Separate wastegate pipe issue...

[MidnightBlueS2]

Hi everyone !

Well it's finally happened, yup, I now have a de-catted 3 inch SS twin silencer exhaust system fitted !

I went to the fitter two days ago at about 10pm to pick the car up and we went for a test drive.

Nice idling sound, deep and powerful.
Set off, fabulous very deep roar that turned into heaven on wheels when the turbo kicked in, at this moment the grin on my face feels so good, the revs kept climbing up and then as the RPM's hit about 5000, the wastegate started chattering and as I had asked for an external WG pipe that was about 80cm long and pointed towards the ground, the WG chatter sounded like a horrible bag of nails being fed to the engine !!!

No more grin at all !

A friend of mine who was standing outside while this happened waved me in when I made a u-turn worried about engine damage ! He said it sounded awfully wrong and I couldn't help but agree with him... So we all spent 4 hours taking the exhaust out, modifying it so that the WG pipe would connect to the downpipe just like the stock exhaust but since the 3 inch pipe is so wide, we had to cut the dowpipe in half so that the lower section could fit through the hole near the driveshaft as it would've been impossible to fit the turbo flange end of the downpipe that was now even bigger due to the wastegate pipe being welded to the main downpipe. So after a lot of sweating and patience, everything fitted pretty well !

Next test drive, the WG chatter can still be heard ( though it's now like a growl at high RPM and it happens at full throttle with overboost on only ) but I'm wondering why since we copied the stock down pipe and I never heard it chatter before ?

Could it be because the downpipe diameter is much larger and it's sort of created a "resonating chamber" within the downpipe for WG gasses to expand in ?

Any help would be greatly appreciated !

Gratefully yours,

David

[MidnightBlueS2]

Exhaust tip 2x70mm

...

[Faheemo]

The Stainless steel u used for the wastegate tube is probably 1.6mm dia, the stock is cast iron but much thicker.
cant really tell but seems that u have a reduction on the wastegate pipe also, maybe this affects the acoustics.

I have a very similar problem, ive got a divorced wastegate thats 80cm as you describe and exhausts to atmosphere just below the gearbox.
The noise is awful when the car is on boost...
Going to try to get a silencer in or re route to join down pipe but at the bottom, furthest away from turbo.

[Sweeper]

Mine sounds like a chopper on high revs , but the exit is near rear passenger wheel.

[audiman]

My wastegate pipe sounds fine???? Cant really hear it over the noise of the garrett spinning hard

Plus my wastegate is 50mm which might make a differnece over stock 32mm??

[Dan_s2_coupe]

Is it possible 2 buy a pipe that comes out the wastegate and straght 2 the floor and blank off where it should connect into the exhaust

[MidnightBlueS2]

Is it possible 2 buy a pipe that comes out the wastegate and straght 2 the floor and blank off where it should connect into the exhaust

I doubt that such a kit exists all made up and retailed as is... but any good exhaust fitter that has pipes and can weld could make one for you...

[volcano rs]

Is it possible 2 buy a pipe that comes out the wastegate and straght 2 the floor and blank off where it should connect into the exhaust

isn't that what seperate wastegate pipe is ?

[Dan_s2_coupe]

does it sound good when it dumps it straigh out the pipe

[1975DCS]

Why not make a seperate pipe for the wastegate with it's own silencer? By choosing different silencers you can create different accoustics for wastegate and exhaust...

[volcano rs]

people who've had them soon got rid of them it does your head in after a while

[Mark Halligan]

people who've had them soon got rid of them it does your head in after a while

Absolutely, I did mine a few years ago......way too noisy, nail it and everyone (including Police) in a 1/4 mile radius drop their sandwiches and gawp at you flying by, last thing you want if you are looking to make some progress.

Although I have noticed that the sound does seem to differ with different cars and set ups (EM's, back pressure etc.).

I just made and fitted a 4" DP and reintegrated the WG pipe, I'm much happier with it now.

Cheers

[Corey]

How many of those people that have had a seperate w/g vent has just had a small pipe that comes from the w/g and just points at the floor?
Who has copied what all race teams do and have the vent follow the exhaust all the way to the back of the car?
There would be nothing stopping a small silencer being put into this system to stop some of the loud noise.

[tom]

Do You have complete Supersprint exhaust system?

[Acidburn]

Anyone got any pictures of the exhausts/pipes when they was fitted? Or even a video?