[Harleyguy]

I wanted to post the difference between the original muffler compared to the Bosal Muffler . The first set of pictures are the original and the last three pictures are the new designed muffler .You can tell the them apart pretty easy .
You can also see the flange that breaks off and causes the exhaust leak . The broken ring is what some shops are attempting to weld back on .

 

[Lormax]

Those extra plates welded on to the sides of the Bosal are what differentiates the Bosal from older and newer styles. The older ones don't have them.

 

[SoCalGuy]

Is it me or does the Bosal one look much smaller?

 

[Fabulist]

Is it me or does the Bosal one look much smaller?

That may be an optical illusion due to the distance of the camera from the subject. The older muffler looks like a DIY project with all the extra straps welded on. The Bosal actually looks manufactured in a factory.

 

[Harleyguy]

I can tell you this that Bosal muffler is very well made and since its the only muffler made for the Karma your pretty well stuck with it . I can also tell you that if you need one and your local dealership doesn't have one in stock my dealership will be able to supply your dealership or a customer with one . I"am also in the process of having the muffler available for Lomax to purchase directly from us . When all the details are finished more then likely will make a post with contact information on how to purchase .

 

[Lormax]

Is it me or does the Bosal one look much smaller?

It's slightly smaller, but not by too much.

 

[drliu]

Thank you Harley and Lormax! Could you please post detailed instructions for how a (non-car-expert) owner could identify which muffler he or she has, without having to disassemble anything, if that's in fact possible?

Alternatively, what is the VIN number beyond which the Karmas were all made with the Bosal muffler?

Thank you!

 

[Harleyguy]

To tell what muffler you have look under the car in the center between the two mufflers and look at the bottom of the center muffler . Compare that too the pictures I posted if the bottom is flat it's a Bosal has ribs it a Stillen . Also I don't think vin males a difference as for me we only changed them as they failed .

 

[Lormax]

I don't know of any VIN cutoff on the Stillen vs the Bosal. Identifying it is pretty easy though, it can be checked with the car parked. Just take a look underneath the car. Squared off corners is a Stillen, more rounded is a Bosal.

 

[Ira]

This is from the November, 2011 Motor Trend pre-production test drive. Page down to the middle for a mention of the Bosal exhaust system.

http://www.motortrend.com/roadtests...ma_pre_production_first_test/epa_edition.html

I have the Stillen in my Karma, vintage December, 2012. It seems to be okay at the moment.

Anyway, did Fisker intend to use Bosal and then switch to Stillen in production?

 

[Harleyguy]

All I know from the get go they were having problems with the center muffler even during the road shows they admitted they had problems . Only thing I can guess at was to try another companies design . Side by side they aren't even close to looking the same

 

[Lormax]

The exhaust cans on the sides have always been Bosal. There used to be a Y-pipe instead of a resonator in the center, but anyone that experienced the road show cars knows just how loud those were, so the center resonator was created. In fact, 2 weeks-ish after I started at Fisker HQ, I was on the team that designed the first one. Anyway, a number of different versions were mocked up and tested, and Stillen was given the account to build them. On a side note, and this I heard second-hand, but I was told that Bosal initially told Fisker that putting a resonator there couldn't be done. The motortrend article is probably going by the older info when it was just a y-pipe and cans, since the very first few cars were built with Y-pipes. There were a few of us technicians that were cycled in and out at the port in NJ mainly to install the resonators onto the cars as they came in. I was part of that port work.

So, fast forward some months. The Stillen exhausts started breaking on the engineering cars. Repeatedly. 4 Bosal prototypes were brought in, and the NVH team wired up a car with microphones all over the interior and tested each one. There was also 2 passengers in the car, one in the front and one in the back to give a subjective thought on each one. This I know for sure, because I was the one that had to uninstall and reinstall the next prototype whenever the car came back from the test. I also took the passengers on at least 2 of the road tests.

Ultimately, one of the Bosal prototypes was chosen and production was started after that. This was some time after the car had already hit production though, so LOTS of cars were built with the old Stillens, thus there are still plenty out there. Bosal was quick to figure out that their arms couldn't handle the stress and would break, and added the reinforcement welds. Only a few slipped through without the extra welds.

The Bosal is hands down a better product. I've only seen one car with an exhaust part break that had the Bosal installed, though it wasn't part of the actual exhaust. It was the bracket that held the Catalytic Converter. This is definitely a part I'd recommend changing out.

 

[Ira]

The exhaust cans on the sides have always been Bosal. There used to be a Y-pipe instead of a resonator in the center, but anyone that experienced the road show cars knows just how loud those were, so the center resonator was created. In fact, 2 weeks-ish after I started at Fisker HQ, I was on the team that designed the first one. Anyway, a number of different versions were mocked up and tested, and Stillen was given the account to build them. On a side note, and this I heard second-hand, but I was told that Bosal initially told Fisker that putting a resonator there couldn't be done. The motortrend article is probably going by the older info when it was just a y-pipe and cans, since the very first few cars were built with Y-pipes. There were a few of us technicians that were cycled in and out at the port in NJ mainly to install the resonators onto the cars as they came in. I was part of that port work.

So, fast forward some months. The Stillen exhausts started breaking on the engineering cars. Repeatedly. 4 Bosal prototypes were brought in, and the NVH team wired up a car with microphones all over the interior and tested each one. There was also 2 passengers in the car, one in the front and one in the back to give a subjective thought on each one. This I know for sure, because I was the one that had to uninstall and reinstall the next prototype whenever the car came back from the test. I also took the passengers on at least 2 of the road tests.

Ultimately, one of the Bosal prototypes was chosen and production was started after that. This was some time after the car had already hit production though, so LOTS of cars were built with the old Stillens, thus there are still plenty out there. Bosal was quick to figure out that their arms couldn't handle the stress and would break, and added the reinforcement welds. Only a few slipped through without the extra welds.

The Bosal is hands down a better product. I've only seen one car with an exhaust part break that had the Bosal installed, though it wasn't part of the actual exhaust. It was the bracket that held the Catalytic Converter. This is definitely a part I'd recommend changing out.

That was an EXHAUSTIVE history. Thanks for sharing!

But do you mean replacing the bracket for the Bosal?

 

[Lormax]

Not sure what you mean by the bracket?

 

[Harleyguy]

I believe Ira is referring too the short bracket that is welded in place that supports the pipe for the outer resonator

 

[Lormax]

The Bosal is hands down a better product. I've only seen one car with an exhaust part break that had the Bosal installed, though it wasn't part of the actual exhaust. It was the bracket that held the Catalytic Converter. This is definitely a part I'd recommend changing out.

If this is the bracket he meant, then I believe it's a GM part, and I believe the breakage was a fluke. I should have made my sentence clearer. I definitely recommend changing out the exhaust to the Bosal.

 

[Ira]

Now I get it. Thanks!

 

[SoCalGuy]

How much does the Bosal unit cost?

 

[Ira]

There was no price listed for the Karma in Bosal's online catalog.

 

[Lormax]

How much does the Bosal unit cost?

I don't know, but I know they weren't cheap. Fisker of OC wouldn't stock them on-hand because of cost.