3 Liter 16v Turbo build
12-14-2012, 06:24 PM
#31
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I remember reading that chris white said it has nothing to do with the balance of the components but it's because it's an i4 being such a large bore it causes vibration because 2 pistons are always going up while 2 are always going down.
, Sid doesn't have them but his engine is internally balanced so really not needed.
12-14-2012, 07:31 PM
#32
Drifting
That's my impression as well. On each cycle there is a point where all the pistons are stopped. If the reciprocating mass was reduced to zero then the vibration would go away, but until then there would always be a second order vibration. I think the costs of deleting the balance shafts outweigh the benefits. Stuffs going to break sooner without them.
12-14-2012, 08:40 PM
#33
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Non-ideal flat-plane 4-cylinders will always have the second-order vibration, which can only be canceled with balance shafts. Internal balancing of components does not cancel this vibration. It has to due with the fact that the pistons on the upper half of the stroke are accelerating faster than the pistons at the bottom half of the stroke. This is because of the rod-angle being different on the upper half vs lower half of the stroke... If the rod was infinitely long, then there would be no second-order vibration - but obviously that cannot be the case in reality.
12-15-2012, 06:49 PM
#34
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Sorry for the late response, had a "year-end party" at work.. With hotel and you name it.. Needed to get some rest today.
After the first reponse about the balance shafts i've been looking into the balance shaft delete topics and soon found out that removing them is not the way to go for me.
Ofcourse i'll balance the crankshaft and sorts but now i understand why this doesnt have any effect on the vibrations in the engines.
And as i'm not going to knive-edge the crankshaft i'm not loosing a lot of weight there and i dont need to adjust the weight of the balance shafts.
But i got a message from a friend from Belgium that he has a set of very nice turbo rods for me for not too much money so i'll be picking those up some time soon!
Btw, what are the thoughts about the exhaust here? I'm almost sure that 3" is plenty for the downpipe. I wont be getting the wastegate into the exhaust but just a screamerpipe, just because i can..
After the first reponse about the balance shafts i've been looking into the balance shaft delete topics and soon found out that removing them is not the way to go for me.
Ofcourse i'll balance the crankshaft and sorts but now i understand why this doesnt have any effect on the vibrations in the engines.
And as i'm not going to knive-edge the crankshaft i'm not loosing a lot of weight there and i dont need to adjust the weight of the balance shafts.
But i got a message from a friend from Belgium that he has a set of very nice turbo rods for me for not too much money so i'll be picking those up some time soon!
Btw, what are the thoughts about the exhaust here? I'm almost sure that 3" is plenty for the downpipe. I wont be getting the wastegate into the exhaust but just a screamerpipe, just because i can..
12-16-2012, 07:40 AM
#36
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12-16-2012, 05:13 PM
#39
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Downpipe and exhaust will be 3" for sure. I'm still thinking of what to do with the header to turbo piping. A friend of mine is building a complete header for me so we're thinking of getting 2 pipes from the left to the right side of the engine and combine them just before the turbo, to get some more out of the venturi to spool up the turbo faster.. So many ideas.. And luckily plenty of time to work them out!
12-17-2012, 04:55 AM
#40
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Non-ideal flat-plane 4-cylinders will always have the second-order vibration, which can only be canceled with balance shafts. Internal balancing of components does not cancel this vibration. It has to due with the fact that the pistons on the upper half of the stroke are accelerating faster than the pistons at the bottom half of the stroke. This is because of the rod-angle being different on the upper half vs lower half of the stroke... If the rod was infinitely long, then there would be no second-order vibration - but obviously that cannot be the case in reality.
Downpipe and exhaust will be 3" for sure. I'm still thinking of what to do with the header to turbo piping. A friend of mine is building a complete header for me so we're thinking of getting 2 pipes from the left to the right side of the engine and combine them just before the turbo, to get some more out of the venturi to spool up the turbo faster.. So many ideas.. And luckily plenty of time to work them out!
12-17-2012, 07:40 AM
#41
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12-17-2012, 08:52 AM
#43
Three Wheelin'
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I'll try to find something but until now the camera's on the track have been in the "slower" car so you won't see him. I know that on the 6th on january he'll be racing again so i'll take my GoPro along and put it in his car (if he wants to ofcourse!)
{edit}
You can use mine!
{/edit}
12-17-2012, 08:52 AM
#44
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It is 1&4 and 2&3 actually, like on the stock headers, and it has to be fully separated including the waste gate ( preferably two). Works best with a matching divided turbine housing.