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Author Topic: Quietest turbo back for stage 2  (Read 2821 times)

Offline ksamyui

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Quietest turbo back for stage 2
« on: November 12, 2022, 09:27:24 pm »
Looking to go stage 2 but not interested in any extra noise other than what’s necessary to free up flow. What’s the best turbo back option?

Offline breeze

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Re: Quietest turbo back for stage 2
« Reply #1 on: November 13, 2022, 07:29:03 am »
Good question.

I’d guess:
Sports cat and factory catback to be quietest, then something like a resonated Milltek catback. Resonated Milltek is very quiet. BCS Prestige gets good reviews, not clear if it would be as quiet as the Milltek.

Is it a K03 or K04 car and what are your power and torque goals?

Offline ksamyui

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Re: Quietest turbo back for stage 2
« Reply #2 on: November 13, 2022, 07:59:57 am »
Good question.

I’d guess:
Sports cat and factory catback to be quietest, then something like a resonated Milltek catback. Resonated Milltek is very quiet. BCS Prestige gets good reviews, not clear if it would be as quiet as the Milltek.

Is it a K03 or K04 car and what are your power and torque goals?

Thanks for that, it’s a Ko3; I don’t have any specific goals on power and torque, but now you’ve got me thinking :-D. I’ve always held that the power of my e46 M3 was just about perfect for UK roads, although could have done with a little more torque. That from memory was around 340bhp and 360nm torque.

Obvs I know this isn’t an M3, so somewhere around 270bhp, 290torque?

When I bought the car a few weeks ago, I was toying between something heavily modified (tried a couple of ed30 highly tuned, the power delivery was quite incredible ) or something strong and standard to mod a little. I opted for the more standard, only because the modded ones, in my price range, were all super high mileage, dubious history or category damaged.

« Last Edit: November 13, 2022, 08:07:06 am by ksamyui »

Offline colesey

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Re: Quietest turbo back for stage 2
« Reply #3 on: November 13, 2022, 08:38:26 am »
If you want torque, then you’ll be needing an upgraded hpfp more than a cat back. Vis are a popular option. For quiet, sports cat downpipe / stock catback / stock airbox / vis hpfp / s3 intercooler will give you around 270bhp / 320lb ft.

Another approach would be to convert to K04 / K03 hybrid but keep it at stage one. Quiet and no mot hassles.
« Last Edit: November 13, 2022, 10:58:00 am by colesey »

Offline ksamyui

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Re: Quietest turbo back for stage 2
« Reply #4 on: November 13, 2022, 11:39:54 am »
If you want torque, then you’ll be needing an upgraded hpfp more than a cat back. Vis are a popular option. For quiet, sports cat downpipe / stock catback / stock airbox / vis hpfp / s3 intercooler will give you around 270bhp / 320lb ft.

Another approach would be to convert to K04 / K03 hybrid but keep it at stage one. Quiet and no mot hassles.

Would those figures be ok on a stock clutch?

Offline colesey

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Re: Quietest turbo back for stage 2
« Reply #5 on: November 13, 2022, 01:44:57 pm »
Depends how worn it is / how spikey map is / driving style etc but yes they are still on the manageable side for stock clutch.

Offline pudding

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Re: Quietest turbo back for stage 2
« Reply #6 on: November 14, 2022, 08:49:19 am »
Milltek resonated is probably the quietest of the usual suspects as it's 2.75" bore as opposed to the more common 3.0".

The best way to get quiet is to build a custom system with the biggest silencers that will fit under there.


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Offline bobby_fodge

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Re: Quietest turbo back for stage 2
« Reply #7 on: November 14, 2022, 09:37:28 am »
Milltek owner here. On it's own I couldn't tell a difference between it and the standard exhaust. Even after adding the Milltek sports cat, the exhaust only make a slightly more interesting sounds.

It's far from a Fiesta ST in sound, which I like.

Offline Octoparrot

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Re: Quietest turbo back for stage 2
« Reply #8 on: November 14, 2022, 07:03:31 pm »
I've got a Milltek non res with standard cats and it's not loud which is fine by me.

Offline ksamyui

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Re: Quietest turbo back for stage 2
« Reply #9 on: January 02, 2023, 11:11:45 pm »
I’m going with:
  • 3” sports cat 200 cel dp onto standard cat back
  • APR HPFP
  • REVO intake
  • FORGE Intercooler

Question is do I throw a K04 (or F23T) into the mix now or not. Money is an issue as I’ll be getting most of this fitted by my tuner; I have no time these days :(

Offline breeze

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Re: Quietest turbo back for stage 2
« Reply #10 on: January 03, 2023, 10:11:19 am »
I’m going with:
  • 3” sports cat 200 cel dp onto standard cat back
  • APR HPFP
  • REVO intake
  • FORGE Intercooler

Question is do I throw a K04 (or F23T) into the mix now or not. Money is an issue as I’ll be getting most of this fitted by my tuner; I have no time these days :(

Seems like a sensible solution from a exhaust perspective. Do be aware that cheap 200 cell cats don’t have a reputation for lasting that long.

Since you aren’t keen on noise and have mentioned the K04, have a think about doing just the K04 and injectors. With everything else left standard. You could map and effectively end up with a Stage 1 Edition 30 performance level, maybe slightly more responsive because the Edition 30 runs lower compression (I think). Stage 1 is around 300bhp 300lbft and gives you the platform to get to in the region of 360 and 390 later. Just a thought, K04 kits on Facebook used to sell for around £750.

Offline ksamyui

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Re: Quietest turbo back for stage 2
« Reply #11 on: January 03, 2023, 10:47:41 am »
I’m going with:
  • 3” sports cat 200 cel dp onto standard cat back
  • APR HPFP
  • REVO intake
  • FORGE Intercooler

Question is do I throw a K04 (or F23T) into the mix now or not. Money is an issue as I’ll be getting most of this fitted by my tuner; I have no time these days :(

Seems like a sensible solution from a exhaust perspective. Do be aware that cheap 200 cell cats don’t have a reputation for lasting that long.

Since you aren’t keen on noise and have mentioned the K04, have a think about doing just the K04 and injectors. With everything else left standard. You could map and effectively end up with a Stage 1 Edition 30 performance level, maybe slightly more responsive because the Edition 30 runs lower compression (I think). Stage 1 is around 300bhp 300lbft and gives you the platform to get to in the region of 360 and 390 later. Just a thought, K04 kits on Facebook used to sell for around £750.

That's cool, thanks for that. I've already got the bits in the bullet points sat in the Garage :-D.

I am toying with the K04 turbo as well. As it's going to be custom mapped - my local performance garage have a really good tuner that works out about the same price as going down the REVO route - I'm quite keen on looking at the F23T Hybrid K04 (circa £300 used) or even the Turbo Technics S257 Hybrid K04 (circa £960 new), which are both direct bolt on replacements for the K03 and don't need the extra pipework.

Offline breeze

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Re: Quietest turbo back for stage 2
« Reply #12 on: January 03, 2023, 10:28:50 pm »
Ahh OK, it’s all good stuff… If you are in for the long haul you will use it all anyway.

On tuning, consider the companies that will give you free upgrades on the stages. You can spend quite a bit mapping if you don’t do it all in one go. It all adds up.

Is the F23T the one that is really a K03 hybrid? I’ve always thought a K03 hybrid in a AXX/BWA engined car would be really peppy and probably come on boost a bit faster than a K04. Probably more fun to drive.

Offline ksamyui

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Re: Quietest turbo back for stage 2
« Reply #13 on: January 03, 2023, 10:46:36 pm »
Ahh OK, it’s all good stuff… If you are in for the long haul you will use it all anyway.

On tuning, consider the companies that will give you free upgrades on the stages. You can spend quite a bit mapping if you don’t do it all in one go. It all adds up.

Is the F23T the one that is really a K03 hybrid? I’ve always thought a K03 hybrid in a AXX/BWA engined car would be really peppy and probably come on boost a bit faster than a K04. Probably more fun to drive.

I don’t know too much about it tbh. I’ve started another thread trying to find out a bit more :-D. There’s one going at a good price; it’s described as a K04 without needing all the K04 pipework, which I think is for the diverter valve? They’re meant to be good for 350bhp with the usual bigger injectors and fuel pump.