Pre Cat with or without High Flow Cat?

[opal]

couldn't see any threads on this so i pose the question:

if i install a 3" precat should i automatically add a high flow cat at the same time?

ie will the benefits of the larger turbo dump be lost or signif reduced without modding the cat??

[currently i have Lukey 2.5" cat back with 3" tip on SriT]
Obviously i dont want to spend $300 - 350 on new cat if i can avoid it...:o

if high flow cat is a goer - then what do ppl recommend?

[CNBLU]

i have recently put on a 2.5inch mandrel bent with a high flow steel cat but i got all of that for 400. not mates rates just a good customer:D

i do have a 3inch dump pipe with 3inch pre-cat going on wednesday so i can tell you the results then....

[CAL.16V]

why fit a pre cat aswell.. ditch the precat and get a dump pipe going down to a flexi and then into a hiflow cat.. then normal cat bcak with muffler...

[Mr T]

^^^^^^^

Yeah what he said.

[auzvectra]

i didnt even notice that in the 1st thread, as cal.16v said, ditch the precat all togeather, just stick a 3" dump on it.

[xplosv57]

After spending last week learning about cats and pre cats, yes ditch the bloody thing, its useless except for emissions so get rid of it and go for a dump pipe!!!

[1OPL2C]

what does the flexi thing do?

[CAL.16V]

for fwd and 4wd cars.. allows the exhaust to move freely from the engine, instead of with the engine

[auzvectra]

get rid of it too, but 1st put a powerflex front engine mount in.
it basically stops vibration, n breaking the exhaust.

[CAL.16V]

why its straight through and only costs $50 for a stinless 3" double braided one

[auzvectra]

that all hey.

[opal]

ok - that's one of the problems...
whats the diff b/w pre cat and dump pipe - i thought they were the same thing!

to be clear i have the dump pipe already.

so i now need to decide if it's worth getting a high flow cat (quote $300).

i read Pauly J reckons they're a crock...
what do others think?

[auzvectra]

high flow cats are just a high volume cat, basicaly they flow more, depending on the brand, and u will never get a definate answer, some will say yes, some will say no.
personally i say yes, but i still have a stock exhaust, so my opinion doesnt mean much :).

[CAL.16V]

yeah got mine for $45 delivered off ebay.. at exhuast shops they are an extra $80 when i was getting mine..

hi flow cats are $150 delivered off ebay.. they are teh same ones most places use.. stainless ones.. liek xforce or something..


if you want a really proper hiflow cat they are about 3-400 for a metalcat or catco big hi flow job

[PaulyJ]

i read Pauly J reckons they're a crock...
what do others think?

Hi-flow cats are a necessity if you want more power and keep your car legal. I never said they were a crock. If i did, it was in a sarcastic manner.
I dont have a cat at all, just a 2" pipe going thru it... but thats my choice.

[opal]

Hi-flow cats are a necessity if you want more power and keep your car legal.


can you be more specific? like is adding a 3"dump pipe making it illegal?

[auzvectra]

paul talking the main cat, not the precat.
replace the dump pipe (precat) with a 3" without a cat in it.

[PaulyJ]

Fair enough
I'll leave the turbo talk to you guys.