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Old 24th March 2009, 21:56   #16
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Check the eleventy trillion forums which deal with real tuners running real rides and see beyond the marketing.
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Old 24th March 2009, 21:58   #17
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this product has come into the market recently.
i dont just read and believe. It is installed in a friends car. forums are not 100% accurate.

p.s. dint know so many forums existed.

since you love google try wikipedia I dont think they "market".

Supercharger - Wikipedia, the free encyclopedia

Last edited by iceman91 : 24th March 2009 at 22:09.
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Old 24th March 2009, 22:09   #18
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Quote:
Originally Posted by iceman91 View Post
check the website of the brand we were discussing clearly states 98%
Amit saar getting a mechanical item to run at 98% efficiency is next to impossible. It would need frictionless bearings which would cost the earth and their own supply of compressed air to run them efficiently.

Since when did you start believing in marketing talk?

Edit: Which portion of the link are you referring to? I went through it and could not find what you are referring to.

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Old 24th March 2009, 22:09   #19
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Quote:
Originally Posted by iceman91 View Post
this product has come into the market recently.
i dont just read and believe. It is installed in a friends car. forums are not 100% accurate.

p.s. dint kniw so many forums existed.
Just curious as to how you guys verified the compressor efficiency (assuming that's what you're refering to, not mechanical efficiency). I've looked at doing this with a turbo-compressor and the kind of instrumentation required is more expensive than what I'm willing to spend right now. And I cant really do anything with the data. You get what you get as far as compressor efficiency is concerned.

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Old 24th March 2009, 22:10   #20
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vikram check the link.

I dont understand why it is so hard to believe. hence read the link article. WE MIGHT BE DISCUSSING 2 DIFFERENT THINGS.

STraight from the link:
"For any given roots blower running under given conditions, a single point will fall on the map. This point will rise with increasing boost and will move to the right with increasing blower speed. It can be seen that, at moderate speed and low boost, the efficiency can be over 90%. This is the area in which roots blowers were originally intended to operate, and they are very good at it.

Boost is given in terms of pressure ratio, which is the ratio of absolute air pressure before the blower to the absolute air pressure after compression by the blower. If no boost is present, the pressure ratio will be 1.0 (meaning 1:1), as the outlet pressure equals the inlet pressure. Fifteen psi boost is marked for reference (slightly above a pressure ratio of 2.0 compared to atmospheric pressure). At 15 psi boost, roots blowers hover between 50% to 58%. Replacing a smaller blower with a larger blower moves the point to the left. In most cases, as the map shows, this will move it into higher efficiency areas on the left as the smaller blower likely will have been running fast on the right of the chart. Usually, using a larger blower and running it slower to achieve the same boost will give an increase in compressor efficiency
"

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Old 24th March 2009, 22:14   #21
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ananth was done in a tuning house in malaysia
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Old 24th March 2009, 22:19   #22
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Quote:
Originally Posted by iceman91 View Post
vikram check the link.

I dont understand why it is so hard to believe. hence read the link article. WE MIGHT BE DISCUSSING 2 DIFFERENT THINGS.

STraight from the link:
"For any given roots blower running under given conditions, a single point will fall on the map. This point will rise with increasing boost and will move to the right with increasing blower speed. It can be seen that, at moderate speed and low boost, the efficiency can be over 90%. This is the area in which roots blowers were originally intended to operate, and they are very good at it.

Boost is given in terms of pressure ratio, which is the ratio of absolute air pressure before the blower to the absolute air pressure after compression by the blower. If no boost is present, the pressure ratio will be 1.0 (meaning 1:1), as the outlet pressure equals the inlet pressure. Fifteen psi boost is marked for reference (slightly above a pressure ratio of 2.0 compared to atmospheric pressure). At 15 psi boost, roots blowers hover between 50% to 58%. Replacing a smaller blower with a larger blower moves the point to the left. In most cases, as the map shows, this will move it into higher efficiency areas on the left as the smaller blower likely will have been running fast on the right of the chart. Usually, using a larger blower and running it slower to achieve the same boost will give an increase in compressor efficiency
"
The first highlighted point is correct with moderate speed & low boost being the operative words. The second one is really vague. It does not say by how much the efficiency will increase.

Edit: I saw the graph. But to run a bigger blower at lower speeds to get 90% efficiency would mean a really really big blower.

Last edited by vikram_d : 24th March 2009 at 22:24.
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Old 24th March 2009, 22:22   #23
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I will send you the pic and graph will be clear


p.s. sorry was not shouting caps lock was on
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Old 24th March 2009, 22:26   #24
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Quote:
Originally Posted by iceman91 View Post
At 15 psi boost, roots blowers hover between 50% to 58%. Replacing a smaller blower with a larger blower moves the point to the left. In most cases, as the map shows, this will move it into higher efficiency areas on the left as the smaller blower likely will have been running fast on the right of the chart. Usually, using a larger blower and running it slower to achieve the same boost will give an increase in compressor efficiency
"
1st highlight: Means a bigger blower at lower rpm for the same boost but efficiency still drops to 55-58%.

2nd highlight: is theoretical depending on the sizing of the blower and its efficiency map

Hence the bigger Supercharger would be more effective comparatively.
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Old 24th March 2009, 22:31   #25
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Still lagging behind, don't know which website. JR/Eaton/HKS? Can you link please?
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Old 24th March 2009, 22:56   #26
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@v1p3r - The wikipedia link on top of the page.
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Old 25th March 2009, 00:08   #27
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Interesting about the 98%, i didnt think if they were that efficient - if they are. When i meant negligable earlier is - How much did the Supercharger increase the BHP in comparision to the loss?
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Old 25th March 2009, 00:45   #28
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Samir,
Sorry went off on a tangent.
basically today turbo or supercharge both work equally good enough. so losses are almost similar when comparing to power gain
Main criteria to decide between the two being:
1. car in question
2. MOney
3.application of car
4. Tuners ability/preference
5.owners preference
6. availibilty of goods/spares at location.

Last edited by iceman91 : 25th March 2009 at 00:47.
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Old 25th March 2009, 04:08   #29
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Quote:
Originally Posted by iceman91 View Post
.
basically today turbo or supercharge both work equally good enough.
my real world experience says no. At the OEM level, I'd agree. Not for an enthusiast/aftermarket type situation. From a purely practical standpoint, here's why:

1) Superchargers are typically much more expensive to both buy and keep running.

Example: I put together my turbo system for less than $1000 using various used parts. No custom machining involved. A USED supercharger would probably cost as much a brand new turbo, plus there is a lot of precision fabrication involved. Compare prices of equivalent kits out there (which will get you to the same power level) and come to your own conclusions.

2) You cant change or control the boost without investing in a new set of belt and pulley. More cost there. With a turbo its a simple matter of adding a wastegate bleed valve aka MBC.

3) Going above a certain power level presents a lot of challenges. You usually trade off throttle response in a situation where you run such a high boost that a large intercooler is almost mandated. In this case you might have been better off running a turbo in the first place. Fooling around with water injection might help to some degree but again, you might have been better off running a turbo in the first place.

4) Turbochargers are typically more flexible. You can underdrive a supercharger only so much: they lose efficiency very quickly once they are past their optimum window. Compare a compressor map back to back, then see where the efficiencies stand over an engine's typical operating range (pressure ratio vs flow). this is why peak efficiency numbers are almost irrelevant.
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Old 25th March 2009, 09:21   #30
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see I am not here to argue which is better. This debate has been goin on for a while and still go on. My above post still holds good for your points.
The only thing I have to say is superchargers are not as bad as they are portrayed.

cheers
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