Thread: Exhaust for '93 Disco'

My experience with 3.5s and 3.9's leads me to suggest a cheap but effective fix.
I have fitted a "Flowmaster" lightly baffled muffler to my 3.9 with an offset straight through resonator with a centre air chamber. I have used the original pipes as they are 2.25 inches anyway.

I was advised against extractors by Graeme Cooper,as they are noisier inside the car, they move the torque band up the range, and are not as durable as the standard EFI manifolds which are quite efficient.

I personally took extractors off a 77 I had ( because they were leaking)and replaced with EFI manifolds and detected slightly better power up to say 3700RPM.
Mine now has a quiet but noticable sound like a small block Chev with noticable throb at low revs, and more importantly NO DRONE.
In addition the car has noticably more power at over 4500RPM. In normal day to day use there is no difference as the standard muffler is a high volume design.

Regards Philip A

As PhillipA said; I also had a chat with Graeme Cooper who said: forget the extractors, wont make any difference, when you need to replace the rest, just get a better flow system - but my 'system' is still mighty fine and has been for years - must've made that very well

BTW: The exhaust on the 30 year old X1/9 is the original and is good as new - unlike the Falcons we've had which chew thru pipes at a prodigious rate.....

GQ

you dont need to go any bigger than 1 and a half twins or 2.5 single, hotdog muffler and small resonator,,

at 260K the old girls a bit tired around the cams and followers, no problem, just keep it away from 7000

I changed my exhaust in two stages. First up was from the muffler back. Higher flowing muffler (not straight through though), 2.5" pipe and a smaller resonator. This improved resonsiveness & economy straight away as well as sounding quite nice without being OTT. Second was a set of HM Headers. Cabin noise was virtually unchanged and there was a definite improvement above 3 grand but virtually no change below that.

Go for the muffler back option at the very least.

Low and behold, the rear muffler ( resonator), has snapped off this morning from what appears to be a very old rust break. Funny I never thought the girl sounded louder.

So, how small a resonator can I get away with or more to the point, what was the size you used? I'll go with the 2.5" as suggested for the pipe.

I'll be getting this done either today or tomorrow so any additional advice/specs at this point is appreciated.

Twin 1" 3/4 and keep the standard manifold if there in good condition, Single systems suck, they all sound the same BORING

Extractors are a waste of money, as the gains are extremely small

yea but twins cost twice as much,,
fall off twice as much,
weigh more,
you have to have a balancing tube anyway
so they sound the same,,

mind you

after all that--

visually-- nothing like seperate twins out the back

Originally Posted by Pedro_The_Swift

yea but twins cost twice as much,,
fall off twice as much,
weigh more,
you have to have a balancing tube anyway
so they sound the same,,

mind you

after all that--

visually-- nothing like seperate twins out the back

Obviously your NOT talking from experience, 1" 3/4 kink bent twin system is marginally dearer than 2" 1/2 and with a balance pipe they still sound a million times betterer Ever had a twin exhaust??