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Inlet trumpet dyno testing


kpr

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I just finished testing  that abortion that i built.    Its roughly  9-10L      Best i could get it to work was with a 4" hole and no intake pipe.  although with the pipes there wasn't much difference.

It changed the power curve a bit.  vs the open throttles.    just traded power here and there  rather than one beating the other over all.  So in my case at least, the airbox can match the open throttles  but no better.      

Kinda limited testing.    but conclusion I've come to so far,  Is the airbox needs to be big as possible along with feed pipe.   and is basically used to direct cold air, which is where the gains are , rather than the box doing anything fancy  itself 

 red -   airbox with 4" hole
 blue - open throttles

both above identical trumpets

green is the plenum off the hilux.   which i though did pretty good.  considering how the last one performed na

 

1706758581_4inchholevsopenthrottlesvshiluxinlet.png.b91e79d252cf5501b9e99e46a024ee7b.png

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Pretty sure airbox (maybe wheelie bin) on the end of trumpets ( I'm thinking those road cones you threw into the paddock) should net around 200kw..

 

This has been cool to watch / read, and the road cones showed real potential but then fell very sharply. I was sure they were going to punch a new all time high number.. 

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that's actually quite amazing that theres a solid ~1200rpm where you get a fair smidge more power from it.

As in, I wonder if changing the volume or whatever of the plenum could end up with that bump further up and stack it on top of your existing peak.

Very interesting that the pipe off the front made no positive difference! Maybe it has more of an effect when the plenum volume is very small.

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Thought the inlet size would be brought up.   Way i see it,  once the inlet pipe is that big, its just a way to direct cold air rather than  some kind of intake tuning.  We already know cold air makes more power so isn't really relevant.   There wasn't much difference in the 3" hole vs the 4" hole.    

red 3" hole
blue 4" hole

small difference in favor of 4" hole.   but could almost go down to slightly different temps rather than a gain to 4" hole.    But even giving the couple of kw gain  to the 4" hole.  would be diminishing returns  going even bigger

1379918559_ab3inchholevs4inchhole.png.6ed2c814dfbb7cb832690829b0fe83eb.png

 

 

1 hour ago, Roman said:

that's actually quite amazing that theres a solid ~1200rpm where you get a fair smidge more power from it.

As in, I wonder if changing the volume or whatever of the plenum could end up with that bump further up and stack it on top of your existing peak.

Very interesting that the pipe off the front made no positive difference! Maybe it has more of an effect when the plenum volume is very small.

Could probably move that bump at 7500 up the rev range  a bit.  but would likely drag the dips up with it as well.  So to me looks like would end up with the same power curve as the open throttles.     below is the same chart but the green hilux inlet  run removed. so can see the difference more clearly.  can see how it just trades power

 

1920278049_4inchholevsopenthrottles.png.8434175d9cc2bfb710adbdbc1c82e3b0.png

 

 

 

 

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59 minutes ago, Celica RA45 said:

kpr was your air intake running in colder air also were you using your map inside to see if it was holding the air back 

from entering your new air box  on ram tubes i try to have then 60mm away from any part of the air box lid 

In the tests everything would be close to the same ambient temps.     bonnet open.  and dyno fan blowing fresh air in.     I dont have a radiator in front of  the inlet.  so temps aren't an issue with the open throttles soon as car is moving  on road.     but as i said in previous post  the air temps aren't what im chasing in these tests

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ok fair enough, i use to use a 100mm dia tube going into my air box at the race track ,we put the map sensor into the side to check the air volume so at idle etc was on 100 at 50 percent throttle was 95 at 100 percent throttle is went down to 80 ,i then put a 6inch hole into my air box and the map sensor stays at 100 from idle all the way to 9200 redline 

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Yep,  seems the moral of the story is  get cold air in there in some how,   air box or no airbox.    Maybe something in the airbox itself, but probably very little. We at least know needs to be big as possible to pose no restriction

my junk will easy make an extra 5kw on a cold day  vs a warm day.    with the dyno correction turned off

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I've got a new scheme I might print for you to try. 

Basically a runner with a smaller inner entrance but then a chamber area around the perimeter to see if you can amplify a reflected wave back down with minimal energy loss / max doorts


2i5ltjgs.fha.png
yad5kfl5.lqw.png
wlrgusbm.odm.png
 

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10 hours ago, Roman said:

I've got a new scheme I might print for you to try. 

Basically a runner with a smaller inner entrance but then a chamber area around the perimeter to see if you can amplify a reflected wave back down with minimal energy loss / max doorts


2i5ltjgs.fha.png
yad5kfl5.lqw.png
wlrgusbm.odm.png
 

The people who design this stuff for a living are mathematicians/scientists/wizards/witch doctors. But the "guys at home" like yourself who dream up stuff like this will on a good day put the aforementioned group to shame.

I look forward to the results!

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Bunch of motogp bikes have variable inlet runners from a quick google if thats it? looks pretty much exactly like the old F1 ones before it was canned. As we said somewhere they have small rev range and high rpm so don't have to move far. (pic is road bike promo version I think, the might be just two step to lazy to look)

ducati_Glasgow_V4_15.jpg

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