MOST POWERFUL LS3 INTAKE EVER? SUPER RICHIE DUAL-PLENUM, ADJUSTABLE RUNNER LENGTH AND PLENUM VOLUME
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- čas přidán 25. 08. 2024
- HOW MUCH POWER IS PLENUM VOLUME WORTH? HOW TO MAKE DIY LS3 INTAKE MANIFOLD. MUCH POWER IS A CUSTOM INTAKE WORTH ON AN LS3? HOW MUCH POWER IS RUNNER LENGTH WORTH? DO DUAL-PLENUM INTAKES MAKE MORE POWER? ARE DUAL THROTTLE BODIES BETTER A SINGLE THROTTLE BODY? WHAT HAPPENS WHEN YOU SHORTEN RUNNER LENGTH? CHECK OUT THIS VIDEO WHERE I RAN A CUSTOM DUAL-PLENUM INTAKE EQUIPPED WITH DUAL 92-MM THROTTLE BODIES. THE CUSTOM INTAKE ALSO FEATURED ADJUSTABLE RUNNERS TO DIAL IN THE EFFECTIVE RPM RANGE. THE OTHER ADJUSTABLE FEATURE INCLUDED THE ABILITY TO EFFECTIVELY (MORE THAN) DOUBLE THE PLENUM VOLUME. CHECK THE RESULTS OF THE POWER GAINS AND ADJUSTABILITY VS A FAST LSXR INTAKE.
Symmetrical and parallel intake tubes cry for an rpm-controlled slider setup. Optimize that runner length for the best of all worlds! Thanks for a very interesting test, Richard!
I have slight feeling that the plenum thing might have more to do with the fact that plenums and their cylinders get connected, not so much the volume change. Vacuum pulses between two banks can interact, make scavenging effect, increase power in some particular rpm range, and f things up elsewere. When seperated, there are interactions just within each bank... just a theory... and premonition ;)
This is basically what BMW does with their inline 6 engines. They put a butterfly valve in the middle of the plenum. When the valve closes, it's divided into 2 plenums (the front 3 and the back 3 cylinders). When the valve opens, it becomes a single plenum. They claim that when the valve is closed, it improves low-end torque. And they say when it opens, the resonance helps to feed the opposing cylinders in the firing order (at higher RPM).
very common on inline 6 motors to run 3 and 3, connecting the plenums changes plenum volume
@@richardholdener1727 ...aaaaand creates COMMON plenum ;) 🤝
How much different than a Dodge Viper?
We’ll he’s saying the kegladon did nothing but the common plenum might be a thing
I love that you’re testing these on LS engines, the ford ones were cool too!
try a third dbw throttle body that connects the rear together : )
POINTS
On a carburetor application the plenum volume would be a lot more crucial because of signal to the booster on fuel injection you can give it the fuel regardless of signal.
The super richi intake awsome! and it makes power. makes plumbing nitrous real easy lol
The LT6 engine in the Z06 Corvette has three valves between the two banks of the plenum. First one opens, then the other two open, resulting in power increases through the RPM range.
We use the Fast manifold here on aus on the Camaro supercar. 5.7 7500rpm limit. 600hp. They have an inlet restrictor as required by rules
Ferrari and Porsche looked into this a ton in the 90s and possibly even earlier. The Ferrari 348 then 360 and virtually every NA engine after ran manifolds like these. Porsche 964 and 993 and after ran this only they had internal butterflies as well to actively vary chamber volume
Hell, even Honda did this on their J-series V6. Minivan power!
Interesting that the crossover point is around 3500 RPM, for the twin vs common plenum setups. The activation point for the plenum divider valve in my BMW is around 3400-3500 RPM. Just a coincidence?
My old 99 Mercury Cougar V6 had a secondary larger set of lower intake ports, they kicked in at 3450RPM if you were over something like 75% throttle
@@yeahitskimmel Honda switched a plenum butterfly between 3800-4000 rpm on their V6
Same thing with the runner control valves in a Mark 8 Lincoln and the other early 4v motors i think
Looks like something off a formula 1 engine.
Tunnel rams still rule. One.day, just maybe one day soon, Richard might test a efi ram with two 4v throttle bodies on a engine like that. The more the engine has, the more a ram compliments it.
that video is already up
An excellent and very informative video.
👍🏼👍🏼
Put a drive by wire third throttle body as your plenum on/off switch, program rpm open closing you want.
Super-Super Richie intake.
Richard, I would like to propose two tests: the first would require a four-cylinder with a conventional tunnel, ram style manifold. The question would be how does the length of the hem, Holtz resonator, the tube in front of the throttlebody, affect torque in power.
The second test would require a V-8 set up similar to what you have but I have a concept : dual plenums that are divided, in a similar fashion to a duel-plane intake manifold, where a pair of cylinders from each bank cross over to the other bank. My hypothesis is that this would dramatically improve torque across the entire rev range provided the correct runner length is selected. This would also be a neat manifold to test the crossover tube on as well.
I'M CURIOUS-WHY DO YOU THINK A CROSS OVER WOULD CHANGE POWER WITH THE SAME RUNNER LENGTH-AND I HAVE RUN ENDLESS TESTS ON AIR INTAKE TUBES ON 4 CYLINDER HONDAS. PLUS YOU CAN'T HAVE A CONVENTIONAL (V8 STYLE) TUNNEL RAM ON A 4 CYLINDER.
I've done some testing years ago on the dyno as it was common urban myth that no intake pipe and a pod on the throttle was the best way, and the results were completely the opposite. What I found is there is a sweet spot length for the ram pipe before the TB and the gain was inversely proportional to the harmonic number. So lengths that were tuned to the 1st harmonic gained the most, but where ridiculously long, near 2m on our engine. There is a fair bit of testing to get the ideal length that also fits the engine bay. But if you don't care, anything is way better than straight throttle and/or pod and as long as you can practically make it. The diameter I didn't test but I assume going too small is bad, same like how a too small runner kills power quick smart but going too big isn't anywhere near as bad.
I also found plenum volume to not do much, but my understanding is a big plenum is very helpful when the TB is too small due to increasing the efficiency of the TB when it is too small. Such as a restricted class in racing. But for anything else, too big of a plenum makes the throttle response lazy due to the finite speed of sound.
I love these intake videos. Can you try extending a pipe pre throttle body . My mind was blown when you said that would be part of the plenum volume
I tested that also
I think the rear extension allows for cooler rear cylinder Temps and more power
that's not what is going on
Edelbrock LS3 CrossRam is likely the best ever made.
Reminds me of the 3.9 LZ9 from GM, It had a variable length intake stock.
And no one made 1 for the LS
So you need a wastegate actuator on your runners that can make the runners shorter as boost rises. 🙂
Please cover the 8.8 PSI🙏
Awesome work as always. I wonder how your intake would do with a turbo setup on 5.3
What about increasing plenum volume around the venturi instead in the back. I wonder if it would help more
intake venturi?
Yes the funnels ducts that are in the plenum add volume there to perhaps unshroud them.
It would be interesting to see this test done in a boosted application. I'd like to see how it responds with adjustments to the plenum volume.
I wish we could see you play around with a LT6 so we can see this effect in a super car level
they already did a good job on the LT6 induction system
@@richardholdener1727 yea but I love how you break it down for us mere human. You need to start selling your own line of LS upgrades or open up a store since we already trust your recommendations
Rich maybe I missed it but have you ever tested "barrel intercoolers"...
Great video Mr. Holdener! Based on your test results, I would suspect no change in engine output if a carb style 180 deg 'dual plenum' was run. What say you?
a dual plane intake (carb style) would hurt power
Sooooo ls motors need a integra gsr type intake 🤔🤔🤔
Curious about same test that changes runner cross-section, also.
Could it be that varying runner cross-section will move power around the rpm band?
What hp difference would having tapered runners make?
very little
You ever do a comparison with individual throttle bodies?
I have run them if that is your question
@@richardholdener1727 What did it do to the power curve compared the fast. You could probably play with intake length too on individual throttles
Richard, do you think the gain in that mid region is a function of plenum volume or taking advantage of a harmonic between the two banks? My Porsche Cayman (987.1 S) has the same concept with a flapper valve in the middle.
What do you think changing plenum volume does? It changes the Helmholtz resonating frequency
I wonder how this would be on a lower rpm motor
works well with the right runner length
Could it be that the size of the pipe joining the plenums together is specific to certain rpm ranges? Where a different size pipe might see gains at a different rpm. Then if you had say 3 different sized connectors all with separate opening valves they could be opened at the correct rpms for more consistent gains? Maybe this wasn't a test of plenum size but one of joining the plenums...
I'd say you might be able to measure something. But given that many OEMs use a simple butterfly valve between two chambers with no pipes at all, I don't think it'll make a massive difference. Remember the pipe lengths between plenums are really short.
the pipe size does change plenum volume
@@richardholdener1727 so if you were to change the 2 plenums separately to match the increase you made with the cross over pipe you think the results would be identical then?
Do this test with boost next please
DOES THE SAME THING
Did I see a photo of stand off injectors at one point? How well did that work?
not well on that application
@@richardholdener1727 thanks for taking the time to talk about that in the live Q&A video that followed.
Is it possible to build a single carb SBC tunnel ram that makes big low rpm power for a boat ?
dual plane would likely be better
Sure, you could build one, or you can buy a single 4bbl mounting flange for a tunnel ram
So I’ve been looking to build a manifold for a 2.5T, is there a measurement to calculate a good size for plenum size? I’ve found 1/2 the size of motor to be ideal is this true?
Depends on how much rpm the motor will see. If it's a sub 6000 rpm engine, plenum volume plays a minor role. Start spinning up near 8k+ and you'll want multiples of the engine volume - more the higher you go. I don't think I'd go any smaller than half the engine size though.
@@ChurchAutoTest great info. What I’ve calculated out with a lambo lower intake and fabricated plenum and all its around 1.8L. Will be a turbo motor spun to about 7500. I’ve used a number of measurements from integrated engineerings 2.0 manifold runners as it was nice to rev up to 8000 rpm. Figured some of that info should be decently close to the swap motor. Thanks mate really helped with assuring I’m along a correct line. Even if not perfect.
Would a 20% merge (x-pipe) do anything on intake runners? 1-2, 3-4, 5-6, 7-8
merging the intake?
Is there a way to run a dual throttle body on a sc 3800 build? Because that looks so dope, I want to get building on my 3800 🤣
THERE ARE NOT DUAL INLETS INTO THE BLOWER UNFORTUNATELY
@@richardholdener1727WHAT? SPEAK UP!
@jasonbirch1182 suppose you could run duel superchargers....
@@jimlathrop8603 good luck with the belt.
@@jimlathrop8603 or I can run a dual filter inlet adapter in place of a throttle body and run 2 throttle bodies on top of that. Might be super silly
#wrongheaders
Lol
This is crank horsepower correct ?
yes
Wrong cam 😂
Any cam is a wrong cam!
I be needing that dual-plenum cam
@@richardholdener1727 I was just kidding about the wrong cam, we all use to joke about it on sloppymechanics, plus he had the shirt on today. On another note could vvt possibly do that? LOL
the dual-plenum cam was a joke
When you say increased/decreased volume are you removing the entire u turn assembly or just capping where the center joiner is? Im wondering if the resonance change from them not being connected is as big a factor as volume. A throttle body between them would be interesting to see the effect.