View Single Post
Old 11-04-2014, 04:41 PM   #159 (permalink)
Master EcoModder
Ecky's Avatar
Join Date: Dec 2011
Location: New Zealand
Posts: 5,016

ND Miata - '15 Mazda MX-5 Special Package
90 day: 40.51 mpg (US)
Thanks: 2,869
Thanked 2,514 Times in 1,554 Posts
The Insight's ECU case:

The blue connector is the one we're interested in.

Added some connectors to the TPS signal line (red/black) and ground (green/black) so I can take the mod out easily. I don't believe everything I read on the internet, especially before cutting into essential wiring, so before making any cuts I checked the voltages with a multimeter, then pulled the TPS off and tested again.

Smoothing circuit installed:

Just enough extra wire to let it poke out from the box if I need to adjust it.

I took it around the block, and my first impression was... no, no no NO NO NO!! Horrible! I could not drive the car like this. Taking my foot off the pedal caused the RPM to shoot up ~500 and stay there for a moment, before dropping slowly back down. After taking my foot off the accelerator and pressing the brake or pressing my regen lever, regenerative braking would take a half second or more to engage.

I drove it around for a good 45 minutes, testing both extremes of settings and everything in between, and found that at around 20-25% I actually really like this mod. Dialed back enough, regenerative braking has no noticeable delay. Throttle hangs for just a moment and drops more slowly after releasing gas and clutch than without the mod, but doesn't overshoot, which should be good for my wife's generally-a-little-slower-than-mine shifting. Assist seems to be determined partly by the TPS (small changes) and partly by load, so even at the max setting, mashing the pedal would still apply full assist. However, with this mod in place, assist doesn't kick in quite so suddenly with small pedal changes, but rather, gradually ramps up, resulting in a much smoother transition.

It's far too early to have any MPG numbers, but the car seems to be more pleasant to drive without any obvious downsides or performance loss. I'm not sure what the exact resistance is at the setting I have it at, but if the pot I have is linear, I'd want something like a 2k resistor rather than the 5k recommended over on InsightCentral.
  Reply With Quote
The Following 2 Users Say Thank You to Ecky For This Useful Post:
KFM (03-06-2015), Xist (11-04-2014)