Exhaust Problems: Poor Performance?

Hello everyone!

I drive a Golf 4 TDI (ALH) with a Tuneline chip.
I bought a rear silencer from Remus and had it installed by the workshop.
Unfortunately, I have a feeling that the car is performing worse now than it did with the original exhaust muffler.
I also went to the VW workshop the very next day to have it checked.
The master and a colleague then took a test drive with a measuring computer.
The technician examined the device and assured me that everything was perfectly fine and that there would be no loss of performance.
I was a bit suspicious and drove to a different Volkswagen workshop.
They assured me there that everything would be alright.

It still seems to me that I have less performance than before.


Could it be, or is it really just an illusion on my part ?



Please help me.
I don't want to have the exhaust system re-tested; I want it to be modified.
Since it costs quite a bit, and I don't have the means to do it myself.

Dear Marie,

Hello Marie,

If you had done the Ulf test beforehand, you could now understand whether your car is performing worse .
Regardless, if it were me, I would reinstall the original muffler and sell the aftermarket one.
It's completely pointless to replace the rear silencer on a TDI unless the old one is severely rusted. It won't improve performance anyway.

Best regards, Rainer.

Okay, so my car (which isn't running properly -> 1Z) once drove for a whole week without a muffler, just the catalytic converter, a short pipe, and nothing else. When I then put two brand new mufflers on, it somehow ran worse. So, the acceleration was better without the exhaust. But it didn't make a huge difference...

Speaking of which...

In my Corrado, everything from the catalytic converter onwards is G60 ... so the MSD (Multiple Spark Discharge) and the ESD (Electronic Spark Discharge).
So far, everything is going quite well. However, I recently noticed that the pipe from the G60 is at least 20 percent thinner than the one from the TDI, which is a significant reduction in diameter. Consequently, much less air can flow through it compared to the original pipe.

Even though it sounds silly, could it be that using TDI MSD, ESD, or similar products might increase power, improve torque, or offer other positive benefits?

Regards,
Arne.

Arne wrote:

Even though it sounds silly => could it be that I might have more power or better acceleration, or any other positive characteristics, with TDI MSD, ESD, ...?

Hi Arne,

For optimal performance, the "exhaust" must also be adequate, and a 20% thinner diameter (cross-section) only provides approximately 64% of the intended cross-sectional area, so it might be possible to achieve more power with the original TDI caliber.

Because I don't believe that, in today's era of cost-cutting, the standard cross-sections are so oversized that a 36% reduction wouldn't make a difference.

Hi Ulf,

Thank you for the response.
Okay, I'll try to get the original exhaust system installed in the future. I just need to find a new exhaust silencer (ESD).

Regards,
Arne.