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Discussion Starter #1
I have searched and reached out to other sources, but have yet to find what I'm looking for. I am in the process of research and putting together some information about going with the full exhaust upgrade (headers to tail pipes). I am currently looking at the complete Supersprint system; however, through research on this board, I have learned that the SS cats tend to throw CEL which I'm hoping to avoid. This same board has also recommended HJS cats on multiple occasion which is who I'm looking to go with. According to many people on this board and Fabspeed themselves, it is claimed that these cats do not throw CEL's and pass emissions.

Fabspeed on he east coast appear to be the only North American dealer for HJS cats whom I have subsequently reached out to. After going over what I am looking to do, they have asked for dimensions of the SS cats which is where I need help. It is my understanding the SS exhaust is 2.5" dia. Does anyone have or is able to verify the dimensions of the SS cats?
Overall diameter"
Overall length from end of cone to end of cone?
Length of the cat filter itself?
Location of the O2 sensors related to the cat?

I have looked through multiple threads and came up with this posted by the HJSUSA member (HJS Catalytic Converters) where he recommends three different model no. based on engine size & hp. For what I'm looking at, I would use two of the 90-95-0080 cats, but they don't list them on their website anymore (possibly due to being replaced with another model number) (Universal catalysts - HJS Motorsport & Tuning)

Any assistance in this would be greatly appreciated.

Thank you.
 

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I have searched and reached out to other sources, but have yet to find what I'm looking for. I am in the process of research and putting together some information about going with the full exhaust upgrade (headers to tail pipes). I am currently looking at the complete Supersprint system; however, through research on this board, I have learned that the SS cats tend to throw CEL which I'm hoping to avoid. This same board has also recommended HJS cats on multiple occasion which is who I'm looking to go with. According to many people on this board and Fabspeed themselves, it is claimed that these cats do not throw CEL's and pass emissions.

Fabspeed on he east coast appear to be the only North American dealer for HJS cats whom I have subsequently reached out to. After going over what I am looking to do, they have asked for dimensions of the SS cats which is where I need help. It is my understanding the SS exhaust is 2.5" dia. Does anyone have or is able to verify the dimensions of the SS cats?
Overall diameter"
Overall length from end of cone to end of cone?
Length of the cat filter itself?
Location of the O2 sensors related to the cat?

I have looked through multiple threads and came up with this posted by the HJSUSA member (HJS Catalytic Converters) where he recommends three different model no. based on engine size & hp. For what I'm looking at, I would use two of the 90-95-0080 cats, but they don't list them on their website anymore (possibly due to being replaced with another model number) (Universal catalysts - HJS Motorsport & Tuning)

Any assistance in this would be greatly appreciated.

Thank you.
Many years ago (10 or so?), one of the car magazines did a 2 part article on adding SS headers and SS race cats. I think it was European Car. They did a bunch of dyno runs to show the HP gains. They had to redo the baseline for part 2 (cat install) because the pre install numbers didn't match up to the ending HP numbers from the last time. I point that out only to say that perhaps a story that in depth has the dimensions of the cats you are considering. I am surprised SS cannot give you exact dimensions. They have been making this product for 10-15 years.

I would guess that if the SS cats throw a CEL, it can be addressed. The post cat O2 is probably "seeing" too much gas flow; it is outside the programmed range. I suspect a good tuner could take care of that. Or you can get an O2 extender (something like $10) which screws into the post car O2 sensor bung, and then the O2 sensor screws into that. It moves the sensor farther away from the gas flow so that it does not "see" as much exhaust gas flow and hopefully puts it back within the programmed amounts. BTW, HJS cats are a high quality product.

Personally, I don't think there is much bang for the buck on high flow cats; the headers are a relatively good value.

Regards,
Jerry
 
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Discussion Starter #3
Thank you Jerry, I have an email into Turner Motorsports to see what they can provided, but I ill contact Supersprint directly as well.

It is my understanding from this board as well as HJS (via Fabspeed) that the HJS cats won't throw a CEL and they are higher quality, that's why I'm looking to replace the SS cats in the complete system with the HJS cats once I do upgrade the exhaust system.

I do find it odd though that SS cats are known to throw CEL in our cars, but HJS's don't seem to even though SS cats are made with HJS cats based on what I can find.

Thank you once again.

Etienne
 

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I have never seen SS cats throw a code (at least not on the 7 cars I know with them including mine, 3 have different tunes, 3 are stock, mine only has Dinan stage 1 to bring the throttle map to euro spec). Have seen 2 cases where a high mileage O2 sensor gives up the ghost after being removed to replace cats, that’s the only CEL I know of personally regarding these.

I wonder if anyone with a SS cat throwing a code replaced them with HJS (which as previously stated are the same thing) and not gotten the code (without changing something else?). Gotta be careful with board info; rarely is it anything but anecdotal.

The stock cats are excellent, so unless they are broken or very old don’t expect much power, even no cats get you about 3hp, you can find the dyno sheets online.

The Supersprint (HJS) cats are about 5” in diameter. Sorry plastic is in the way a bit on this pic. You can clearly see the HJS stamped on the cat itself- look just above tape measure. Quality of stainless pipe and welds are excellent.

If you are doing SS headers do the SS cats, they bolt right up and you’ll save yourself any difficulties that might arise from matching different cats (such as welding).

939898
 

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Discussion Starter #5
Thank you mattparsons, I appreciate your response.

Below is one of the threads I came across that did not have a good experience with the SS Cats and you are right that the codes could be coming from something other than the cats, Richard M539 is not the only one who has brought this up.


When I do the complete system, I only want to do the cats once and when I found within a couple threads that come members were experiencing CEL's and often within the same thread some recommends HJS cats, that is what got me on this fact finding expidition. I have yet to come across (not saying that it doesn't exist, I just that I haven't found it) anyone bringing up issues with HJS cats (direct from the manufacturer and not through SS) throwing CEL's. This item itself seems weird if SS cats are HJS cats, but then it may have to do with what I'm confused about below.

gsfent, I have an email out to Supersprint and waiting for their response.

I am somewhat confused though and I can't remember if I asked SS this or not. There are many places that call out the SS cats as being 200 cell counts and that they are HJS units; however, when reading the discription of the exhaust system on SS's website towards the bottom of the page, they reference "100 cpsi catalytic" (Performance sport exhaust for BMW E39 M5, BMW E39 M5 5.0 V8 '98 -> '04, BMW M, exhaust systems) which according to HJS's website they also make 100 cell cats under their motorsports section of the website (Catalysts - HJS Motorsport & Tuning) so this leaves me wondering which cell count SS cats actually are.

Thank you,
 

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Thank you mattparsons, I appreciate your response.

Below is one of the threads I came across that did not have a good experience with the SS Cats and you are right that the codes could be coming from something other than the cats, Richard M539 is not the only one who has brought this up.


When I do the complete system, I only want to do the cats once and when I found within a couple threads that come members were experiencing CEL's and often within the same thread some recommends HJS cats, that is what got me on this fact finding expidition. I have yet to come across (not saying that it doesn't exist, I just that I haven't found it) anyone bringing up issues with HJS cats (direct from the manufacturer and not through SS) throwing CEL's. This item itself seems weird if SS cats are HJS cats, but then it may have to do with what I'm confused about below.

gsfent, I have an email out to Supersprint and waiting for their response.

I am somewhat confused though and I can't remember if I asked SS this or not. There are many places that call out the SS cats as being 200 cell counts and that they are HJS units; however, when reading the discription of the exhaust system on SS's website towards the bottom of the page, they reference "100 cpsi catalytic" (Performance sport exhaust for BMW E39 M5, BMW E39 M5 5.0 V8 '98 -> '04, BMW M, exhaust systems) which according to HJS's website they also make 100 cell cats under their motorsports section of the website (Catalysts - HJS Motorsport & Tuning) so this leaves me wondering which cell count SS cats actually are.

Thank you,
I am going from memory here. I have owned a lot of cars over the years, so I may have this wrong.


Stock cats are 400 cell (cells per square inch). The high performance cats are 200. The race cats are 100. Race cats will be loud, high performance not too bad.

However, you need to determine if spending money on performance cats is really much of a benefit. At best you are looking at single digit horsepower gains at the wheels. I doubt you could feel the difference. A lot of $$$ for just a few ponies.

I have a Vortech supercharger, SS headers and some other goodies, but stock (original) cats. I still put out over 600 hp at the crank. Cats are not that big of a limiting factor like the exhaust manifold itself.

Regards,
Jerry
 

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GSfent makes an excellent point- I replaced mine as the stock ones had a rattle, the internal structure had broken; I would not have replaced them otherwise.
 

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Discussion Starter #8
Thank you to the both of you, I will keep this in mind. When the time is right, I will certainly consider if it is justifiable to replace the cats with the complete system headers to tail pipe or just leave them stock and replace everything fore & aft.

I'm still waiting to hear back from both Turner Motorsports and Supersprint themselves.

Thank you,
 

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Discussion Starter #9
Nothing to follow up on yet, have not heard back from either Turner Motorsports or Supersprint. I may put this on the self until I get closer to proceeding with the exhaust upgrade.

Thank you all for your comments.
 

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Discussion Starter #12
It just seems odd that there have been reports of the SS cats throwing CEL's where as the factory direct HJS Tuning cats are not known to do that (at least not that I've come across) even though SS cats are sourced from HJS Tuning.

Thank you,
 

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Some of the posts I have seen with the cats throwing 02 codes have actually been caused by dirty air mass meters caused by too much oil on aftermarket air filters, non oem replacement o2 sensors, and o2 sensors with high mileage giving an error after being removed and re-installed. I have never personally seen them throw a code that was caused by the cats themselves. I have them on my car and I do not have any errors. My setup is Dinan stage 1 ecu, SS headers + cats, Dinan mufflers, intake sensor relocation, stock air boxes and filters.
 

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Discussion Starter #14
I understand, thank you. That makes sense.
 
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