Although it looks cool i have a couple of questions and thoughts about the design that may be completely incorrect:

1. I can't really understand why you ditched the rear carbon diffuser for what appears to be a heavier piece. I doubt it would produce the same amount of down force at speed due to the fact that you more than likely haven't tested it in a wind tunnel.

2. You have placed the exhaust next to the tires which could produce extra heat near the rear tires which could be detrimental to performance of the tire in regards to longevity and i wonder if it could possibly cause more wear if the car idles at a standstill?

3. The exhaust is placed in a position where it could be damaged by rocks that flick up from those huge tires.

All in all i love the idea and creativity of what you've done, i'm just not sure it's more than an exercise in appearance rather than functionality.

 

What exists currently on the CLK Black is not actually a diffuser but rather a cosmetic piece that covers the differential cooler. It is styled like a diffuser but does not create downforce.

That said, I am not sure that what they created will create downforce either.....

As I mentioned in the other thread, I like the creativity and the side dump exhaust but the jury out as to the performance enhancing ability of the diffuser they added.

 

1. The stock "diffuser" is not a diffuser, but more of a cosmetic piece and a aerodynamic parachute. Also, The stock mufflers and tips are not very aerodynamic! See pic below. You are correct, we did not use a wind tunnel, We consulted an aerodynamics specialist from Boeing, he used to work for Sauber and Swift.He used some simple...surprisingly simple math and a CFD program to calculate theoretic gains. He is a personal friend of ours...Good to have him around. As for being heavier, yes our diffuser weighs 8.5 pounds and the stock rear valence is only 3 lbs, but our exhaust is 39 pounds lighter then the stock unit and produced 31 HP and 34 lbs of tq to the wheels.

After building the diffuser, we did not have a place for the exhaust to exit. We liked the idea of behind the rear tires.

.



2. The closest the exhaust gets to the tires is 5.5inches and that is when the suspension is at full droop, when the car is on the ground, it is almost 6 inches away. We used a ceramic coating on the inside and outside of the pipes. That ceramic coating reduces radiant heat by 55%. On the dyno with little airflow around the exhaust, the hottest the integrated tip got to is 137degF. We checked this by using an inferred temp gun. We were also concerned about this, but we are very impressed how well the BASF coating works. After a hard run, you can place the palm of your hand on the exit and hold it there with out getting burned.


3. The material that the tips are made out of aluminum-lithium and the pipe welded to it is 6061 T6 alloy. We used this light weight alloy because of its high strength and its ability to dissipate heat and not retain it like stainless steel. As for the rocks, We felt that the metal is stronger then the plastic that was in it place behind the huge tires.

Thanks for the points of discussion.

Kindest

 

Thanks for the response Betim. Sounds like a lot of hard work and i for one commend you.

 

I like it. Would love to hear some sound clips/see some vids of this beast! keep up the great work guys!

 

cool,

We should have some vids up next week!

 

Betim u are so ridiculously talented it is scary, you and your team hats off man!

 

BTW Betim vid sound clips please and where the heck is Dana? - u hear from him lately ?

 

DJ - I am still alive! Reports of my demise are greatly exaggerated. Check out the Off Topic Lounge and the Moderator Forum to catch up!

The car is an absolute MONSTER! When it starts up, it doesn't matter what anyone is doing they stop and take notice. It is a special car.

I love the pics Betim. My favorite one is the shot of you building the exhaust in your flip-flops . . . Good thing you are fully insured.

Here are some shots my son took of it when DUB Magazine came by to do a story on BBI.