Targa Miata
June 29, 2011 - Good news!
The engine computer is back from being reflashed, and it's working far, far better than before. Many more horses now live under the hood. It's not yet perfect, but it's now running in closed loop and with long term trim so it'll get better. Best yet, I can now get in to the computer to tune it. So we're well on the way.
I also discovered an advantage to flexible air dams. There's a piece of road nearby that was torn up for construction and hasn't been repaved. There's a slight drop down to the gravel/dirt level. Well, when I (purposefully) took this at a high rate of knots, the air dam bottomed out and became a snowplow. A truly impressive cloud of debris was raised. Back in the garage, there's no damage to the dam and a few screws that have pulled out. I was going to replace those with bolts anyhow, so no harm done. And yes, I do need to lift the car up. I'm pushing it right now to find out where the weak areas are.
entry 865 - tags: power, V8, air dam, aero
March 2, 2012 - With the car off the dyno, I took advantage of the fact that I was at the FM shop to hijack a lift.
Step one was to clean up the front aerodynamics a bit. Previously, there was nothing between the air dam and the skid plate. I did have ducting around the radiator so that air was well used, but otherwise it was just plain messy from an airflow point of view. Not anymore!
The plate can easily be removed if I need to get in there - it's held in with a few machine screws around the bottom of the air dam and four bolts at the back. You can just see some rivets in this picture for one of three stiffening ribs that keep it from flexing, and I also did a bit of work at that corner by the wheel to add a lip for more strength. Since it's made of thin aluminum, it weighs very little. But it should do a lot to clean up the airflow.
One downside is that the airdam is no longer flexible - and the car is also much lower than it was at the Targa. So it's going to be more prone to damage. I'll have to behave myself over drops from now on.
entry 1022 - tags: aero, air dam
March 2, 2012 - I'm also looking at adding a splitter up front.
Made of 0.090" aluminum, I'll probably make it adjustable so I can fine-tune the amount of front downforce on the car at speed. The green tape shows the approximate outline.
I've been doing a lot of aero reading and picking of various people's brains. Jeff at Slick Auto (who donated the carbon fiber headlight lids to the car) has been particularly helpful. His suggestion was for a full belly pan to smooth out the airflow under the car from axle to axle. I'm not sure I can pull that off due to my exhaust, but I'm going to spend some time looking and thinking. The front undertray was really the low hanging fruit. I've got some ideas that will be fun to play with, too.
entry 1023 - tags: aero, splitter, air dam