How can you tell if the stock cat is plugged? any DIY tests or way you can check the flow of the cat. When i look through my cat i can see a small amount of light at the other end. not sure if that means anything… thanx for the help.
its white and you can see through to the other end. its like a honeycomb. it doesnt always mean your cat is good tho
well i can see slightly through the other side, i can just see light about a an 1.5 inch circle, the honeycomb is still there although its turining brownish, any other info it feels like im losing some power on the top end, maybe its in the mind i dunno…
Grab that drill bit I mentioned, and drill a hole in that sucker:p
if you drill a hole wouldnt that defeat the purpose of the cat? not being smart or anything just wondering, are there any negatives to doing this? why not just hollow the entire thing?
Did you read the previous pages of this post? If you hollow the entire thing you get nasty turbulence goin on. . . When I drilled mine, there was no turbulence, and everything flowed better. Not sayin this is the best alternative. . . But it did work really well for me personally.
ya you should only see about a 1" circle of light, but move the cat around while its perpendicular to your eye. you should be able to see straight through at all sections. i guess white/brownish is ok, but if its getting all dingy/crusty then i would replace it. even my old ones looked perfectly in tact, albeit slightly beige if not off-white.
if its already on its way out, go ahead and gut it and try it out. either youll keep it or get a carsound… at least youll know what its like.
as far as turbulence, why does it matter if with the catalyst in tact, it already forms an obstruction and the gases need to squeeze through the other end anyways. guess its a matter of sound
cool thanx for the info and advice guys!
the law of thermodynamics states that gasses act as liquids even though their a different state. Like said before hollow cats are alright, honda tunings done it before, but a race cat is much better more scrubbing power=less honeycomb
i have personaly seen a dyno chart of a b17a in stock form it just typical bolt ons put out 125hp to the wheels, with a removed cat it made like 154hp to the wheels and it was all because of a plugged cat maybe in a brand new car hollowing the car wouuldnt do shit or loose power but in this case it wasnt like that
i have a test pipe for sale for 40$ if your interested.
i have personaly seen a dyno chart of a b17a in stock form it just typical bolt ons put out 125hp to the wheels, with a removed cat it made like 154hp to the wheels and it was all because of a plugged cat maybe in a brand new car hollowing the car wouuldnt do shit or loose power but in this case it wasnt like that
those must have been some off-the-wall typical bolt-ons! i only put down 145whp with i/h/e/ign, stage3 cams, fpr, intake manifold, tb, and ecu!
did you even tune the fuel and timing cause thats some really low numbers for what u have what type of dyno where you using here look a the dyno numbers of a b16a with typical bolt ons and its at 145 no cams nuttin. http://www.turbomagazine.com/tech/0206tur_aemrail/
it was a dyno-tune session, so they tuned it as they dynoed it. plus, they didn’t take it to redline since my ecu cuts revs at 8500 instead of the 7200 that they stopped off at. it was a DynoJet dyno I think, but the sheet doesn’t say. I notice that a/f ratio is perfect up to 6000, then it starts to drop b/c i need a fuel computer. another big factor is that my compression ratio is shot due to the burnt piston rings and unbalance in the motor. After all, it has 116k on it! Finally, I never installed the upgraded ignition wires b/c the dick on Ebay sent me the ones for a vtec motor, and since they are too long for non-vtec motors, they are useless p.o.s. to me! I might as well have no ignition system right now, b/c stock wires do not utilize the MSD spark system like aftermarket ones do. All-in-all, I am happy for now, b/c I know that when I have the money saved, I will have a fully built 2.26L stroker motor with 11:1 c/r.
i looked at my cat recently and its a nice even white. looks brand new even. a little bit of a dark shaded circle on the engine side, probably due to running extremely rich while tuning bigger injectors. i expected the sucker to be black and falling apart…
Gut the cat, then stick a pipe through it. That way you don’t get turbulance
To who ever keeps hitting the NARC button to ask questions, stop. It won’t get your questions answered.
by hollowing your cat?..will it harm my car if I backfire too much?
well ur rong and rite, hte best thing to do if u dont ming the hole ieagle thing is to go get ur cat taked on and go get a honda reasonatior and put it where the cat used to be and than go get a resnatior off a 94 5.0 muckstang u w :manual: ill feal a hudge throutle responce and a hudge top end and bottom end dif. i
i had a 91 LS w aem shortram,megan racing header, and a full custom bent 2.25 exaust with no cat to some no-name dual tip muffaler…the power i noticed after putting the header/exaust on was amzing…i also had an AEM fuel rail and pressure reg…it backfired alot… but there really wasnt much smell…i also removed the ps and ac and advanced the timing…never dynoed or tuned…but all and all i felt the biggest gain when doing the exaust