Yay, I Just Got My Roe Hi-Flow Cats Installed!

[Zentenk]

I'm sure you will be fine, let us know how everything goes...

I'm still undecided on what I'm going to do. I haven't been this stressed in awhile trying to decide which headers to go with... I currently have the RandomTech High-Flow Cats which I was told has a 300-400 cell count. I have no idea what the Belanger Cats are, but I was told the Roe Racing's cats are 200 cell count and from American Racing's website, theirs are also a 200 cell count. If I decide to get the American Racing headers, I will most likely purchase their high-flow cats to go along with the headers since they have a lower cell count. If I get the Belanger Headers, I will probably end up keeping my RandomTech Cats unless the Belanger Cats happen to be a lower Cell Count.

I was just told the lower the cell count, the better performance and the louder the sound. In my book that's worth switching to another Cat. Unless the difference is extremely subtle, I'll just save my money and keep the RT Cats I currently have.

I was also told that these Header companies don't produce their own cats anyway, so they could be getting them from anyone. However RandomTech is a well known American brand so you know what you're getting. I just really want the lower Cell Count, if it infact matters

I have also read that the 100 cell count may smell more like cat-less. I want a little cleaning of the smell/fumes and most performance possible. I had random tech previously on the car but a fouled O2 sensor messed it up. Check your O2 sensors!! I originally wanted bassani cats, they look well made, but I could not find them for sale anywhere.

I e-mailed the two shops to see what was going on with my order. Hope they don't **** me around, that is real annoying. Good luck with your Viper!

 

[costanZo]

I have also read that the 100 cell count may smell more like cat-less. I want a little cleaning of the smell/fumes and most performance possible. I had random tech previously on the car but a fouled O2 sensor messed it up. Check your O2 sensors!! I originally wanted bassani cats, they look well made, but I could not find them for sale anywhere.

I e-mailed the two shops to see what was going on with my order. Hope they don't **** me around, that is real annoying. Good luck with your Viper!

Thanks man, goodluck to you as well. I was actually suggested to buy new 02 sensors so most likely I probably will when I do the Header install

 

[Vipuronr]

O2 sensors....I'm assuming Chuck checked these when he installed the Roe cats. Wouldn't a bad sensor give some reading that shows on the dash?

 

[Zentenk]

O2 sensors....I'm assuming Chuck checked these when he installed the Roe cats. Wouldn't a bad sensor give some reading that shows on the dash?

I did get a check engine light and scanned it... don't remember what it was. I think it said something about catalytic threshold efficiency low or some junk.

One O2 sensor was new on my car, the other was old (when I replaced them). What ***** replaces just one? Previous owner was not very bright.

 

[JonB]

Depends, I am picking my high flow cats based on cells per inch and found some that are 100 cells per inch which is the best I have found. I think Random Tech is 300~ or more cells which is more restrictive. Ask Roe and American Racing how many cpi their cats have.

Flow rate in CFM depends on SUBSTRATE LENGTH and CELL COUNT. See below.

Also ask WHO makes the cats ?! BASSANI was mentioned above..... like many others, just buy and brand the cats some un-named cat manufacturer. Many are built in Asia, for the import market, and adapted to Vipers.

Not so for US-made Random Tech cats. AND: Random Tech DOES offer 100-CPSI (and even 50 cel) cats, up to 5" diameter! 'Race cats' are fully functioning, but wont meet OBD-2 requirements. The problem is, 100-cells WONT scrub the emissions enuf to be street-legal, might NOT pass a sniffer test, and might throw a Check Engine light. Designed for race applications where the rules (or the drivers nose) requires a cat. Example: some Rally and circle-track and even indoor or stadium applications.

Note: The LENGTH of the 100 cel substrate needs to be longer to effectively (legally) scrub the same CFM of emissions as a shorter, lighter 300 cell cat. So, the resulting CFM of the
'legal' cat could be the same. CFM matters not CPSI counts.

Random Tech has the formula to achieve high CFM flow rates, and DOT compliance, US made and TESTED for flow. To my knowledge ONLY RANDOM TECH publishes and guarantees flow rates in CFM. Cats and the substrates made in USA. And extra-procees 'wash' applied to the substrates. 5-year written warrantee.

Circle Track Magazine just performed a test of the Random Tech 100 CELL cats, showing they flow almost the same CFM as open catless pipes. And yet the CFM of the RT VIPER CATS flow almost that same CFM as these 100-cell race cats. Next Issue...expect a link.

Trivia: Back in year 1998-2000, we also had "PartsRack Racing Cats". No More. Made overseas. Great profit margins. Unknown CFM flow rates. We actually got a DOT-Fed warning letter and a $35k threat over 2 of our products. I learned waaay more about cats back in 1999-2000 than I wanted to know at the time. Can you say "Voluntary Compliance"?

Bottom line: OBD-2 compliant cats that FLOW MORE CFMs THAN YOUR CYLINDER HEADS CAN PRODUCE is all you really need! And Stink Is bad. And ratty sound is bad.
Know who manufactures your cats or substrates...know what they flow. CFM matters, not just CPSI.

 

[Zentenk]

Awesome post Jon!

Thanks for that information, I am contacting the builder of these cats to see if he can provide some CFM/substrate length.

 

[costanZo]

Flow rate in CFM depends on SUBSTRATE LENGTH and CELL COUNT. See below.

Also ask WHO makes the cats ?! BASSANI was mentioned above..... like many others, just buy and brand the cats some un-named cat manufacturer. Many are built in Asia, for the import market, and adapted to Vipers.

Not so for US-made Random Tech cats. AND: Random Tech DOES offer 100-CPSI (and even 50 cel) cats, up to 5" diameter! 'Race cats' are fully functioning, but wont meet OBD-2 requirements. The problem is, 100-cells WONT scrub the emissions enuf to be street-legal, might NOT pass a sniffer test, and might throw a Check Engine light. Designed for race applications where the rules (or the drivers nose) requires a cat. Example: some Rally and circle-track and even indoor or stadium applications.

Note: The LENGTH of the 100 cel substrate needs to be longer to effectively (legally) scrub the same CFM of emissions as a shorter, lighter 300 cell cat. So, the resulting CFM of the
'legal' cat could be the same. CFM matters not CPSI counts.

Random Tech has the formula to achieve high CFM flow rates, and DOT compliance, US made and TESTED for flow. To my knowledge ONLY RANDOM TECH publishes and guarantees flow rates in CFM. Cats and the substrates made in USA. And extra-procees 'wash' applied to the substrates. 5-year written warrantee.

Circle Track Magazine just performed a test of the Random Tech 100 CELL cats, showing they flow almost the same CFM as open catless pipes. And yet the CFM of the RT VIPER CATS flow almost that same CFM as these 100-cell race cats. Next Issue...expect a link.

Trivia: Back in year 1998-2000, we also had "PartsRack Racing Cats". No More. Made overseas. Great profit margins. Unknown CFM flow rates. We actually got a DOT-Fed warning letter and a $35k threat over 2 of our products. I learned waaay more about cats back in 1999-2000 than I wanted to know at the time. Can you say "Voluntary Compliance"?

Bottom line: OBD-2 compliant cats that FLOW MORE CFMs THAN YOUR CYLINDER HEADS CAN PRODUCE is all you really need! And Stink Is bad. And ratty sound is bad.
Know who manufactures your cats or substrates...know what they flow. CFM matters, not just CPSI.

Wow Jon, thanks for the info. I def don't want anything that I have to worry about not passing emissions, have a strong smell or have a ratty sound. If the Cats I have, which I'm assuming are the Stainless steel, ceramic substrate do those in fact have a 300-400 cell count? Do they make a 200 cell count that would pass emissions, not smell and not have a ratty sound? If not, I won't bother..especially if it's not worth it in the end.

 

[plumcrazy]

great post jonB

 

[Vipuronr]

Wow, seems like you got your answer...and more! Can always count on Jon to provide not only a detailed answer, but the technical support as well!

 

[Vipuronr]

Since we're talking about flow rates, maybe Sean can chime in here and provide flow rates for his metal substrate cats...or, if someone happens to know...cool.

 

[rudedawg]

Nice informative post Jon, that's why I purchased my Random Tech high flow cats from you.You allways point me in the right direction,Thanks Again !!

 

[costanZo]

Since we're talking about flow rates, maybe Sean can chime in here and provide flow rates for his metal substrate cats...or, if someone happens to know...cool.

I posted them in an earlier post within this thread lol... I was told this anyway, so it might not be 100% accurate.

I'm sure you will be fine, let us know how everything goes...

I'm still undecided on what I'm going to do. I haven't been this stressed in awhile trying to decide which headers to go with... I currently have the RandomTech High-Flow Cats which I was told has a 300-400 cell count. I have no idea what the Belanger Cats are, but I was told the Roe Racing's cats are 200 cell count and from American Racing's website, theirs are also a 200 cell count. If I decide to get the American Racing headers, I will most likely purchase their high-flow cats to go along with the headers since they have a lower cell count. If I get the Belanger Headers, I will probably end up keeping my RandomTech Cats unless the Belanger Cats happen to be a lower Cell Count.

I was just told the lower the cell count, the better performance and the louder the sound. In my book that's worth switching to another Cat. Unless the difference is extremely subtle, I'll just save my money and keep the RT Cats I currently have.

I was also told that these Header companies don't produce their own cats anyway, so they could be getting them from anyone. However RandomTech is a well known American brand so you know what you're getting. I just really want the lower Cell Count, if it infact matters

 

[Slithr]

I learned waaay more about cats back in 1999-2000 than I wanted to know at the time.

OK, smarty paints! What's the difference in metal and ceramic substrates, pro's and con's of each please.

 

[Zentenk]

The cats I found are 100 cell 3" in/out 18" long with 12" substrate.

 

[Vipuronr]

The person with the best knowledge on metal vs. ceramic substrate, in my opinion, is Jon from Parts Rack.

As for my question on flow rates for Roe, the earlier post talked about cell count, that Roe is at 200 and RTech were at 300-400. I'm not sure what the effect is combining factors to determine flow rate, if there is any impact, cell count and metal vs ceramic substrate. I think RTech is ceramic (not sure if they have metal) and Roe is metal (not sure if they have ceramic).

Is flow rate only a measure of air flow through the cat, or does it somehow affect the emission cleaning capability? I don't have any idea, only asking the question.

 

[JonB]

Awesome post Jon!

Thanks for that information, I am contacting the builder of these cats to see if he can provide some CFM/substrate length.

GOOD LUCK, but most cat manufacturers only rate their cats like the feds do: by "Cubic Inches" they are rated to handle. REAL EXAMPLE: Back in the day, one might ASSume that a single cat that was rated to handle a 390ci Ford Truck (1 cat) could be considered to be a "hi flow" cat.

These were actually sold to Viper tuners and owners under the [mistaken] theory that "if it will handle 390 cubes by itself, then TWO of em can handle 780ci, but only have to handle 488 cubes....so it must be hi-flow!'" And it FIT in a Viper sill! And I have to confess that I initially bought into that premise for about 3 months, til we tested them. Well, it does NOT work that way. The longer substrate surface area that is needed to scrub 390 cubes is only a midrange-flowing cat. But quite a few Vipers were sold these cats under the false premise above.

The 2 major cats that are widely re-branded are designed for the MUFFLER SHOP MARKETS of the world. And a third brand is actually manufactured by the first! Almost always of softer 400-series stainless. They are designed simply trying to get a car to cheaply pass emissions with a good mufflwer-shop profit margin. They are NOT manufactured with high HP / custom applications in mind. In this, Random Tech differs.

Random offers the OPTION of ceramic or metal honeycomb. For example CORSA states that they prefer the sound TONE of the ceramic cats....they say the metals make their system too loud for their tastes. CFM = air AND decibels. Random's Ceramic HF substrates flow more CFM than your stock heads can produce. I guess that a shop that specializes in blowers would prefer metal honeycomb: If your motor has a blower, you can benefit from the higher CFM that metal cats allow....and ASSuming you dont have rich-running tuning issues, metal cats can last longer. Both substrates have a 5-yr warrantee.

But until about 2001, blown Vipers used ceramic cats....the metals just were not avail in US!

 

[Zentenk]

metal is more durable.

 

[Vipuronr]

As I said, Jon has the knowledge. Question...the other two "major" cat distributors do not have cats made to their specs, e.g., specs for a Viper specifically? Just askin'

 

[JonB]

The person with the best knowledge on metal vs. ceramic substrate, in my opinion, is Jon from Parts Rack.

As for my question on flow rates for Roe, the earlier post talked about cell count, that Roe is at 200 and RTech were at 300-400. I'm not sure what the effect is combining factors to determine flow rate, if there is any impact, cell count and metal vs ceramic substrate. I think RTech is ceramic (not sure if they have metal) and Roe is metal (not sure if they have ceramic).

Is flow rate only a measure of air flow through the cat, or does it somehow affect the emission cleaning capability? I don't have any idea, only asking the question.

Im gonna deflect that kind compliment and say Dave at Random Tech is my primary guru.....and the fact that car-mags use his expertise validates my opinion of him.
For a small fee, say $50, Random would even flow-test your 'mystery' brands of cats!
But this debate can become 'principled' vs real-world, like the tire-age debate also degraded.

Flow rate in CFM is just that. A 100 cell cat flows more, but WONT clean emissions to OBD-2 requirements. PS. Inlet-outlet and case design also affects flow!

ps THE YEAR MATTERS !!!

 

[JonB]

As I said, Jon has the knowledge. Question...the other two "major" cat distributors do not have cats made to their specs, e.g., specs for a Viper specifically? Just askin'

Over a decade ago, my company stopped reselling our 'featured' brand simply because they would NOT spec out a 'Viper' cat for us, for a 560HP 1997. Their 3" offering was running too hot. They would NOT flow-test the cats they provided. Their territory sales rep was here twice, conference-calling with their US engineer. But no deal. Why? They cater to the muffler-shop markets/margins. We were too small. Maybe too demanding. But Random Tech welcomed us. I like being able to speak to the manufacturer.

A lot has changed since 2000-01, and IMPORT CAR DEMAND [and turbo cars] has driven cat manufacturerers to produce HF cats in greater numbers, that FLOW greater numbers, at better prices. Still aimed for the muffler-shops + tuners. But I have not looked back in 10 years at that specific company who now makes two of the 3 brands.

 

[costanZo]

But I have not looked back in 10 years at that specific company who now makes two of the 3 brands.

I don't blame you, seems like you obviously made the right decision. Once again I appreciate all the time you take on the forums and on the phone to help give great explanations and advice as always.

You've basically talked me into keeping my current cats and stock clutch instead of spending money on new ones.. if it's not broke and works perfectly why try and fix it? Also, you along with other members have made me lean more towards the Belanger Headers now, which is what I've always wanted in the beginning anyway. I'm not sure exactly when and what I'll be buying in total of everything yet, but you will be getting some calls from me in regards to buying some more stuff. I'd especially like to speak with you again about my different options with gears and what might be best for my car and the mods I plan to do.

Once again, thanks Jon for all your help.

 

[JonB]

OK, smarty paints! What's the difference in metal and ceramic substrates, pro's and con's of each please.

First off, my posts are answers to questions being posted in this thread...I dont want to be a hijacker.

As with most things, there is no "free lunch" with catalytic converters. Improvements in one area typically come at the expense of characteristics in another. As an example, all technical specs being the same, metallic substrates offer higher flow rates than ceramic substrates because the cell walls are thinner. Ceramic material is extremely hard, but it lacks certain strength characteristics, so the walls between cells in a ceramic converter are thicker than those in a metallic core converter. You can actually see light and shapes thru a Random Tech metal honeycomb cat!

Another consideration is that a ceramic core can crack, a metallic core won't. So the trade-offs are: a metallic core offers higher flow rate and will not crack, but is more expensive to manufacture. A ceramic core has a lower flow rate, is cheaper to manufacture and can crack. Another consideration is that the same characteristics that restrict flow, restrict noise, so a ceramic converter will reduce exhaust sound levels more than a metallic converter.

The same type of trade-offs exist with respect to cell counts. Cores with higher cell counts (300 versus 100 for example) offer more surface area to scrub pollutants from the exhaust stream, but that increased surface area offers more flow restriction than would exist with a core having a lower cell count. Core length has a similar trade-off-- the longer the core, the greater the surface area. the greater the surface area, the better the "scrubbing" effect and the lower the flow. In fact, it's possible to have a 100-cell converter that flows less than a 300-cell converter (as a result of a length difference.)

Random Tech (and possibly other) 100-cell converters offer the same type of emissions-reduction characteristics as their 300-cell converters (the chemistry is identical), but with less surface area, these converters won't provide the oxygen content profile that an OBD-2 system is looking for. So even though these converters should enable a vehicle to pass a sniff test with no problem, they can trigger a "Check engine" light-- not because the converter isn't working properly, but because the vehicle computer still "thinks" a stock converter is installed, and it isn't receiving the data it expects.

Finally: Back on thread topic - Most any Hi Flow cats sound better, run cooler, and can release a few HP. But proving incremental HP and allocating that to a cat alone is hard for a 98.5% accurate dyno to do. Why? The 1.5 - 2% margin for error is about what a HF cat creates in a 500HP motor! Hence, the principled debate.

 

[JonB]

I don't blame you, seems like you obviously made the right decision. Once again I appreciate all the time you take on the forums and on the phone to help give great explanations and advice as always.

You've basically talked me into keeping my current cats and stock clutch instead of spending money on new ones.. if it's not broke and works perfectly why try and fix it? Also, you along with other members have made me lean more towards the Belanger Headers now, which is what I've always wanted in the beginning anyway. I'm not sure exactly when and what I'll be buying in total of everything yet, but you will be getting some calls from me in regards to buying some more stuff. I'd especially like to speak with you again about my different options with gears and what might be best for my car and the mods I plan to do.

Once again, thanks Jon for all your help.

You made my day.........Ive been spewing advice to owners since 1993....and I promised to provide the same advice even AFTER PartsRack began. My CPA listens a lot, and says I have a 'reverse conflict of interest', since I frequently talk owners out of making buying decisions that dont always meet their stated goals, budgets, or rational choices vs emotional ones.

Thanks .

 

[Vipuronr]

That last line is why you have the reputation you have!