Thread: TDI300 Exhaust upgrades??

Fusion has a straight through on his Tdi. I followed him around on the Blackwood day and sounds Ok for a diesel I guess and not to loud (It's No V8). I don't know what it's like inside but I think he said it drones on the hwy. I thinks you can hear it in the Otways Report.

All I did was remove the main (middle) muffler and replaced it with a 2 and a half inch straight through muffler. Nice little hum and let's the gases out quicker.

i diched the main muffler in mine it aint that loud made a huge difference tho

I replaced my centre muffler with a straight through sports one also.
May have made a difference on slightly earlier spool up but that may be wishful thinking, no facts invloved here and the extra noise can give one the thought of a performance increase. But in reality, how could it possibly?

There is no science to back that up anywhere and it has been proven via dyno tuning that size does matter and too big and too little back pressure does drop performance.

So, I tweaked the pump, better intercooler and gas and now she goes well for a Tdi. Still no dyno figures but I do have the on/off switch for the gas and its definately noticeable.

The drone from my old V8 RRC was at times very annoying, it was fine the first 15-30 minutes of a trip and after that not even the tyre noise blocked that out.

I would recommend do very little, I have personally not seen any factual evidence to make a noisy exhaust worth your while.

Just my thoughts, I did hear HBWC's exhaust the other day in Adelaide and that was not too noisy but I also do not sit in it for hours.

Originally Posted by big guy

................ and it has been proven via dyno tuning that size does matter and too big and too little back pressure does drop performance.

I think you will find that is not the case with turbocharged engines. The turbo spins up faster with less back pressure from the exhaust. The engine probably does not get to see much of the effects of the exhaust system as the turbo provides the back pressure towards the exhaust ports.

Originally Posted by big guy

I replaced my centre muffler with a straight through sports one also.
May have made a difference on slightly earlier spool up but that may be wishful thinking, no facts invloved here and the extra noise can give one the thought of a performance increase. But in reality, how could it possibly?

There is no science to back that up anywhere and it has been proven via dyno tuning that size does matter and too big and too little back pressure does drop performance.

I would recommend do very little, I have personally not seen any factual evidence to make a noisy exhaust worth your while.

Just my thoughts, I did hear HBWC's exhaust the other day in Adelaide and that was not too noisy but I also do not sit in it for hours.

thanks it dont drone in the cab if i dont have the window down i carnt even hear it in the cab

also to little back pressure is really only in the petrol world the turbo will supply more that anoth pressure in a diesel application

Originally Posted by big guy

I replaced my centre muffler with a straight through sports one also.
May have made a difference on slightly earlier spool up but that may be wishful thinking, no facts invloved here and the extra noise can give one the thought of a performance increase. But in reality, how could it possibly?

There is no science to back that up anywhere and it has been proven via dyno tuning that size does matter and too big and too little back pressure does drop performance.

So, I tweaked the pump, better intercooler and gas and now she goes well for a Tdi. Still no dyno figures but I do have the on/off switch for the gas and its definately noticeable.

The drone from my old V8 RRC was at times very annoying, it was fine the first 15-30 minutes of a trip and after that not even the tyre noise blocked that out.

I would recommend do very little, I have personally not seen any factual evidence to make a noisy exhaust worth your while.

Just my thoughts, I did hear HBWC's exhaust the other day in Adelaide and that was not too noisy but I also do not sit in it for hours.

Quote:"There is no science to back that up anywhere and it has been proven via dyno tuning that size does matter and too big and too little back pressure does drop performance."
Where do you get this crap from, greatest load of horse **** I ever heard.
How many F1 and Drag Cars (to name but a few) do you see running around with mufflers and restrictive exhausts, how many high performance racing cars have mufflers, why do Ferrari and others spend millions building free flowing exhausts that will be accepted by rego authorities, use a bit of commonsense, if you restrict the flow of exhaust you will lose power, same as if you restricted the inlet side of an engine, after all it is only a pump, Regards Frank.

Originally Posted by slug_burner

I think you will find that is not the case with turbocharged engines. The turbo spins up faster with less back pressure from the exhaust. The engine probably does not get to see much of the effects of the exhaust system as the turbo provides the back pressure towards the exhaust ports.

spot on. between engine and turbo is a different story, but post turbo you just want to the get gasses out ASAP.

i replaced the centre muffler with a straight through bit of pipe. made no difference to performance and barely any sound difference. slighty deeper at idle, but anything above idle the engine just drowns it out anyway.

I'll be making a full 2.5" system when i get around to it, with single straight through muffler in the rear.