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Looking for advice on best Exhaust system upgare for 1.8

Hi.

I have a late model
  Mk1 1.8i Karmann Cabriolet LHD NL Import and am considering uprating the exhaust as the current original VW one is coming to the
end of its life.

The car itself is 100% original so I don't want anything that will sound or look vulgar but I really would like a few extra horse power and a nicer
exhaust note ( something raspy rather than that awful bass'y drone that the Suburu's have )

I have been told that the standard manifold is hard to better and so not worth replacing ?

Any advice ?


IMG_8802.JPG
 

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Not sure where you got the standard manifold being hard to better.

The cast manifolds are toilet, genuinely in some cases they have the "toilet bowl" design.

But which ever of the manifolds you have it is easily bettered as the original castings are so rough inside.

Any 4-1 or 4-2-1 will be better whether is be stainless or mild steel

Current rides:
2003 Honda CRF450R (impossible to start)
2003 BMW 330d Manual Saloon Msport
1985 GTI cabriolet black edition (42k miles)
2004 Mk1 Octavia VRS (250bhp) For Sale
2002 Yamaha R1 track bike (crashed badly)

Screenshot_2018-10-01-20-38-11.png

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I'm with 1985 on the manifold… the original VW design with the big C clips restricts the exhaust flow as is not very good.

I changed to a stainless 4,2,1 manifold and kept the original size exhaust and found the exhaust sounds fruitier and freed up some extra horses higher up the Rev range.
I did wrap my manifold all the way to the joint/end and had to wrap the rubber UJ boot as the new manifold does run very close the the boot.

If you look at my build thread towards the bottom of page 1 you can see it..

https://vwgolfmk1.org.uk/forum/index.php?
page=topicview&id=projects%2Fyour-mk1-golfs_2%2Fmy-daily-dri
ve-1988-gti


Please don't use that typeface in your posts as it's very difficult to read that small… or perhaps I just need some glasses..  :lol:

1988 Mk1 Golf GTi Cabriolet 1.8cc DX, K-jet. Daily drive. 300,000 miles and counting
1978 Mk1 Scirocco GLS 1.6cc FR, Webber carb. Weekend toy.

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Exhaust Upgrade

Mine was dropped to the fabricators yesterday. 4-2-1 stainless manifold being fitted and the 2 1/4 inch stainless all the way with a single back box (delete the middle box)

God I hope it sounds ok.

Cost with me supplying the 4 branch and manifold gaskets. £500 ish. Find out when finished for sure.


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Backinblack said

Mine was dropped to the fabricators yesterday. 4-2-1 stainless manifold being fitted and the 2 1/4 inch stainless all the way with a single back box (delete the middle box)

God I hope it sounds ok.

Cost with me supplying the 4 branch and manifold gaskets. £500 ish. Find out when finished for sure.

Sent from my iPhone using Tapatalk

Please could you share images and overall experience and if it was a positive outcome who did this for you?

I'm in the same predicament right now and after reading varying advice and options out there of making the choice of off the shelf product versus a bespoke fabricated it's not making it an easy decision.

Many thanks

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Exhaust Upgrade

Don’t worry I shall be putting it on here for sure. The forum is like a potted history of my cars progression (or regression).

I went for fabricated for a couple of reasons.
My 4 branch was an eBay special and needed a new flange fitting. So needed to get that fabricated
The cost is about the same as buying a reasonable quality non stainless system
I wanted stainless so I don’t have to worry ever about changing it again
I was going to have to pay someone to fit it anyway (not doing that on the floor) so may as well get them to fabricate and fit.

I’m not doing it for power etc just to be another thing done. A few extra horses will be nice but not the main aim. My current exhaust is badly fitted and rattled on the fuel tank shield plus other places. It looks terrible but I will mis the sound it is very raspy for a standard system.

Will put pictures up in about 3 weeks. Remind me about if you see nothing as it means I have lost the post [emoji85]

Thanks


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Hi everyone  Thanks for all the advice.. Any recommendations on best off the shelf brands or fabricators ?  ( I'm based in Mid Wales )

Used to be Janspeed and Peco but I guess I'm showing my age now   :)

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Exhaust Upgrade

Magnaflow but not cheap.


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Regarding the original manifold, I've read (a long time ago) that this was one of the areas the engineers spent a lot of time on to increase the output, may be wrong, but given it is effectively a 4 - 2-1 system (with the standard down pipe) I'm not sure it can be classed as rubbish. I'm talking about an 83 gti, and I don't have C clips. I'd go as far as to suggest that given the short length of the manifold and the initial velocity of the exhaust gasses means that the casting finish is of negligible impact on a standard car.
That said it would be interesting if anyone has any rolling road before and after figures (based on just changing the manifold).
Also bear in mind that a 4-1 and a 4-2-1 have an effect on where power gains are seen in the rev range.

My rebuild thread I will try and keep up to date: here

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Gets complicated quickly :-)
Performance Exhaust System Design And Theory

My rebuild thread I will try and keep up to date: here

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When I removed my original manifold (admittedly it was the C clip version) I was surprised by apart from how rough it was inside just how heavy it it was.

You'd save a lot of weight by changing it alone.

I ran a Jetex 2" system on the original down pipes and manifold for a year, once I fitted the Ashley manifold the car seemed to rev more freely.
I cant honestly say it has more power but somehow feels easier to drive

Current rides:
2003 Honda CRF450R (impossible to start)
2003 BMW 330d Manual Saloon Msport
1985 GTI cabriolet black edition (42k miles)
2004 Mk1 Octavia VRS (250bhp) For Sale
2002 Yamaha R1 track bike (crashed badly)

Screenshot_2018-10-01-20-38-11.png

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Say what you want the 90'ish redesign from the Toilet Bowl Flange fitment of the head to the re-designed single downpipe  was a  step backwards in my honest opinion.  The Head Casting was Cost reduced, probably due to accounting, and was weakened.  

I have had 3 Cabriolets all 90's and they all suffered from cracked manifolds between the Cylinders, now some of it could be from poor maintenance, bad mounts and vibration effects but I am firmly convinced it was a step backwards. But the Cracks were all in the same general area..



The g60 4-2 manifold was a step up.
but getting the dual down pipe (TT-Tuning) was an expensive option that I did on my green one.



The draw back on it was the relocation of the o2 sensor to a new bung on the right hand side, as it afforded more room, and easier to get on or off.

I have had the Pace setter header installed on my 90, and it was a wonderful addition (even with the heating of the pipes and bend adjust to clear the Sway bar and more shielding to prevent heat from attacking my power steering, same as I had to do with my 4-2 G60.  it was an easy 50-60 HP gain (Seat of the pants feel :) ).



I have a Cat Delete Raceland header that I need to install on my 93, Since my 93 doesn't have need  the emissions.



On my 93 to pass emissions I did find a g60 manifold and had my Muffler guy build me a dual down sort of, after I mocked it up…  and it does serve me well with no
nox leaks.

My crappy welds were taken care of, but you can see the location of the o2 bung same area for my tt-tuning one.



If you go the cat delete you still need the flexure between the header and the front silencer (we call it a Resonator, but it is a Pneumatic Harmonic reducer).



My 2 pence….




What do Divorces, Great Coffee, and Car Electrics all have in common?

They all start with GOOD Grounds.

Where are my DIY Links?

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BABJ said

Hi.

I have a late model Mk1 1.8i Karmann Cabriolet LHD NL Import and am considering uprating the exhaust as the current original VW one is coming to the
end of its life.
Just for your information all Cabriolets are Karmann it isn't an edition, it was where the Cabriolets were designed and built at the Karmann Coachworks. All Cabriolets were imported, as they all are German Built.  I suppose that if you bought yours in Germany, then it isn't an import…. The Plaque on the side denotes the Design plant, not a "special thing"…  Now back to our regularly scheduled thread.

What do Divorces, Great Coffee, and Car Electrics all have in common?

They all start with GOOD Grounds.

Where are my DIY Links?

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Had someone in Audi dealership tell me my Mk5 golf gti was worth less trade in as it was "an import"  :lol:I casually looked around at the brimming showroom and said "so are all of them"  :lol:He laughed, and then gave me what i wanted for it  :lol:As for the manifold question, standard does the job, if your not looking for upping power and need
reliability

4 branches on a Mk1 are usually a Problem, cracking on the branches or melting your steering boot! Unless your engine and gearbox mounts are brand new or solid your asking for issues

Mines going to keep its toilet bowl manifold for those reasons alone
I found a guy in Germany who fabricates stainless systems (no centre box) in 45mm outlet and bore so looks standard, and they have the correct cabriolet hangers on the back box as well

Less than £300

Nowhere in the Uk can get anywhere near those prices

Will be ordering mine shortly

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Ya know I am being a smarty pants, but does anyone actually use the search function any more?

I searched for Exhaust Upgrades, and there were over 1000 hits… Yes, I suspect that the hits just keep on coming.

Screen Shot 2019-06-19 at 5.28.15 PM.png


Yes, I know I am a smarty pants…. but I wear them well.

What do Divorces, Great Coffee, and Car Electrics all have in common?

They all start with GOOD Grounds.

Where are my DIY Links?

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1988 Mk1 Golf GTi Cabriolet 1.8cc DX, K-jet. Daily drive. 300,000 miles and counting
1978 Mk1 Scirocco GLS 1.6cc FR, Webber carb. Weekend toy.

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I just had a manifold back exhaust custom made with 2 silencers and upsweeping tail pipe. I have the 1.8 auto and it sounds amazing its not too loud but loud enough to know its there and when it gets hot if I let off the throttle I get a nice burble  :)

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Anton_cabrio said

I just had a manifold back exhaust custom made with 2 silencers and upsweeping tail pipe. I have the 1.8 auto and it sounds amazing its not too loud but loud enough to know its there and when it gets hot if I let off the throttle I get a nice burble  :)

Please can you share how much you paid for this and where you got it done? I think we may be local to each other so if it's in our area even better.
Thanks

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I paid £550 all in from the guys at style dynamics in Hayes. They are so professional and very friendly  

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