For solely street use car
is a 200 cell hjs can fit to stock exhaust (a local shop in hk is famious in doing weiding for echsust) without any issue
if yes it seems to be a relative cost effective improvement ( many bimmers including me just replace downpipe in their BMW and the gain is good)

 

If you're installing 200 cel hjs catalytic converters, that's $2k in catalytic converters alone at retail price. That's some expensive HP. You will probably net 5-10 HP only imo.

 

From looking at the pic of the melted 200cel core can only imagine what the car sounded like. The pic of the 100cel looked like new.

 

http://vibrantperformance.com/catalo...oducts_id=2670

 

I've had/have HJS 100 and 200 cells, both should work well and on a turbo car shouldn't fail... GT3 and other N/A are harder on cats because of exhaust pulsing

 

Kline is a nice exhaust. Here is a 2.75" Kline full Inconel Kline with HJS Motorsport 100cell race catalysts (you can also get this with standard 200 cell cats or bypass pipes). The set up is extremely light, quiet, and high flowing all while passing emissions. Great to have options, options, options..

 

Nice setup. Great build quality, too bad its hidden.

 

Almost artwork...like the SS heat exchangers I once put on my '71T -- almost looked too good to use.

 

no doubt. i have the "basic" 2.5 and its ( as far as i can tell ) a great performance exhaust. even better with the decat pipes installed. i couldn't really justify the added cost of the inconel setup for my use, but yeah, felix ( and christian ) have done good work. given its relative low cost and that the OP needs cats anyway? i'd give some serious thought to their "2.5". sambo sells em, and at really great prices. i do wonder though, if the 100 cell cats would pass smog now that its obd and no more sniffer. i get when it comes to cats. less ( cells ) is better! but none is best lol

 

It's not about 100 or 200 cell, that's what most people don't understand and why I brought up the conversation in the first place. Not all 100 cell cats are the same. The ability of a catalyst to scrub the pollutants (thereby keeping the CEL out and efficiency as ready) largely depends on the amount of precious metal that is present in the catalyst. A large diameter high end 100 cell catalyst like the HJS/Emitec Motorsport catalyst will have greater surface area and more platinum than many smaller 200 cell cats. The larger diameter will not only have as much or more precious metal present but also more "voids" which allow the catalyst core to flow freely in comparison to 200 cell cats. This is why the cost is so high on the good stuff but you get to have your cake and eat it too.

I've never had a car fail the OBDII emission test (or sniffer) with the high end 100cell Motorsport cats. Never. If you look at the cats that Europipe uses on their exhausts, they are all the expensive large 100cell HJS motorsport versions. Zero issues with passing emissions with Europipe in Cali or elsewhere. Why does Europipe use these? Again, to provide a highest flowing catalyst possible while ensuring it remains emission compliant. Again, so you can have your cake and eat it too.

 

If it were me I would just watch for a used Kline 2.5" to come up at a great price. There is zero drone and the exhaust is not too loud. Even under full throttle the exhaust likely wouldn't get you in trouble. I would say it is appropriately loud. Save the stock exhaust and put it back on when you sell the car and sell the Kline for what you paid for it. I recently swapped a fabspeed out of my car ( mega drone) with a used Kline that I got for a song. I put new wide bands in and have been enjoying 2-3 mpg better fuel economy and zero drone to go along with a more appropriate sound exhaust.

 

that all makes perfect sense to me ( now! lol )

 

thats good advice. some say ALL aftermarket free(er) flowing exhausts have drone, but my kline doesn't ( at all ) and most x pipe designs seem to have that issue pretty well dealt with.

 

I have a 2 1/2" kline exhaust and it is great. I put a stock exhaust on for Laguna Seca (shaved 3 Sec. off my lap time) as i got black flagged for sound with the kline, It was 98Db and the requirement is 90 they let us slide to 92. I even got tagged for sound with the stock exhaust, but only once out of the whole day. It was towards the end and i was exiting 5 with more speed and on the gas sooner. They said i was at 93 Db, i just held off a pinch and was OK the last 2 sessions.

I will put the Kline back on for Thunderhill later this year, i can feel the difference. The kline spools sooner and keeps pulling where the stock tapers off up top.

I have a 3 to 5 hour commute i do once every week or two and the stock exhaust makes it less tiring The wife just rode with me down to Monterey car week for the Werks Reunion and she said the turbo was the most comfortable long range car we have ( the others are a 2011 Cayenne S and a 2010 Audi Q5). With the Kline on the car she would not ride in it.

But i sure do miss the whale of the Mezger when i am getting on it, the Kline sounds great.

Ideally i would like a stock exhaust (with better cats) and a manual bypass (switch on the dash). If done right it would still look like a stock exhaust and pass smog here in lovely California and open up and put the power down. I am an engineer (Ex welder, porsche and heavy equipment mechanic) and like building stuff, so we shall see.

 

ha yeah a dash button would be nice..our cars are definitely missing the "PSE" button