So, truthfully, this is a copy of a post that I just made in our
Intake Development Thread, but I thought that it could definitely stand on it's own as a resource for those not yet interested in spending the money for a full intake system just yet.
http://www.ft86club.com/forums/showthread.php?t=50492
Stock AirboxDyno Testing
Ok, Here we go. We'll go through these in pretty much the same order that we approached the dyno testing. As far as test procedure, we brought the car to the dyno that morning with a completely stock intake setup. The panel filter in the car has 10k miles on it. After strapping it down and finding a tach signal, we reset the ECU. We reset the ECU between every configuration to ensure consistency in testing method for comparable results. We utilized an OFT with a stock rom file, but changed the IAM (ignition advance multiplier) to start at 1.0 instead of .7, and scaled the o2 sensor's lowest reading only for datalogging purposes, otherwise no changes were made from the stock rom.
For each configuration, three pulls were made in 3rd gear and three pulls were made in 4th gear. We'll look mostly at 4th gear pulls, but we recorded both to show that there's no funny business. If you're interested in seeing a specific pull or set of pulls in 3rd gear, just ask. All pulls were back to back. After a set of pulls was completed, the car was shut down, ECU reset, intake configuration swapped, datalogs saved and then we went back to it. This kept the time between sets of pulls consistent as well (around 15min).
The dyno is a Dyno Dynamics unit and reads pretty low compared to others. We had two industrial fans feeding the radiator through the day - this is their standard setup. The dyno cell hovered around 41F, 32% humidity and 30.11 inHg all day. I'll post a handful of photos in a bit.
Results - Stock Airbox Configurations
Ok, the fun stuff. Parts not mentioned (airbox, filter, snorkel) in a given configuration are stock unless otherwise noted. Here's the list of configurations tested:
1. Stock
2. Modded Snorkel (I'll post photos in a bit)
3. K&N Drop-In
4. K&N Drop-In and Modded Snorkel
5. K&N Drop-In and Modded Snorkel and Silicone Elbow
6. K&N Drop-In and Silicone Elbow
7. Silicone Elbow
On with the charts. We'll keep our thoughts/theories and analysis for the end.
Completely Stock
Modded Snorkel
K&N Drop-In
K&N Drop-In and Modded Snorkel
K&N Drop-In and Modded Snorkel and Silicone Elbow
K&N Drop-In and Silicone Elbow
Silicone Elbow
Lastly, here's a comparison of Stock, K&N Drop-In, K&N Drop-In with modded snorkel and then the K&N Drop-In, Modded Snorkel and Silicone Elbow. The legend up top should help you identify which is which. I can clarify if needed. For each configuration, I selected the run in each set of three pulls that was closest to the average power gain.
Well, not a whole lot different than expected, right? A nice little bump in power (4-5whp), but she's looking pretty lean. The modded snorkel appears to richen things up a bit but maintain the gain. The silicone elbow doesn't appear to have much of an affect on performance (1-2whp with the stock filter and less with the K&N). All in all, the K&N drop-in and modded snorkel are not a bad gain for such a small investment, but we're not wild about the change in AFR.
At this point, our goal with the
GrimmSpeed intake is still to show a solid gain, but with stock-like AFRs. This should provide a great bolt-on solution without any concerns with AFR and also be very tunable. After seeing the K&N results on the dyno, we were a bit nervous. Our design methodology was sound, but who knows!
Alright, so that wraps up our testing of the various intake setups using the stock airbox. This, we thought, provided an excellent set of baseline setups for comparison against our prototype designs.
Discuss!
Matt Beenen
Engineering