Thanks crcrain. I enjoy the testing, if I don't keep myself busy on projects I get very bored and irritable. This round of testing was from no longer being able to sell the V2's, lucky for me and many customers it happened at this point.

The plenum size, I am unsure how it all effect each other at this point. When testing the stock stuff if the runner length is changed by porting then the plenum is changed at the same time. It makes it hard to determine which one effected what.

I think the only way to do this is run an intake with the same plenum and change runner lengths on it. Then find the ideal runner length and change plenum sizes and then probably do it all over again and make sure one wasn't ruined/effected by the other. It is going to be a lot of work and will more than likely end up being more work than I can actually do.

I could be wrong but it seems as though all the programs being used are great in theory but maybe not so great in the real world.

I am having a tough time deciding how to go about this all. With so many intakes out already just building another one like the rest is pointless, as I have said.

I believe I am going to try something different than what's out there now.

 

Thanks for the reply and look forward to hearing about what decisions Buschur Racing makes in the intake manifold market.

 

You're welcome crcain.

We got out first batch of material in this morning. I have to have some holes cut in the base plate of the plenum. If all goes well I will have the first intake built late tomorrow. This very first one is going to be built "like all the rest" basically but with the longest runners I can manage to get in the car. It will be a good test. Then I'm going to remove it and cut the plenum down to the smallest size I can get it to and run it again. Then I may cut the runners down and shorten them to the shortest I can make work. So I should get three good dyno tests out of our very first shot at this.

As the week goes on I am waiting on a different runner/velocity stack material to show up and I have a few more ideas to try.

I am considering making the runners as short as possible and cutting them in half. Then use a hose connection in the center so I can vary the length by simply swapping coupling lengths. This would let me change the runner length by any amount I want and I could even stagger the runner length from one end of the head to the other.................I think that sounds like a good idea.........

 

Dave, I don't know if you already have a place where you are buying velocity stacks from, but here is a site that I have been looking to purchase stuff from and they have a wide variety of stacks available, looks like a lot of "do it yourselfers" use them.
They also have some cool calculators in there for determining runner length.

http://www.velocity-of-sound.com/

It might be helpful to you in some way... OR not...

good luck with the tests

 

Holly hell that is a lot of info

 

Back on the flow bench today.

I cut the runners and plenum off one of the stock intakes that we had been porting on. I needed a flange to start testing with.

We got our runner material in today and I cut a short section of the tubing and had Trent weld it to the head flange. The runner is rectangle shaped very similar to the stock head port.

I then placed the head flange with this runner on the flow bench and flowed that runner.
298 CFM.

Very interesting that it flows that low. That is inline with the stock #1 runner on the stock intake with no porting and the plenum intact.

I then placed the velocity stack we plan to use on top of the runner and holy crap did the flow pick up.
382 CFM.

For reference the closest we got to that number before was 345 CFM and that was the stock intake on port #4 without a plenum on it.

That is a huge increase. As I have been studying the design of the stock intake it all makes more and more sense as time goes by. If you take a look in the plenum of a stock intake you will see that the plenum itself acts like a funnel on the top and back side of the runners. It directs the air right into the runners.

When I started really thinking about all of this a few weeks ago the one thing that did not make sense to me in all the designs I was seeing was the plenum/velocity stacks. All the plenums have a big flat floor in them by the runners and they all have the velocity stacks raised up from the floor. I am no engineer and probably won't even get to play one on TV (haha) but to me, it doesn't make sense. If you put that in the bottom of a bucket and filled it with water the water would not flow out of the bucket as good as it would if the velocity stack was on the bottom flush and it would never empty the bucket. Now that right there is some redneck fluid dynamics for you!!! (I'm hilarious today! hahahahahaha)

Anyway, I drew up a picture (with my daughters Crayola's-told you I was funny) of what I wanted and was mentioning it to someone else in the industry and he knew where I could buy exactly what I was looking for. This is making the project go much quicker than I had originally expected. When I'm done if it works I'll let everyone know where you can buy the stuff if you are interested.

I'm not getting my hopes up to high on anything since the flow bench has basically lied to me so far but that is by far the highest flow of any port we have had on the bench yet. It seems promising even if it ends up for super high RPM only.

Thanks for reading.

 

Thanks for the link antilag, I appreciate it!! I have some I am using already though and from the results/fitment right now I am happy as could be!

 

I have tested "flush stacks" vs. Protruding stacks...flow wise having them flush in the plenum will flow quite a bit more. I haven't YET tested the difference on a dyno. In my opinion keep the stacks flush unless you can't reach your desired runner length. IMO the runner length is much more important than how the stacks sit in the plenum so if you have to raise the stack in the plenum to gain an extra inch or so, the gains will be worth the sacrafises...

I don't know if there will ever be a "Perfect" intake manifold...much like turbo's its give and take...

 

So I paypaled my buddy money to send my IM in for Wilson treatment and he called me back and said buschur doesn't do that anymore. I was like, "What do you mean they don't do it?"

Now I run into this. I have more information than I thought existed regarding the reasoning behind my IM not going to wilson.

Thanks dave. You saved me some money and I didn't even have a choice! hahah

 

jesse, thank you for your input on it. I have just started doing the flow bench testing and trying to cross that information over to the dyno. So far not much is making any sense. I'm hoping by the time I am done with this I can make much more sense of it all, not looking good so far though! haha The plenum/velocity stack certainly makes sense and when I look into the stock intake manifold Mitsubishi actually has the stock intake set up much like I want to set up the plenum/velocity stack on what I am doing. As I said today to some of the guys at the machine shop, if it fails I'll have a bad *** looking intake to put in my rec room!

Also, looking into it all more I don't see a single EVO intake manifold being built with the velocity stacks build into the floor of the plenum. Either nobody tried it or they did and I am going to run into a dead end. Time will tell.

olmoscd, you don't know how happy it makes me to know I helped save you money on that part. Just send the intake to us and we'll do the normal port job on it, save you $1440 and you will be faster.

 

ross machine sell all the parts to do them flush

 

Jesse,
I ran flush stacks and raised stacks for the same runner length... raised stacks made more power. I've tested this on NA neons, boosted neons, and again...the carbon fiber F4i manifold.

Runner length has the largest affect on the power band. I did a lot of testing on runner taper as well. A lot of SAE papers suggest 2-3 degrees of taper, but 7-10 degrees showed more gains.

Best Intake manifold combination that has held true for all of my engine dyno experience...
- the largest plenum you can fit.
- Use Elliptical stacks that are raised off the port floor. (there is an SAE paper that details how to determine the multiradius elipse.)
- tune your runners to your power band. you may end up using the 5th or 6th wave of Helmholtz resonance...but you need to tune it regardless.
- For cylinder imbalance.... make the delta in area when entering the plenum as large as possible. This will promote a huge pressure loss (reduce flow capability) but balance the flow to each cylinder. NOTE: having a HUGE plenum makes this very easy.

And one of my thoughts that I havent tested yet...is a reverse stack on the backside of the throttle body mounting plate that allows the air to distribute into the plenum. I'll get to test this probably at the end of this year on another 600cc 4 cylinder or maybe a 500cc parallel twin.

DB,
you can't correlate your flow bench work to the engine because the flow bench doesn't simulate the valve events on each cylinder.

If you really want to correlate cylinder variance... EGT probes will help significantly. (you have to have dynamically(NOT STATIC) flow matched injectors!!!!) You could run an emissions probe off of each cylinder to determine which cylinder is receiving more or less air. (more air = higher temperature = higher NOx)...or you could run cylinder pressure sensors and figure it out that way. That is the CORRECT way of determining flow imbalance. The solution? maybe you would remake your intake manifold... I would adjust that cylinder's injector scaling to inject the correct amount of fuel.

I know that AMS has a cylinder pressure sensor as well as Full-Race. You're pissing in the wind without one Dave.

 

RMR does machine work... it's simply easier for them to make them flush. It's not because it's "better."

 

Looks like Hypertune has used most of the things you mentioned.

Raised elliptical stacks and a reverse taper on the inside of the TB flange and nice tapered runners. Some one has done their homework

here's a pic of the hypertune without the TB plate

 

Still IMo the baddest intake manifold to date.. And it truly isnt an arm and leg for what you get!!

Mike