... since the majority of the high flow cats for the Z seems to be using Magnaflow's "Car-sound" metal (and ceramic) cats... i've taken the plunge to custom make my own for my tt'd Z.. i'm going with the universal center-center spun cat with a 2.75" ID. (300 cell), part # 59958. there is a nice selection of angle-offset ones in 2.5" (metal and ceramic) that would fit in the oem location, however i need the 2.75" to match my evott exhaust.

i know Cats probably won't flow as good as test pipes, but i cant stand the smell anymore. I'd also been thinking of adding flex portions to my exhaust so it won't have any chance of cracking my cast exhaust manifolds. (call me paranoid but they've cracked before.. eh gurgen?)

the cheapest online place for car-sound cats i've found is:

https://www.hottexhaust.com

enter coupon code: chgp1 for ~23% off (weird # but it works...) and they always have free shipping too. (and no tax!!1)

well. next up is the hardest part. finding the pipes and flanges. my fabricator, Richey@Technosquare is going to get the pipes from:

http://www.burnsstainless.com/

they have a WIDE variety of choices of pipes.. but i'll probably have Technosquare fab up the 2.75" flanges since they are not readily available.

i'll post picts up when i get the cats in and when the welding starts. woot.

 

Yay for people like cheston taking the initiative...and doing custom work. way to go man

 

That is a nice find. Nice work man...
Looking forward to seeing a final product...

 

Hey Cheston,

how much is TS charging to weld the pieces together? I have some new headers for my FJ that i have to do the same thing, weld on some cats to them (stock fj has ex-manifold/cats welded together). I guess i'll give them a call and see since it's a little different from what you're doing. Just trying to get a pre ballpark figure.

thanks,

Mark

 

ive heard this before, but can you explain the smell. is it like the smell of a motorcycle? i understand why the smell is there, but i want more of a description. i know i smell after riding my R1. im kicking around tp or hfcs once they come out for the 07

 

The smell is basically just like unburned fuel vapors...


Your engine puts out the following:

CO + CO2, odorless
H2O, odorless
NOx, odorless
Unburned Hydrocarbons, NOT odorless

catalytic converters burn up the excess stuff in your exhaust by making them undergo a chemical reaction. This reaction is self-activated by the heat of the exhaust.

traditional cats that come on your car from the factory are very expensive to produce and are very efficient at doing 3 things (hence the terminology "three-way catalytic converter):

a. reducing NOx (contributes to smog)
b. reducing CO (poison gas)
c. reducing unburned hydrocarbons (groundwater pollution, smog)

most aftermarket cats generally just get rid of unburned hydrocarbons if I remember correctly. They don't have the expensive prescious metals like rhodium, platinum, and palladium to get rid of NOx and CO, but they will cut down on the bad smelling fuel vapors

 

i don't own a sport bike,

but its like smelling of gasoline, but its inside the car, comes thru the vents etc. gives me a headache once in a while, and everyone outside behind me can smell it too- so eh. i'll take a little hit in hp so i dont smell like a fuel-air bomb.

 

i got the cats in.. pretty fast shipping.

we just ordered the pipes and waiting for them to arrive.

picts of the Carsound Cats











we're thinkin we can put these in the factory cat positions.. they're relatively short in length..

i'll update more when we get closer to welding everything.

 

did you consider the 3" to minimize backpressure? why not attempt to insert the above cats into your existing test pipes rather than building one w/ piping de novo?

very interested to see how it works out...

 

update:

sorry for late post... i only get to drop by once in a while for them to test fit everything.

here are the picts:

test fitting.. the pipes being used are 2.75"OD and custom cut flanges:



the reduction to meet up with my 60mm turbo down pipes.




substrate:


comparison via my oem-size test pipes


and with the OEM cats (i accidentally used the wrong side. but u get the idea)





and whala.. sorta done.. missing O2 bung for oem o2 sensor and o2 for lambda meter



next up is to get the driver side installed and then figure out what to do with the Greddy EvoTT's ypipe design..

FYI: if anyone is interested in a 2.75" HFC flow comparison, TechnoSquare will be putting these on the SuperFlo machine to see how much CFMs they get compared with the test pipes. They have a jig setup so these could be mass produced if anyone is interested

 

I wish you all the luck in the world. I had carsound HFC on my Altima and destroyed them in about a year. Hottexhaust is big over on the alti site but these guys are a little cheaper over there too. I just hope I had a bad pair. Let us know how they work for you. Good luck.

 

I made my own custom using carsound on my previous turbo cars, couldn't stand the smell as well especially when the turbo timer was ticking. Badass for doing it on a Z. Looks like you have an excellent welder as well, no boogers.

 

Good luck man! until now, it looks Good!! keep up

 

That looks pretty damn close to Fast Intention HFC(they also use Magnaflow)

 

form follows function! except they dont make a 2.75"!!!

 

They can customize to any size you want. I've heard they've done some radical stuff for other cars. Would love to see the flow data if you have it.

Thanks.

 

I know you are using a different size but the site you listed puts up a set of HFC's that are direct fit for less than 300 bucks so with your discount thats a hell of a deal! If you're using stock size cats then why not just do that?

 

i ran a series of tests yesterday with the 2.25" test pipes, OEM cats, and the New 2.75" HFC.. on the flow bench. (yay for superflow)

i'll post em up (with video) in another thread.

you'll be amazed at what we saw.

 

I read $500 for Magnaflow direct fit. What am I missing?

 

stock sizing?