Restrictor Tube Poll!

[DISTURBED]

put one on a truck and slapped it on the dyno....this was with a true 3 inch charger. made 927 without the tube. with the tube in with the bell part facing out so it funneled the air in it made like 735 and with just a blunt restrictor tube without the bell it only made like 707. quite the difference i would say. 200+ hp decrease

I think it maybe a viable idea, but did you all just put the tube on with the same tune and fuel as the true 3.0 or did you play with it? If you used the exact same tune those numbers mean nothing

 

[nwpadmax]

I think it maybe a viable idea, but did you all just put the tube on with the same tune and fuel as the true 3.0 or did you play with it? If you used the exact same tune those numbers mean nothing

I don't think they mean nothing...yes you will for sure tune for it and see that number come back up a bit, but I don't think you'll ever get 100 ponies back, or even close, with tuning.

But let that be an area for innovation.

 

[DISTURBED]

On a 3.0 setup you could over fuel a 2.6 charge by 100 hp easily. Thats why i asked. The over fuel aspect of it alone is alot if nothing was changed other then the tube. Im torn thats why i asked. In some ways i like the idea and others ways i dont

 

[Got Milk?]

If anyone knows the Profarm tractor rules their "bushing" for the turbo has to be 2.4" I.D. within 2" of the wheel. They all have had custom restrictors that meet the rules and can flow the same amount as no bushing at all (not lieing, its been tested)

So my point is people will always find a way around bushings/restrictors$.02

 

[nwpadmax]

If anyone knows the Profarm tractor rules their "bushing" for the turbo has to be 2.4" I.D. within 2" of the wheel. They all have had custom restrictors that meet the rules and can flow the same amount as no bushing at all (not lieing, its been tested)

So my point is people will always find a way around bushings/restrictors$.02

Then the bushing design isn't specified well enough.

I'm still sticking to my guns that the thin plate orifice is the one that can't be gotten around. All the other "aerodynamic" restrictors you can play games with.

 

[Joesixpack]

If anyone knows the Profarm tractor rules their "bushing" for the turbo has to be 2.4" I.D. within 2" of the wheel. They all have had custom restrictors that meet the rules and can flow the same amount as no bushing at all (not lieing, its been tested)

So my point is people will always find a way around bushings/restrictors$.02

All that shows that they were not achieving the necessary minimum pressure ratio for choked flow. (The bushing was not small enough)

Then the bushing design isn't specified well enough.

I'm still sticking to my guns that the thin plate orifice is the one that can't be gotten around. All the other "aerodynamic" restrictors you can play games with.

Better research that some more, its my understanding the thin plate orifice mass flow can be significantly increased to the point of full vacuum.

 

[nwpadmax]

Better research that some more, its my understanding the thin plate orifice mass flow can be significantly increased to the point of full vacuum.

Negative. Once you approach the speed of sound, it's done, and that's all there is to it.

What the heck is "full vacuum" anyway? Vacuum is a variable state just like pressure.

 

[Joesixpack]

Had to dig a bit, found this on wiki, as far as I'm concerned you need some length to guarantee choked flow. Likely why they ARE built that way and not thin orifice plates.

Thin-plate orifices.....

The flow of real gases through thin-plate orifices never becomes fully choked. The mass flow rate through the orifice continues to increase as the downstream pressure is lowered to a perfect vacuum, though the mass flow rate increases slowly as the downstream pressure is reduced below the critical pressure.[8] Cunningham (1951) first drew attention to the fact that choked flow will not occur across a standard, thin, square-edged orifice.[9][10][11]

 

[Joesixpack]

AMS pikes peak rally car build!!!! WRC Turbo and all! - Page 2 - Mitsubishi Lancer Register Forum

Check this thread out, show's a good profile of a restrictor, before and after dyno. Yeah it cuts its nuts pretty good, looks like the fellow spent a deal of time maximizing the tune while on the choke.

 

[SPEAKSUP]

I think it would be good for Work Stock the most. 2.6 guys will never adapt this I just don't see that happening.

 

[Smokem]

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. To date Curt Haisley's Clipped 3.0 charger has been the best clipped charger at 816hpish for a reference point. Either way this idea works and would definitley limit the power being produced. Then we can argue about something else.

 

[nwpadmax]

AMS pikes peak rally car build!!!! WRC Turbo and all! - Page 2 - Mitsubishi Lancer Register Forum

Check this thread out, show's a good profile of a restrictor, before and after dyno. Yeah it cuts its nuts pretty good, looks like the fellow spent a deal of time maximizing the tune while on the choke.

That's a venturi tube....not as mean as a flat plate. The flow equations are different there. But still, neck it down and of course it impedes mass flow.

 

[Smokem]

AMS pikes peak rally car build!!!! WRC Turbo and all! - Page 2 - Mitsubishi Lancer Register Forum

Check this thread out, show's a good profile of a restrictor, before and after dyno. Yeah it cuts its nuts pretty good, looks like the fellow spent a deal of time maximizing the tune while on the choke.

I posted that information in the other thread.