Jump to content
SAU Community

Recommended Posts

But said Venom cat doesn't work at lowering emissions, and isn't even legal. Best flow would be a single cell cat, just punch the stocker out. Unless the OP gives us some idea of what he wants the cat to be good at, I can't suggest the best cat...

Shame, it takes more energy to make a cat then sell it to us suckers, than it would ever save in emissions. We are better off capturing carbon from the atmosphere in ice blocks, or simply running ethanol in all vehicles that will run on it, as in Brazil.

  • Like 1

They're not about global warming style emissions. They are about NOx and CO. CO is poisonous, and in heavily built up emvironments the amount of CO from vehicles is a serious health hazrad (or it was...before decent cat converters). NOx is both a greenhouse gas in its own right, poisonous in its own right, a trigger chemical for photochemical smog (which causes high ozone concentrations in the lower atmosphere - which is not good) and is a very bad thing to have in the upper atmosphere when it eventually gets up there. NOx is worth stopping. Most of the work I do in gas firing in industrial installations is about reducing NOx emissions. I have clients spending hundreds of thousands of dollars on CFD modelling to predict the NOx generation of new burners we design for them to try to keep the EPA happy.

The less cells, the more free flowing it will be, the more cells the more restrictive.

The less cells the harder it is to be EPA compliant, the more cells the better scrubbing it is.

So if your worried about EPA go for a 300 cell high flow, if you want power, punch out your old substrate and just leave a shell there so the police dont notice a decat pipe, if you get a EPA defect bolt a stocker in for the test.

There will not be much of a change in sound by changing cats, change the hot dog for a straight through muffler for the next noise level down or just add a straight through muffler....

About running a straight pipe instead of a punched out cat, its financial suicide, any idea about the on the spot fine for not running a cat? At least it wont be obvious to whoever checks the car when pulled over.

There will not be much of a change in sound by changing cats, change the hot dog for a straight through muffler for the next noise level down or just add a straight through muffler....

About running a straight pipe instead of a punched out cat, its financial suicide, any idea about the on the spot fine for not running a cat? At least it wont be obvious to whoever checks the car when pulled over.

A straight pipe through the cat, inside it, not cut out the cat and replace it.

The hassle is, if they drop the cat it will be obvious, if they measure the heat of the cat it will be colder than the pipe. At least if they see the insides are gone, there is no way they can fine you, as it obviously just dropped out one day officer...

Don't ever try and punch out a metal cat, only attempt it on the stock ceramic ones.

Don't ever try and punch out a metal cat, only attempt it on the stock ceramic ones.

It can be done, I did it in 5 mins the other week. Bit of inch pipe and lump hammer.

Which leads to my next point, metal cats arent worth the space they take up. Iv killed my second well known brand 100 cell cat in less than a couple of thousand kms. They are rubbish. They get hot, fold over and holy back pressure.

The 'best' cat for purpose is a bf xr6t cat, 3 inch, and mine was running euro3 standard on the emissions test.

You must be buying crap cats Amon. :P

The Xforce substrates are welded to the body, they won't move ever, and punching one out took me over an hour. Quicker and easier to make a pretend one from 4 inch stainless and two reducers.

  • Like 1

A straight pipe through the cat, inside it, not cut out the cat and replace it.

The hassle is, if they drop the cat it will be obvious, if they measure the heat of the cat it will be colder than the pipe. At least if they see the insides are gone, there is no way they can fine you, as it obviously just dropped out one day officer...

Don't ever try and punch out a metal cat, only attempt it on the stock ceramic ones.

That is the best way, the chances of them dropping the cat is zero at the point your defected, you usually have a time frame to bring the car in for a check, enough time to put a stocker back in to pass emissions testing.

I run a 100 cell FIA approved race cat, having said that i don't think its epa legal anyway but so far it never failed in the GTR.

At least i have a cat to show, if i was tested the stocker would magically fly in.

when I punched out a 3inch cat, it sounded terrible like id created backpressure,

got a 100cell cat from Eliteracing and a 3inch Xforce oval muffler and "boom!!" awesome raw breathing sound without the crap drone or loudness that attracts cops..

. Iv killed my second well known brand 100 cell cat in less than a couple of thousand kms. They are rubbish. They get hot, fold over and holy back pressure.

Amon please PM me the brand of cat that failed.

I would like to know this too if you don't mind, I've used magnaflow 200c metal cats on two of my cars with no problems, and they're fairly cheap on the scale of cats.

While there may be issues passing emissions with a 100c cat, I'd much rather take my chances of "maybe/maybe not" passing a test, than certainly being screwed running no cat.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Who did you have do the installation? I actually know someone who is VERY familiar with the AVS gear. The main point of contact though would be your installer.   Where are you based in NZ?
    • Look, realistically, those are some fairly chunky connectors and wires so it is a reasonably fair bet that that loom was involved in the redirection of the fuel pump and/or ECU/ignition power for the immobiliser. It's also fair to be that the new immobiliser is essentially the same thing as the old one, and so it probably needs the same stuff done to make it do what it has to do. Given that you are talking about a car that no-one else here is familiar with (I mean your exact car) and an alarm that I've never heard of before and so probably not many others are familiar with, and that some wire monkey has been messing with it out of our sight, it seems reasonable that the wire monkey should be fixing this.
    • Wheel alignment immediately. Not "when I get around to it". And further to what Duncan said - you cannot just put camber arms on and shorten them. You will introduce bump steer far in excess of what the car had with stock arms. You need adjustable tension arms and they need to be shortened also. The simplest approach is to shorten them the same % as the stock ones. This will not be correct or optimal, but it will be better than any other guess. The correct way to set the lengths of both arms is to use a properly built/set up bump steer gauge and trial and error the adjustments until you hit the camber you need and want and have minimum bump steer in the range of motion that the wheel is expected to travel. And what Duncan said about toe is also very true. And you cannot change the camber arm without also affecting toe. So when you have adjustable arms on the back of a Skyline, the car either needs to go to a talented wheel aligner (not your local tyre shop dropout), or you need to be able to do this stuff yourself at home. Guess which approach I have taken? I have built my own gear for camber, toe and bump steer measurement and I do all this on the flattest bit of concrete I have, with some shims under the tyres on one side to level the car.
    • Thought I would get some advice from others on this situation.    Relevant info: R33 GTS25t Link G4x ECU Walbro 255LPH w/ OEM FP Relay (No relay mod) Scenario: I accidentally messed up my old AVS S5 (rev.1) at the start of the year and the cars been immobilised. Also the siren BBU has completely failed; so I decided to upgrade it.  I got a newer AVS S5 (rev.2?) installed on Friday. The guy removed the old one and its immobilisers. Tried to start it; the car cranks but doesnt start.  The new one was installed and all the alarm functions seem to be working as they should; still wouldn't start Went to bed; got up on Friday morning and decided to have a look into the no start problem. Found the car completely dead.  Charged the battery; plugged it back in and found the brake lights were stuck on.  Unplugging the brake pedal switch the lights turn off. Plug it back in and theyre stuck on again. I tested the switch (continuity test and resistance); all looks good (0-1kohm).  On talking to AVS; found its because of the rubber stopper on the brake pedal; sure enough the middle of it is missing so have ordered a new one. One of those wear items; which was confusing what was going on However when I try unplugging the STOP Light fuses (under the dash and under the hood) the brake light still stays on. Should those fuses not cut the brake light circuit?  I then checked the ECU; FP Speed Error.  Testing the pump again; I can hear the relay clicking every time I switch it to ON. I unplugged the pump and put the multimeter across the plug. No continuity; im seeing 0.6V (ECU signal?) and when it switches the relay I think its like 20mA or 200mA). Not seeing 12.4V / 7-9A. As far as I know; the Fuel Pump was wired through one of the immobiliser relays on the old alarm.  He pulled some thick gauged harness out with the old alarm wiring; which looks to me like it was to bridge connections into the immobilisers? Before it got immobilised it was running just fine.  Im at a loss to why the FP is getting no voltage; I thought maybe the FP was faulty (even though I havent even done 50km on the new pump) but no voltage at the harness plug.  Questions: Could it be he didnt reconnect the fuel pump when testing it after the old alarm removal (before installing the new alarm)?  Is this a case of bridging to the brake lights instead of the fuel pump circuit? It's a bit beyond me as I dont do a lot with electrical; so have tried my best to diagnose what I think seems to make sense.  Seeking advice if theres for sure an issue with the alarm install to get him back here; or if I do infact, need an auto electrician to diagnose it. 
    • Then, shorten them by 1cm, drop the car back down and have a visual look (or even better, use a spirit level across the wheel to see if you have less camber than before. You still want something like 1.5 for road use. Alternatively, if you have adjustable rear ride height (I assume you do if you have extreme camber wear), raise the suspension back to standard height until you can get it all aligned properly. Finally, keep in mind that wear on the inside of the tyre can be for incorrect toe, not just camber
×
×
  • Create New...