Just wondered if someone could clear it all up for me, Angel tuning said that i would lose performance from doing so due to not enough back pressure, they are pretty well reviewed so was a bit confused as alot of other people on forums say otherwise. i have the PD100 Engine.

cheers

Lack of pressure could over spin the turbo, it's designed to have a certain pressure against it, if a standard turbo over spins it could be to much for it as they don't have bearings on the centre shaft. Seen a few die this way, but maybe it would have happened anyhow.

hmmm yea fair enough..

reacon a straight pipe from cat back would be safer?

A few on here noticed a drop in performance with a mufflerectomy from what iv read.

yea thats what ive seen in recent seraches, im 30bhp behind a vrs already, dont want to make it worse lol.

yea thats what ive seen in recent seraches, im 30bhp behind a vrs already, dont want to make it worse lol.

I have a pd100 and had a mufflerectomy and I didn't notice any power drop just a slightly (but not much) louder noise

I then got a decat so now so it's a straight through, and I have noticed a lack of power slightly.

I was told the mufflerectomy is to far back to affect anything?

It doesn't matter where a restriction is in an exhaust it will still effect the engine.

Think of a hose pipe, pinch it just at the tap and or by the outlet, same effect.

And as Matt said when Miltek designed the Fabia vRS exhaust on my car we found better results with a sports cat rather than decat on a standard turbo. Power was the same but torque dropped a little on the decat.

hmm I'm getting my vrs mapped Saturday by angel tuning and was thinking of having a straight through backbox made shotgun style

but don't want the turbo to **** it's self :/

anyone running a straight through bb on a generic angel tuning map?

Yep I am, turbo went about 5k miles later, whether it is related I have no idea, did drive it pretty hard though. Replaced with a PD150 turbo now which (I hope) is much stronger.

cheers for the reply bud think the vrs exhaust will stay standard I'm not going to risk popping the turbo for a tinny bit more of sound

On my Cupra TDI I noticed a reduction in low down torque, but increased spool-up time, and an increase in power further up the rev range with a Milltek decatted system.

It doesn't matter where a restriction is in an exhaust it will still effect the engine.

Think of a hose pipe, pinch it just at the tap and or by the outlet, same effect.

And as Matt said when Miltek designed the Fabia vRS exhaust on my car we found better results with a sports cat rather than decat on a standard turbo. Power was the same but torque dropped a little on the decat.

like the example on the hose pipe make's sense..

I did notice a change when I had my mufflerectomy done ages ago. I'm still running the standard cat though. Just seemed like there was less of a shove in the back. I'm tempted to make it a bit quieter again now so might get a small in line rear box put in.

I had heard of this problem caused by chavs sticking enormous exhausts on Imprezas thus reducing the performance as well as making a racket.

All pub talk i think

I had heard of this problem caused by chavs sticking enormous exhausts on Imprezas thus reducing the performance as well as making a racket.

It can do in extremes, whilst you want an exhaust to be free flowing some engines require exhaust gas speed. It's quite a complex thing working out air speed into an engine (and thus out) with biggest not always being best.

I did notice a change when I had my mufflerectomy done ages ago. I'm still running the standard cat though. Just seemed like there was less of a shove in the back. I'm tempted to make it a bit quieter again now so might get a small in line rear box put in.

did you get the owl sound with a standard cat still on?

sam.

Yes I do, but you have to drive in a certain way to make it happen

so with this back pressure talk if you was to get a mufflerectomy, would you be better to up the bore to 2.5 like i have seen people do or staying with the same size bore pipe or is there little init that it makes near enough no difference? May sound silly but you never know.

so with this back pressure talk if you was to get a mufflerectomy, would you be better to up the bore to 2.5 like i have seen people do or staying with the same size bore pipe or is there little init that it makes near enough no difference? May sound silly but you never know.

its a good question, would like to know the answer too..

ive got a mufflerectomy on my vrs and havent noticed any power loss and drop in torque, if anything it feels a bit quicker

ive got a mufflerectomy on my vrs and havent noticed any power loss and drop in torque, if anything it feels a bit quicker

what bore pipe did you replace the back box with?

what bore pipe did you replace the back box with?

Sorry to bring back this thread.. but would be good to know the answer to this :p

otherwise, is it worth saving up for a while and getting milltek?

I put 2.5 on my mufflerectomy

Waking this old one up, I've just swapped my standard exhaust for a straight pipe decat 2.5" and have noticed a deffonate lack in power makes me want to change back lol hopefully a remap will sort it out