Monday, July 12, 2010

Improving Perfection

Hi everyone.
I've got an 2004 S2000 AP1 Rev2 F20C. Not too long ago I decided to install a CAI.
I tried to go for something that would render top end power, but without loosing torque curve immediately under VTEC engagement point.
After some consideration I decided to go the AEM V2 way. Why? Well, under 400€ is was the very best thing.
The car felt stronger, but I've always felt that I got more torque than high RPM power.
VTEC kick in got noisier, and that was coherent with the pipe inside pipe "resonance design". But that also meant that the car was struggling more to get air at that particular point. But was still an improvement.

Having a degree in Technology of Mechanical Engineering, and a "thirst" for knowledge on every thing that is both mechanical and efficient, I invested some time thinking on a way to improve the car.

Studying all the intake improvements for the s2000, I realized that the you could divide them into 3 groups.
1 - Torque oriented - Like the standard CAI from AEM and so many others. Basically it's a long thin pipe that stretches from the throttle body assembly, all the way down to the front bumper just under the front right headlight.
2 - Power oriented - J's racing carbon unit and a couple of items from other manufacturer's. It's a carbon elbow from the air filter box to the throttle body assembly curving in an enlarged section tube.
3 - Middle term - It's the Full spoon assembly and the AEM V2 - It's a combination of an enlarged pipe to increase Peak Hp with an extension of the intake system providing better torque curve. The AEM V2 is very similar to the standard CAI but has 2 tubes (on inside the other) and works the sound wave to force air to swirl differently depending on the rpm and emulating both a large short tube (loud intake and power at high rpm) and the thin long tube (lower intake sound and torque at low rpm).

Not too happy with this result, I decided to do a small test. I cut the dummy hole in the bumper, directly in front of the AEM V2 air filter. I thought that, if fluid mechanics didn't abandon-me, the high pressure air forced by the car's body into that hole would create an increase of pressure in that compartment under the headlight. This would help the VTEC transition and should be noticeable but the less loud "powaaaaaa". Did it work? No! Too many respiration and water purging holes, so very little pressure was created. I had to do something more radical.
I was thinking about protecting that entire section and make it impermeable when I found the 4th type of S2000 Intake!

As you can see in this photo, from my friend Nuno Santos shop Autopamplona, this intake system provides a huge potential for high rpm power, but also has an extension, trying to preserve torque.

But this is far from the catch to this intake...

It also has a HUGE catcher that enables it to channel high pressure air from the front of the car into the intake system. and that's exactly what I was trying to do. Only their approach was... rather radical, and ultimately better.

So I started my own project to change my AEM V2 into something like this. And this time, IT WORKED!

1st - Grab your laptop, check the S2000 maintenance manual and then disassemble the front bumper. Easy 5mnt procedure as the manual shows.

You can see clearly look at the AEM V2 AirFilter in this next picture.
2nd - Since you're disassembling the car's intake, clean the air filter, dry it, and spray new airfilter oil.
3rd - The fabrication begins. Get the materials. The best way to do this is to buy fiberglass, paper tape, silicone and sheet of metal grid. The metal grid will allow you to:

  •  - Mold the forms you want.
  •  - Hold that forms during fiberglass coating
  •  - Gain a few scars

4th - Mold the chamber in a balloon shape around what was the air filter space. Read a couple of book about aerodynamics  first so you can come up with a design that helps to squeeze air into the filter.
REMEMBER TO place the bumper to test for clearance, and the good thing about the steel grid is that it deforms to the bumper to you can check the areas to workout next.
...and you should come up with something like this.
5th - Use the paper tape to cover everything and make smooth surfaces.
6th - Time to wrap-it-up in fiberglass!
... and you should come up with this. I made a section cutting to remove the steel grid and to allow space to mount the air filter on the CAI. The small part on the floor is the cover I've cut.
7th - Give-it some color and install-it.
This is where the silicone comes in. It will seal the fiberglass box to the CAI and will also smooth the box's interior, removing any imperfection the fiberglass on paper might have left. 
REMEMBER to allow space to install the air filter. And after the silicone is dry, install the air filter.
8th - Close the Box, with the cover cut out earlier, and seal everything with either silicone or some polyester filler.
The filter is visible at the end of the air box, and so is the silicone smoothing partially done.
9th - Spray some black ink, and mount the front bumper.
10th - Take it out and rev-it-up.

Did it work? YEAH! My VTEC entry is so smooth that you no longer ear-it, you just feel-it. It gets very clear that the faster you go, the better throttle response you get. The car feels stronger and a small uphill that I used to end at around 180Km/h to 185Km/h, now comes in at over 190Km/h as THIS VIDEO SHOWS...and it's UP-hill, so both torque and high rpm are very important features.

Here is a new video on a different (longer) uphill.

Another UP-HILL 100-to-200 video, why always up-hill? Cause I'm trying to archive Hi-end power AND torque.

Hope you liked it.

NEXT on to-do list :
  - 3 step aerodynamic improvement
  - Brake cooling improvement
  - Better Intake
  - Ultimate exhaust system

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