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bertieboo

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N. Ireland

18th Jul, 2009 at 11:57:42am

I will be using a super cool 2 core and an electric fan...I currently have the standard yellow plastic fan blades...would they be worth changing to another set? I think I remember someone said that the 4 blade type fan is the best.

wil_h

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Betwix Harrogate and York

18th Jul, 2009 at 07:50:07pm

The plastic one is best, lightest and most efficient.

We use the 4 blade steel one as my brother seems to think they have a slight flow advantage at speed. I'n not convinces and will be donating it to his hillclimber and putting a plastic one on.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph



On 2nd Jan, 2013 fastcarl said:
the design shows a distinct lack of imagination,
talk about starting off with a clean sheet of paper, then not bothering to fucking draw on it,lol

On 20th Apr, 2012 Paul S said:
I'm mainly concerned about swirl in the runners caused by the tangential entry.


Mr Joshua

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Luton Bedfordshire

19th Jul, 2009 at 12:05:35am

The size and aerodynamic profile of the metal blade fans says different.

The blade of a six bladed fan has a greater blade area therefore produces more wash at a higher speed off of its trailing edge. Their rigidity reduces the amount they flex unlike the plastic ones

Own the day


stevieturbo

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Northern Ireland

19th Jul, 2009 at 12:44:59pm

I tried a steel 4 blade I think it was....

Holy fuck they make some noise at 8000rpm...cant imagine how much power they are sapping too.


Plastic FTW.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will


Mr Joshua

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Luton Bedfordshire

20th Jul, 2009 at 10:01:18am

I can spare the odd horse or two. *tongue*

Own the day


Ben H

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3329 Posts
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Melton Mowbray, Pie Country

20th Jul, 2009 at 01:10:58pm

The problem with the 11 blade fan is that it is great at low speed and tickover, but after that it just gets in the way. The best fan is the one that works for you. The best solution I wold say is an electric fan and totally ditch the mechanical fan. Why this has not been done on the race car I don't know?

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

wil_h

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Betwix Harrogate and York

20th Jul, 2009 at 01:17:06pm




On 19th Jul, 2009 Mr Joshua said:
The size and aerodynamic profile of the metal blade fans says different.

The blade of a six bladed fan has a greater blade area therefore produces more wash at a higher speed off of its trailing edge. Their rigidity reduces the amount they flex unlike the plastic ones


I'm not sure what you are saying here, it may just me being stupid? I think what Ben says is right, i.e. the 4 blade is better at speed and the plastic one at tickover. (in relation to how much air it moves)

As I see it, tickover is important as we spent a lot of time doing it, using an electric fan would flatten my battery quite quickly. Once at speed there is enough airflow to not need the fan at all, so the one with the least drag at speed would be the best.

thinking about it, Ben is using a front rad on his hillclimber, so the 4-blade can go on the wall!.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph



On 2nd Jan, 2013 fastcarl said:
the design shows a distinct lack of imagination,
talk about starting off with a clean sheet of paper, then not bothering to fucking draw on it,lol

On 20th Apr, 2012 Paul S said:
I'm mainly concerned about swirl in the runners caused by the tangential entry.


PaulH

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Dublin Ireland

20th Jul, 2009 at 02:20:01pm

I tryed runing just an eletric fan one of the race cars and it over heated put the steel 4 blade back on and hay presto no over heat problams :)

On 17th Feb, 2009 Rob H said:
I find the easiest way is to super glue the bolt to the end of one of my fingers.

______________________________________________________

CR#

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140 Posts
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Cape Town, South Africa

20th Jul, 2009 at 03:30:02pm

I think in conjunction with the electric fan, one needs to go with an electric high flow water pump if you are going to ditch the mech fan altogether to get adequate cooling while stationary. Really been interested in doing that myself.

Neil8p

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South Yorkshire

20th Jul, 2009 at 04:00:34pm




On 20th Jul, 2009 CR# said:
I think in conjunction with the electric fan, one needs to go with an electric high flow water pump if you are going to ditch the mech fan altogether to get adequate cooling while stationary. Really been interested in doing that myself.


Is this with a side mounted radiator? The mpi minis have a standard water pump and no mechanical fan, but they do have a small alloy rad at the front with an electric fan.

Mr Joshua

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Luton Bedfordshire

20th Jul, 2009 at 05:16:27pm

Wil-h the fan blades are basicaly aerofoil saped due to the greater surface area of the metal blade fans the air is traveling faster off of the trailing edge, much more than the plastic ones. As for drag, how many blades on the plastic fan? Its going to be much of a muchness.

Own the day


wil_h

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Betwix Harrogate and York

20th Jul, 2009 at 05:55:04pm

So use the plastic one as it's lightest.

Neil - You are right, despite what I said above, the side-mount rad is not very well positioned for airflow, compared to a front mount. So although the permanent fan could in theory be removed, in Pauls experience it is needed all the time to direct air.

I think if you wanted to remove it then some clever ducting would be needed.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph



On 2nd Jan, 2013 fastcarl said:
the design shows a distinct lack of imagination,
talk about starting off with a clean sheet of paper, then not bothering to fucking draw on it,lol

On 20th Apr, 2012 Paul S said:
I'm mainly concerned about swirl in the runners caused by the tangential entry.


fab

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1497 Posts
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Parisien Turbo Expert

Paris\' suburb

20th Jul, 2009 at 06:46:57pm

don't bother
the 2 core rad, will cool just anything.
just put an elctric fan over your std platic if you're stucking in the traffic jam.
mine come on after one hour stuck in Paris traffic, (this mean one hour to make about 2 or three miles)

Fabrice

On 18th Jul, 2009 bertieboo said:
I will be using a super cool 2 core and an electric fan...I currently have the standard yellow plastic fan blades...would they be worth changing to another set? I think I remember someone said that the 4 blade type fan is the best.

Turbo Shed

1303 Posts
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Epsom, Surrey

21st Jul, 2009 at 08:15:54am

i use a 2 core rad with an electric fan under the wing, i dumped the mechanical fan and have no cooling problems

philc

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bromsgrove

25th Jul, 2009 at 08:48:28am

i have a four bladed fan, 3 core rad and never have had an issue, i think vizard covers this in his yellow book
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