what are the downfalls of cheap 100 cpsi cats? something like this http://www.ebay.com.au/itm/3-INCH-C...ccessories&hash=item5d2f8412d8#ht_3734wt_1163 -A
Isnt it true that the more CPSI the better? If so if they are sending 200CPSI instead of 100CPSI isnt that better? Anti have a look on ebay as i have seen 300CPSI or even 400 CPSI cats for around $170...there was also a site where i was able to find Magnaflow 400CPSI cats for around $160 if i remember correctly...i posted up the link in the Technical section in a thread somebody posted. It was last year sometime...it would be good to have the link again if anybody can find it. Abraham
The LESS CPI you have the LESS surface area is available for the catalyst to convert the nasties in the exhaust into its constituent molecules. LESS CPI means MORE FLOW but LESS effectiveness (for its intended purpose). 90% of the cost of a cat converter is the catalyst itself- this is why exhaust shops keep them in a seperate bin out the back, and why they sel them off and melt them down into their precious metals when the metals market price is right. Platinum, palladium and all the other rare earth metals are not cheap. If you wanted to remain legal, I'd look into some OE stuff from the big aussie 8's. Run 2 of them, which are good for that euro 5 standard, and will be able to flow twice the volume (remember its a 3L V8 bank as opposed to a 1.5L bank in the VG30). I got pretty close to big fines with my emissions control defects, probably have my car on the DECCW blacklist too ... so yeah, know what you're getting into before you succumb to the marketing details of XXX CPI cats on eBay of all places...
It also follows that the more cells you have=better/cleaner exhaust emissions, something you should seriously consider if you are going to be sent over the Pits for a Roadworthy(after being stopped for being too low).:br::rofl::rofl::zlove:
you mean OEM cats for a ls1 or boss or something? clearly I am; I'm fabricating an exhaust from scratch and actually buying cats
Yeah, scrap value for something like that should be around $100. Plenty of commodore and falcon people are swapping out stock exhausts to put their wanker pipes on, so waste not want not As far as the law goes, you need to run factory to be legal, UNLESS you get it tested by the EPA / DECCW testing station at botany bay. This is what will happen when you get caught- you will either need to swap back to stock cats in stock pipes, OR get it tested. And 100CPI cats off ebay will do NOTHING for emissions, whereas something out of a commodore would likely exceed the emissions specs of the early 90's. Not sure about it's flow though, but considering that the V8 engine is TWICE the size of a VG, its ball-park for forced induction on 14psi (approx 2 atmospheres pressure, where your 3L FI engine acts like a 6L atmo engine).
I'm going for 20 PSI with high flows. I thought I would get away with having cats fitted? What's the point if they're just as illegal as no cats? The OEM cats thing sounds fine so long as the flow's alright
My non standard cats got me 2 vehicle inspections at $65 each, 1 defect notice, 1 cancelled rego notice, cost of stock cats and labour to weld in... not to mention a total mind**** right in the middle of uni exams. So just tread lightly. I'm not scaremongering, but them's the breaks you get to look forward to, keeping in mind the cats will also be an issue on top of being too low, wheels too big, wheel spacers etc etc etc.
Save your breath Mitch, I already had this discussion with Martin on Sunday(he didn't listen then either).:br:
I understand. There definately is a point of no return with modifications, it's just a matter of how risk averse you are I guess.
This is the Magnaflow 400CPSI i was talking about Linky Anti if your trying to do it properly then do it properly...if not and your just after performance, then just get a screwdriver and go away at the insides of your stock cats or even just go and get yourself a straight pipe system. When i do finish off my exhaust system i shall be getting the above Magnaflow cats as that is great value for money Abraham
Abz, if you're going to advocate this sort of stuff on a public forum make sure you put a disclaimer about how illegal it is. There's a whole bunch of hearsay about $12-15,000 fines from the EPA but I've never heard of someone actually being handed down such a fine. Mitch is probably is probably the person whose been closest to receiving, by all accounts.
I meant in no way approve of what i said...i meant it as a joke and it should be taken in that manner...im trying to get him to get it done properly instead of getting huge fines and all the hassles. If i was to get 400CPSI cats for myself, i would be giving the same advice to others. My apologies if it came out wrong. Abraham
Having gutted cats, no cats, or 'high flow' 100cpi cats are all as illegal as each other. The line is in the sand- stock or not. If 'not', then needs to be tested for compliance. That being said, most likely to get away with it would be gutted cats- they look the same, but do not get hot when operating (the catalyst causes the cat to heat up as it operates, which is what our AIV's do- assist heat-up time). I was toying with the idea of stock cat shells welded over high flows
that last one is by far the best if you aren't going for actually legal, gutted cats tend to create a drone and degrade your exhaust note. If you can also pack the cat shell with a heat sync material (I've heard steel wool suggested for this) it will stop them from sounding hollow and might get you by on the heat gun test, depends how hot it gets though as steel wool does burn pretty well. on the topic of after market being the same as no cat unless the car is tested they are different because one is much more obvious, the OEM V8 idea works because they look like stock cats, most high-flow/race cats just look like a hot dog so its much easier to pick
Super interesting read the biggest thing that gives ''my mates'' decat car away is the smell! Smells like its on LPG but being NA it gives him much needed top end power and like me he lives in Bendigo VIC which is pretty close to bogan central. you do get that Whirr and even though his car is highly modded visualy and mildly modded performance-wise because it dosent say ''skyline'' on the back and dosent have a cannon and stickers everywhere he gets next to no attention though he flogs it everywhere. why cant u decat and have a spare 2 cats if its as punishable as anything that dosent relinquish the engine of a heap of power such as ebay cats that dont have super thick honeycomb structured metal in them?? just leave the 1st resonators and change the rear ones for high flow...
Now I'm bloody confused. What do people normally do in this sort of situation? I find it hard to believe everyone fits Holden cats :\
