Flexi in AE86 exhaust system ?

[jondee86]

I was considering if it is worth inserting a piece of flexi-pipe in
the exhaust system on my AE86. Presently it has the factory cast
manifold, two-into-one section, and a custom 2" over diff system.

Does anyone have first hand experience in comparing noise/vibration
levels inside the car, before and after fitting a flexi ??

Cheers... jondee86

[frost]

i did that on my old set up, no difference at all noise wise, vibration difference is minimal, if your car is really low then a flex can save your exhaust from dents when going over speed humps and stuff,

[evil_si]

i prefer fitting flexis to RWD cars, its might not make much difference, but i know of a lot of cars that have annoying rattles and vibrations throught the exhuast that a flexi would solve,
and they dont cost that much, shop around, flexonics, chase exhaust etc/

[Xylotrope]

Our 86 rally car has a flexi joint ..

yesterday in maramarua many people had their headers or exhaust ripped apart by chicken sized rocks on the track ..

ours survived ..

it gives the system more flexibilty to absorb the knocks of which there are many for a rally car ..

reccomended if you want to drive to max !!

[jondee86]

Thanks for the replies. The reason I asked about this is that I just
took the car out for the first time after fitting a full set of TRD bushings
in the back to replace the old OEM rubber.

Straight off I noticed a big increase in "exhaust" resonance inside the
car. Nothing was changed on the exhaust, and it is a new system and
in good condition. Most noticable increase is in the 2500 to 3500 range.

Thinking about it a bit more, I guess what has actually happened is
that the the amount of engine vibration being transmitted to the body
has increased. If there is metal all the way from the engine to the back
axle, then the stiffer bushings will pass more to the body.

The frequency will be similar to the exhaust note, and so it will seem
as if the exhaust resonance has got louder. Just a theory, but I would
be interested to know if anyone else has noticed the same thing when
upgrading to TRD or urethane bushings.

Cheers... jondee86

[frost]

its most likely road noise feeding through the axle to the chassis, thats the down side to harder bush,
how stiff are the rubbers holding the exhaust up, and do the exhaust hangers touch the rubber pads on the body? they can transfer a lot of vibration onto the flour pan,