Inlet trumpet dyno testing

[mjrstar]

Aaw geez, I had a soft spot for green swirl and was hoping for a groundbreaking revolutionary new intake design taking over the world.. 

[Yowzer]

Keen to see a revised screwdriver handle, see if it can reach the performance of the rest of them

[ThePog]

Easy, cut it off at the mount.

[mjrstar]

31 minutes ago, ThePog said:

Easy, cut it off at the mount.

Or maybe bore a hole a decent sized hole in the the end and see if the slots make any difference then. I assume its boundary layer/ surface friction causing the drop in flow. Assuming the calculated total surface area = inlet pipe diameter. 

[cletus]

I wondered if mounting the SUPER TORNADO STAR OF DAVID staggered up and down so they aren't sucking air next to each other might improve them? 

[ThePog]

2 minutes ago, mjrstar said:

Or maybe bore a hole a decent sized hole in the the end and see if the slots make any difference then. I assume its boundary layer/ surface friction causing the drop in flow. Assuming the calculated total surface area = inlet pipe diameter. 

Yea. The problem is really that thin slots mean the surface stagnation is a much higher percentage of the flow, whereas a bellmouth is absolutely minimising that.

[kpr]

I just figured it out,  they spin the wrong way for the southern hemisphere.

but yeh,  been taking to  @Roman about it.   I might do some butchery, to see if can get them to work any better.      I think making the slots bigger would be the first thing to try.  cutting a hole in the end would kinda defeat the design

[ajg193]

Would be interesting to try and make a runner that makes use of the ram air effect at points that it is out of tune with the engine rpm by generating little turbulent jets around the periphery to reduce the boundary layer thickness. Could theoretically improve flow between the harmonic points.

 

Maybe I will model something up.

[Yowzer]

Chuck four of those AliExpress electric intake turbos on it

[Roman]

The point of the swirl design was to see if having a capped end meant you could reflect a stronger wave. 

The idea of swirling it in sideways was that there is no straight accoustic path to the outside, its at 90 degrees.

But there were no interesting peaks or troughs.

I dont think its an issue with surface area of the slots, just that swirling the air in is hugely counter productive.

Especially as it approaches the throttle plates that are trying to make the air go straight 50/50 under and over.

You might end up with high air speeds around the side and none in the middle, and none if it helps get the air moving in the direction its meant to go. 

In summary:

A++ will submit more silly designs in the future 

 

[cletus]

Suggestion from a caveman who knows nothing about air flow dynamics

What about a trumpet with a built in flat bit that directs air flow over the throttle blades in a more streamlined fashion? 

[deankdx]

future test, for space challenged cars 

a banana runner (like the difference fitting side draught to down draught for space confines. or hole in the bonnet look) 

what about the screwdriver style but 45 degree drilled holes aimed at the centre of the port. 

anyone tested the golf ball effect on runners? been ported heads having positive and negative effects. not sure you could print in bumps or holes on the inner surface smoothly?

just some brain farts for consideration. 

 

 

[kpr]

bends dont really have any effect, probably a tiny bit in it if your runner size is borderline already.    your average long radius bends are fine.   those cast aluminum elbows are a bad day though.  somewhere on my youtube i tested them

About 1 million people have asked me to test dimpled ones.  haven't had any sent my way yet though.   

 

 

[Yowzer]

Looking at the graphs it appears that the runners aren't a limiting factor for power, I wonder if it'd be worth decreasing the diameter so they become restrictive and therefore design differences will be more apparent

[Roman]

If you look at cars that need to run restrictors on the inlet, like FSAE or whatever. 
They basically all have super duper bellmouths/tapers on the pipes. Because getting the air as straaiiiggghhhttttt as possible is absolutely necessary when you're trying to fit as much as possible through such a tiny hole. 
So I think you're right @Yowzer in that a smaller runner would amplify the differences. BUT.

If your runners are so small that it has a massive effect, then the first thing to do is make the runners bigger. (So long as you're allowed, which 99.9999% of cars are) 
As I dont think KPR has seen any instance of where smaller runners actually helps? 
Yet the gains from making them big are good, so long as the length is right.

We live in a world where 1600 NA engines thrive on 52mm throttles and 3" exhaust, have the rules of physics changed since the 90s?
Where this all would have been insanity? haha
God I love that we have the technology to do all this stuff and the awesomeness of @kpr to test it all and break down myths that should have been extinguished 30 years ago.
 

[kpr]

Not the best example,   as length was slightly off.   but can see on the skinny blue runners.  how they fall over up top, with only minimal gains down low.

Pretty much everything ive tired diameter wise,  to make a gain in the bottom end,  will take a big hit in the top end. 

Waay more forgiving going oversized.  example being something  completely silly like the noodles.  they hardly loose anything down low.

 

 

 

 

[GARDRB]

On 11/12/2021 at 12:32, cletus said:

What about a trumpet with a built in flat bit that directs air flow over the throttle blades in a more streamlined fashion? 

Almost like a reed in a wind instrument

[GARDRB]

Could you test different intake setups with some sort of smoke machine without detriment to combustion?

Put a smoke machine by the drivers side guard and see how the air flows into the different trumpets?

Also, @kpr do you want an old 32" TV for the dyno? I've got one in Kamo and could give it to David T to bring out to your place sometime.

[GregT]

On 11/12/2021 at 23:35, Roman said:

We live in a world where 1600 NA engines thrive on 52mm throttles and 3" exhaust, have the rules of physics changed since the 90s?
Where this all would have been insanity? haha

 

To one extent they have changed. Injection has changed the porting game in my time doing it. When you had carbs, you had to maintain a gas speed in the port which would work with your carbs. When the fuel is being sprayed in under pressure there's no requirement to keep the airspeed up.

A good example is the late 1098/1198 Ducati. I was asked if someone could put carbs on one for a specific class. The answer is NO. the inlet ports are huge and I doubt you could get carbs to work on one.

Enjoying what you're doing. Carry on.

[kpr]

On 15/12/2021 at 15:05, GARDRB said:

Could you test different intake setups with some sort of smoke machine without detriment to combustion?

Put a smoke machine by the drivers side guard and see how the air flows into the different trumpets?

Also, @kpr do you want an old 32" TV for the dyno? I've got one in Kamo and could give it to David T to bring out to your place sometime.

Cheers for offer re tv.   will pass though. the crappy little crt fits with my shed tetris at the moment.

Not sure about the smoke thing,   since engine is consuming something silly like 7000L per min,  likely  wont see a lot unless have lots of smoke.