exhaust neck down at cats

gary o

Registered User
my friend tells me to replace the short piece of exhaust tube between the manifolds and the cats as this is the worst part of the factory exhaust. is this difficult for an exhaust shop to do? seems it might be tricky to weld a new piece to the tapered cone entrance of the cats-any opinions? or could i delete the cats altogether? (where i live there is no emissions testing) would removing the cats effect the fuel metering or screw up the eec in any way? any opinions are welcome as i would like to have less backpressure in this lousy factory system. thanks gary o.
 
You can get catless downtubes from www.texasthunderbirds.com
If you DO decide you want cat with those downtubes, you can always get a set of high flow cats and cut them into the downtubes.

As for the rest of the exhaust or where the most restriction is.... the worst choking point in the stock exhaust is the stock resonator. The exit of the stock resonator is absolutely tiny. roll under you car and check it out for yourself, if you haven't already you will be amazed to see what kind of garbage Ford hung under these cars for exhaust. That resonator is just rediculous.
 
interesting

maybe the resinator was what my friend was making reference to as some unexplained pinch point in the exhaust. if you were to do one thing to the stock system what would see the most improvement-opening up the resinator or something else? thanks again gary o
 
I think general consensus is that replacing or removing the resonator is the best place to start if you cannot afford a complete exhaust. Next best thing (and a close second) would be better cats (or none at all if you can get away with it.

Just be aware that you may not be happy with the sound if you just delete the resonator. Seems to be a problem with a nasty drone around 2000 RPM (which is the RPM range most people are in when just cruisin' around in town).

Check out the outlet side of the stock resonator
(if image doesn't show, just go to www.supercoupeperformance.com and look through the exhaust for the SC)

thumbBuilder.aspx
 

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Re: Nasty D-R-O-N-E

XR7inWI said:
Just be aware that you may not be happy with the sound if you just delete the resonator. Seems to be a problem with a nasty drone around 2000 RPM (which is the RPM range most people are in when just cruisin' around in town).
Yep BAD drone from 1800 - 2000 rpm. BUT I have Headers, 2.5" down pipes, NO cats, NO resonator, 3.5" center, & 2.5" turbo muffs. So basically there is nothing much to muffle anything.

I'm pretty sure that if I used a dual 2.5" in / 3" out resonator, that the D-R-O-N-E would go away.

I really don't mind the drone though. Cuz when I hear it in 2nd gear, I know I'm doing exactly 25 mph.

68COUGAR
 
thanks

i see what you mean about the resinator i will ask at the muffler shop if they can substitute the resinator with a better one as i have heard about that odd sound they make without one. i am not trying to get more power just get some cheap insurance against blowing head gaskets again(i bought the car that way and i just replaced them-quite an involved job) so i will start with this and work my way foreward from there-thanks very much. gary o
 
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