Thread: Vortex fitted

Phil, do you now run just a single Vortex in the center or do you still have the end one in place? Did it replace a straight through pipe or a muffler?

my system is 3'' mandrel from turbo to diff then i kept the 2 3/4 over the diff and out with the rear OE muffler. the smaller rear section is to keep the gas speed up. the vortex is 300mm rear of where the main muffler would have been.

cheers phil

Thanks Phil.

I made a 3" perforated centre tube muffler a few months back for the Tdi and amazingly it smoothed out the whole drivetrain.
There was a harshness/vibration at 100km/h (whatever that is in RPM's in fifth, and it did it at the same revs in each gear) that was eliminated with the muffler.
It's either acted as a mass damper on the exhaust (it weighs a ton, I used a small pressure vessel case ) or tamed a harmonic, but it feels like it's made the power delivery smoother too, but I put that down to perception because it's quieter.

I'm still sceptical of the Vortex concept, but the tinkerer in me really wants to try one after all the positive reports on here.

i honestly didnt think i would ''feel'' such a change, but i did.
with tombies big chip and IC and all the ''other'' mods ive done, the power delivery was sharp, kinda like a 2stroke hitting band, it hit at 2000rpm ish... now its still there but it has taken the edge of the hit.
it seams to have lowered it by 200rpm and extended it 400rpm.

im still quite supprised

cheers phil

Originally Posted by rick130

Thanks Phil.

I made a 3" perforated centre tube muffler a few months back for the Tdi and amazingly it smoothed out the whole drivetrain.
There was a harshness/vibration at 100km/h (whatever that is in RPM's in fifth, and it did it at the same revs in each gear) that was eliminated with the muffler.
It's either acted as a mass damper on the exhaust (it weighs a ton, I used a small pressure vessel case ) or tamed a harmonic, but it feels like it's made the power delivery smoother too, but I put that down to perception because it's quieter. <snip>

That's an interesting thought about an exhaust mass damper. In an attempt to eliminate the flexible joint in my D2 from suspicion of causing similar harshness, I've bolted exhaust clamps above and below the flex joint and pulled the 2 together with a turnbuckle. This has lessened the harshness at the old revs (starts at 2500rpm) but seems to have introduced harshness at other revs, so I'm not really winning yet.

Originally Posted by discowhite

i honestly didnt think i would ''feel'' such a change, but i did.
with tombies big chip and IC and all the ''other'' mods ive done, the power delivery was sharp, kinda like a 2stroke hitting band, it hit at 2000rpm ish... now its still there but it has taken the edge of the hit.
it seams to have lowered it by 200rpm and extended it 400rpm.

im still quite supprised

cheers phil

Over twenty years ago on one of my Jeeps that had the 4.2l/258cu in six in it, Dad and I installed a set of US designed headers that used 1.75"x 36" long primaries feeding into two large box collectors and was designed for a dual exhaust system.
The bloke from Liverpool Exhausts reckoned to get them into a single 2" pipe ASAP which we did and it stayed like that for a few years.
Every other Jeep headers available used 1,5/8" primaries in an interference type system. Better matched the ports and in theory made better torque.

When the muffler and exhaust finally died, I bought a 2x2" in, 1x2.5" out muffler and sand bent 2x2" secondaries 54" long. (1.5x the primary length and I swore I'd never sand bend pipe ever again, but i did...)

It broadened and extended the torque curve really dramatically, increased the usable rev range by well over 500 revs just as you describe, even made it torquier at the bottom end just off idle.
The design went against conventional thinking for a low RPM torque type engine/exhaust but just plain worked.
Surprised the crap out of me too !

Originally Posted by Graeme

That's an interesting thought about an exhaust mass damper. In an attempt to eliminate the flexible joint in my D2 from suspicion of causing similar harshness, <snip>

I think that the improvement in harshness in mine is through the introduced weight, not any noise cancelling/absorbing effect as the diameter is too damn small (only 4" OD, so there is only 1/2"or less of packing)

The resonance/harshness has been there since I made the 3" exhaust.
I didn't use a flex joint either when i made it, didn't even think to as the OE system didn't use one.

On the D2 you could just bolt some steel to the exhaust clamps and add and subtract some weight or move it around a bit to see what happens.

Originally Posted by Graeme

That's an interesting thought about an exhaust mass damper. In an attempt to eliminate the flexible joint in my D2 from suspicion of causing similar harshness, I've bolted exhaust clamps above and below the flex joint and pulled the 2 together with a turnbuckle. This has lessened the harshness at the old revs (starts at 2500rpm) but seems to have introduced harshness at other revs, so I'm not really winning yet.

Graeme,
Have you removed the flex(Steel bellows type, 2002 on) and seen the restriction it offers?
I'd be taking it out and welding in a stainless wire type one, they are a whole lot less restictive, the bellows type necks down a lot, and is all sharp edges

JC