L-Cupra performance Exhaust System

[JUS CRU-ZN]

Hey all,

So i need more advice please

In South Africa everybody seems to be doing 76mm all the way incl decat with total of 2 or 3 boxes.

I noticed alot of UK systems are 76mm (3") dowpipe and 70mm (2.75") for the rest of the system incl 1 or 2 boxes. What are the benefits of this??

Thx

 

[Al]

There has not been any conclusive tests done on 2.75" systems vs 3" systems yet, so it would not be possible for anyone to comment on the benefits of the smaller or larger diameter being more effective. One would assume that a 3" system from front to back would be better than a smaller diamter system especially considering the power the Cupra is capable of, but Revo and Milltek will both tell you that this is not always the case.

I am a believer that boxes (silencers) may stop air from free flowing as well, and therefore believe that a non resonated (non-silenced) system would be better than a resonated (silenced) system.

 

[JUS CRU-ZN]

Thx djhorace... Hmmmmm maybe we could get somebody to do a test situation.

I guess then 3" all da way would be best if one is gonna do many mods. thx

 

[Cupra_Ary]

Thx djhorace... Hmmmmm maybe we could get somebody to do a test situation.

I guess then 3" all da way would be best if one is gonna do many mods. thx

yeah mate,
I did 76mm/ 3" al the way fromTurbo, DP, Decatted straight into back box, Still 2 back boxes which are stock.
It works very well as my 1/4 mile is now:
Standard - 14.7 @ 157km/h
With DP + Decat - 14.1 @ 163km/h

No Intake, no software, just DP.

 

[jon-tfsi]

The 3"pipe diameter is more important at the turbo end of the system as the exhaust gasses are much hotter. As they pass through the system they cool down and dont require such a large diameter to flow at the same rate. The 2.75" system was used by milltek for this reason as it saves weight, materials, costs and is supposed to sound sweeter

 

[chrisboyle999]

i believe the standard is around 2.5" so if your going to change it you may as well go for more than a 1/4" gain.