Andyinchville1
Veteran Member
HI All,
Just thought I would post my findings on a 3" Turbo back exhaust system on my car (mods listed in signature)
Having had a 4" exhaust on a stock first gen Cummins Dodge Pick up and seeing some benefits , I was wondering what good things could (would?) happen if a 3" system was put on our cars.
While many have said that there would be be little or no gains with light mods (or heavy mods for that matter) on the little TDI .... I pressed ahead and got a Kerma TDI 3" turbo back system (resonator only no muffler) system and finally got it installed ( I had it for many months so I was quite anxious to get it on). Go big or go home right ? HA
Anyways here is what I found :
1) Noise at idle is not really noticeable ... you can hear turbo whistle and a little low tone growl ... when you start up you know something is NOT stock BUT in a good way!
2) No real drone until about 1875 RPM up through about 2350 RPM .... I imagine the exhaust would sound nice BUT drone drowns out the turbo whistle and growl mostly.
3) Boost happens MUCH faster than before ....
hit a couple overboost check engine codes without trying hard at all .... Learned to roll throttle more than quick jab to give the actuator time to pull back boost .
May not be a good thing if you are trying to punch it to quick merge into traffic , boost gets high and you end up limping in front of a huge tractor trailer you probably shouldn't have pulled out in front of in the first place ! (OK that did not happen BUT that COULD happen if you ecpect power to get you outta there ... maybe a tune is needed to fix that?). Maybe a stock system would still limp mode out under those conditions too?
4) I can't say for sure if boost is higher in general BUT it does happen quicker.
5) OK for me this is one of the BEST parts ..... My car typically gets between 50 and 53 MPGs on the highway ... I cannot remember the last time I got under 50 MPG on a tank ... I have had a 54 MPG tank BUT subsequent tank was low so I assume that was a fluke.
Anyways .... drum roll ...
I just took a trip to Pittsburg last night for work .... On the way up I got 55.2 MPG and on the way back I got 55.4 MPG !!
I have NEVER gotten 55 before (much less on 2 separate fill ups (same gas station , same fuel pump, manually calculated) SOOOO I believe a good exhaust is a plus !!
In all fairness and in full disclosure , at the same time I had the exhaust done I had the following done also :
1) 1" spacer to raise the front end to make the car sit level ( I had previously installed a metal skid plate and of course that reduces ground clearance so I wanted to get that clearance back and level the car out for better aero (my theory being a level car slices the wind easier .... if it is raked front low then the car gains weight at speed due to wind pushing the car body down ... of cousre it the front is high relative to the rear aero is lost as the speed increases since now the energy wants to "lift" the car ..... knife edge level just "cuts" the wind for better aero ? ... well thats my theory at least
2) Advanced the timing a bit (according to the VAG COM it was not advanced enough (towards the green line per guru tom ... theorized maybe timing belt stretch caused it to be a bit low ? 71K on timing belt
In conclusion , I NEED to research to kill the drone BUT other than that about 2 MPG more is GREAT !!
Maybe not cost effective for 2 MPG or so .... BUT the MPGs AND sound ( if I can get rid of the drone) ..... wow ... wish I did it sooner !!
For those with real power mods maybe the exhaust would help you more .... this was just based on my car with my driving style / habits and listed mods
Side note : NOW I cannot wait to put in a freer flowing INTAKE ... I already have the BRM intake .... ( like to get OMI and PD150 piping / air box), better side mount inter cooler ..... and Yes maybe even a turbo! Let me stop before I break the bank! HA
Andrew
Just thought I would post my findings on a 3" Turbo back exhaust system on my car (mods listed in signature)
Having had a 4" exhaust on a stock first gen Cummins Dodge Pick up and seeing some benefits , I was wondering what good things could (would?) happen if a 3" system was put on our cars.
While many have said that there would be be little or no gains with light mods (or heavy mods for that matter) on the little TDI .... I pressed ahead and got a Kerma TDI 3" turbo back system (resonator only no muffler) system and finally got it installed ( I had it for many months so I was quite anxious to get it on). Go big or go home right ? HA
Anyways here is what I found :
1) Noise at idle is not really noticeable ... you can hear turbo whistle and a little low tone growl ... when you start up you know something is NOT stock BUT in a good way!
2) No real drone until about 1875 RPM up through about 2350 RPM .... I imagine the exhaust would sound nice BUT drone drowns out the turbo whistle and growl mostly.
3) Boost happens MUCH faster than before ....
hit a couple overboost check engine codes without trying hard at all .... Learned to roll throttle more than quick jab to give the actuator time to pull back boost .
May not be a good thing if you are trying to punch it to quick merge into traffic , boost gets high and you end up limping in front of a huge tractor trailer you probably shouldn't have pulled out in front of in the first place ! (OK that did not happen BUT that COULD happen if you ecpect power to get you outta there ... maybe a tune is needed to fix that?). Maybe a stock system would still limp mode out under those conditions too?
4) I can't say for sure if boost is higher in general BUT it does happen quicker.
5) OK for me this is one of the BEST parts ..... My car typically gets between 50 and 53 MPGs on the highway ... I cannot remember the last time I got under 50 MPG on a tank ... I have had a 54 MPG tank BUT subsequent tank was low so I assume that was a fluke.
Anyways .... drum roll ...
I just took a trip to Pittsburg last night for work .... On the way up I got 55.2 MPG and on the way back I got 55.4 MPG !!
I have NEVER gotten 55 before (much less on 2 separate fill ups (same gas station , same fuel pump, manually calculated) SOOOO I believe a good exhaust is a plus !!
In all fairness and in full disclosure , at the same time I had the exhaust done I had the following done also :
1) 1" spacer to raise the front end to make the car sit level ( I had previously installed a metal skid plate and of course that reduces ground clearance so I wanted to get that clearance back and level the car out for better aero (my theory being a level car slices the wind easier .... if it is raked front low then the car gains weight at speed due to wind pushing the car body down ... of cousre it the front is high relative to the rear aero is lost as the speed increases since now the energy wants to "lift" the car ..... knife edge level just "cuts" the wind for better aero ? ... well thats my theory at least
2) Advanced the timing a bit (according to the VAG COM it was not advanced enough (towards the green line per guru tom ... theorized maybe timing belt stretch caused it to be a bit low ? 71K on timing belt
In conclusion , I NEED to research to kill the drone BUT other than that about 2 MPG more is GREAT !!
Maybe not cost effective for 2 MPG or so .... BUT the MPGs AND sound ( if I can get rid of the drone) ..... wow ... wish I did it sooner !!
For those with real power mods maybe the exhaust would help you more .... this was just based on my car with my driving style / habits and listed mods
Side note : NOW I cannot wait to put in a freer flowing INTAKE ... I already have the BRM intake .... ( like to get OMI and PD150 piping / air box), better side mount inter cooler ..... and Yes maybe even a turbo! Let me stop before I break the bank! HA
Andrew