Care to elaborate?? It's been shown by Magnaflow and Flowmaster both that the performance drop from using their cats is negligible.. They were designed for lower emissions while not increasing backpressure. I plan on using a couple of 2 1/2 Flowmaster cats on mine when I'm able to go through the exaust on it so I can pass the visual part of the inspection here in Va..
Cats or no cats
- Thread starter Adam Vinnicombe
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Care to elaborate?? It's been shown by Magnaflow and Flowmaster both that the performance drop from using their cats is negligible.. They were designed for lower emissions while not increasing backpressure. I plan on using a couple of 2 1/2 Flowmaster cats on mine when I'm able to go through the exaust on it so I can pass the visual part of the inspection here in Va..
Azhurel Mendes
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I personally prefer dogs
Fivestangs
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I went with a pair of Magnaflow cats on a BBK off-road H to cut down on the decibel level. It is still pretty loud with the 10 Series Flows the previous owner put on it! Plus no exhaust smell! I don't mind it on my older Mustangs but it just doesn't seem right on a "late model" like a '96 GT.
I don't mind the exhaust smell from anything Foxbody back.
I don't mind the exhaust smell from anything Foxbody back.
I'm planning on either a set of 40's or 44's on mine, can't make up my mind on it which way to go tho... It's got a 351M right now, but I'm starting to lean towards a big block swap sometime in the future...
DKblue98GT
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I added Magnaflow 8" cats behind my longtubes this spring to pass emissions. Car is quieter and doesn't smell like gas and throws no codes.
tvsn95
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about the only way you will ever see an increase in power /torque is if the back pressure counters some of the overlap of the cam. Back in the day carbs and some throttle body setups were so limited in the ability to adjust themselves that you could get an increase at high RPM due to the fueling going lean from the extra air passing through and not being metered.
either way, its an old wives tale that has endured.
ttocs
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I know I have talked to dyno people that have run cars with cut outs and said there was little to no difference with them open or closed. I could see it effecting how the car could run at idle or low rpm if its too short and the o2 sensor is close to the end.
That's sorta like the common fallacy that every V-8 needs a dual 3in exaust to run well... In actuality unless you have over I think it was over 550 ci and run over like 7500 or 8500 you don't really need that much pipe.. 2 1/2 will do just fine, all you're doing is hauling around a lil bigger exaust.. it goes back to all I. C. Engines are nothing but an air pump and unless you are moving that much air you really don't need it..
ttocs
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to big of exhaust can cause problems. I had a buddy back in the day that got a 95 gt that had 3.5 inch on it. It was loud, sounded like a really big tin can and ran like complete crap. Today I am sure the o2 sensor readings were off at low rpm from lack of back pressure and fresh air reaching them.
You'll see a lot of mish-mashed tech on this.
Fact is:
-OEM performance cars make 800+ horsepower with cats.
-Kenne Bell did testing and saw no performance loss from cats. source
Just put cats on the car.
#1, you wont get nauseous sitting at a red light from the fumes of your own car.
#2, you'll never have to worry about swapping it out for emissions testing.
#3, it'll help make selling the car easier.
#4, as someone who has to breathe the air your car is pumping full of exhaust, I'd appreciate it having cats.
#5, aftermarket cats are literally, like, $50/ea.... What's the big deal?
OP
OP
Adam Vinnicombe
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Ok I get your points 
I will be fitting cats but still trying to figure out what ones to fit, will £50 cats last ?
I will be fitting cats but still trying to figure out what ones to fit, will £50 cats last ?
Ok I get your points
I will be fitting cats but still trying to figure out what ones to fit, will £50 cats last ?
Yes, they'll last. If you go through a reputable vendor and get a reputable brand and keep your paperwork, you'd probably be able to push them to give you a free replacement if they prematurely fail...
https://www.summitracing.com/parts/flo-2230125
Rocco_Roush
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i was just about to say a side exhaust gives extra flavor lololol
but i got my car (2 months ago maybe) and as i was working out the kinks i got a deal on a upr x-pipe...catless...they don't make them anymore.
anywho, i have a buddy with a lift and he had free time so we tossed it on. felt great.
a few weeks later i did the plugs and coils (both motorcraft) because of a misfire. i believe i had 2 or maybe 3 misfiring because when i started her up w it with the new stuff she sounded totally different!!!
anyway, the off-road x-pipe and the Roush side exhaust (magnaflow on mine) it does not sound obnoxious but sophisticated
Rocco_Roush
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I need to! Haven't had nice weather down here so I haven't had the chance to work on her or drive her around. But def on the list!
