Restrictor Tube Discussion

First testing done!

Smokem said:
Part being sent this week to be tested will be used on a Duramax.
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Well this should answer alot of questions for you guys. Got a package from Smokem and got a DMax on the dyno today and did some testing. The truck for the testing was Joe Hill's LLy Fleece built DMax. Ran all the testing on the same tune and it was a surprising difference in power vs. the straight 3.0 cover. Todate Curt Haisley's Clipped 3.0 charger has been the best clipped charger at 816hpish for a reference point. Next week we will have Justin Jones's CR back on the dyno so we will do the same testing on it to see what it does to it and I will post the differences. If you really want to cut the power back it needs to be a solid ring 2" long with no cone on either side and 2.600" diameter. That should keep it around 700hp period. You will then have to watch the guys with holes in the bottom of the boots and comp cover or them not being installed properly...:hehe: Either way this idea works and would definitley limit the power being produced. Then we can argue about something else, lol.$.02
 

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Thanks Mark, keep up the good work. Cone end open to atmosphere, I was looking for 750-800hp.
 
I talked to some tractor guys about this and they said that have done stuff like in the past. But they use the out side dia. Like on a charge pipe use what ever size pipe you want but a certain length had to be say 2" dont matter so much where in a charge pipe. So you could move it on diffent brand truck so it would be easy to tech.
 
So how much (% will suffice since I'm sure you aren't going to divulge numbers) did it drop?!?!

Just one style of restrictor tested?

What "tests" were run? I'm guessing effect of position of restrictor in relation to inlet of charger?


Very interesting.
 
The numbers are on the dyno sheet. Inverting the direction of the restrictor allowed both versions to be tested.
 
So, this is one one turbo? this proves nothing. Of course it reduced power, that is why it is used on la mans cars. but does it even up the field of every make and model of turbo? not every puller runs the same charger? You need to try this on about 15 turbos and see if it keeps the power range to the same amount on every charger. If everyone had the same turbo, we wouldnt have to have any type of restricter.
 
So if i read this right, curts open cover to clipped(2.6 or 2.8?) lost 110 hp. Then the restrictor with cone (similar to a race cover taper i assume) out dropped it to 800hp for a loss of 16ish hp? Thats not very much. Then a true straight bore dropped it almost a 100hp? Thats a significant drop and sounds like it could hold the power back.

How would a protruded bore compare to the clipped i wonder?
 
I think the first one is no restrictor clipped wheel
then the other 2 are with the restrictor, one with the taper facing the turbo, one with it away.
 
RAWdiesel said:
So, this is one one turbo? this proves nothing. Of course it reduced power, that is why it is used on la mans cars. but does it even up the field of every make and model of turbo? not every puller runs the same charger? You need to try this on about 15 turbos and see if it keeps the power range to the same amount on every charger. If everyone had the same turbo, we wouldnt have to have any type of restricter.
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It limits the amount of air flow to the wheel, this takes the inducer size out of the equation. As Mark stated, more testing will be done, I am aware it is easy to be a skeptic when you don't grasp the concept.

ILLINOISRAM said:
So if i read this right, curts open cover to clipped(2.6 or 2.8?) lost 110 hp. Then the restrictor with cone (similar to a race cover taper i assume) out dropped it to 800hp for a loss of 16ish hp? Thats not very much. Then a true straight bore dropped it almost a 100hp? Thats a significant drop and sounds like it could hold the power back.

How would a protruded bore compare to the clipped i wonder?
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The protrusion charger made 816hp, 3.0" wheel with no restriction made 927hp, with the taper to atmosphere it made 799hp, with the step to atmosphere it made 708hp.
 
Concept is understood. You haven't proved that this restricter will even up the power between different turbos and different setups.
 
RAWdiesel said:
Concept is understood. You haven't proved that this restricter will even up the power between different turbos and different setups.
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The part was just received this week? We will continue to keep testing it. But the fact remains, some people are working on this, and some are just saying it won't work. Your arguement might hold more water if you spelled either restrictor or Le Mans correctly also.
 
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JJs truck should b interesting he has had about every charger on that truck at one time even a protrusion charger that would pass the 2011 tri state rules
 
Wow, 219hp drop.... Now if that trend stayed, putting a restrictor in front of a 2.6 protrusion charger, would roughly yield a 600-700whp class.

Hmm, that's def pulling the reigns back!


As for questions of equalizing the trucks, I don't really see where it would if that trend for reduction in power stayed consistent/linear then the guy that was already 100hp short, will still be 100hp short.

So the outcome may be less drivetrain carnage and that's about it. It could still be a big hp class if the class is now only limited by the restrictor because the 3.0 trucks I've seen are surely north of 1000hp. So it still could be an 800hp, torquey, drivetrain busting class! Sweet! LOL
 
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SmokeShow said:
Wow, 219hp drop.... Now if that trend stayed, putting a restrictor in front of a 2.6 protrusion charger, would roughly yield a 600-700whp class.

Hmm, that's def pulling the reigns back!


As for questions of equalizing the trucks, I don't really see where it would if that trend for reduction in power stayed consistent/linear then the guy that was already 100hp short, will still be 100hp short.

So the outcome may be less drivetrain carnage and that's about it.
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The point is you can only pull so much air through the opening, even if you had an hx82 behind it.

The 900hp guy might drop 219, the 850hp guy might drop 200hp, etc.
 
Great Job Weston and Mark. The remarks from engineers from work and Cummins Turbo Technology when I mentioned this is clearly shown in your dyno testing. There are some issues that would persuade a person from using a large wheel behind the restrictor. You should see a HP trend decrease worse as wheel size increased, like stated above..
 
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Timebomb said:
Great Job Weston and Mark. The remarks from engineers from work and Cummins Turbo Technology when I mentioned this is clearly shown in your dyno testing. There are some issues that would persuade a person from using a large wheel behind the restrictor. You should see a HP trend decrease worse as wheel size increased, like stated above..
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Here is the other thing, a guy running a true 66mm charger will probably only drop 20-50hp with this restrictor installed. On the 927hp run the charger produced 58psi as open 3.0 turbo. With the cone installed to atmosphere the charger was only able to make a peak of 41psi and 799hp. When we flipped the cone it only made 38psi and 708hp. The more power and air you are making/moving the more it will pull you back. As stated we will test it on many more trucks in the near future to get more data to compare.
 
I remember back in college I did a study with a few guys about a restrictor like this for formula SAE. It will limit airflow no matter what because of some law of physics I can’t remember anymore, as the velocity of the air approaches supersonic the orifice is unable to flow any more air through the tube, I think it has something to do with frequency too.

So velocity won’t help get more through, and only atmospheric pressure can force air through.
 
Rules are already in place why even test this idea? Throw it out, just away to pad someones pocket with more money when we all have to buy one (If this is not the case then please pass them out free). Dumb.
Brandon
 
sounds very promising Weston. very cool Mark, thanks for getting some testing done!!
 
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