Velocity stacks
Orig. Posting Date | User Name | Edit Date |
Apr 1, 2015 03:58PM | h_lankford | |
Apr 1, 2015 02:19PM | Spitz | |
Apr 1, 2015 01:20PM | DRMINI | |
Apr 1, 2015 12:52PM | h_lankford | |
Apr 1, 2015 10:41AM | wilhite | |
Apr 1, 2015 04:40AM | Dan Moffet | |
Apr 1, 2015 01:32AM | DRMINI | |
Mar 31, 2015 09:57PM | hotwheels_mini | |
Mar 31, 2015 08:46PM | DRMINI | Edited: Mar 31, 2015 09:45PM |
Mar 31, 2015 08:05PM | Shrimps | |
Mar 31, 2015 06:57PM | 1963SV2 | |
Mar 31, 2015 06:52PM | Spitz | Edited: Mar 31, 2015 07:22PM |
Mar 31, 2015 06:14PM | MtyMous | |
Mar 31, 2015 05:52PM | Air2air | |
Mar 31, 2015 05:38PM | Hunter2 | |
Mar 31, 2015 05:08PM | Spitz |
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I would think flared end of a Ram pipe and a stub stack might be analogous - effects on smoothing airflow.
then there is that "stand-off" effect . kinda sorta related
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Vizards chapter tends to deal more with Ram Pipes, length of them , and shape of the end of the Ram Pipe.
"Everybody should own a MINI at some point, or you are incomplete as a human being" - James May
"WET COOPER", Partsguy1 (Terry Snell of Penticton BC ) - Could you send the money for the unpaid parts and court fees.
Ordered so by a Judge
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On a Weber or Dellorto carb it helps low speed & midrange mixture control. My 1360 with 45 Dellorto (36mm chokes), a Russell Eng 282 cam and 1.5 rockers will pull clean from 40kmh in 4th gear on part throttle.
I'm sure it adds HP too but I do not have figures with/without.
Kevin G
1360 power- Morris 1300 auto block, S crank & rods, Russell Engineering RE282 sprint cam, over 125HP at crank, 86.6HP at the wheels @7000+.
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there have only been a few comments about the original question - does it help performance ?
I am too lazy to get out my Vizard, but I imagine most of the gain is for people trying to scratch out that last 1 or 2 hp at top end or racing power band, etc, not your average seat of the pants around town wiz bang effect. Something like an extra 2 cfm airflow gets you about 1 extra one hp, I think.
Am I correct?
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I remember reading somewhere (Vizard or Calver, I think) that anything more than about 1/2" in depth did not provide any further benefit to a Mini motor. The gist of it is that the radiused edge eliminates the turbulence at the sharp 90 degree edge.
.
"Hang on a minute lads....I've got a great idea."
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Hello Dr Mini.
Do you have these (Weber 45 stacks) for sale? I have the RAMFLO filter just like the one in the picture. My email is in my profile. Thanks.
email sent.
Kevin G
1360 power- Morris 1300 auto block, S crank & rods, Russell Engineering RE282 sprint cam, over 125HP at crank, 86.6HP at the wheels @7000+.
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Hello Dr Mini.
Do you have these (Weber 45 stacks) for sale? I have the RAMFLO filter just like the one in the picture. My email is in my profile. Thanks.
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According to Russell Engineering, anything with a 3mm or bigger radius inside works.
But I believe if made too thick and the filter has a flat lid, they can restrict flow a bit.
I machine thin ones from billet alloy for K&N or Ramflo filters, mine have a 5mm radius inside.
[edit] Weber Dellorto ones too- 40, 42, 45mm.
Kevin G
1360 power- Morris 1300 auto block, S crank & rods, Russell Engineering RE282 sprint cam, over 125HP at crank, 86.6HP at the wheels @7000+.
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They'll probably work best if you also make the vrooooooooom noise with your mouth when driving down the road.
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Vizard has a section in his books on ram tubes/stubstacks etc...
Cheers, Ian
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Thanks for looking Mty.
They're not overly heavy....solid aluminum. They're obviously from something else and made to fit the HS2s, but very nicely adapted. The hold down bolt holes have a nice shoulder machined in for a smaller hex head bolt.
I'm sure they'll help more than hurt I'm going to fit them to my 1275 Midget
"Everybody should own a MINI at some point, or you are incomplete as a human being" - James May
"WET COOPER", Partsguy1 (Terry Snell of Penticton BC ) - Could you send the money for the unpaid parts and court fees.
Ordered so by a Judge
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Just to be clear up front, I'm definitely not an expert on these things, and I've not completed a degree on fluid dynamics... but there is a LOT of theory out there on air smoothing and increasing velocity. I found a website once (literally just spent 30 minutes trying to find it for you) that explained in detail (and with actual test results) the effects of different stacks on a single carb. It also explained the difference that the tube runner made. I really wish I could find it because it had a LOT of good info.
All that aside, I think there is a good amount of benefit with these just for air smoothing, but It doesn't seem like it is the greatest design. The dimples on the surface should be buffed or sanded smooth and the holes for the bolts likely have an impact and introduce some unwanted turblance.
This is my unqualified opinion. But they sure do look cool. Are they heavy? Looks like a solid cast piece.
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I remember reading a bit about them and the effect is along the power band, a bit like a cam. A short or long stack moves beneficial resonance down low or up high in the rev range.
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Haven't seen items as "massaged" as those before, but I did put a similar item into the HIF air filter housing to increase the velocity of air entering the semi-down draught SU.
My install did not require the "shaping" of those in your pictures, but did require some as the carb intake is off centre in the filter housing.
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I spent some time getting a car running today.
It's a small bore....undetermined yet if 850 or 998 ( no tag ), or possibly 1098 I suppose.
Anyway, I had to swap the carbs out as both jet tubes were leaking ( got the car running btw )
The car had these nice proper K&N filters and chrome pancakes.....hidden underneath were these stub stacks.
I doubt they are proper HS2 equip., but they look cleverly done.
What performance gains can one expect from these? They are about 3/4" tall.
"Everybody should own a MINI at some point, or you are incomplete as a human being" - James May
"WET COOPER", Partsguy1 (Terry Snell of Penticton BC ) - Could you send the money for the unpaid parts and court fees.
Ordered so by a Judge