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Discussion Starter #1
I have spent some time on My 350Z site.Very informative,lots of folks modifying and lots with dyno tests.Ther are some complaints about Random,but also a lot of praise,particularly performance.On a Z -8hp through stock exhaust and those #'s go up with headers and mod exhausts!
Most aftermarket cats are legal some are not in some states...you need to check!
 

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bro, you are the 45 pioneer.......



having done cats (and knowing three guys with RT;s) i can say the RT's have a higher-than-comfortable failure rate as of late... granted, its online chatter at its finest, but two guys with G/Z'z had the same thing happen - the cat material collapses and completely clogs the pipe (then its limp-home driving only)

if they fit (RT) then so should crawford (or any resonated testpipe too, i guess).. i know my local shop could take a set of crawford's and cut & reweld the ends to mate p to the oem Y-pipe......

just FYI, thas all......
 

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I will be using a guy in Lancaster that Piniti=FX introduced me to on Friday.I will ask him which brand he uses,and he does a bunch..but I do believe in having someone between me and the manufacturer.There are a bunch of WRX guys using Random and Perf Niss stands behind their use..there is always risk!!!These are universal and will be welded.
My ex's car(before she was my ex,)had a cat failure and they happen from manufacurer's fault and from motor problems...this installer was very up front about that and the difference in the type of failure...which is why I will use him.
 

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re: the actual cat. itself, isn't it a basic gen. piece only manuf. by just 2 or 3 co. with a front and rear pipe welded on to make it fit the specific application? esemes ,with your past in this area , what is your take on this?
 

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Fortunately or not this is true of lots of things that are higher tech than most can or will do!All cats must meet the same Fed standard..Calif is tighter!
 

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my take is fac. cats. have 3 or 4 porceln/ceramic "biscuits" and high/free flow have less (only 2 or 3) - hence higher/freeer! correct?
 

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Discussion Starter #7
esemes said:
bro, you are the 45 pioneer.......

I and many of my friends routinely mod our cars..pretty is secondary,fast and handle is primary!Most of these mods are very familiar,just new to the 45. I did not even know what HID's were before this car although I routinely had 100W hi and low with a wiring harness.
Changing the oxygen sensor voltage to richen it will be the most challenging,maybe the race shop with the dyno is comfortable to play,also have friends with a race shop in Baltimore.

When people know you as a racer or were a racer,they usually help as opposed to laughing and pointing!
 

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I was thinking of cutting off the factory cats and welding on a stock Evo cat. The Evo's is designed to handle the heat and flows really well, better than Random's 2.5" cat at least (someone did testing at the Evolutionm.net forum) The only thing I gotta do is measure out how much room I'll have to work with.

The core is actually about 3" that tapers off to 2 3/8" at the ends, so welding that onto a pair of Helix test pipes (measures 60mm, i think) shouldn't be too hard.

I guess my main question is the 45's cat pipe section and y-pipe section the same as the 35's?
 

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Discussion Starter #9
They are similar in design...not sure on diameter!Mine are scheduled for next Tuesday(the guy hurt himself over the weekend).
Key is better flow, good quality and meets the law
 

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brnjugfx45 said:
They are similar in design...not sure on diameter!Mine are scheduled for next Tuesday(the guy hurt himself over the weekend).
Key is better flow, good quality and meets the law
Are you referring to that of the 35 vs the 45? Or random cat vs stock Evo cat?

No cat replacement meets 'the law' ! :D You know it's illegal to replace a perfectly working cat-con. Be we also know that you ran over that **** piece of 2x4 on the highway and destroyed your stockers, right??? :lol:
 

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Discussion Starter #11
Actually, they must meet the fed standard and CARB for those sold out there.Replacement is "something went wrong."..correct!
A more esotheric discussion is that you do not need them to be clean,thank you big brother!!!Cat's are on the market for 350Z and G35
 

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We have a problem!Nissan/Infiniti has a 4 cat model.This is solved wiht a hi flow dual set-up.However our primary cat(which is too small to function alone) is part of the exhaust header(hope you never have to replace this out of warrenty).
I do not see any releif here,but I took pics and will send them on to several manufactures
 

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Interesting. Can you post pics here? The '35 has four cats as well, but they are incorporated into the down tube that goes between the exhaust manifold and the Y-pipe; we can just replace that section with any of the single, high flow aftermarket offerings.

It has been determined that our engines are very nearly clean enough to run with no cats whatsoever, so going to a single high flow unit is not a problem as far as emissions testing is concerned. I'd wager the 4.5 is in the same boat, so perhaps you could just swap the pipe the lower pipe/cat out with a straight pipe? You'd retain the upper cats and eliminate the lower ones; should help some. The other alternative is to have high flow cat replacements for the lower pipe/cats and gut the upper cats (don't ave to worry about ever replacing them, then.). This would give maximum results.
 

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MustGoFastR said:
Interesting. Can you post pics here? The '35 has four cats as well, but they are incorporated into the down tube that goes between the exhaust manifold and the Y-pipe; we can just replace that section with any of the single, high flow aftermarket offerings.

It has been determined that our engines are very nearly clean enough to run with no cats whatsoever, so going to a single high flow unit is not a problem as far as emissions testing is concerned. I'd wager the 4.5 is in the same boat, so perhaps you could just swap the pipe the lower pipe/cat out with a straight pipe? You'd retain the upper cats and eliminate the lower ones; should help some. The other alternative is to have high flow cat replacements for the lower pipe/cats and gut the upper cats (don't ave to worry about ever replacing them, then.). This would give maximum results.
I swear when I changed the oil last time, this was how the cat setup for my 45 was, too. Dual cats on the downpipe; I didn't see any pre-cats on the manifold itself.

I remember reading about the stock cats burning up (melting, actually) on some of the other cars that share the Fm paltform. (350z, G series). Does anyone know which cat burned up? The front ones, or the rear ones?

I know the Sentra Se and SE-R models were having melting cat issues due to their close proximity to the exhaust ports.

When I was under the car, I remember noting how close in proximity each bank's cat-cons were to each other. Seemed like a poor design to me. First you have the pre-cat so close to the exhaust ports (I know it's 'needed' due to EPA), then not even a foot downstream, the other cat is right there.

Since the exhaust gets hotter after the first cat-con, the temps have to be ridiculous for the 2nd cat-con. My guess is that this one could melt.

Most of the newer cars w/ the cat-cons located so close to the engine have to run really rich under WOT, so not to burn the cat-con. Kinda sucks for performance.

I can't remember where the last O2 sensor is plumbed in, but if it's after the last cat-con, I may just cut out the pre-cat, slap on a SAFC-II and lean out the WOT settings to pick up some HP.
 

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Discussion Starter #15
Language may be different,but the larger cat(2 chamber) is nearly vertical and at the base of the manifold,then a flange,then oxygen sensor,then the after cat(one chamber).In my part of Pa we have a sniffer test,not just a visual inspection...so it has to work and it was our judgement that the larger cat was not clean enough to do it.I can e-mail the pics,but they are too large to post here.You may have more freedom with your laws,some states do not even inspect for safety!!
 

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Dunno about the 4.5 really, but pretty much all of the aftermarket cats for the 3.5 will pass emissions testing (if not visual, i.e. RT).
 

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Discussion Starter #17
Since I had the pics of my cats on the 45,I decided to pass them along to Jason at Perf Nissan and Random Tech and let them make the call on whether or not something could be done!!

We shall see!

I have new brake pads,just ordered cross drilled rotors,waiting on the STB,Paddock and may end up with Proxy's(265/45),frustrated and bored,had to delay my vacation! :evil:
 

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Discussion Starter #18
Random Tech got back to me and they said that replacing the after cat w/o replacing the primary will yield little benefit.

At least the cross drilled rotors are in root!
 
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