance vehicle is one of the greatest thrills of life.

That's why you spend hours and hours tuning the engine, studying the journals, and washing and waxing every inch of its surface. If you're looking for that extra bit of power, you've come to the right place.

From world-famous professional NASCAR teams to the neighborhood teen down the street, at Dr. Gas we've assisted thousands of customers find the right products for their exhaust system. We offer a complete line of street performance products that are perfect for any restoration or auto fix it yourself repair project.

Dr. Gas is renowned for our quality street performance exhaust system products. We've got everything from Y-Pipe Merge Collectors to tandem X-over junctions, Mandrel Bends to frame clearance tubes. You can find Dr. Gas street performance products in garages and car shows around the nation.

Not sure what part you need to get the most performance for your car? Just ask one of our techs. With years of experience in the industry, we have the knowledge and high-level of customer service that you're both looking for and deserve. That's what has made Dr. Gas the industry leader that we are today. We believe in matching precision products with a level of guaranteed service that is almost non-existent in today's electronic world.

To us, your car is an important part of the Dr. Gas family. To that end, we are committed to only providing you with products that we trust in our own vehicles. When you buy a Dr. Gas product, you can rest assured that you are getting the best on the market. We didn't become an industry leader by cutting corners.

We just believe that you should get the best product at the best value with the best level of customer care available. So take a few minutes to browse our online street performance catalog. If you don't see what you're looking for, give us a call or send us an email and we'll get right back to you. Just consider us your local garage mechanic who has global power. We're in your corner. Let us help make your car the best it can be.

-Boyd Butler
aka, Dr. Gas

 

[NytroMisfit]

Well i know typically that reverse design would have flow issues. But these guys take pride in their exhaust and they use them in NASCAR so I am doubting there would be any power robbing from too much back pressure.

 

[NytroMisfit]

I appreciate everyones input keep coming! I had another idea for an exhaust but it was a little crazy. lol

 

[porkchop]

Well i know typically that reverse design would have flow issues. But these guys take pride in their exhaust and they use them in NASCAR so I am doubting there would be any power robbing from too much back pressure.

900hp well tuned, high compression dyno'd race motor VS 130 sled, big difference.... But hey, it works for NASCAR, gotta be ok.
Good luck.

 

[NytroMisfit]

900hp well tuned, high compression dyno'd race motor VS 130 sled, big difference.... But hey, it works for NASCAR, gotta be ok.
Good luck.

You do have a point there is a definite difference. The members above were talking about the muffler being a power killer because of the flow. Just figured I would point out the statement that the company says they are free flowing. There mufflers are not only for nascar but go from pickup trucks to 4cyl cars

 

[RED]

Not to derail your thread, this is what Im going to use. A Hindle Muffler, got it from Hindle factory for #130 Cdn or $100 USD. Its from there discount bin, cant see anything wrong with it. Normally is over $300 Cdn.

 

[NytroMisfit]

Hmmm I wonder how loud it is. Also worried about clearance on the xtx because I may also go with a 2" challenger track later

 

[RED]

I used to have same muffler on my Turbo RX1 Mtn sled. It sounded like a crotch rocket to me. The exhaust used to exit under seat. Have an aftermarket tunnel, aftermarket seat base with a boss seat. Couple years later, the muffler went into the tunnel with a 2.5 track. Never ripped off the muffler.

Boss has a 2014 Nytro XTX, put a MBRP loud muffler in the tunnel. He has the stock 1.75" track, there is good clearance between track/muffler.

We don't have noise cops out West, so don't have to worry about that much. We really don't have a trail system either

 

[NytroMisfit]

The game wardens are not too bad in Maine as long as you are not a jackass with the throttle in or around town.

 

[yamahamm]

Im thinking of modify one like that to use on my nytro turbo with under tunnel exhaust.

 

[SnoBird888]

I bought a $60 magnaflow. cut the header, welded on v band flanges and my muffler sits under were the stock one does. However it has a turn down and is a few inches longer. I welded a stud to the header collector as well which comes up near the rear of the tank to help support the weight. Only problem I am having is on the really cold powder days the powder hits the muffler and the rear of the tunnel becomes a huge heavy block of ice. this year I am going to buy the next size down so about 1" narrower and .75" shorter so it sits up higher and I am going to try and put a guard around it so only the exit and inlet are exposed to the snow dust, obv the header as well. Hopefully it then falls off the smooth cover surface rather than sticks to all the rough edges/welds on the muffler itself.

Sound wise is pretty good but a bit loud for me. I think downsizing the muffler should help with some backpressure and sound. I think extending the turn down some so its below the bottom of the tunnel edge will take away that bull horn affect the tunnel gives.
Performance wise I know using ulmers excel stg 2 kit for K&N filters she was running 0.6-0.8 lead on the top end so she def took more fuel going to this muffler from the super Q.