Decat advice

gollywog

As you know, I just bought a milltek cat back for the gti and am a bit disappointed at how similar it sounds to the stock exhaust. I know where I can get a second hand APR downpipe and Decat very cheap so im thinking about that. Problem is it will trigger the emissions light. The seller say# ill have to remap it to get the light out.
Can I get joe power to do a cat delete or something or would a full remap be required? How much would this cost?
Any other thoughts or advice?
Cheers

challengemaster

Full map would probably be around 3-350 with Joe I'd imagine. The way I'd be looking at it is, if you're going to the trouble of making the full exhaust system less restrictive, why not make the most of it. Otherwise you've probably just cost yourself some horsies.

gollywog

challengemaster wrote: »

Full map would probably be around 3-350 with Joe I'd imagine. The way I'd be looking at it is, if you're going to the trouble of making the full exhaust system less restrictive, why not make the most of it. Otherwise you've probably just cost yourself some horsies.

Ya that's a good point.
So if I get the pipes, i would probably be aswell wait to install it until I could afford a remap.
God, too many decisions!

Supergurrier

Personally i would go with a sports cat with as few cells as possible but then again im a big girls blouse

gollywog

Supergurrier wrote: »

Personally i would go with a sports cat with as few cells as possible but then again im a big girls blouse

That would absolutely be my first choice jim, but there way expensive... And I'm getting the Apr Decat and downpipe at a price that's hard to refuse really... So even tho I'm not completely sold, i dont want to miss it and regret it!

vectra

Will a decat pass the nct?

dar83

No, but you just keep your Cat and bolt it back on when it's NCT time.

I thought you had gotten a full exhaust to begin with, no wonder it doesn't sound much different, the most restrictive parts would be the down pipe and the original Cat. Get them changed and you'll hear a difference.

As for the engine light you just need to buy a lambda spacer and it should take care of the light coming on for you. Look up '42 Draft Designs' for one of the best ones you can get, just be sure to get an angled one and not a short one. Think the website that sells them close is called awesome-GTi.co.uk or something.

Chriscl1

^^^ what he said. There's no need for an expensive remap, a good spacer and your good to go.

Drummerboy08

Chriscl1 wrote: »

^^^ what he said. There's no need for an expensive remap, a good spacer and your good to go.

That's all well and good, but you won't really see the full benefit on the exhaust without a remap....

ShadowHearth

You will need full remap m8. Hiding the light is useless anyway.

Decating n/a car has no disadvantages, but when you do all that to turbo car it can get very dodgy. Keep in mind without remap liamda will be reading "milks boiling temperature", and not what it should. It's very dodgy when turbo cars are very sensitive to petrol mixture.
My car has full decat and full exhaust from turbo. It's not remapped. new age wrx ecu is self learning so it can work around it. Problem is it is still not perfect. It will use more fuel and not more power will be added. Some power might be even gone. It is still a bit dangerous to drive car like that too.

This is the reason I am getting my old standard exhaust going on scooby, while having oil change. I won't be taking out the engine this time though.

Chriscl1

Drummerboy08 wrote: »

That's all well and good, but you won't really see the full benefit on the exhaust without a remap....

Your right there about the full benefit but you'll still see a big difference in power, responsiveness and sound over a standard set up even without the remap. Btw who remaps vw's and such over here?

dgt

It won't pass the nct (unless its somehow diesel :pac:)

once the downstream sensor gets a decent supply of fresh air, the light will stay off.

Should be a bit raspier with no cat

gollywog

Cheers for the reply lads
Im really unsure what to do now tbh.
My mechanic is making me a cold air intake at the moment too so I might just get that on and see how I feel then?
But I might just buy the decat and downpipe anyway, as its such a good deal,
Then even if I decide not to do it, I could probably just sell it on easy enough.
How much is it to remap a gti with joe power?
Has anyone had him do it?
Its like £500 in england

vectra

gollywog wrote: »

My mechanic is making me a cold air intake at the moment too so I might just get that on and see how I feel then?

Not sure if you will be able to read this or not.

http://www.briskoda.net/forums/topic/251116-carbon-speed-cold-air-intake-virtually-new/

gollywog

vectra wrote: »

gollywog wrote: »

My mechanic is making me a cold air intake at the moment too so I might just get that on and see how I feel then?

Not sure if you will be able to read this or not.

http://www.briskoda.net/forums/topic/251116-carbon-speed-cold-air-intake-virtually-new/

Damn that looked good vectra... It's gone now
Cheers for the link anyway.

Rang joe power earlier, remap is 320 so im seriously interested now. Will prob buy the pipe, get it fitted just before I decide to give joe a visit

My mechanic took the car for a spin when I was down earlier, heard him driving by and the car has a great sound, really nice I think especially with the DSG fartiness, but needs to be a touch louder for my taste

challengemaster

Chriscl1 wrote: »

Your right there about the full benefit but you'll still see a big difference in power, responsiveness and sound over a standard set up even without the remap. Btw who remaps vw's and such over here?

If anything you'll probably lose responsiveness and probably power too just throwing a free flowing exhaust onto a turbo without a remap. The ECU from factory is set up for a certain amount of back-pressure being provided by the standard exhaust. You're almost guaranteed more lag. The only thing you will have for certain is more sound.

gollywog

challengemaster wrote: »

Chriscl1 wrote: »

Your right there about the full benefit but you'll still see a big difference in power, responsiveness and sound over a standard set up even without the remap. Btw who remaps vw's and such over here?

If anything you'll probably lose responsiveness and probably power too just throwing a free flowing exhaust onto a turbo without a remap. The ECU from factory is set up for a certain amount of back-pressure being provided by the standard exhaust. You're almost guaranteed more lag. The only thing you will have for certain is more sound.

Ya I've basically made my mind up now i'll just do it all properly, get the pipes to make a full system and a new diverter valve to handle more boost, then when I can afford the remap get it all sorted.

Then after that I'll just enjoy the bloody yoke!

vectra

challengemaster wrote: »

If anything you'll probably lose responsiveness and probably power too just throwing a free flowing exhaust onto a turbo without a remap. The ECU from factory is set up for a certain amount of back-pressure being provided by the standard exhaust. You're almost guaranteed more lag. The only thing you will have for certain is more sound.

Sidelining the thread for a second.
If a Back box was removed from a Diesel turbo car. would the same apply? ie. Loss of power and turbo lag?

dar83

I'd be surprised if a new enough Golf doesn't have an ECU capable of learning/adjusting based on feedback from the sensors. I know in the ST with a DeCat it improves throttle response and spool time due to the decrease in back pressure on the Standard map, but the ECU does cater for enviromental variables in its calculations and optimises the timing/mixtures accordingly.

Nope, it applies more to nasp petrols anyway rather than turbo petrols. With turbos you want to minimise backpressure.

gollywog

Has anyone here had their gti remapped? How is it afterwards?

Supergurrier

On Briskoda.net alot of people seemed to be impressed with it, smoother power curve etc

Chriscl1

challengemaster wrote: »

If anything you'll probably lose responsiveness and probably power too just throwing a free flowing exhaust onto a turbo without a remap. The ECU from factory is set up for a certain amount of back-pressure being provided by the standard exhaust. You're almost guaranteed more lag. The only thing you will have for certain is more sound.

I had a jap import Impreza turbo with a standard exhaust and I replaced it with a resonated turbo back system and did not lose any responsiveness or power.

dgt

vectra wrote: »

Sidelining the thread for a second.
If a Back box was removed from a Diesel turbo car. would the same apply? ie. Loss of power and turbo lag?

You would get a serious boooooooooooooo.....

I run a straight through ie no cat and a straight through backbox and the car is far quicker low down

Supergurrier

It's threads like this that make me poor



Must Hide Credit Card... :pac:

vectra

gollywog wrote: »

Has anyone here had their gti remapped? How is it afterwards?

This is a members car on Briskoda. He is from up north.

Petrol vrs:


Engine/ Tuning:

Shark Perfomance Remap Stage 1 - 250bhp
AI Autosport Rolling Road Day – 260bhp

Shark Perfomance Remap Stage 2 - circa 280bhp
Autotune Rolling Road– 295bhp

Milltek Cat Back Exhaust System – Resonated
Milltek Down Pipe and High Flow Sports Cat
OEM Audi TTS/S3 Intercooler
APR Carbonio Stage 1 &2 intake system
Neuspeed Torque Arm insert
OEM revision D Diverter Valve
OEM Audi TTS/S3 Short Shifter

gollywog

vectra wrote: »

This is a members car on Briskoda. He is from up north.

Petrol vrs:


Engine/ Tuning:

Shark Perfomance Remap Stage 1 - 250bhp
AI Autosport Rolling Road Day – 260bhp

Shark Perfomance Remap Stage 2 - circa 280bhp
Autotune Rolling Road– 295bhp

Milltek Cat Back Exhaust System – Resonated
Milltek Down Pipe and High Flow Sports Cat
OEM Audi TTS/S3 Intercooler
APR Carbonio Stage 1 &2 intake system
Neuspeed Torque Arm insert
OEM revision D Diverter Valve
OEM Audi TTS/S3 Short Shifter

some good figures there
Stage one would be as far as i'd be taking it though,
Its just a daily driver after all

You all must think im mad but its a hobby I guess, and im not able to drink anymore so this helps fill the gap!

ShadowHearth

Chriscl1 wrote: »

I had a jap import Impreza turbo with a standard exhaust and I replaced it with a resonated turbo back system and did not lose any responsiveness or power.

catback will have have really very small noticable performance gain or loss. when you are talking about the whole decatting and full exhaust change, then there is a difference.

without any RR it is imposible to say if it gained or loss any power. for osme people louder = quicker. My very first car had stupidly loud exhaust, but when i put on standart quiet exhaust on it, it felt a lot more quicker, because it was not screaming it guts out on low revs.

Chriscl1

ShadowHearth wrote: »

catback will have have really very small noticable performance gain or loss. when you are talking about the whole decatting and full exhaust change, then there is a difference.

he said he was thinking of adding a down pipe and de-cat to add to his cat-back so dont see what your getting at here?

ShadowHearth wrote: »

without any RR it is imposible to say if it gained or loss any power. for osme people louder = quicker. My very first car had stupidly loud exhaust, but when i put on standart quiet exhaust on it, it felt a lot more quicker, because it was not screaming it guts out on low revs.

i dont like stupidly loud cars thats why my impreza system was resonated. i had driven the car enough to feel there was a difference. i realise the auld arse dyno cant tell the difference on small run arounds but with 280bhp imprezas it will. ive often read of lads making 30bhp with a turbo back system on an imprezza. 30bhp is feelable.

ShadowHearth

Chriscl1 wrote: »

he said he was thinking of adding a down pipe and de-cat to add to his cat-back so dont see what your getting at here?




i dont like stupidly loud cars thats why my impreza system was resonated. i had driven the car enough to feel there was a difference. i realise the auld arse dyno cant tell the difference on small run arounds but with 280bhp imprezas it will. ive often read of lads making 30bhp with a turbo back system on an imprezza. 30bhp is feelable.

i am at: just because you put a catback system on car, and you think its faster, does not mean it is. For some people, just because its different noise, it might look faster/ more responsive.

30hp with a full system+decat from a turbo to the tail and remap 30hp looks like normal to me. Though if they do say that its 30hp with no remap and liamda reading your mums horoscope, then just send those people far away.

Chriscl1

ShadowHearth wrote: »

i am at: just because you put a catback system on car, and you think its faster, does not mean it is. For some people, just because its different noise, it might look faster/ more responsive.

.

yes I know that but no one is talking about just a cat back though!!

tossy

Supergurrier wrote: »

It's threads like this that make me poor

Must Hide Credit Card... :pac:

A 'felted St,those mud flaps are horrendous.

ShadowHearth

Chriscl1 wrote: »

yes I know that but no one is talking about just a cat back though!!

Aye m8, my post was more aimed at your post then topic. I know he decided to go for full job, and that's the right way to do.

Just some people still have illusion that of they will put different catback and air filter car will get 5million bhp!!! You know it yourself m8. ( not aimed and people in this thread )

dar83

Shouldn't you be saying booooiiii, instead of mate? :P