Milltek Decat Downpipe or Milltek Hi Flo Sports Cat

[martziniuk]

Decat certainly helped with an earlier spool up time on stage 1 map but I found it didn't really feel much different higher up the rpm. I would imagine a higher state of tune would make more use of it with the lower EGTs.

[tony_danza]

For sure, you've got to have someone who understands the finest points of mapping to maximise the new-found flow's benefits.

Oh, and DSG bangs through a decat... 

[edd30]

Thread resurrection!
Any one else gone down the route of sports cat or better still made the standard cat and decat removeable?
If so what have you done ecu map-wise ? Can you run the decat map with a cat safely ?

Also any one know the dimensions of the standard GTI exhaust ? Would it be much of a restriction for a stage 2, say if I get a 3" DP, decat mated to a standard system ? I'm not wanting any extra noise or drone. Been there, done that. Needs to be discrete.

[GrayMK5GTI]

I've got a 3in Pipewerx downpipe& 200CEL sports cat with has a reducer and mated to my OEM cat back. It's soooo much more responsive, turbo lag between gears is pretty much non-existent.

I'm running stock map for now(only for another week) and it's fine, although long term I'd expect EML on the dash.

Decat will be louder and will give you a few more ponies, they also smell awful (exhaust fumes). I'm more than happy with sports cat, and of course knowing it's legal.

Decat needs a stage 2 map to remove the EML and stop the car from overfuelling. Then there's the hassle at MOT time 

[dan930]

For sure, you've got to have someone who understands the finest points of mapping to maximise the new-found flow's benefits.

Oh, and DSG bangs through a decat... 

+2
Niki from rtech mapped my R with a sportscat,he said if I go decat he can get around 20bhp more out of mine

[edd30]

I had a 3" DP and 200 cel cat on my mk1 S3, it spooled up a lot quicker and held power better. Also improved the mpg on B road blasts and motorway runs, I was getting 33-34 mpg brim to brim figures, before it struggled to get low 30s. Sounded a lot deeper too. I monitored the EGTs and they were significantly lower.

I'm hoping for the same for my Mk5. Still not sure whether to get a cat bypass and make the cat removeable so it can be swapped out easily once a year. I have a limited budget, so will probably mate it to the standard exhaust. I'd get a BCS or Milltek otherwise. I also got plans for an uprated HPFP, IC and Helix clutch ..... but that's the best part of £2k