I finally finished this. Took a long time and much tweaking for clearance. The key is to put the hanger in near the X pipe that attaches to the passenger seat belt through bolt, give a little more ground clearance.

the only thing I don’t like is that the exits points are not symmetrical so exhaust tips are not centered, but that is inherent with our cars anyways. I am just going to use turndowns.

 

Anyone else running this? Any updates?

 

Since posting above I have this exhaust and I did some extra fitment fabrication to hug the bottom of the car. I had many of the sections cut and re tig welded to hug my undercarriage. This was not cheap. I cannot emphasize this enough, as I turned a $300 kit into 4 digit custom exhaust. I have enough exhaust for anything but I am already considering going to a single 4". The drone in unbearable. I will experiment with some different mufflers but fitment is a major issue and I really only have room for bullet style.


Pros:
Leaves no power on the the table
Looks super pretty

Con's
Major expense if you want it to hug without scraping
DRONE
DRONE

 

That's great information and photo!

I'm in a slightly different situation, I have a turbo LS and single 3.5" downpipe I fabricated. I ordered this kit to basically only use the back half of it. My plan is to use a 3.5->3 merge into the two pipes. I do see some of the pie cuts you made in the back to tuck things. Interesting.



I have a 3.5" dynomax race muffler. I was thinking between it and the two mufflers in the kit, AND the turbo, it hopefully won't be too loud/drone.

I also have these SLP mufflers that they used to offer with their "loudmouth" kit:


The reason I didn't just buy the loudmouth pipes is because they are only 3". The mufflers are 2.5". I figure I could try the speed engineering with the bullet mufflers and tips and if it's too loud switch out to these SLP mufflers. The ones I have include the angled tips so the outlets are perfectly perpendicular to the rear bumper. But if I don't use them on this car I might toss them on my 4th gen.

Anyhow.. Interesting feedback and appreciated. I do like the way yours came out. Interesting that you used turn downs instead of the quad tips. Any reason?

Did you use the actual speed engineering kit, or the ebay one? I'm convinced they are both the same, but just curious.

-- Joe

 

As long as you have a something other than just cats and bullet mufflers you should be ok. I am going to experiment with a vibrant bullets and then may use a large dual in and dual out Magnaflow muffler in the same stock orientation. I didn't go with the quad tips because they just don't look right on these cars in my opinion. I wanted the clean hidden look so I used some cheap amazon 304 turn downs. I have them for sale if you want them. They are actually beautifully made given the cost and typical Chinese welding.

EDIT: I actually used the speed engineering 4th gen kit. Hence most of the fab work around the cats.

 

Any photos from the back or side of the car? I'm actually kinda digging the tucked look.

 

Here is a quick shot last year on power tour. I can see if I have more. In its current state, it looks like a normal dinged up 3rd gen. Until I start it up. Ha.

 

Do the ground FX on that Camaro make the bumper lower in the back?

I can't even see your exhaust. That would be cool if I could hide the same on my car:

 

Ye the ground effects help. Without them you'd likely see the exhaust, maybe not the tips, since they are angled up, but right behind the rear wheel (from the side especially).

But in essence, mine is completely hidden, which is what I wanted.

 

Which turndowns did you use from amazon? Were they 90* or 45 and then slash cut?

 

Here is what I used. I will send you a PM with the amazon link. Don't want to archive a link into this thread.

 

Some mock up. It rests against the panhard brace. I may have the brackets to the frame for the muffler support wrong, I gotta look at some photos online.

I'm not sure if it makes sense to use the brackets that connect to the bumper mounts, they would hang lower than I intend on running the turn downs. I have some weld on isolated brackets I might just weld to the frame and the side of the mufflers once it's all tucked the way I want.

My 3.5-3" merge pipe hasn't come in yet. I'll probably get everything loose fitted before I start tacking things in place.

The tips look kinda neat but I think I like the turn down tucked look you did better. Maybe I'll keep the tips for my 4th gen.

 

Here is a short idle clip. The race muffler and turbo take some of the noise out of this. It still sounds like a performance exhaust, but you can actually hear my intercooler pump and fans over the exhaust in this clip, which is kind of funny and sad at the same time.

 

Wow, that's quiet!

 

This threads been dead for a year now. Curious if anyone has done this with a SBC? 305 or 350? Video of it? I'd be highly interested in seeing results

 

In my humble opinion doing this to a 305 or 350 SBC would be a complete waste of time, money, and effort.

 

Why would that be? It's not a stretch to get 450-500 HP out of a 350.

 

Well I inferred since he even mentioned 305 that the 305 or 350 he was talking about wasn't a full blown race engine but something more in the street category.

I may also be confused about which of the exhaust systems talked about in this thread he was referring to. I was talking about a 3" true dual exhaust system.

 

Fair enough Airwolfe. Yes, I can agree that on a pedestrian 305 or 350, there wouldn't be a whole lot of gain for the amount of pain. Pain being measured in $$$.
FTR: I'm referring to the dual 3" setup.
I'm one that suffers from an inadequate exhaust seeing as I'm in that range (or should be) I mentioned. A single 3" after the long tubes and into a entry level Flowmaster muffler doesn't do a whole helluva lot to enhance performance! This is why I'm always interested in the exhaust threads here.

 

Having a very expensive and constantly evolving dual 3" I still recommend a single system for cars under 700hp. A single 4" will support that and not cause all the issues of a dual setup. There is no need for this type of setup on a 500hp 350. Is it cool, yes. Does it sound awesome at WOT, yes. Does it add weight, crazy bone rattleing drone, and scrape on everything, yup!

 

That's very much towards the way I'm leaning.
A single 4" or even a 3.5" (which might be marginal) would simplify the install. Not to mention the weight savings.
As we've discussed before though, a large component of that is the muffler. I've said before that a single muffler that'll move nearly 1000 CFM isn't necessarily going to be quiet!
Cutouts, from a racer's perspective I think is the answer.

 

Totally agree. Cut outs are there in case you're leaving a few ponies on the table with a single exhaust.

 

Given the cork-esque exhaust I have now, what I've seen gained in the 1/8th with just a simple cutout at the 90° bend before the muffler and my new and improved (and as of yet, still unraced) combination I'll bet a "few"ponies is about 20%. It may be difficult to get cutouts done this season but I'll get a baseline for sure. Then take that single cap off and see what's what.

 

I have this setup on my single turbo LS.

I added a vibrant resonator. It's not bad. I'm tempted to swap the mufflers for some large case race mufflers. I'm getting old and like quiet things that run 10s. Lol.

This setup is cheaper than a single 4" and fits better IMO. You can run two quiet mufflers. They don't make a quiet 4" muffler.

 

That's my thinking as well.

 

At my setup single 3"(e bay longtubes and ultraflow muffler) to dual 3" exhaust trap speed went from 113.3mph to 116.7mph.

 

THAT'S what I'm talking about!

 

I believe that. It's all about CFM. I spent a lot of time this fall reading up on muffler technology, calculating CFM. I bought some cheap 100psi transducers and use them to measure exhaust backpressure.

I've decided it's impossible to make 1,000 hp and be quiet lol. Not on a fbody chassis anyway. The truck guys can get away with running legit 3 foot long mufflers and 4" exhaust.

My vibrant resonator cut down the tone a little bit. I might change the two bullet mufflers for some ultraflow muffler I bought last fall. But at the end of the day, flow = loud.

It is amazing how much a reduction of flow can impact performance though.

 

I switched from bullet style to Spintech race mufflers and they didn't really quiet the car down much. I also added a resonator on one leg of the dual set-up (No room on the other bank for a resonator). The car is loud but tolerable. Its the drone that kills you. I agree that there isn't much you can do on these chassis compared to newer cars.

 

I've always thought spintech sound cool but they are some of the worst flowing mufflers available. Kind of like Flowmaster, they sound amazing on a low-hp dual exhaust 68 Camaro but absolutely tank performance.

I'm running a borla style 3" catback on my 4th gen and it's kind loud for a 400hp car. Might be because I have long tube 1-3/4 headers and no cats. But anyway, it's quiet when you are off the throttle but when you get on it, especially with the top down, it's like "jesus christ come on".. I wish I had known that before I bought it.

I also wonder if the 4" tips are adding to the noise?

 

While real estate is certainly at a premium, dual 2.5" and dual 3" for that matter have been run side by side along the trans tunnel.
Would it be possible to add a couple of 2.5" chambered style muffler along that length?
Seems workable from a napkin drawing point of view.
Then the option is there for whatever you might want after the axle.


2.5" Chambered Muffler

 

Where have you seen that they are terrible? That's news to me since most guys run them in race series that have noise requirements.

 

Every forum and group that I reviewed going back to like 2010. The largest spintech muffler flows under 500 cfm, with most under 450. All chambered mufflers flow poorly. Flowmaster being the worst. Spintech are a little better than aerochamber.

In contrast, Dynomax ultra flow mufflers flow 2,000 CFM in the same case size.

Perforated tube mufflers flow the best. Chambered sound the best.


-- Joe

 

I have a pair of those in the shop. I wish I took a photo because I mocked some up a while back. It won't be quiet though, but you can fit two side by side. You can actually fit two 3" ones side by side.

 

Would you clarify the picture posted above as a "perforated tube" type muffler?
If so, what are your thoughts on CFM vs db?
Seems to me that a pair of those paired with another couple of resonators or mufflers might be able to satisfy both sides of the equation.
Edit: Just saw your post.
So what about something complimentary after the axle?

 

Let me go in the shop in a bit and take a photo of my 3rd gen. You can absolutely fit two mufflers besides the trunk instead of the bullet mufflers. You could probably fit two super turbo mufflers (about 500 cfm each, depending on case size) which will support 600-700hp and be fairly quiet.

A perforated tube is like this:


I have a pair of these which will eventually replace the bullets.

A super turbo looks like this:

 

Well heck, I am running the smallest ones they make so maybe they aren't that bad. The butt dyno feels the same.

 

Two ? What case size? How much horsepower?

 

Two 3", 4 inches by 6 maybe. 515 at the wheels on a mustang dyno.

Edit. 9000 series pro street. Internal "swirl" baffles don't completely cover side to side in the case, so some flow goes straight through. Case size is confirmed 4" x 6".

 

That's probably a good combo. Those are very small and flow well, but don't offer much sound reduction.

Usually when people talk about spintech they are talking about the large case street mufflers, like 3000/6000/7000. Those sound wicked cool but don't flow very well because the air is basically going through a corn maze.

 

Depending on how you position mufflers, some typical 9x14 mufflers will fit.

 

Thats how mine are mounted. One side could have fit a larger muffler but wanted symmetry. I added the resonator in the section that runs across the factory muffler location. That did help dampen the sound and drone a bit. Would love to get one on the other bank somehow.

 

So I tucked everything high up so you can't see the exhaust when the car is on the ground, because getting them perfectly symmetrical seemed like a chore.

Made little turn downs. It actually sounds fine the way it is but I wonder if I can't quiet it down a bit with the ultra flows. Even with the turbo, it is loud at 6200 rpm.

 

Just wanted to say I really love how nice and neat you have your exhaust system routed and tucked in.

 

Thanks. I spent a lot of money to have it tucked and tig welded to keep it as tight to the floor as possible. I also wanted cats. If I ever go to a single 4", I'll merge it right after the cats.

 

I ran mine the same. Can't be seen from outside. With the new mufflers and resonator it knocked a few Db's down where I can cruise short distances without hearing protection. Lol.

 

I probably got the exhaust tip idea from you. I don't even remember. I chatted with a bunch of people before laying this out. I hated the tips that came with the kit.

You didn't have an issue with the driveshaft striking the exhaust ? I had to move my pipes more to the passenger side because when at full droop the driveshaft would hit the pipe. I didn't consider the fact that the pinion was at the bottom of the 9", so when I swapped rear ends early in the fall and went to bolt the driveshaft in I was like "oh man". So I cut and moved everything over a little.

Thank god my car rides like a 4x4 for ground clearance lol.

 

Would it be possible to run a couple of bullet style mufflers side by side in the place where the OEM muffler sits? I can't imagine two 4" x 6" bullets taking up more space than what came on the car originally.
That way a single 3.5" or 4" can be run over the axle, make the turn into a Y (run in reverse as in 4" into 2 x 3") and exit two out the left. That way there's the packaging convenience of going over the axle and the CFM gained with two mufflers. You might be able to get the flow and reduced noise too.
My guy could easily build that transition and keep it relatively compact.

 

So I did think about this and magnaflow sells a dual 3"in/out muffler. I could do two on the left exit. I am so deep into this exhaust that I don't have the gull to cut it back up. That could change next winter though after I drive this thing during another power tour. As for driveshaft issue I don't have any. I made sure that was accounted for when instructing the fabricator.

 

I came across that Magnaflow dual in/out when I was researching future exhaust modifications. What I didn't like is that I couldn't find any flow ratings for it. Or any ratings as reported by the manufacturer. There are some random tests posted (and that I've added here a thirdgen) but nothing from the source.
The notion of twin bullets does have its appeal.