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Progessive throttle opening --Please chime in--

Okay, I'm having this thought about the cable guide on the the throttle body. What if it had a raduis that wasn't consistent throughout it's range of motion. What if it could open the throttle plate a smaller percentage during the initial application of your big right foot and then as you bury it deeper it would increase the rate of opening?

Sorry if I'm confusing anyone, as I don't necessarily understand it either.

I'm imagining an egg shaped cable guide (on the TB) where the "tip" of the egg will point down, and as you rolled the throttle open, and the radius of the guide changed, the rate at which the throttle plate opened in relation to the pedal being depressed would increase progressively. Or maybe it would decrease, I don't have the best grasp on what I'm actually thinking about. But all of this comes from a TB that I saw that came off of a honda. It got me wondering about maybe a gain in low throttle efficiency for highway cruising and the like. In our cars, there becomes a point in the throttle where the turbo starts to take over anyway, which accelerates the car rapidly even if you don't bury it. I think it would be interesting to use the first, say, 65% of foot travel to control the first 50% of plate travel, and the last 35% to control the last 50%.

Am I making any sense? Any input?
 

curtis

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May 4, 2003
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Clarksville TN
Yes. Makes sense and alot of cars are this way and would be easy to trim and tack weld to the factory unit. I have Ford dual butterfly I may use and it cracks open the first one for about 25% before the second one starts to open then by the time both are 100% they equal out.
 
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Is there any real advantage that could be proven with this type of setup? I sure there is, if alot of cars are this way already, but what would it be?
 

pauleyman

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Feb 27, 2011
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Progressive throttle is likely more for driveability than anything. Doesn't sound like any performance gains could be made. NVH is a serious topic in design. Progressive throttle might fit in there somewhere.
 

At least in our cars, and any other with a throttle shaft mounted TPS, the ecu wouldn't ever know anything changed by going to a setup like this. The more I think about it, seems like the return would be zero on performance, but it might be a personal preference thing as to whether someone would like it. No measurable gains though.
 

rdomeck

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Indianapolis, In.
944 Porsche's use this from the factory from 1984 on. It is for drivability. I drove a few when I was a Porsche mechanic that didn't have them installed and a lot that did.....I couldn't really tell a difference. Your foot can generally push faster than the engine can spool up anyway! Sometimes you can find a 944 in the salvage yard or

click

That would be a lot easier than making one and the throttle shaft size may be the same size if not it's got to be close. You could easily drill larger or bushing it down in size.
 

grocery_getter

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Jun 20, 2004
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Kent - industrial suburbs of Seattle, WA
The Q45 TB on my gvr4 is progressive as well. Its to aid drivability with a big throttle plate. My bigger throttle plate progressive sprung Q45 TB is easier to drive around the parking lot speed than the smaller plate single sprung Mustang TB. It just add more resolution to the lower range of the operating angles.
 

Sometimes when you're me, you let your mind get ahead of itself.

The stock setup is already progressive.
 

onesickcrx

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Most motor cycles have egg shaped bell cranks /ubbthreads/images/graemlins/crazy.gif
 

Nabeel

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Cyclone Intake Manifold
 

fuel

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Toronto, ON, Canada
Quoting galant1517:
Sometimes when you're me, you let your mind get ahead of itself.

The stock setup is already progressive.



I was just going to chime in here and say that the stock setup is already progressive, though not to a large degree.
 
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