Carbon Fiber Intake Development F10 M5

[Sales@RKautowerks]

Hey guys!

I've been working on these intakes the last couple of months, done a lot of testing and finally got the first pieces in today!

The intakes were produced using state of the art methods from start to end.

1) 3d scanned stock airboxes to ensure fitment is like a glove.
2) 3d scanning ensure the MAF calibration is not tampered with.
3) CFD to ensure the flow was optimized and nothing left on the table.
4) 3d printed to check fitment, flow tested, dyno tested.
5) CNC carbon fiber molds
6) Autoclave carbon fiber production

I'm going to reserve some space for dyno results, i have the prototype intakes dynos, we were hitting abotu 600-625whp with a tune and downpipes. But that's not a final number by any means, the testing was more durability and heat soak, not numbers.

Even then, i feel the flow numbers are what you guys should focus on, well not just flow number but flow numbers as a function of delta pressure. So i'll give you guys a brief explanation on how intakes actually "make" power as you guys like to put it.

I'm sure you've heard that intakes make power, that's a not exactly true, intakes don't make power at all. They FREE up power, the engine is already producing what it can produce at its RON(gasoline) knock limit provided a chain of other criteria are not holding it back. As an OEM(i work for an OEM) we design intakes very differently than the aftermarket, we have noise, vibration, power constraints, costs, and durability in mind. A combination of these constraints are why we leave "power" on the table. In the aftermarket the consumers are usually power and aesthetics drive, not so much concerned about the other constraints.

So with that said, the intake system is purposely constrained from factory. The ECU is calibrated with the intake system and it's shipped off.

So how do you "free" up this power?

The common assumption is that your intakes make power, false. The governing equation/theory/facts behind this is BMEP = IMEP + PMEP + FMEP. Where BMEP is the brake power, the power the engine will produce at the crank rather. Now you have IMEP, the indicated mean effective pressure, the power loop of the PV diagram. This is where the magic happens, IMEP is the boom inside the engine, the working portion of the PV diagram. This is the absolute amount of power the engine can make before it starts sending the power in all sorts of direction. PMEP is where the intakes come in, PMEP is the pumping mean effective pressure. The engine has to utilize some of its IMEP to suck in the air and push the air out, this isn't free after-all. Then you have FMEP, the friction portion of the game, this is your rotating assembly, lubrication, seals, and etc.

Here's a PV diagram to visualize what's going on.




BMEP = crank power = measured using a dyno
IMEP = power loop = measured using in cylinder pressure transducers
PMEP = pumping loop = measured using in cylinder pressure transducers
FMEP = friction = calculated using math by knowing BMEP/IMEP/PMEP

So now that we've established power is only made in the power loop, everyone should be onboard with why intakes don't make power.

Intakes are like straws, us as a humans can suck in x amount of water using a straw that is half an inch wide, we can also suck x amount of water with a straw that is 4x as small. It's easier to drink through the bigger straw right? Same concept with an intake! Which brings me to my next point, an efficient intake is like a big straw, really easy to suck the water through. We call this value "delta pressure" the amount of suction needed to move a certain amount of fluid through a vessel.

With that said, you want to make it easy for the engine to "breath" on a forced induction application, easier for the engine to breath means less power it has to use to suck that air. See where this is going?

Lets put some numbers with our equations.

BMEP = IMEP + PMEP + FMEP
(+) = (+) + (-) + (-)
(end power) = (total power) + (pumping loss) + (friction loss)


BMEP = IMEP + PMEP + FMEP
10 = 14 + (-2) + (-2)

That is configuration A

now we have our new intake, configuration B, the big straw

BMEP = IMEP + PMEP + FMEP
11 = 14 + (-1) + (-2)


You just increased the crank power of the engine, by freeing up power that was always there! This is why when you see flow in LPS, it doesn't hold much value, so you increased the flow? Does it mean anything, because the flow has to have some type of delta pressure associated with it, how much suction did you need to produce that flow. I can take a 2" pipe and flow 500LPS through it, but i had to have a ton of suction on it. But my 3" pipe only flowed 300LPS, but it was barely sucking. Marketing will make you think the 500LPS is better because well...you didn't know, now you do!


With that said, i ran the flow numbers and will demonstrate why our intakes will produce an increase in power.

This graph shows the amount of air an engine is consuming based on your boost pressure (turbo application only). This gives you an idea of how much air your engine is consuming at wide open throttle at a certain RPM.


Now you have what most are used to seeing, the "flow increase" diagram. I have my X axis as a function of delta pressure, which is what you should ask for. But like we discussed earlier, this doesn't help quantify why engine is making more power. You see that you increased flow at each delta pressure, but you don't know what the delta pressure drop is, just what you increased flow by.


This is why you should ask the vendor for this graph. A chart of delta pressure as a function of flow. Now you can quantify, based off how an engine works as explained above, what benefits to expect to see. You can see for yourself in the chart below how this compares. Referencing to my cylinder head flow chart and comparing what delta pressure benefit you have based off the RPM at WOT condition. You can see below how my intakes compare to a competitor and how they compare to stock. I've reduced your pumping loss up to 40-60%, power you were allocating to move the air into the engine before, is now being used to move your car! The lower your delta pressure, the better.


Reason why i bring that up is because it's really easy to quantify the difference between intakes when you conduct testing using a flow bench. It's not easy to compare intakes or really quantify power differences on a chassis dyno because you have so much going on that needs to be accounted for. You need a bench dyno running some state of the art equipment to truly quantify it, stuff i do at work. The flow bench is something anyone who's charging someone several hundreds for an intake should use to validate their product. You can make this entire system go full circle and derive a correlation between delta_P reduction and the pumping loss benefit if you had a system sophisticated enough to accurately capture the PMEP inside the engine. Then you could back out the increase in power as a function of Delta_P. You'll be hard pressed to find shops outside the OEM that have this capability, i know of a handful. Happy modding!




If i haven't lost you yet, here's what most of you guys want to see, the pics lol

I will have more videos and pictures within this next week!


I don't have my M5 anymore so if anyone is in Columbus Ohio, or nearby, please drop me a PM! I'm more than happy to show you in person and you can even test the intakes yourself.

Thanks guys!
-R

PS: Many assumptions were made to simplify this analysis. More than happy to get down and dirty with those interested.

[apexlocator]

Thanks for the lesson in air flow dynamics

But it seems similar to other intakes currently on the market, except this is CF.

What are you thinking the price of admission will be for this intake? You can PM if you'd like. thanks.


ap

edit: so why not 3.5" piping? There must be a point of diminishing returns, or a point when the MAF needs upgrading? This is not my area of expertise, but is interesting....

[Sales@RKautowerks]

Originally Posted by apexlocator

Thanks for the lesson in air flow dynamics

But it seems similar to other intakes currently on the market, except this is CF.

What are you thinking the price of admission will be for this intake? You can PM if you'd like. thanks.


ap

edit: so why not 3.5" piping? There must be a point of diminishing returns, or a point when the MAF needs upgrading? This is not my area of expertise, but is interesting....

The other intakes on the market are inside the enginebay, or they are not a true 3.5"+. The MSR intakes i tested were 3.5" at the inlet of the engine, but where the aluminum portion of the intake begins, it was 3". This will greatly diminish the pumping loss, as seen in my data analysis. 3" diameter vs a 3.5" diameter results in a reduction of 27% in surface area. I could back out what the boundary layer benefits are, but that is going to be well over anyones head.

you are correct with respect to diminishing returns, if you look at the Delta pressure chart, you'll see how the stock has the greatest delta pressure, MSR is next, our intakes are the lowest. You will always have some form of delta pressure, the floor in our situation would be if you cut the section a few inches infront of the MAF. Because the maf is calibrated for that specific diameter tube, you can't tamper with the diameter or its geometry. Just out of curiousity i'll run the flow numbers on what that is, establishing a floor for the lowest delta pressure an F10 M5 intake setup can yield.

You can run a larger diameter Maf housing, an option i considered, but the CFD didn't show too great of a benefit by enlarging the MAF section to 4" because it will taper back down to 3.5" where it meets the engine. The area between the start of the intakes and the maf section are actually 3.5-4". I tried to create that region to be as large as possible to decrease the boundary layer. But a part of the aftermarket game is aesthetics, so i made it a point to balance what the intake looked like and benefits.


I have a submission in with the forum to become a vendor, just waiting on a response.

But i'm shooting for around $1700-2000 as a groupbuy price.


Thanks
-R

[mister2d]

A similar non CF intake would be nice and more practical. I'll be patient for one to arrive on the market.

[TheHouseWon]

My economic models show that given the amount of m5 f10's out there that have owners willing to mod their car with at least an exhaust, you'd maximize profit at $1,000 . Any more and you're leaving money on the table. Any less and you'd have to outsource manufacturing and lose some control of build quality.

This is a back of the envelope calculation

[allmotor_2000]

Please show me a dyno of this intake vs the stock w/drop in filters.

[Sales@RKautowerks]

Originally Posted by mister2d

A similar non CF intake would be nice and more practical. I'll be patient for one to arrive on the market.

I thought about that, but elected not to, if there is interest, i will look into that.

Originally Posted by TheHouseWon

My economic models show that given the amount of m5 f10's out there that have owners willing to mod their car with at least an exhaust, you'd maximize profit at $1,000 . Any more and you're leaving money on the table. Any less and you'd have to outsource manufacturing and lose some control of build quality.

This is a back of the envelope calculation

Mind blown!

I'll have downpipes and a tune to offer with these by end of next week.

Originally Posted by allmotor_2000

Please show me a dyno of this intake vs the stock w/drop in filters.

I'll do you one better, i'll mail you(at my expense), a set of these intakes and you can mess with them yourself. Leave me a 100% refundable deposit and i'll get a set out to you.

Of course i'll have my own dynos as well.

[TheHouseWon]

I have drop ins right now and willing to dyno your intakes at the local tuner's shop

For scientific research of course

[m5james]

I love that these are carbon fiber at a great price. I just wonder if it muffles the sound a little being plastic vs metal?

[momos750]

Subscribing.

To the op, very impressive write up with the technical data. It appears you know your shit!!

[tec333]

From the pics I'm digging this intake. Let me know what the group buy price ends up being. I'm going back and forth between these and the eventuri. Getting a decent price on eventuri and planning on maybe modding it and getting a pipe fabricated to put the filters forward. Just not sure the inverted filter assembly will fit behind the grill.

The MSR looks great but price point is not appealing to me. The above looks great just need to know final price and what kind of filter it comes with, maybe some dyno numbers, etc

[allmotor_2000]

Originally Posted by DallasM5

I'll do you one better, i'll mail you(at my expense), a set of these intakes and you can mess with them yourself. Leave me a 100% refundable deposit and i'll get a set out to you.

Of course i'll have my own dynos as well.

I wouldn't mine trying it out and will dyno next time I run the car.
PM me and we can work something out.

[Sales@RKautowerks]

Originally Posted by TheHouseWon

I have drop ins right now and willing to dyno your intakes at the local tuner's shop

For scientific research of course

I honestly don't have a problem with that, i'm serious when i say i'll have a set you guys can try it. Leave me a deposit and i'll send you out a set.

Originally Posted by m5james

I love that these are carbon fiber at a great price. I just wonder if it muffles the sound a little being plastic vs metal?

the plastic intakes were very thick, about 0.125 wall thickness for durability testing reasons. The Carbon fiber intakes are .030" thick.

Originally Posted by momos750

Subscribing.

To the op, very impressive write up with the technical data. It appears you know your shit!!

Thanks, this is nothing compared to getting grilled at work. Having a multi million dollar dyno cell has its perks along with a 180mph wind tunnel, flow bench, CFD programs, 1d/2d engine modeling.

Originally Posted by tec333

From the pics I'm digging this intake. Let me know what the group buy price ends up being. I'm going back and forth between these and the eventuri. Getting a decent price on eventuri and planning on maybe modding it and getting a pipe fabricated to put the filters forward. Just not sure the inverted filter assembly will fit behind the grill.

The MSR looks great but price point is not appealing to me. The above looks great just need to know final price and what kind of filter it comes with, maybe some dyno numbers, etc

I'll honor the pricing i told you via PM, unless it's lower. I can get you a set this week if you'd like. Not sure why you'd want to purchase both when i've done all the work for you with an optimized setup. Can even set you up with our downpipes and ECU tune as a package deal.

Originally Posted by allmotor_2000

I wouldn't mine trying it out and will dyno next time I run the car.
PM me and we can work something out.

Shoot me a PM whenever you want me to drop ship a set. I don't mind you guys testing out a set for yourself.



messed around with a light booth that i made tonight. Will purchase a DSLR tomorrow along with proper lights to get rid of those shadows.




For those interested in checking out my companies work, feel free to visit us at www.rkautowerks.com or follow us on facebook at https://www.facebook.com/RKAutowerks/


Regarding purchases, I'll honor a groupbuy price of $1850+shipping for the first 10 sets. I have 20 sets on order.


Thanks
-R


Here's a pic of our stage 1 E39 M5 supercharger kit, currently working on a twin turbo F430, 550i intakes, and few other projects.

[m5james]

Originally Posted by DallasM5

the plastic intakes were very thick, about 0.125 wall thickness for durability testing reasons. The Carbon fiber intakes are .030" thick.

I'm more or less thinking metal would help carry the sound more vs the plastic absorbing it. With that said, I'd love if my intakes were carbon fiber because they heat soak like crazy after sitting for about 5 min with the the engine off. The only reason I wanted an intake on my X5M was to reproduce the sound that MSR is making with theirs, but since they didn't have an X5M option, this had to be custom made and I'm helping fellow X5M/X6M owners by having it duplicated.

I was told that going from oval to round would cause turbulence, blah blah blah...I'm guessing with all your reported research that it's not an issue? Do the inlets have velocity stacks where the filters bolt on? That was something I have considered looking into adding onto my intakes.

[ur20v]

99% of cone filters have 'velocity stacks' built in.

[Sales@RKautowerks]

Originally Posted by m5james

I'm more or less thinking metal would help carry the sound more vs the plastic absorbing it. With that said, I'd love if my intakes were carbon fiber because they heat soak like crazy after sitting for about 5 min with the the engine off. The only reason I wanted an intake on my X5M was to reproduce the sound that MSR is making with theirs, but since they didn't have an X5M option, this had to be custom made and I'm helping fellow X5M/X6M owners by having it duplicated.

I was told that going from oval to round would cause turbulence, blah blah blah...I'm guessing with all your reported research that it's not an issue? Do the inlets have velocity stacks where the filters bolt on? That was something I have considered looking into adding onto my intakes.

I have plans to knock out the x5/6m intakes as well. Just need to find a car, I'm willing to offer anyone who has one intakes for next to nothing if they'll let me scan their car.

It depends on the velocity of the flow, to say it's going to go turbulent is a very loose statement. Define what turbulent and laminar are. I suppose we could get into reynolds numbers, but honestly with the setups on these cars, that's really not a concern. The flow will never go supersonic which is all that really matters.

-R

Originally Posted by ur20v

99% of cone filters have 'velocity stacks' built in.

To some extent yes, but the benefits are extremely marginal because of the turbulent nature of the flow in that area.

[Sales@RKautowerks]

Here are better pics for those that asked, or were interested.









Thanks
-R

[Sales@RKautowerks]

Ran a part analysis to see how accurate the intakes are to my CAD model.

Doubt you'll get this from others



-R

[tec333]

The silicone 45 degree coupler...one end is oval?

[Sales@RKautowerks]

Originally Posted by tec333

The silicone 45 degree coupler...one end is oval?

no, it's round, it slides over the intake and the intake tapers out to create the seal. If you look closely at the inlets, you'll see the first inch is smaller than the rest. I did that so there was clearance for the hose clamp and to make it easy for everyone to get the hose clamp on. It seals like it should and is easy to install.

-R

[evilb]

The video on your Instagram account shows that there is virtually no intake sound increase with these. Do you have other videos, or is that in fact true?

[Redrckt135]

Originally Posted by evilb

The video on your Instagram account shows that there is virtually no intake sound increase with these. Do you have other videos, or is that in fact true?

+1 I'd be interested if these sounded like my MSR's.