Time for another update.
I had been preparing the car for D4C 2018 making sure that I could make the 1000 miles, but also have reliability with the varying mountain passes and varying conditions. You saw some of this detail in my last posts. Next up, I finished the installation of the passenger front sport seat which has everything working except the headrest motor.
A great video highlight of D4C 2018 here
gives you a good idea regarding the meet itself.
Here's a recap of my trip. Not as many photos as with my M5 last year, but still fun to tell the story a little:
My 2018 route:
Group departure from Denver
Picking up more in Salida, CO
Group meetup in Durango, CO
Purgatory and the event drives
Burt made the group photo too
Some moisture on the drive back
My brother's euro 3.1L turbo 325iX, also Diamondschwarz
We took a few extra days to explore and I took my wife to Mesa Verde. Neat sculpture on our extended route home.
My beautiful hiking partner
A night stay near Ridgway, CO
Unexpected road hazard!
General check up on the car and setting up the mic before a new mountain road
Neat to see the railroad right next to this coal mine that we got to drive under
Dinner stop at a historic inn
Our night stay near Glenwood, CO
It was over 1000 miles, about 14 passes over 9000', about 24mpg, and the car didn't skip a beat. I did have to adjust a few megasquirt settings for idle at the high elevations, but the cool temperatures really offset the less dense air of the higher altitudes.
Here is a collection of video (sights and sounds) from the trip with my car:
After the trip, I have been readjusting my fuel and ignition maps for driveability now that I know my baro and temp corrections are about right. Very little air temp correction, I suspect because it is coupled with baro, but sitll it is less aggressive than I thought I would need.
EGO control seems to give me more problems that I want, so I decided to shut it off and see about running open loop only. This leads to multiple days of tuning to try to dial in my fueling map. I have touched boost regions but have to continue fine tuning.
Here's where I am at currently.
One of the biggest changes so far was some reading on ignition timing and reviewing my map. I am running 91 octane, but a great short summary I found was here: http://www.autospeed.com/cms/A_109132/printArticle.html
Basically, I decided to add a little timing in the normal driving range up to 3000rpm. This seemed to really wake up the car in terms of response and build boost. I am trying to gauge driveability and feel if the car likes it or not. I haven't touched much in the boost region as I think I really need to get on a dyno to optimize this setup. Still, seems like better driveability and I think it will improve my MPG in normal cruise as well. I have been removing timing when I notice slight bucking and have gotten transitions pretty smooth now.
Here's my MAT retard and TPSdot accel enrichment. Any comments on these settings would be welcome! Sometimes I get lean spikes, sometimes rich spikes for the same TPS and I am wondering if that's why the slider is available for MAPdot.
Lastly, I decided to do a 3rd gear pull on my drive home and see how it compared to my curves in the dense air of January and the initial setup in the 633. Same colors as before. The 535is has a shorter diff, so it is faster, I'm thinking 3rd gear may not be the best for the dyno plot. I still need to dial in the fueling and I am sure I could get it to a dyno and really get the timing set for the boost level... but for now I'm learning by tweaking it myself.
The first run (Orange) was run with my Callaway Log, old noname intercooler and 2" piping at about 6psi.
In warmer weather I had bumped up the boost to about 10psi and taken a log (Green). It probably isn't a fair pull to use in terms of RPM and gear, but an increase of only 20lb-ft torque is all that this plot indicates. Maybe this is due to the richer fuel mixture or warmer temperatures that day, but I didn't extensively test 10psi so I can't really make a judgement on this curve.
Pull without an intercooler (Blue). This is with the TCD manifold (ceramic coated), valve job, and new exhaust flange coming off the turbo. Interestingly this log with increased IAT's still gave number similar to the old setup at 10psi.
New setup with intercooler and larger charge piping (Red) in january 2018. With the same turbo and same boost level this data shows about a 10% increase in performance.
Today's pull (lime) with 535is chassis, different intercooler piping to fit the e28. A very similar boost level and timing values, but I was able to run the curve out almost to revlimit at 5700rpm. With 3000 miles on the engine, I don't often do this with the a long pull. You can see torque and power drop off, so there isn't much reason the exceed this point anyway...
Similar numbers as early January which is encouraging since we are now into summer.
I'm on the fence of tuning for higher boost levels, but I may just leave it as is because if I turn it up, I may not want to turn it down! 10psi (or 147kpa) is really my track use goal for durability.