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Posted
Tuesday, Jul 1st 7:29am [Edit] [Quote] [IMS] [View car] |
Post nr. 23
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Anyone have before and after info about this? I have driven some customers cars that spent WAY to much $$$ at Dinan on 325i's and not been impresed including extrude hone and I was thinking the bang for the buck may not be so good. It costs like $450. direct! |
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Posted
Tuesday, Jul 1st 7:40am [Edit] [Quote] [IMS] [View car] |
Post nr. 70
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I have heard the same, not worth the 500.00. It is like one of those last ditch measures to eek out the little bit of HP that may be hiding in your engine. But then if you are doing this you may as well get a larger displacement engine.
Never understood it. If turboed engines do not benefit from this process then why did Dinan use this manifold on the turbo e28? Kind of a screen door on an airplane effect. Dinan has been questioned on a lot of their "engineering". Some parts work others do not. Like the 22mm rear sway I installed this weekend to complement the 25mm front one on the e28. Now that does work. Some code breakers have read the Hexadecimal they have used for their brand of chips and have said the "modifications" are modest and not at all extreme. Let me pass the soapbox... |
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Posted
Tuesday, Jul 1st 12:07pm [Edit] [Quote] [IMS] [View car] |
Post nr. 107
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Forgive my my ignorance, but what does "Extrude Hone" mean? I know extruding, I know honing, but not what the two together refer to  |
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Posted
Tuesday, Jul 1st 6:00pm [Edit] [Quote] [IMS] [View car] |
Post nr. 71
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Tri, the extrudehone process is a patented process of polishing intake/exhaust manifolds heads and anything else that air flows through with a putty like substance with abrasives in it. They mount the part to a machine that pushes this stuff under pressure and as it flows through the passages it abrades the pieces and removes flash, irregularities and polishes the piece almost if not close to a mirror polish.
The theory and practice is that this putty can squeeze itself into places that a die grinder can not.
Of course with the lesson in fluid dynamics provided by Nic last week it is hard to say that this process is of any benefit to the BMW engine. Thus leading to question Dinan's use of this technology in an engine that does not respond well to intake polishing. |
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Posted
Tuesday, Jul 1st 7:50pm [Edit] [Quote] [IMS] [View car] |
Post nr. 98
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It seems to me that the extrude honed process is more a of "keeping up with the Jone's" kind of thing. In all honesty there isn't much benefit to the process because we aren't dealing with fast moving gases. Engine speeds get big and they flow lots of air. Even so, in a fluid dynamics arena these things don't flow THAT much air. I wish I could show you guys some movies I saw in my class. Very counterintuitive stuff. Working fluids seperating from walls around hard corners. Turbulent flows traveling much faster then laminar flows. Very neat stuff.
I'm pretty sure it all started with Big Block Bob showing his neighbor Small Block Steve his extrude honed manifold for his 454 with a weiand blower running 40 PSI. Steve was in awe and went to blow 500 bucks on doing the manifold on his V6 camaro. He couldn't feel a difference so he told everyone he could so they wouldn't make fun of him. In a drag motor like Big Blcok Bob's the extrude honed process would make a noticeable difference. But in a stock motor you'd just be wasting your money. |
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Posted
Wednesday, Jul 2nd 5:44am [Edit] [Quote] [IMS] [View car] |
Post nr. 92
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So is that a yes on extrude honing for forced air setup's?
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Posted
Wednesday, Jul 2nd 10:39pm [Edit] [Quote] [IMS] [View car] |
Post nr. 103
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well a streetable turbo set isn't really "extreme amounts of air flow". You'd have to calculate the reynold's number through out the rpm range and see where the fluid is (yes we call air a fluid in this case). If you read my prevous post carefully you'd see that Big Block Bob is running a weiand blower with 40 lbs of boost. THAT's extreme flow. Especially since he's making that kind of pressure on 8 cylinders.
Turbo charging usually over comes a great deal of the imperfections in the intake track. Rough surfaces and mis-matched ports don't really make that big of a difference. Since you're putting a force on the air it moves rather easily through tough spaces and turns. Extrude honing is usually used for squeaking as much HP out of a motor as you can. About all that would happen if you extrude honed your 5 psi setup is that you can tell your friends it's extrude honed. There would be no seat of the pants feeling at all. |
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Posted
Thursday, Jul 3rd 12:12am [Edit] [Quote] [IMS] [View car] |
Post nr. 97
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OK so overall
extrude honing = big waste of money
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