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Old 04-03-2008
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Default Shock pistons????

What is the difference in "feel" of a drilled piston compared to a factory piston?

Will it pack more because of the sharper edges around the hole??

i am after personal experinces here, not what you think it might do, ash
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Old 04-03-2008
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Well if you drill out two holes to the 'standard' holes and leave one smaller you will get more pack than a std piston. I quite like my drilled ones, the car feels quicker overall, but slightly less stable over bumps imo. Im going to try some standard ones to do a back to back test as i have been running them since southport nat.
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Old 04-03-2008
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Yeah i understand that if you leave one hole smaller it will give more pack, but i have heard people say that a drilled piston feels different to a std piston with the equivelant holes
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Old 04-03-2008
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If they are talking about a square edged entry like the AE pistons they are talking out of their behinds ....... on this planet we call Earth the laws of fluid dynamics are clearly defined .....

If your talking about comparing a bell mouthed entry to that of a square edged entry then there will be a difference, and what is more that difference will change as piston speeds change. The square edge piston will feel like it's gaining "pack" at lower piston speeds, this is to do with the transission between turbulent and laminar flow as the fluid goes through the holes.
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Old 04-03-2008
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I have wonderred this too.

Roger I think you are talking about the edge of the piston, i.e. the Losi is rounded edge vs the AE is square edge, and its an interesting & relevant arguement. But what Lee asked about is regarding the profile of the hole.

I have heard a drilled piston feels nicer than its equivalent moulded piston... the question is... why?
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Old 04-03-2008
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The holes on a moulded piston are tapered (have some draft angle on them) to make it possible to remove from the mould.

G
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Old 04-03-2008
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Quote:
Originally Posted by Northy View Post
The holes on a moulded piston are tapered (have some draft angle on them) to make it possible to remove from the mould.

G
With that in mind, you should fit pistons the same way both sides to get the same feel/effect.. That's nice and easy on say a HB or AE piston, but not so on a Losi that doesn't have any markings.
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Old 04-03-2008
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Quote:
Originally Posted by _sleigh_ View Post
With that in mind, you should fit pistons the same way both sides to get the same feel/effect.. That's nice and easy on say a HB or AE piston, but not so on a Losi that doesn't have any markings.
The Losi pistons have a circle where the ejector pin has pushed it outa the mould - I have always put them in with this facing down and never really been sure if it mattered - just me being obsessive about detail, but other than this there is no markings.
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Old 04-03-2008
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Quote:
Originally Posted by Lee View Post
Yeah i understand that if you leave one hole smaller it will give more pack, but i have heard people say that a drilled piston feels different to a std piston with the equivelant holes
Drilled ones should be more accurate size than std ones, if you drill them straight....
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Old 04-03-2008
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Quote:
Originally Posted by Chrislong View Post
The Losi pistons have a circle where the ejector pin has pushed it outa the mould - I have always put them in with this facing down and never really been sure if it mattered - just me being obsessive about detail, but other than this there is no markings.
I do the same Chris. injection point down. plus it looks better

You really dont want to start thinking about laminar and turb flows anyway, not much fun. You could then start to look at the heat losses etc and that is ZZZZZZZZZZZZZzzzzzzzzzzzzzzzzzzzzzzz.........
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Old 04-03-2008
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. plus it looks better
.
Danny you got Clear shock caps then ???
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Old 04-03-2008
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The piston holes don't need to be drafted as the material shrinkage would open the holes out. Certainly don't darft IDs on our mouldings at work.
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Old 04-03-2008
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Quote:
Originally Posted by RogerM View Post
If they are talking about a square edged entry like the AE pistons they are talking out of their behinds ....... on this planet we call Earth the laws of fluid dynamics are clearly defined .....

If your talking about comparing a bell mouthed entry to that of a square edged entry then there will be a difference, and what is more that difference will change as piston speeds change. The square edge piston will feel like it's gaining "pack" at lower piston speeds, this is to do with the transission between turbulent and laminar flow as the fluid goes through the holes.
de ja vu !!!!!
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Old 04-03-2008
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i run white pistons.....
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Old 04-03-2008
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Quote:
Originally Posted by RogerM View Post
. double post
lol Roger they were an hour apart from each other !!!!
and said word for word ...
what book was that out of ???
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Old 04-03-2008
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Danny you got Clear shock caps then ???
No, but in my head i know it looks better and a Happy Danny = A Friendly Danny
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Old 04-03-2008
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lol Roger they were an hour apart from each other !!!!
and said word for word ...
what book was that out of ???
The book of the "hung Win 2K PC"
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Old 04-03-2008
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The book of the "hung Win 2K PC"
is that an engrish book?
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Old 04-03-2008
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is that an engrish book?
It sounds like some sort of chinese gay porn
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Old 04-03-2008
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Quote:
Originally Posted by Lee View Post
It sounds like some sort of chinese gay porn

LOL .... does a little.

I meant I am running a Windows 2000 OS and Internet Explorer 6.x combination that sometimes, only really on this site, hangs a page and won't be shut down without resorting to the task manager.
It's only normally a problem with PMs, which always hang the machine and force me to end all IE sessions and restart after sending a PM.

In this case it hung, I copied the post out to notepad and then restarted my oople session and posted ..... obviously the hung pack didn't end properly and finally made it to posting!!!
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