Werks

Having been involved in modding my vette for a while now I have to say that it's not too often that I come across a product that impresses me anymore lol. Over the years my car has gone from completely bone stock to a bit of a track monster. Starting here:

http://forums.corvetteforum.com/c6-z...ech-style.html

Then:

http://forums.corvetteforum.com/c6-z...63-engine.html

Which resulted in this:

http://forums.corvetteforum.com/c6-z...ack-463-a.html

and this



So to say that the car ultimately turned out to be more than I could have ever expected when I started all of this would be an understement. Hewever one of the areas that I have never been happy in has frankly been one of the first modifications that everyone seems to do, installing an aftermarket exhaust lol!

I've looked at Corsa, I looked at Borla, I looked at B&B and to me it made zero sense to spend money on replacing the exhaust system with one of those when I would gain virtually nothing in performance and in most cases actually add on more weight than the OEM exhaust just in order to make some more noise. It probably sounds funny looking at my build thread above but everything that I have ever done to the car has not only been about appearance but also about performance. Everything looks good but it also either reduces weight or in some way, shape or form increases performance! So after changing virtually the entire car in the first build thread I was still running the stock NPP exhaust simply with an exhaust commander. A few months down the road after the car came back after researching exhausts some more I decided to take the plunge and order a Titanium Akropovic exhaust system with Carbon tips. It was god awful expensive at something like $3.5k but it finally did one thing that none of the other exhausts seemed to do, offer a substantial weight reduction over stock! They look great, installed it and unfortunately after about 10 days on the car I took it off and sold them because I could not stand the intense drone that the exhaust caused or the fact that it seemed to be louder with the flaps closed rather than open!

So for the next year I left the OEM NPP exhaust on, went back to Katech and got a new engine making a whole lot more HP and then started thinking again it's crazy to have nearly every single part changed on my car but I'm still running around with this heavy stock exhaust system. So I started looking around again and ran across a post about a new exhaust system that Burns Stainless was supposedly building. I knew of Burns as they supply the mufflers and exhaust tubing for all of the factory Corvette race cars i.e. the C5R, C6R and C7R as well as most of the cars running the Tudor series. So I knew that their stuff was quality product and I also knew that the mufflers they put out are all stainless and known to be some of the lightest mufflers made! So I called them up, spoke to them for a bit and then decided to take the plunge and a week later a box arrived with my nice new all stainless steel exhaust system that looked like this:



As I track the car a lot and was concerned about sound I went with larger 6.25" mufflers initially along with single tip outlets so that I can run turn downs if needed at tracks that have extreme sound limits like Laguna Seca. With the larger mufflers the entire stainless steel exhaust system weighed in at 27lbs, a savings of 23lbs over stock, nearly a 50% weight reduction!

Here is a under car picture of the exhaust with 6.25" mufflers installed as you can see it's a nice and clean set up!



A better look at the dual tip's:



The muffler design that Burns makes is a straight through design, similar to motorcycle mufflers if you have ever seen those. So there is little if any restriction in exhaust flow (and they are rebuildable too!) which I'm sure helps performance versus OEM like I had. With the big displacement engine and cam that I have I was a little worried about being too noisy! So after getting everything installed I pulled out my DB meter to check sound levels and at idle about 10 feet back from the car it was measuring at 74db, exactly the same as the OEM NPP exhaust with flaps open. So actually rather quite! At the next track day I had the officials check sound while I was out and they measured me at 97db, I was the quietest vette out there lol and actually quieter than my car was with the NPP exhaust on it and flaps open but now with a much less restrictive exhaust that weighed nearly 50% less! As an added bonus if I run turn downs I think that I can easily cut the sound down another 3-4db making it possible for me to run at 95db days at Laguna Seca without having to jump through hoops!

Now I also drive the car on the street at times so I was also concerned about the level of drone and in car sound level as the last thing that I wanted was to end up with a grumpy SO! In that regards I'm happy to say that inside the car the sound level is slightly less than with stock NPP mufflers open. Cruzing around you can easily have a conversation with your passenger, talk on the phone, hear the radio etc. etc. There is a little bit of drone at the 1500-1700rpm range (which to be honest I'm not at too often) but even then it's low enough so that you can easily hold a conversation and nowhere near the headache inducing volume that the Akropovic system that I used to have put out!

After running the system like this for about a month to see how I liked it I decided to pick up a set of the smaller 4.5" diameter mufflers (these are the ones that come stock with the exhaust system) to drop another 5lbs out of the exhaust system


Here is a picture of the 4.5" muffler set up"



That now brings the entire exhaust system down to only 22lbs! Here are some pictures with the 6.25" mufflers next to the 4.5" for comparison sake:



As you can see the 4.5" mufflers are significantly smaller and they weigh 50% less than the 6.25" versions.

Here is another under car shot of the system with 4.5" mufflers installed showing how neat and clean the layout is:



And from a different angle:



With the 4.5" mufflers the exhaust is now 5db louder at idle (82db). At cruise it is still easily possible to talk in the car, hear the radio, talk on the phone etc. There is still a little light drone from 1500-1700 but you can easily talk over it and at WOT it just sounds mean! It's also cut an amazing 28+lbs off the weight of the exhaust system in total! Best of all is that to cut all of that weight cost way, way, way less than the Akropovic Titanium system. So you lose an equal amount of weight, end up with a system that does not drone as much and you spend nearly $2k less doing it at the same time. Burns Stainless is selling these systems in the $1800 range and it's important to note that all of them are custom made to order! So while I chose a 2 tip design so that I can run turn down, for those of you street only they can make it a traditional 4 tip design if you prefer that. So all custom made, all made here in the US, all made from stainless steel and all made with exactly the same proven mufflers that are used on the C6R & C7R race cars! I don't often rave about a product but in this case I'm 100% pleased with the service before the sale, the product that I received and the quality and performance of it. Burns calls it the "No Holds Barred" exhaust system and I think that they are going to grab a big part of the market for performance oriented vette owners that do not just want an exhaust for a sporty sound but also want to actually gain performance through improved exhaust flow and a huge reduction in weight!

Bad_AX

Thanks for a great writeup! This is what I'm going to put on my Z06. I just need to decide which of the two mufflers to go with. I assume there would be no difference in performance? BTW, what mid pipes are you running?

double06

Do you have any shots of the car as it sits from someone standing in the back.

double06

I see you did a great job on documenting sound anything on the performance gain before and after the NPP.

tim414

nice post. luv your Z....sweet! thanks

Werks

Personally unless you run on tracks where sound is an issue I'd go with the stock system which uses the 4.5" mufflers. It will save you 5 lbs, bringing you from an already crazy light weight of 27 to 22 lbs lol and even with the smaller mufflers the car is just a little bit louder than the NPP with flaps open at WOT but it sounds meatier if that makes sense.


Not right now, other than the ones from below but I'll try to snap one for you tomorrow. Also as mentioned these are all custom made so if you want a more traditional 4 tip version they can make that for you


I have not ran the car on the dyno since making the change but the 28lbs weight loss right on the tail of the car is noticeable. With the amount of exhaust my bigger displacement engine is pushing out though I have to assume that the stock NPP was a restiction and the straight through mufflers that this system uses had to have resulted in an increase in power.

Thank you

Dirty Howie

Nice setup, nice write up, nice car …………. NICE !!!

Now you just have to add an audio clip !!


DH

devojrx7

I see this as I'm waiting on my B&B fusion system to ship. Damnit. Great write up.

Rupert pupkin

Holy sh* t.... This is exactly what I wanted to do with bullet style mufflers, but I cant justify spending that much still.


Based on the dimensions of the smaller muffler, do you think theres room to incorporate J pipes to try and reduce drone?

EX1

I got to be honest, 3 things about this SHOCK me.

1. These bullet style mufflers drone less than the Akra system with the NPP closed?! That is certainly hard to believe but I have never ridden in a Z with Burns before.

2. You said that the Akra system seemed louder with the valves closed compared to open? My car is noticably deeper with more bass with the valves open on my Akra.

3. Burns has an exhaust for us now lol!

Thanks for the write up. Please post a soundclip!

skxf430

Sound clip please.

Bad_AX

Ron,

Are you still running factory mid pipes? I was looking at Burn's website and see they have a 1-Stage and 2-Stage muffler. Yours looks like the one stage?

Werks

Here are two that I snapped for you:



FYI I had another car parked behind my vette so I was about 4 feet off to the right when I took these pictures which makes the tips look a little cocked. They are actually perfectly straight when you are directly behind the car.

Werks

Why bother, there is hardly any drone to start with and any that there is really is not that loud. As I mentioned I can easily hold a conversation with my SO while putting around in 6th gear at 1700rpm which is prime drone rpm and with a big cam just about the lowest rpm that you can run at without bucking. It's so insignificant that I would save the headache and drama of figuring out how to reinvent the wheel lol

To address your comments:

1) It was s shock to me too which is why I went with the larger 6.25" mufflers to start with. I thought that frankly the straight through mufflers would be loud as hell and drone like crazy! Well the proof is in the pudding as the saying goes, 74db at idle mesured on my db meter, 97db driving measure by the officials at the track. At idle that's the same as the NPP and driving on track I was the quitest vette out there ironically with the biggest engine and the most hp lol! As far as teh drone is concerned it might be the fact that I have a carbon rear hatch with lexan windows (so a hard surface that revereberates sound well) or it might be the Torquer 110 cam that I was running at that time but with the Akrapovics after 10-15 minutes in the car I would get a headache. It droned so loud in car that I would have to pretty much yell at my passenger to be heard. Trust me when I say I'm not making my dislike for that system up because even though I have a lot of money in my car who in their right mind would want to drop $3k+ on an exhaust system only to turn around and lose a bunch of money selling it used a week later???

2) On my car it seemed the opposite. It seemed to make more noise (or possibly drone) with flaps closed than with flaps open. There was also not really a major noticeable difference in sound levels between the two like with the stock NPP where flaps closed is quite, flaps open is loud. With the Akra to me it was flaps closed is loud with a lot of drone, flaps open is loud with a lot of drone. Again though it could be the cam, it could be the carbon rear hatch, it could be the headers etc. All that I know is that I'm still a young guys that has been around loud stuff my whole life racing bikes and tracking cars and loud exhausts don't bother me, drone does and the Akra's gave me a headach lol.

3) That I agree with you on. I know Katech used to offer exhausts with Burns mufflers and I was thinking about trying to have them make me a one off system when I heard a rumor about this exhaust system coming out and jumped on it!


That is the one thing I do not have lol, need to find someone with a video camera!


No just about the only thing that was still stock on my car was the NPP exhaust. For mid pipes I'm running Kooks along with their LT headers. As far as teh mufflers are concerned Burns does offer 2 stage mufflers that are even quieter, I went with the 1 stage mufflers for both set ups and honestly I can see no reason to make the exhaust any quiter than it was with the 1 stage 6.25" mufflers unless you are trying to say get really, really quite (say 90-95db for certain track events). Keep in mind too that the sound levels that I mentioned is on my car with LT headers and a 463ci engine with a big cam and 13:1 compression ratio! So I would assume that on a relatively stockish car the sound levels with this exhaust will be even lower that what I was seeing!

Z06Ronald

Thanks for the GREAT writeup!
I found the following sound clip on YouTube:

Werks

Yep that is what it sounds like lol! The video shows their 4 tip set up but the sound is exactly the same, strong, meaty, v8 sound without being obnoxious!

Ronald can you add the Burns NhB sytem to the weights list? The 2 tip Burns NhB system with 6.25" mufflers is 27lbs, the 2 tip Burns NhB System with 4.5" mufflers is 22lbs.

Z06Ronald

More explanation. Jack Burns ... I like this guy!

Z06Ronald

That immediately came to my mind, I will sure do!!!

Z06Ronald

Their website says it weighs 25.5 lbs ... Different dimensions, maybe?
BTW, your Z06 is pictured here!

OJCrush08

Nice write-up on the Burns exhaust and good info to share. I must say that my drone experience with my Ti Akras differs from yours. The drone on my car is not an issue. I am running the Katech 110 cam, but I am NOT running headers OR the Katech Lexan/CF rear hatch. That may account for the difference...