GolfGTIforum.co.uk
Model specific boards => Golf mk2 => Topic started by: wopdat on 02 March 2009, 12:02
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Hi peeps, I need to know if anybody has tried and tested exhaust systems on a valver. :huh:
My valver came with a full janspeed DTM exhaust system when i bought the car a few years back which consisted of 4 boxes including the one on the downpipe. Because i can't stand DTMs i swapped the back box for a small powerflow jobby which had to be modified as it was off scrapped punto. This worked a treat as the pull improved greatly but caused asome bellowing when idling and more so on the motorway.
Next came a miltek 4 in 1 which got rid of the box on the downpipe and increased power. I did notice a slight lack in torque but it was worth it for the power gain at high revs. (system = 3 boxes) :smiley:
I then picked up a straight through pipe with a supersprint mid box a sebring rear box... this got rid of the bellowing and sounds lovely when idling (system = 2 boxes) :wink:
However, i have lost alot of torque for top end power (revs easily upto 7500 rpm)... but my valver is fookin slow off the line untill it gets goin. :cry:
Is this due to a lack of backpressure cos of the lack of boxes? or is it due to the mixin and matchin of the boxes concerned? Or is it somethin completely different? :undecided:
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the actual boxes themsleves shouldn't have a massive effect really. the 16v is sensitive to it's exhaust but the inportant stuff happens in the 1st half of the sytem. but exhaust theory is a dark art
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I have had a full supersprint system and a full jetex system on the same 8v gti, and to me the supersprint felt like the car pulled harder, especially from lower revs. Don't know if it did actually make a difference or whether it even helps :huh:
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Alright fella, with a NA engined car, the exhaust should be matched/tuned to the manafold and engine.
Its all about getting the exhaust pulse flow correct.
On a turbo car smaller pipe run and biggest diameter pipe (up to a point) after the turbo will allow for better turbo response and you dont really have to worry about exhaust pulse flow the same as you do on a NA as the the turbo charger is a big restriction in the exhaust.
Sounds to me like your car is not very nice to drive as your loosing out on Low down torque which is much more usable around town and day to day driving rather than having to ring the cars neck to get it going.
You could try advancing your timing 2 degrees which will help with pickup but will make your car more prone to pinking if you use 95 ron fuel.
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anyone suggest a good system to keep or add more torque?
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anyone suggest a good system to keep or add more torque?
stock OEM system
If you really want extra torques only real option is stroker/bore to 1.9liters or fit a SC or Turbo
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Torque wins races BHP sells cars :smiley:
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Torque wins races BHP sells cars :smiley:
Torque gets you off the line, BHP gets you over it :wink:
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torques for tractors
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Power gives you speed. Torque gives you pulling power.
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re manifolds i have read 4-2-1 favours torque and 4-1 favours power, how much difference it actually makes i have no idea
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current thinking favors 4-2-1. if desinged right gives inprovements of uc wide part of the powerband, starts sooner and goes as high in the revs
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I'm sure the volume of the boxes and the baffles will make a difference... my cars sounds great but i need more torque!!!
i just can't pull away quick enough but i sure an catch them!!! But like i said the torque is definately missed so what would be the best system to use in conjunction with my miltek?!
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there is no definitive answer, they onlt really way to tell is to dig out an enigne dyno and strap a test engie to it and see what effect diffrent systems have, i have the use of an engine dyno and can get hold of a 16v motor quite easy but somewhat lacking in exhaust systems
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Torque wins races BHP sells cars :smiley:
Torque gets you off the line, BHP gets you over it :wink:
Torque gets you off the line and skill gets you over it :smiley:
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Torque is cheap, but power corrupts :grin:
No seriously. I had a mk4 2.0 gt tdi, which was awseome to drive because of the Torque. All the fun in driving is the acceleration, the short sharp squirts of power between corners...all of which increases with torque - pulling power.
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really it's nether, it's the area under the graph that counts if you want a fast car. loads of torqe but no revs is pants but loads of revs and no torqe is pants, loads or torqe for loads of revs = :> by default it has shed loads of power
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Torque is cheap, but power corrupts :grin:
No seriously. I had a mk4 2.0 gt tdi, which was awseome to drive because of the Torque. All the fun in driving is the acceleration, the short sharp squirts of power between corners...all of which increases with torque - pulling power.
because its great fun changing gear at 4k isnt it :grin: :rolleyes:
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Torque for 0-60mph (Overcoming inertia)
Power 60mph+ (Overcoming aero resistance/drag)
Have a Magnex on my mk2 valver at the mo witha 4 into 1 mani which is ok. Not too noisey.
Went from a mk2 8v, to mk3 16v, to mk2 16v, felt a bit gutless to compared to mk3 hence my upcoming engine swap for ABF... :grin:
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I have another powerflow box which is much smaller than the sebring i'm using so i'm gonna try that and see if it makes a difference. I also feel losing the front box & manifold box has severly affected the torque so gonna swap n change to see wot happens.
Will the exhaust setup affect the timing? I mite check that tonigt, a quick job. :undecided:
Also danny, where you based? I could be tempted to visit you and conduct a comparison experiment using the different boxes!! :huh:
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i'm based in ross-on-wye , herefordshire