Ramee's Tiguan Build Thread 155KW DSG

[Wynnston]

Hey Ramee,

How come your inputs are RCA's? Isn't the line level input on the MRXV70 a special plug, or will it take RCA's for the line level as well?

[Ramee]

Hey Ramee,

How come your inputs are RCA's? Isn't the line level input on the MRXV70 a special plug, or will it take RCA's for the line level as well?

I am sure MRXV70 special plug is for speaker level inputs. RCA connectors of the AMP needs a line level signal (pre amp). So I enabled line level(pre amp) signals from RCD510 using a VAGCOM cable.

Funny thing is even though MRX amp's manual mention signal sensing power on work only with speaker level inputs, It will still power up with pre amp outs from RCD 510 feed through RCA connectors. This will save you from trouble of wiring separate remote wake up line for the Amp.

[Ramee]

After looking for many weeks for a ready made down pipe ( 3 inch), I decided to custom build one from a local shop. It was not a easy job as it looks IMO and had to do few iterations to get it done. Now It is at a functional level but need some work to make it look nice

[Ramee]

3 inch down pope with 200 cell cat makes car much more enjoyable to drive. I can clearly feel the increase torque at low rpms due to earlier turbo spool. Our DSG tigs always try to keep engine RPM low like 1500 or below so turbo spool around 1700 is always a good thing when need a quick acceleration.

With the new down pipe car sounds mostly OEM and I like to keep it that way because want to preserve Tig's sleeper characteristics .

Another thing I realised with the mod is I now can easily feel the limits of the turbo, It seems to be maxout around 4500 5000 RPM

[Ramee]

My subwoofer build is almost complete.. Did a test run, it sounds great. I will try to use some polyfill and see it makes any difference

[CCAMO]

This is a great thread Ramee.

As a soon to be Tig owner there is some great info here.

Thanks

[tigger73]

3 inch down pope with 200 cell cat makes car much more enjoyable to drive. I can clearly feel the increase torque at low rpms due to earlier turbo spool. Our DSG tigs always try to keep engine RPM low like 1500 or below so turbo spool around 1700 is always a good thing when need a quick acceleration.

With the new down pipe car sounds mostly OEM and I like to keep it that way because want to preserve Tig's sleeper characteristics .

Another thing I realised with the mod is I now can easily feel the limits of the turbo, It seems to be maxout around 4500 5000 RPM

I do think the turbo does spool better with a 3" DP, however not because of the larger diameter. If anything the larger diameter will actually slow the velocity of the exhaust gases not speed them up.

I think the reason that it performs better is due to the high flow cat and removing the restriction/horrible contraption right at the turbo.

I'm not an expert in thermodynamics, however there's a few theories floating around. Here's an interesting read on the effect with some VCDS logs which shows very little difference between the spool rate for stock and 3" DP: Turbocharger Spool Up Test | MyAudiS4

[Ramee]

It is a good experiment.. But I noticed there is a significant difference at the initial stage of his graphs ( First two seconds period) which could explain the difference we feel. After that I think may be ECU is taking over the control of boost so probably need a new map to capture full potential of the upgrade.

I do think the turbo does spool better with a 3" DP, however not because of the larger diameter. If anything the larger diameter will actually slow the velocity of the exhaust gases not speed them up.

Actually what makes turbo spool faster is the pressure differential from input of the turbo to exit of the turbo. So if we could get the turbo exit pressure low as possible then turbo will sense increase pressure differential and will spool faster. So how we make less pressure at the turbo exit that is by removing the resistance to flow after the turbo. To do that we remove cats / remove sharp bends/ polished internal surfaces of the pipe (to create laminar flow and less surface friction) and larger diameter pipes . Actually larger the diameter less resistance so less back pressure. I can not remember those equations I studied but pipe diameter certainly affects the flow resistance.

[Ramee]

This is a great thread Ramee.

As a soon to be Tig owner there is some great info here.

Thanks

Thanks mate.. Good luck with your TIG

[Wynnston]

I am sure MRXV70 special plug is for speaker level inputs. RCA connectors of the AMP needs a line level signal (pre amp). So I enabled line level(pre amp) signals from RCD510 using a VAGCOM cable.

Funny thing is even though MRX amp's manual mention signal sensing power on work only with speaker level inputs, It will still power up with pre amp outs from RCD 510 feed through RCA connectors. This will save you from trouble of wiring separate remote wake up line for the Amp.

Hmm. Does anyone know if you can do the same (enable line level) for the RNS510?

I think for the RCD it's "VW Sound System" and disable "Monitoring" but I don't have my VCDS on me to check atm.