Why does the throttle plate look like it does

Road-race engines and ancillaries - general discussion
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stooges
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Why does the throttle plate look like it does

Post by stooges » Fri Dec 21, 2012 11:56 am

...on a carburetor? Should it not look like "valve" with a small diameter and increasing diameter with full throttle?

From the conclusion by DEEPAK RANJAN BHOLA (1) at page 34 (Link) where I guess Deepak found that the pressure and flow will be "disturbed" if a throttle plate change angles, I guess that a change of pressure and flow of air into the carburetor due to the "throttle plate angels" also could effect the performance of a engine, especially during “full throttle".

...but with a “mechanic valve throttle” (with a small diameter (at low speed (less air)) and large diameter (at full throttle (lot of air)) you could perhaps decrease that disturbed flow and pressure into the carburetor and get more performance out of the engine especially during “full throttle"?

….........what do I miss?

...Is there or has it been any research of different throttle plates? and if it has been, were there any conclusions?

Reference:
(1)
CFD ANALYSIS OF FLOW THROUGH VENTURI OF A CARBURETOR
National Institute of Technology Rourkela, India.
By DEEPAK RANJAN BHOLA (2011)

Link:
http://ethesis.nitrkl.ac.in/2296/1/final_report.pdf
Last edited by stooges on Sat Dec 22, 2012 12:00 am, edited 18 times in total.

Guy Croft
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Re: Why does the throttle plate look like it does

Post by Guy Croft » Fri Dec 21, 2012 1:49 pm

Your link is approved Ulf

However if your question refers to something in the pdf research you need to take time to explain to readers here (who may not have time to read the document). Do not quote from the research directly but you can refer to it like this

"at page 2 line XXXX the researcher suggests that...."

and make the point in your own words.

This is legitimate discussion. Copying anything from his research and putting it here is coyright enfringement and not!

G
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nabihelosta
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Re: Why does the throttle plate look like it does

Post by nabihelosta » Sat Dec 22, 2012 11:36 am

Do you mean this?

If yes, BMW Motorsports did this in mid-eighties on the E30 M3.
There is another variation also, called "barrel-type throttle valve", which gives even more control over the entire throttle opening range.

ONLY with Guy's permission, I will take some time to post a review here with useful links.

Thank you

N
Attachments
slides-8.jpg
BMW slide-type DTM throttles.
slides-8.jpg (152.14 KiB) Viewed 3436 times
slides-7.jpg
Full throttle, no restriction.
slides-7.jpg (161.58 KiB) Viewed 3436 times
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stooges
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Re: Why does the throttle plate look like it does

Post by stooges » Sat Dec 22, 2012 1:28 pm

nabihelosta wrote:Do you mean this?

If yes, BMW Motorsports did this in mid-eighties on the E30 M3.
There is another variation also, called "barrel-type throttle valve", which gives even more control over the entire throttle opening range.

ONLY with Guy's permission, I will take some time to post a review here with useful links.

Thank you

N
Thanks:-)
Do you know if BMW found any advantage of their system?
However, my thought was something like a aperture in a camera.

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Re: Why does the throttle plate look like it does

Post by Guy Croft » Sat Dec 22, 2012 3:36 pm

There have been many variants of control device for intakes over the years.

The fundamental thing to remember is that a competition engine - ideally, will see zero obstruction at full throttle and, again, ideally - when the pedal is pressed - the thing should - maybe - go to 'zero intrusion' instantly. Which is impossible of course, it will always take a finite time.

When I worked with Hart F1 he was using barrel throttles (if you look at Titan Motorsport's website you can examples). Other teams however were using butterfly throttle plates. And interestingly I know that if you inject onto the throttle plate (if your engine has fuel injection) the power goes up - simply because the turbulence helps still further to mix the gasoline and air.


GC
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nabihelosta
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Re: Why does the throttle plate look like it does

Post by nabihelosta » Sun Dec 23, 2012 7:48 am

And interestingly I know that if you inject onto the throttle plate (if your engine has fuel injection) the power goes up - simply because the turbulence helps still further to mix the gasoline and air.
Nice point here Guy, but we should remember that almost every engine with ITBs, has the injectors located AFTER the throttle valve, in the air path. Except for very new WRC engines (Mini, Ford, Citroen, Toyota, Skoda...) S2000 NA engines, which have their injectors located far upstream in the air horns! Interesting setup.

As for (Stooges) question, BMW really experience a near zero gain with this setup. Say the DTM car has a 2.5L NA engine putting 365bhp at the time, this setup never pushed one single horse on the dyno, but believed to make the torque curve broader, and gave them some fraction of a second on the track. Engineers at the time described it as "One last hopeless shot to cope with the Mercedes Benz 190 and the Audi competitors, as the competition was fierce and the BMW engine was outdated". Though, they won that season, thanks to the awesome M3 E30 chassis and balance :)

Thank you

Nabih
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Guy Croft
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Re: Why does the throttle plate look like it does

Post by Guy Croft » Sun Dec 23, 2012 12:39 pm

MODEL POST!

good work as ever Nabih!

G
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stooges
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Re: Why does the throttle plate look like it does

Post by stooges » Mon Dec 24, 2012 8:52 am

nabihelosta wrote:
And interestingly I know that if you inject onto the throttle plate (if your engine has fuel injection) the power goes up - simply because the turbulence helps still further to mix the gasoline and air.
Nice point here Guy, but we should remember that almost every engine with ITBs, has the injectors located AFTER the throttle valve, in the air path. Except for very new WRC engines (Mini, Ford, Citroen, Toyota, Skoda...) S2000 NA engines, which have their injectors located far upstream in the air horns! Interesting setup.

As for (Stooges) question, BMW really experience a near zero gain with this setup. Say the DTM car has a 2.5L NA engine putting 365bhp at the time, this setup never pushed one single horse on the dyno, but believed to make the torque curve broader, and gave them some fraction of a second on the track. Engineers at the time described it as "One last hopeless shot to cope with the Mercedes Benz 190 and the Audi competitors, as the competition was fierce and the BMW engine was outdated". Though, they won that season, thanks to the awesome M3 E30 chassis and balance :)

Thank you

Nabih
Thanks again:-)

nabihelosta
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Re: Why does the throttle plate look like it does

Post by nabihelosta » Mon Dec 24, 2012 11:57 am

No need..

It's good to know about virtually everything.. what we are missing and what we're not!

On an other side of the discussion, as long as we're talking air induction, it would be interesting to discuss and share the newest technology that Fiat themselves introduced last year, in their new series of engines called "Twin Air". There is absolutely no throttle valve of any kind. The quantity of air entering the chambers, is exclusively monitored by some kind of electro-hydraulic valve lifters, controlled by the ECU, which can vary the valve lift from 0 to 11mm, infinitely at any given time. Genius eh?

N
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Uros Piperski
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Re: Why does the throttle plate look like it does

Post by Uros Piperski » Mon Dec 24, 2012 8:43 pm

Didn't Renault use electro-hydraulic control of the valves in the '90s F1?

Guy Croft
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Re: Why does the throttle plate look like it does

Post by Guy Croft » Tue Dec 25, 2012 1:20 am

http://www.carnetdevol.org/reportages-b ... um-va.html

http://www.google.co.uk/imgres?q=zeppel ... ,s:0,i:115

'Twin Air', nothing new here, yes, sorry to rain on the parade, but essentially an idea that has been around for decades that any good automotive engineer could dream up in the bathtub. It is a system I suggested at university in 1978 but was laughed at by the lecturer and quite right too for in those far-off days that was an impossible idea, I did my degree on a slide rule. These things only become reality when the power to sign the cheque and the foresight to believe in them are from one and the same person, and Fiat have always been fantastic at innovation, probably ahead of anyone..

Do have a look at Maybach - if I am not mistaken the world's 1st multivalve engine - 3 valves. To be honest I should know but I cannot remember, I think she had two exhaust valves per cylinder. It took me ages to find the right links, the photo may be the wrong one but I am 99% certain I am right about the world's first multivalve...

If you know little about Count Zeppelin it is truly fascinating story - exploring the extreme limits of engineering in the most innovative ways possible - for its day, in my view, equivalent to - perhaps even more impressive than - putting a man in space for the first time...


G
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TomLouwrier
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Re: Why does the throttle plate look like it does

Post by TomLouwrier » Wed Dec 26, 2012 3:32 pm

Don't know that much about Maybach, except their mighty v12's in the WW2 panzers.
I can however name the Peugeot Grand Prix car from 1912: bronze head for good heat transfer, twin cams and 4 valves per cylinder. Must have been the mother of them all, surely?

regards,
Tom
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