RBM-CLK

You beat me to it. Busy week here at SEMA. The car is on display with Mobil 1 Racing. Enjoy the video.

Maverick1975

Very nice cutouts!

jrcart

...so where's the blown diffuser? That's the coolest part of the exhaust IMO. Did you guys change your minds on it? I saw the blown diffuser when it was like 85% complete in person.

wonsuk_utmb

Sorry, I thought you were busy @ sema

FluidMotorUnion

We had the blown diffuser off the car for the dyno runs, solely to remove any potential for the diffuser coming in contact with the dyno. If the aluminum were to bend or scratch off the powdercoat, we'd be F'ed, as there wouldn't have been enough time to make a new piece or re-powdercoat the old one. All the road-testing shots were done just before the truck arrived, so all the pieces were in place for that (same goes for the fireball shots towards the end of the video). The final set of fireballs at the end of the video (the close-ups of the tailpipes) were taken from an earlier video I made while the EBD was out getting powdercoated. It was a bit of a hodge-podge, but I wanted to make sure that I included as much video as possible.

We did a pre-SEMA iPhone video of the BS shooting flames, which you can see below. Granted, it's at night, but you can see just how crazy the EBD makes the fireballs as they shoot out of the tailpipes onto the diffuser.

http://www.youtube.com/watch?v=FWRQCKutF20

I'm going to have pictures and everything of the car (finished, in terms of FMU's work -- the front lip, roll cage and interior were done after getting to SEMA) up on the blog today, along with a description of the exhaust-blown diffuser and our reasons behind incorporating that design from Formula 1's Red Bull RB6 chassis.

Thanks for the kind words, though, everybody! I and the service techs are holding down the fort in Plainfield while the rest of the guys are in Vegas, getting the name out there. We have some crazy things coming up, from what I've been told. Keep an eye on the blog for more SEMA and BS stuff as the week draws to a close

-Andrew

jrcart

If the owner can drive this car will easliy win the Optima Street Car invitiational, I assume he was invited, or qualified and a regional event.

_AMG_

Now that's what I'm talkin about!
Sounds amazing, never seen an AMG shoot flames like that before.

CLKBSVegas

I need flames! Can someone post or pm me what i need to do to my car to get that sound and flames. Might have to start saving!

Sincity

You don't need the RV.......

CLKBSVegas

Please tell me this set up is street legal in NV....

Maverick1975

I guess the flames are from fuel unspent fuel reigniting ion the hot exhaust gases but why does that happen on this particular set up?? Can some one explain??

FluidMotorUnion

Thanks

Email mmarzano@fluidmotorunion.com and we can point you in the right directions!

If catless exhausts are street legal in NV, then you're all set for some fireball action.

The RBM Black Series is able to shoot fireballs so easily for a few different reasons in conjunction. Without giving away all our secrets, I can give you a rough rundown of what will help pop serious flames like that.

-Colder engines run richer
-Resonator/muffler choice plays into it
-You need a cat delete
-A richer-running tune has a better chance of popping fireballs also

Obviously the tune portion was out of our hands (Weistec handles software flashes for all their supercharger systems), but the rest can be done in the creation of a proper exhaust system. Start the car up, rev 'er up a couple times, and boom, fireballs.

rage2

haha called it!

Really cool concept, been waiting for someone to do one up on a road car. How functional is it? I mean, even the smaller F1 teams can't get it running right, so unless you have Newey giving you guys a hand...

FluidMotorUnion

Ours is significantly less intricate than anything being put out by the Formula 1 teams, and they have specific software maps to back it up (such as the ability to maintain a constant exhaust velocity even during off-throttle time), so while there's a lot more that goes into it, and a lot more that can go wrong, there's also a lot more benefit to be taken from it.

Ours is a bit simpler. Exhaust exits into the diffuser onto the "shovel" in the middle of each side of the EBD, which funnels it in a laminar flow through the diffuser, taking the slower surrounding air with it (as air is viscous), thereby speeding up the majority of the diffuser's airflow and adding downforce. With those diffusers incorporated into the underbody paneling, when the exhaust is blown through it, we're seeing a twofold increase of downforce at lower speeds. At least, according to SolidWorks we are. It hasn't hit the track juuuuuuust yet. But it will soon!

jrcart

Is this car running in the Optima Street Car race tomorrow out in Parump?

RBM-CLK

I wish I could have made it out to the event - unfortunately had to return to Seattle promptly. We'll have it out at the tracks here pretty darn soon!

FluidMotorUnion

There's one remaining piece of the build that we haven't mentioned yet, nor have we shown you the final look of the car before it left our shop, so let's do that!





When showing off photographs or videos of the rear end of the Black Series, up until today, we kept the full assembly off the internet, choosing to let SEMA be the big reveal. Now that SEMA is in full swing, we finally figured we would clue you all in to the final piece of the puzzle — the exhaust-blown diffuser (EBD) — and our reasons for implementing it as we did. The idea for utilizing an exhaust-blown diffuser came from Formula 1, as have other ideas we’ve spawned. Given the sheer amount of money being thrown into F1 year after year, even with all the constant guideline changes and engine requirements, F1 constructors still manage to theorize cutting-edge technology and implement it within guidelines thicker than the Oxford English Dictionary.

While theorizing ways to make the Black Series sit apart from all the other cars at SEMA, we came upon the idea of using an EBD. Being the ones in charge of making the exhaust, we knew that SEMA was a place where the ordinary just won’t cut it. And regular ol’ exhaust tips weren’t really seeming like an interesting idea, or one that would turn heads. So we set about hiding the exhaust tips within our own custom aluminum creation. After plenty of time at the drawing board, and even more time on the CNC mill, we’d figured out a way to incorporate the basic functionality of the EBD while still maintaining a form that was easy on the eyes (and easy enough to create in our time with the BS). A perfect mix of form and functionality.





The science behind the EBD isn’t too tough to grasp. You can see on each side of the carbon-fiber, there’s an aluminum diffuser that we’ve created. In the middle of each of those diffusers is what we call a “shovel.” Essentially, the shovel’s job is to direct the flow of the exhaust as it exits into the diffuser. Without the shovel, the air would be turbulent and wouldn’t produce any extra downforce. The exhaust gas is almost always moving faster than the air around it, especially at lower speeds; also, if you remember science class, air is viscous or “sticky.” The faster-moving exhaust gas exits the tailpipe onto the shovel, which directs it into a laminar flow (the opposite of turbulent flow) as it exits the diffuser. That laminar flow of exhaust gas will “grab” the viscous air around it, speeding it up as well. This increased velocity contributes to the pressure differences in the diffuser that create downforce.

Now, a proper Formula 1 exhaust-blown diffuser relies on a boatload more theory than this, but it was this basic idea that spurred us to create the EBD you see on the Black Series. We’ve flow tested it in SolidWorks, and having the diffuser blown by the exhaust almost doubles its effectiveness at lower speeds. Additional increases can be extracted from the exhaust by taking advantage of its thermal load. Using the exhaust to heat the air traveling under the car causes thermal expansion which further reduces pressure, increasing the effectiveness of the diffuser system. For that to be possible, you’d need a much more complete undertray system and other changes to the system as a whole. For those of you interested in this sort of aerodynamic work, good luck finding it online; as it’s really a trade secret between various F1 manufacturers at this point, there’s not very much official information on how EBDs work. Forum posts on this topic are abundant, but you can never really tell who actually knows what they’re talking about on the forums.





So there you have it. Not only did we eschew the long-standing notion that exhaust tips had to be just that — old-fashioned plain metal tips — but we also managed to bring in some extra functionality with it. Essentially, an EBD just uses what the car is already producing (exhaust gas) to have some sort of beneficial attribute above what it normally does. These last three pictures will show the parts of the car that you don’t normally see in a regular picture. First, we have the engine bay. The M156 should be well north of 600 bhp with the Weistec Stage 1+ supercharger kit, and it’s helping to stay cool with an Aquamist HFS3 water-methanol injection kit, supplied by Howerton Engineering.



Next, we have our Silence To Violence switch. The toggle on the right controls the electric cutouts in the exhaust system; with the cutouts open, the mufflers are bypassed and the unmuffled exhaust is let straight into the EBD. Both settings empty into the EBD, so loud or not, you’ll still be producing downforce. The switch on the left controls the WOT Box, which we’ve installed for one reason and one reason only — violence. It’s not a normal 2-step like you get with a WOT Box; instead, we’ve wired it to dump fuel into the exhaust, which in an overrun situation will cause a fireball like none you’ve ever experienced. Your humble narrator first heard the WOT Box fireball inside the office as the Black Series was being road-tested. It’s not your typical fireball; this sounds more like a rifle shot happening five feet from your face. It’s that singular POP you hear in the Black Series feature video. Why would we create a switch that wastes fuel for the sake of mind-blowing fireballs? Because we can. CAFE standards quake in our presence.



And finally, a shot of our EBD system, which we incorporated into a rear undertray, connected to the BS through that bar-and-arm system we showed you a week or so ago. Since you haven’t seen it before in its completed state, here’s the back half of our exhaust system:

_AMG_

Easily one of the sickest CLK BS on the planet!
Only thing that's missing is the AMG logo on the calipers.

I really like the silence/violence valve switch.

FluidMotorUnion

Thanks! We thought the valve switch was the perfect compliment, as we'd been using the "Silence to Violence" theme throughout the build. The devil's in the details

And by the by, let's add a couple more shots. These are with the other wheel choice, made specifically for the track. BBS wheels and Pirelli tires are a combination with more history than a Survey of The Roman Empire class.

Here are the ones snagged by Teamspeed.com:






And here is the BS in its current home, the AMG Performance showroom at Fletcher-Jones Imports, Las Vegas, NV:

Maverick1975

The previous iteration of the car was fantastic but i think that the silver BBS wheels make this car look just disgutingly good. This thing looks awesome, even the wing is starting to grow on my a little!

RBM-CLK

Thanks for the props man! I knew the look of the wing wouldn't appeal to everyone but it's construction and true function are both amazing. It's the Varis Japan Euro GT Wing; full carbon plane, stands, and mounts. The BBS really go well with that wing and I'll use this setup during Time Attack events. I have a second trunk with the Vorsteiner Rear Spoiler that I'll run with the ADV.1 wheels which are just TOO sick looking to not have on the car!

jrcart

You guys should post up some pics of the bar and brackets in the trunk, I think it would help show how the exhaust blown diffuser works and transfers that downforce to the chassis I saw it in person and its self explainatory when you can see the entire set-up but might be difficult for peop.le to understand from these photos.

I love the BBS wheels on it too.

SMP

Saw the car last week at SEMA. Very well put together ..... but the custom color is my favorite!

FluidMotorUnion

Definitely JR! Here are a few images of the rear bar design.

Initial Rendering:








Then, this image sort of gives you an idea of where the cut-outs come into play. When you they divert straight through into the blown diffuser. When shut, exhaust is pushed up into the mufflers and then dumped into the diffuser!


Thanks for the kind words guys, we really appreciate the support.

_AMG_

WOW, and I thought it couldn't get any better!!