Milltek on a diesel

[Trekmeister]

What sort of performance gain would a milltek decat make on a stage 1 diesel  and would a full milltek improve the performance further?
Would the map need tweaking for best gain and does less back pressure have any negative effects on the turbo?

[DFish]

Full system would be the best option, depends on how deep the pockets are. Quicker spool-up due to having no blockages in the system.

I would have the map at least checked over to make sure everything was ok though.

Fish

[jason_rmh]

Ive got full system with decat and panel filter on my tdi.  As already said, turbo spools much easier / quicker.

Also worth doing with a remap to get the best out if it.

Jas

[AndrewJB]

i ran a complete straight through on my PD170, and when i say straight through i mean straight through, Milltek DPF Delete downpipe and then a pipe from there to back, No boxes at all

[xjay1337]

Trust me on this as I have done it.

Cat Back - no appreciable difference, it will sound nicer and that's about it. It may spool very slightly faster but not enough to notice unless you were eagle-eyeing your boost gauge.

Turbo back - The cat is the most restrictive part of the exhaust system on a TDI - So it would be the best way. Removing the cat without mapping the engine accordingly can cause problems, not only will you get an error light but depending on your particular car you can encounter boost creep, which is where the car cannot control the boost it is producing, because it's expecting a certain amount of resistance but getting far less. This can push your car into limp mode at high speeds.

If you want actual performance increase then get a turbo back with an EGR delete (as this is going to be the best part getting quality clean soot-free air into your engine) and have it mapped at the same time.

On a standard car you would notice little to no difference from changing an exhaust alone.

[Jimbo_h]

As Andrew said above, get a de-dpf downpipe plus remap to get best performance results. Exhaust will give minimal performance gains but it will sound nice (go non-res, straight through it bloody noisy for daily use). The remap is key because as jay said, you'll get problems pretty much straight away if u don't. Oh and make sure your map is from a reputable tuner

[AndrewJB]

My PD170 set up was

Milltek DPF Delete downpipe, 3" Pipe from downpipe to back, EGR Delete, Shark Stage 2/ Stage2+ mapping

[xjay1337]

Jimbo, noise is a matter of ones own hearing. My car is non res (straight through from Turbo) and is LOUD. But from inside as the noise is a) all the way at the back of the car and b) pointing away from you, it's actually relatively quiet on the inside considering the noise from the outside.

I've found that diesels with silencers actually don't sound of anything much at all. Have a listen around on youtube for different sounds and go from there as to what you want...

 

[Andy]

i  have a milltek non res and the sound in side is additive and on  the  motor way is quite as oem
 

[Matto]

I will be able to give you my two-penneth after saturday. I will be having the Darkside DPF delete pipe fitted plus non res Milltek. From what I have heard and what Maxitrol says, the noise is addictive and I cannot wait 

[AndrewJB]

I found DPF Delete pipe + Milltek Non-Res was a little to quiet for my liking (i didn't want chav sounding but wanted louder)

Hence why i asked scorpion to make me a pipe with no boxes at all (Milltek has a big suitcase rear box)

i think if i was asking scorpion again i would ask for 2.75" instead of 3" and also tell them to fit a fake box (box with a pipe welded through it so it looks like it had a box) because the exhaust was super loud, think Scania V8 truck with box-less pipes, it was that loud that when i went past Scania's they used to flash there lights (Most Scania owners are into modifying their trucks)

[DFish]

Looks like the OP has a GTI 140, which from memory wouldn't have a DPF. Might be wrong though.

Trek, where in the country are you? Maybe meet up with someone with a complete system to hear what the noise is like.

Fish

[Jimbo_h]

Jimbo, noise is a matter of ones own hearing. My car is non res (straight through from Turbo) and is LOUD. But from inside as the noise is a) all the way at the back of the car and b) pointing away from you, it's actually relatively quiet on the inside considering the noise from the outside.

I've found that diesels with silencers actually don't sound of anything much at all. Have a listen around on youtube for different sounds and go from there as to what you want...

 

Well it sounds like your straight through is a little different to Andrews old scorpion unit (who made yours jay?). I went for a blast around with him in his and it was as he said,  "think Scania V8 truck with box-less pipes" haha. I ended up going for a non-res scorpion with most of the sound deadening material removed from the back box. Not too loud but loud enough to know its not standard.got some pics somewhere if anyone's interested?

[xjay1337]

Non resonated should be a straight through. A resonated would have additional boxes.
I have a Darkside/Piper hybrid exhaust system. Cat-back section is Piper and the turbo back to cat-back pipe is Darkside, although when it comes to noise that makes little difference. 

140s don't have DPFs so nothing to worry about.. do an EGR delete with turbo back system, straight through and it'll be loud from the outside but from the inside it will not be annoying at all.. I do loads of miles and I find mine fine. If you wanted to quieten down the external noise a bit if you put a small rear silencer on that should take the edge off the noise at idle and low speed driving.

How mine sounds.

[Jimbo_h]

Errrmmm non-res has 1 rear box, resonated has 2 and straight through has none
I know this link is for a mkVI but same applies

http://www.vwtuningmag.com/milltek-performance-exhaust-for-the-golf-mkvi-gti/

Nice sounding exhaust though