Street datalogging

[sltous]

Got the car hot with a few miles before I started adjusting for flow.  Peppy, clean downshifts, a good starting point.  Started at ~6kg/s on all four cylinders, using a 6mm and a 6.1mm drill bit for setting the idle adjustment screw I think my intakes at idle were right around 6.1mm without any further adjustment from the weekend.  This might want to be adjusted down just a hair but I'm relatively happy with the car.

1. Adjusted to 5kg/s per the Caterham guidance
   1. This was way too low, my idle was unstable dropping down into the 800s.  Car drove OK once I got on the beans a little but was not lively pulling away from a stop and overall not the Caterham experience.  Maybe if my idle was set a little lower this would be OK.
2. Adjusted to 5.5kg/s
   1. This was OK.  Intake felt really gulpy and the car was not as lively as at 6kg/s.  Idle was good, right around 1k rpm, not particularly stable.
3. Adjusted back to 6kg/s
   1. Maybe not 'correct' but I'm generally not going for any max power or fastest lap times, just a nice peppy streetable setup.  Idle is back up to ~1100 rpm
   2. Next steps probably I should make a real 6mm pin and tweak the idle back down a hair.  Using a drill bit I was running into the stamped numbers and getting some drag.

I think I'm going to put some more miles on at the 6kg/s flow at 1100 RPM at throttle position 1 and see if I continue to like it.

[ashyers]

Just sent you a PM.

 

I took second look at your maps and I think you're on target at 1100 RPM. There is a valley built into the map there, but I think you may be able improve the idle quality. I wouldn't worry too much about drill bit diameter or flow rates, they are used to get things close to target, you're there. Now you can do a bit of tuning to get what you'd like.

[sltous]

Took the car to work today, at 6kg/s air flow, right around 1100rpm idle it's a surprising sweetheart in light traffic.  Not planning to do a lot of stop-and-go but it's easy to drive slow and still has all the get up and go while keeping pretty decent downshift blips I was looking for when I got to open the revs up.  @ashyers I may reach out in a bit to try and smooth the idle out a touch more but I'm feeling really good about it right now.

[ashyers]

Glad to hear it's running well!

 

I'm learning a bit here, which is kind of fun! I was able to open up the advanced features on your ECU's maps and it has MANY more goodies than the earlier versions. This includes idle control with ignition timing. This is something I have to do the old fashioned way with the 967. This system has a ton of adjustablity, if you're inclined to dig into it.

 

FYI the target idle target speed is set at 1100 RPM (you nailed that) it may be adjusted for operating temp, but this has not been done. The system is currently set to adjust idle at throttle site 0 with a road speed of <5 MPH. From what I can tell it controls idle on the high side, once you exceed the target +500 RPM (1600 RPM) it pulls timing. Seems to me the trick would be to set the idle via airflow a bit on the high side at the proper location on the map and allow the ECU to smooth things out via timing. Even when you do this manually, without computer controls in the ignition maps, it works pretty darn well.

 

Andy

[sltous]

Not my parts but there is a Solo DL and an AIM Smartycam HD 2.1 on eBay right now for ~900.  To the best of my research this is one of the lowest cost barrier to entry, easiest to use, ways to get CAN data from the Caterham ECU onto a track map video with an external microphone.

 

I have the same setup (although no external microphone yet) and it has worked well for me the one track day I had the camera setup.

 

https://www.ebay.com/itm/115619310252?hash=item1aeb72aaac:g:JzsAAOSwMd9jg7Sm

https://www.ebay.com/itm/115619296885?hash=item1aeb727675:g:dNUAAOSwXcljg8aP