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Discussion Starter · #1 ·
You have to bear with me as i dont know much about exhausts but i presume the faster the gas can get out of the exhaust system the quicker the cars turbo will spool up.

Now with this in mind how does the likes of a milltek cat back exhaust increase you power by 8-10%. Surley it would be better to fit a larger bore downpipe with high flow cat rather than the cat back system. (doing both at the same time is a tad expensive, but would obviously be the best option).

Ive been looking at exhausts and was wondering.if its worth/possible to run a standard exhaust with a highflow cat and larger bore downpipe instaed of a cat back system

which combination would give the best bhp?

1) Golf 1.8t with a 3'' downpipe and high flow cat mated to the standard exhaust system

2) Golf 1.8t with a 2.5'' downpipe and high flow cat mated to the standard exhaust system

3)Golf 1.8t with standard downpipe and cat with the milltek cat back exhaust system

i would have thought it would be number 1...... anyone tell me if im barking up the wrong tree[:)]
 

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I have the Milltek 2.5" downpipe and sports cat fitted to the standard exhaust on my car. Spoke to a few people in the states running this setup before trying it. Milltek suppply a reducer tube and clips free of charge if you ask them too for this purpose.

I went this route as loud or boomy exhausts are not an option for me. There was a guy on the vortex that had performed dyno runs with the various parts fitted. Adding the cat back after fitting the downpipe only added a few extra bhp, which I'm happy to live without for a quiet as standard system. The conclusion seemed to be that the a big downpipe and free flowing cat was best, then the cat back was the icing on the cake.
 

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Now with this in mind how does the likes of a milltek cat back exhaust increase you power by 8-10%.
It won't, simple as that!!

I have a Milltek 2.5" turbo back exhaust but recently spoke to Awesome for a price on a 3" downpipe and decat.

They advised against this due to it being too large for a K03 /
K03sport and said that a 3" exhaust is only recommended for big turbo
applications where you need to shift a lot of air.

Considering the results I've been getting of late on Awesomes rolling
road then I can't disagree with their advise, after all this was at the
expense of a possible sale.
 

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Discussion Starter · #4 ·
Now with this in mind how does the likes of a milltek cat back exhaust increase you power by 8-10%.
It won't, simple as that!!

I have a Milltek 2.5" turbo back exhaust but recently spoke to Awesome for a price on a 3" downpipe and decat.
They advised against this due to it being too large for a K03 / K03sport and said that a 3" exhaust is only recommended for big turbo applications where you need to shift a lot of air.

Considering the results I've been getting of late on Awesomes rolling road then I can't disagree with their advise, after all this was at the expense of a possible sale.
ooooh.... so the blurb for the milltek cat back systems on the awsome site is wrong?....

thats where i got the 8-10% increase from.

This is what It says this on the milltek cat back section of the site for the golf

' Enjoy the exhilaration that Milltek stainless steel systems give you with a genuine power gain of 8-10%.

Many sports systems have a characteristic drone and boom - not so the Milltek. A Milltek system will ensure that you have the power and the looks but the sounds stay outside! '

false advertising maybe ??
 

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I just can't see a remapped car which gives around 210bhp gaining another 21bhp after fitting a catback exhaust.

I hardly noticed a difference when I had the catback fitted, after
fitting the 2.5" DP and high flow cat thats when I noticed a real
difference.
 

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Discussion Starter · #6 ·
I have the Milltek 2.5" downpipe and sports cat fitted to the standard exhaust on my car. Spoke to a few people in the states running this setup before trying it. Milltek suppply a reducer tube and clips free of charge if you ask them too for this purpose.

I went this route as loud or boomy exhausts are not an option for me. There was a guy on the vortex that had performed dyno runs with the various parts fitted. Adding the cat back after fitting the downpipe only added a few extra bhp, which I'm happy to live without for a quiet as standard system. The conclusion seemed to be that the a big downpipe and free flowing cat was best, then the cat back was the icing on the cake.
what difference's did you find when running this setup? more torque/bhp ?

....just wondering if its worth doing.
 

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what difference's did you find when running this setup? more torque/bhp ?
This is the setup I'm running now. I can say how much extra its given me over a standard downpipe as I fitted all my upgrade parts at the same time before mapping. I did the research like you are and then just made a leap of faith and went for it.
 

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Discussion Starter · #8 ·
Ive been trawling the web for comments about them and it says they give the car more mid range punch and the turbo comes in a little earlier.

all the threads ive read have said it makes a very noticable difference[:D]

are the downpipe and cat 1 whole section or are they 2 seperate parts?

does any one else make them other than milltek and apr??
 

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before i sold my existing exaust i had

2.5" SYSTEM turbo back, hi flow cat through tto the back box.

the lads whom do these system do work for Touring cars, morgan gragages, they even had a F2 car in for a sports sytem, they do Stainless, and titanium systems, they say that 3" is too big for soem thing of the size of my engine and turbo so thats why they fitted a 2.5" system.

with that set up the power increse was unreal more toruqe and power i had them down in two stages cat back one week and then the turbo to hi flow next, was unreal the smoother revs etc etc etc

Just been back today to get the new dual r32 exaust style fitted and then back in feb to get the down pipe and hiflow cat or de cat done ;-)

?500 all in for the full system not bad conciderign "riptek" sorry miltek charge about that just for the sports cat and down pipe.

if any ones intrested in a down pipe and hi flow cat they price is around ?160 inc vat or 185 for the slightly higer flow cat.

thisis my 7th system from them over the years no problems at all either....

andy
 

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Discussion Starter · #10 ·
before i sold my existing exaust i had

2.5" SYSTEM turbo back, hi flow cat through tto the back box.

the lads whom do these system do work for Touring cars, morgan gragages, they even had a F2 car in for a sports sytem, they do Stainless, and titanium systems, they say that 3" is too big for soem thing of the size of my engine and turbo so thats why they fitted a 2.5" system.

with that set up the power increse was unreal more toruqe and power i had them down in two stages cat back one week and then the turbo to hi flow next, was unreal the smoother revs etc etc etc

Just been back today to get the new dual r32 exaust style fitted and then back in feb to get the down pipe and hiflow cat or de cat done ;-)

?500 all in for the full system not bad conciderign "riptek" sorry miltek charge about that just for the sports cat and down pipe.

if any ones intrested in a down pipe and hi flow cat they price is around ?160 inc vat or 185 for the slightly higer flow cat.

thisis my 7th system from them over the years no problems at all either....

andy
cheers mate ive been searching the internet for the past few hours to see if anyone else makes them

.... any contact details/web address where i can get myself one of these cheaper hi flow cats and larger downpipes?
 

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Hi mate sure. Ring Stewart at AAS. (advanced automative systems) ill get u the number when i get home ther located in "newburn" NEWCASTLE UPON TYNE if you ask him a price when he does my exust im sure he can make mine and do a copy for you ;-) but if you want it fitted you can pop up mee thte lads etc etc et cplease state i recomended them my names andy greer
 

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i had the Milltek 3" sportcat downpipe added to my remapped mk4 gti 1.8t , before fitting i was 199bhp, after fitting it rose to 207bhp this

was added to the stock OE VW rear pipe by way of an adaptor from miltek.

now i have been thinking off getting the miltek rear added as the vw warranty is almost up, so were saying no point adding a 3" rear section

now???????????????

p.s on the mk4 gti to get the rear pipes added you have to fit a 4motion vallance, forgive my ignorance but does that mean removing the

orig and fitting another or adding onto the existing valance?? anyone had this done and taken a pic??
 

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Gessss... all this tosh about 3" DP's! all a turbo wants to do is get rid of the gas asap! bigger the hole the more will go through it! It wont over spool and blow up or need back presure or make your wing mirror fall off! I would of bought a 3" for mine but it wasnt available at the time I bought mine except from the US (forced motion make one) so I bought the 100 cell Miltek.... and cant justify the upgrade price now..
 

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Am motorsport are now selling 3'' downpipes with sports cat.....tad pricey for me though.......dont really want to be spending 250+ if i can help it

http://www.am-motorsport.co.uk/main.htm
Yeah they've been doing that for a while now, but fitament is for Ibiza's only at the minute. If you don't want to spend ?250 + on a downpipe/cat then the only option you really have is to either by a second hand one or to get a downpipe/decat combo made up, as these metalic high-flow cats are expensive.
 

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This is a reply to a post on Vortex where a guy made lower torque than he thought he would:

"Although 3" is a vast improvement on the stock
system, I believe its too big for the small stock turbo. And this
doesn't help torque. 2.5" is ample, and I think it would have helped the
torque some.."

I always seem to make very good torque with my 2.5" system which is why
Awesome advised me to stick with what I have and not go for a 3" DP.
 

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Discussion Starter · #19 ·
anyrg is having a downpipe and sports cat made up by aas (advanced automotive systmes) for ?180.

Looks like i'll be giving them a bell because the next cheapest i can find is milltek at around ?289 (im sure it was ?350 this weekend just gone)

prices and companys ive found so far are as follows

Apr 2.5 '' downpipe and sports cat - 375

milltek 2.5'' downpipe and sports cat - 289

Blueflame - (no price)

aas (advanced automotive systmes) - ?180

My serahces on the net for other companys who make the downpipes and sports cats have proved fruitless :<
 

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This is a reply to a post on Vortex where a guy made lower torque than he thought he would:

"Although 3" is a vast improvement on the stock system, I believe its too big for the small stock turbo. And this doesn't help torque. 2.5" is ample, and I think it would have helped the torque some.."

I always seem to make very good torque with my 2.5" system which is why Awesome advised me to stick with what I have and not go for a 3" DP.
good point as my torque stat didn't increase or decrease. but there wasn't much diff in the price between the 2 to the 3" so what the heck
 
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