Intake Manifold Design

dvst8r said:
Just to really throw a wrench in it, in a promod car it is almost exclusively 4" piping and they run low to mid 50's psi of boost.
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10-4, that's what I thought I had seen in the pics, just went conservative on the post. That's gotta be 5-10X the CID then.

And with the others, I'm not sure the increased volume helps keep the charger out of surge just by itself. Thinking in terms of a compressor map, you're just driving the mass flow to the left into surge. If the engine is swallowing less mass, it doesn't matter how big or small the plenum behind it is, IMO - of course assuming the air density and VE aren't changing dramatically at the same exact time.
 
one of the best designs is so called Lehmann manifold, there's also other names for it, good charge distribution between cylinders and wide operating range. Runner length is calculated as usual, it's only plenum design. You can see one version in this video at about 1:46 [ame="http://www.youtube.com/watch?v=Kx17b-7ORvI"]FIA Truckracing 2011 MKR-Technology Engine Test Bench (2010) - YouTube[/ame]
 
While I'm not going to say I know enough about intake manifolds to get into a deep discussion about them, I have ideas that I plan on implementing and they will take more work than most anyting I've seen on a 12 valve Cummins.


I find it interesting that these guys pretty much have unlimited resources, are able to do whatever they want, are at the top of what they do, and they keep it simple.


hypermax_zps8fa8c45e.jpg
 
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Pressure overcomes a lot, on a lower pressure single setup I could see a Lehmann type manifold being quite interesting.
 
9724VF350 said:
I find it interesting that these guys pretty much have unlimited resources, are able to do whatever they want, are at the top of what they do, and they keep it simple.


hypermax_zps8fa8c45e.jpg
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Diesel dragster. Is there any real competition between them? I've never seen them race against other dragsters, they are mostly doing solo runs.
 
Smokem said:
Pressure overcomes a lot, on a lower pressure single setup I could see a Lehmann type manifold being quite interesting.
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Someone said that if you can't tune the engine just up the boost or use nitrous.

Those racetrucks use about 4-4,5 bar boost (58-65 PSI) and suck the air through 65 mm restrictor. They make about 1150-1180 hp, no smoke allowed.
 
Leiffi said:
Diesel dragster. Is there any real competition between them? I've never seen them race against other dragsters, they are mostly doing solo runs.
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[ame="http://www.youtube.com/watch?v=TQePSdT9QEQ"]Marty Thacker sets new NHRDA Top Diesel Record 6.79et.wmv - YouTube[/ame]
 
Leiffi said:
Diesel dragster. Is there any real competition between them? I've never seen them race against other dragsters, they are mostly doing solo runs.
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You realize he isnt refering to the dragster he talking about all their pulling tractor engines that run that intake.
 
kjpcummins said:
You realize he isnt refering to the dragster he talking about all their pulling tractor engines that run that intake.
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I guess I should have pointed that out. I do sort of get the impression that Leiffi is from across the pond, so I wasn't expecting him to be right on top of things going on here, though I may be wrong about that.

I agree with Weston, though while somewhat dated, 5 or so years ago one of the best superfarms in the country made 100+ dyno runs tuning. Pretty sure it was a riverside engine. They gained a total of 8hp tuning, and the stock 619 intake made the most power.

Same goes for what was previously (until the end of last year) the top pro stock semi in Ohio, who also spanked many of 4 charger semi's at bowling green for several years. After dozens of dyno runs and half a dozen manifolds that cost stupid amounts of money, the stock KTA manifold is making the most power. I haven't seen what Fink put on the latest top dog in the class.
 
Smokem said:
Honda-Tech - View Single Post - Dual Plenum Intake Manifolds
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I really like these types of pictures and the simulations, but they never seem to want to show if that beautifully equal distribution extends all the way across the rpm/flow band.

What I'd like to see is a sim of a stock manifold air distribution at 2, 3, 4, and 5k rpm, and the same thing with the new and improved super wackadoo manifold.

Because it seems to me if there are "substantial midrange gains," then you should be able to show that a stock manifold really has crap distribution and/or flow within that range. (and assuming the CFD is set up correctly and is really reflective of what's happening in reality)

Or am I looking at that incorrectly? Seems to me that even on the super manifold, it probably ain't perfect at every flow level....it's optimized somewhere....unless you really can have your cake and eat it too.
 
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This may not be as applicable as I want it to be for this discussion... but... with duct plenum design, the spec for equal distribution in a plenum is to have plenum velocity at a maximum of half that of the branch/exit port velocities.
 
In the tiny bit of dyno testing I have been privy to, at the end of the day, it always came back to the compressor. If there was enough turbine and fuel, all that head, cam, intake manifold did, was allow for less boost needed for the same final power.

Now what head, cam, intake did do, was change things like drivability, off boost response, and mid range power. Obviously less boost is probably worthwhile in and of its self.
 
Leiffi said:
Someone said that if you can't tune the engine just up the boost or use nitrous.

Those racetrucks use about 4-4,5 bar boost (58-65 PSI) and suck the air through 65 mm restrictor. They make about 1150-1180 hp, no smoke allowed.
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Exactly my point, they are making impressive power with the air they are allowed. It boggles my mind that people are too stubborn to adapt ideas that have been used in other motorsports for some time now.

nwpadmax said:
What I'd like to see is a sim of a stock manifold air distribution at 2, 3, 4, and 5k rpm, and the same thing with the new and improved super wackadoo manifold.
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This would be ideal, I'm willing to bet the stock shelf isn't as restrictive as people have been led to believe. Many times I have seen people pay for a crap valve/port job and slap on a runner manifold and think they have something, when in reality a good valve/port job and the stock manifold would have made more power.
 
Smokem said:
Many times I have seen people pay for a crap valve/port job and slap on a runner manifold and think they have something, when in reality a good valve/port job and the stock manifold would have made more power.
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Which is why it would be nifty to put the entire assembly through high pressure flow bench testing to see what that data tells you, not just the single parts most folks focus on.
 
any one have any EGT data for cylinders #1 and #6 in a high hp rig with the stock shelf?

hard to believe that the restrictions in the path to #1 intake runner can be over come with just a port/valve job
 
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