Author Topic: 8v GTi exhaust/manifolds  (Read 4997 times)

Offline matty1664

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8v GTi exhaust/manifolds
« on: 27 December 2013, 10:03 »
Hi all! I hope everyone has had a good Christmas.

I'm just after a bit of advice about which exhaust to get for my 8v GTi (1991). I've done things a bit arse about face and gone and got my cylinder head polished and ported before upgrading the manifold and exhaust so I'm taking the hit and doing it all in one go. I'm thinking along the lines of Jetex but wondering if anyone knows of anything better?

On VW Heritage there is only 1 option for performance manifolds and it is stainless 4-1. Can anyone tell if this is good and what the difference would be compared to a 4-2-1? Can only seem to find 4-1 manifolds on eBay etc though.

I have got a K&N panel filter also.

Any advice much welcomed and appreciated.

Matt

Offline Gambit

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Re: 8v GTi exhaust/manifolds
« Reply #1 on: 27 December 2013, 10:16 »
Ebay manifolds are sh!t fit. The std manifold and 8v down pipe flows quite well. If it was me id just get the std manifold port matched to your head and take it from there. You have no silencer in your downpipe like 16v's have so no restriction

Offline matty1664

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Re: 8v GTi exhaust/manifolds
« Reply #2 on: 27 December 2013, 10:30 »
Ok cool, so do you think it's not worth getting a jetex exhaust either? Do you think I will see a decent gain from the P&P head with my OE exhaust?

Cheers

Offline Gambit

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Re: 8v GTi exhaust/manifolds
« Reply #3 on: 27 December 2013, 11:33 »
Id get the jetex system yes as it will be free flowing compared to std system but use original manifold and downpipe.

P&p head if done right and run with a cam will give a decent improvement. Who done the head job for you?

Offline gazareth

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Re: 8v GTi exhaust/manifolds
« Reply #4 on: 27 December 2013, 14:18 »
I welded a nut with a caliper bleed screw in it on to my exhaust to check for back pressure with a vacuum gauge. haven't tried it properly out on the road but tried it when it was still on ramp and up to 5krpm wasn't reading any back pressure so  the standard exhaust seems to be quite decent for everyday use. Ernst btw.

Offline Foreveryoungaus16v

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Re: 8v GTi exhaust/manifolds
« Reply #5 on: 27 December 2013, 14:23 »
I would only change your exhaust if it need changing, ie broke. Not great difference between standard exhaust and Jetex. Just get manifold matched to your ported head and lightened flywheel.

KW V2, TEAM DYNAMICS PRO RACE 1.2, EIBACH ARBS, DS 2500 PADS, BLACK DIAMOND DISCS, LIGHTENED FLYWHEEL, CHIPPED ECU, VIBRA TECHNIC MOUNTS, JETEX DECAT,  FULLY POLYBUSHED
163 BHP (TSR POWER RUN)

Offline matty1664

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Re: 8v GTi exhaust/manifolds
« Reply #6 on: 27 December 2013, 14:34 »
Id get the jetex system yes as it will be free flowing compared to std system but use original manifold and downpipe.

P&p head if done right and run with a cam will give a decent improvement. Who done the head job for you?

Tipton Garage near Sidmouth are doing the head mod. I haven't had any work done by them before but they sound pretty good and seem to have a lot of experience.

Thanks, very useful replies on here. I will need to have a good think. I will see how it drives to start with then make a decision as to what I will do with the exhaust. Last thing I want to do is shell out for something that may make little or no difference. As far as cams go I may go for a mild fast road use one eventually but not to start with.

Cheers
Matt

Offline gazareth

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Re: 8v GTi exhaust/manifolds
« Reply #7 on: 27 December 2013, 14:34 »
so many people associate noise with power which is bol%^x. I think the price of so called performance exhausts is ridiculous these days. but in saying that they do last a lot longer. depends on your budget and how long you plan to keep the car though. as said get the manifold matched  to the head. bolt it all up and get it back on the dyno first to see how it performs. you could allways upgrade once your current pipe has rotted off.

Offline gazareth

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Re: 8v GTi exhaust/manifolds
« Reply #8 on: 27 December 2013, 14:39 »
Id get the jetex system yes as it will be free flowing compared to std system but use original manifold and downpipe.

P&p head if done right and run with a cam will give a decent improvement. Who done the head job for you?

Tipton Garage near Sidmouth are doing the head mod. I haven't had any work done by them before but they sound pretty good and seem to have a lot of experience.

Thanks, very useful replies on here. I will need to have a good think. I will see how it drives to start with then make a decision as to what I will do with the exhaust. Last thing I want to do is shell out for something that may make little or no difference. As far as cams go I may go for a mild fast road use one eventually but not to start with.

Cheers
Matt
well if the head is done right you should notice your engine running a heluva lot smoother at higher revs :smiley:

Offline Foreveryoungaus16v

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Re: 8v GTi exhaust/manifolds
« Reply #9 on: 27 December 2013, 14:42 »
so many people associate noise with power which is bol%^x. I think the price of so called performance exhausts is ridiculous these days. but in saying that they do last a lot longer. depends on your budget and how long you plan to keep the car though. as said get the manifold matched  to the head. bolt it all up and get it back on the dyno first to see how it performs. you could allways upgrade once your current pipe has rotted off.

I totally agree. Only change your exhaust if it needs replacing or you want a deeper note. The Jetex will last a lifetime but will do little in the performance department.

KW V2, TEAM DYNAMICS PRO RACE 1.2, EIBACH ARBS, DS 2500 PADS, BLACK DIAMOND DISCS, LIGHTENED FLYWHEEL, CHIPPED ECU, VIBRA TECHNIC MOUNTS, JETEX DECAT,  FULLY POLYBUSHED
163 BHP (TSR POWER RUN)