Cat Info

[F6 UTE]

Just like 'Simon Says' (haha... pun intended ) the stock cat will flow 300rwkw, BUT, at what cost to the cat/components

AFA 'hi-flo cat' is concerned.. is it 100, 200, 400 cspi?? Not alot of ppl let u know..

Here's an example..

See how the density of the mesh changes??

You may have a 400 cspi 3" cat, that aint much good to u at all, and with a 100cspi, you won't pass emissions here.. 200/300 is the way to go, good flow and still serves it's purpose..

I am going for the same setup as a member here (xlnt6- great thread), found this when researching cats.. 4" dump to 4" cat then twin 2 1/2" to factory flange..

4" dump/cat install thread

AFA the 4" being too much for what you need, well if you have NO restriction for your current setup, then wouldn't that be better than guessing if you had any or too much?? AND they aren't THAT expensive.. Some ppl say gut the cat, meh, off u go..

SMB quote Metallic substrate 4" in 4" out 437 CFM.. Pretty good match for the rest of the system. Dump pipe fitment for me is purely for bringing boost & Torque on earlier in the rpm range, not really for HP gains, also for ease of CAT install..

I know for a fact my car will stop at edit/injector/exhaust mods.. Some ppl might wonder if they will go further, changing parts all the time is a costly and time consuming excersize.. Car modification rule #1.. Yes twin cat's would be great, matched to a big dump pipe would be orsm..

Mine will be a full bolt in arrangement, and will be removed when the lease expires. Back to stock it goes, flog the dump/cat off and it doesn't cost so much..

Let you know how it goes on Thursday

[F6 UTE]

can anyone suggest a cat under $350??

the SMB is a 4' isnt it? waste of time me getting that if its gunna be redused back to 3' strait after

<{POST_SNAPBACK}>

AArgh. Stock exhaust is twin 2 1/2", that's 3 1/2" single. SO, do u really want to restrict your exhaust with 3" pipe??

[Trough Lolly]

can anyone suggest a cat under $350??

the SMB is a 4' isnt it? waste of time me getting that if its gunna be redused back to 3' strait after

<{POST_SNAPBACK}>

AArgh. Stock exhaust is twin 2 1/2", that's 3 1/2" single. SO, do u really want to restrict your exhaust with 3" pipe??

<{POST_SNAPBACK}>

I was told by numerous exhaust shops that its a 3' dump to a 3' cat inlet to twin 2 1/4 outlets then continues 2 1/4 the whole way.

can anyone here really shed sum light on this??

anyone feel like climbing under with sum verniers to solve this?

[Flukey]

I have a hi flow cat and a stock exhaust it makes 308rwkw easy,with the stock cat was giving up around 250rwkw.

What was the cost to upgrade your Cat? I am at 245atw and have run out of puff so will probably need to change mine.

the best ive seen and tested is the SMB option, they are around the 400.00 mark

Is that a direct replacement?

[Adam]

The SMB cat is $382 + GST.

The SMB dump pipe is $676 + GST.

What about the X-Force exhaust system, I've read good reports about them?

[bugster70]

I am going for the same setup as a member here (xlnt6- great thread), found this when researching cats..  4" dump to 4" cat then twin 2 1/2" to factory flange..

Mine will be a full bolt in arrangement, and will be removed when the lease expires. Back to stock it goes, flog the dump/cat off and it doesn't cost so much.

Okay, I've had a look at the SMB site and can see the 4" cat you're talking about costs a fairly reasonable $382. But the 4" dump pipe adds a whopping $676 to the price!!

Also, they don't seem to offer a 4" to twin 2 1/4" (I'm sure that's what the standard system is, not 2 1/2"?!) converter - all their stuff is for a single system. Where are you having your twin converter made? And how much please? Finally, are you using the $676 SMB 4" dump pipe too? Thanks for your patience with all these questions mate!

[Xtreme F6]

.... This is really hard to type out but ill try again. If you re read my first quote posts you will see where I stipulate that the factory exhaust flows 560 cfm, why would you put a cat in that will restrict this?? an open bit of 3 inch pipe flows over 660 cfm.. so even if you reduce the 4 inch smb unit down the 3 inch will still out flow it.

Its not a direct replacement but any zorst shop worth 2 cents will have no problem adapting it to your original system.

[bugster70]

GTP, I'm still not sure I know what you're trying to get at, sorry. Who's talking about fitting a cat to restrict the system?! By your own admission, the SMB cat is the best aftermarket replacement out there, yes?

But there seems to be some discrepancy between your claims and the SMB claims. You've said that the SMB 4" cat will flow 660cfm, but SMB claim it will 'only' flow 437cfm? Even at 437cfm, it's better than the stock cat by a good margin, so seems worthwhile doing. The major expense as far as I can see is getting the matching 4" dump pipe!

[Xtreme F6]

GTP, I'm still not sure I know what you're trying to get at, sorry.  Who's talking about fitting a cat to restrict the system?!  By your own admission, the SMB cat is the best aftermarket replacement out there, yes?

But there seems to be some discrepancy between your claims and the SMB claims.  You've said that the SMB 4" cat will flow 660cfm, but SMB claim it will 'only' flow 437cfm?  Even at 437cfm, it's better than the stock cat by a good margin, so seems worthwhile doing.  The major expense as far as I can see is getting the matching 4" dump pipe! 

also if you have a look at what they are quoting in there flow figures they say by no means are they in relaition to the standard flow rates. I use a flow bench designed for flow testing carbies and cylinder heads. Its worth well over 30k and is one of the most accurate flow testing devices in the country. I went through the entire exhaust system from front to back and flowed it. You cant get much better then that.

If you wanted the best you would use the dump pipe aswell, other wise you could get it modified to fit without using it.

Factory cat on our bench flows 300 cfm

SMB on our bench flows 660

The factory exhaust flows flows 560.

Cats the restriction.

[bugster70]

Right, got it.

That's really great info GTP, thanks for clearing that up and being patient with us!