straight pipe vs cat

[90cb7matt]

i was wondering what different peoples opinions are on having straight pipe vs having a cat.... and if anybody has put flowmaster or magnaflow cats on, i knw there the best for V8 but wasnt sure for the 4cyl

[pcggattnc]

have u ever seen the honey comb structure in a cat. before? after a while it starts getting cllogged with all these little particles and creates alot of back pressure. but this is its job to colect these particles. straight pipe does the oppisite, no back pressure.
it depends if u want back pressure or not. whether your racing, or daily driving, obd1, obd2, exc...

[deevergote]

When the hell do you WANT backpressure?

Use a cat. Regardless of the structure, the cats we use are actually very free-flowing. In anything but an all-out race car, you don't need the extra 1-2hp a straight pipe may give you. Removing the cat will make your car sound terrible, smell terrible, and be illegal according to federal law (though I'm sure in Kentucky they don't give a rat's ass about your emissions... yet... they will eventually, trust me.)

Also, the cat should not clog, as there should be no particles exiting your exhaust valves. If there are particles to be collected by the cat, then you have far worse problems than a clogged cat! Clogged cats are usually the result of engines that run way too hot, and end up melting the catalyst (which is difficult to do, as the cat is designed to be VERY hot.)

['93CB7Ex]

Straight pipe will be loud with or without a cat. Mine had a header high flow cat and 2.5" exhaust. It was extremely loud.

[90cb7matt]

yea thats why i was considering going with a better flowing cat but still "filters" and still has back pressure

[deevergote]

Straight pipe will be loud with or without a cat. Mine had a header high flow cat and 2.5" exhaust. It was extremely loud.

I think he might be referring to a test pipe.

['93CB7Ex]

I think he might be referring to a test pipe.

Either way it'll be loud.

[90cb7matt]

or would a flowmaster brand cat make any difference than the factory cat

['93CB7Ex]

or would a flowmaster brand cat make any difference than the factory cat

Yes not as good quality. I have to replace mine every year.

[90cb7matt]

Yes not as good quality. I have to replace mine every year.

you replace your cat every year?? for what?

[deevergote]

Most aftermarket cats are not as good as the OEM units.

[90cb7matt]

Most aftermarket cats are not as good as the OEM units.

makes sense....i knw the oem cat is built like a tank

[904dr]

you replace your cat every year?? for what?

x2



I didn't feel any power difference between the stock cat,test pipe, or magnaflow high flow cat(stock F22 w/ 200k+). The ebay test pipe doesn't fit as well, not surprised of course.

So if you want to make more noise go with the test pipe. Between the stock or aftermarket cat, I didn't notice a power difference.




I guess it might make a noticeable difference on a fully built engine.

[904dr]

most Aftermarket Cats Are Not As Good As The Oem Units.

Shiet!!!

[90cb7matt]

thanks for the input