1989 Mondial t Dyno run!

The chipsss came back this AM. By chipsss I mean 2 SETS of 2 chips. I received a "custom" set AND a "slightly-more-aggressive-custom-timing" set. Since I am leery of detonation (it is a 10.4:1 motor after all), we decided to put in the "custom" set. I still have not gotten the car back but the tech at WWoC says it starts great, idles well, and has great pep. I'm rather relieved it just runs. WWoC will also run A/F tests (not dyno) to ensure my lean condition at low RPM has been rectified. Dyno next Friday, so we'll see.

In parallel, the next project is the octane adjuster input on the Motronic 2.5. Here's the gist: Put the even more aggressive chips in the car. Wire one of the famous unused switches on the Mondial t dash to a voltage source that hits that pin. If I run 94 octane fuel, the switch is off. If I have to put in 93, turn on the switch to retard timing a bit. I have to dig into the Bosch manuals a bit on this but in theory it's doable.

When it's all done, this will either be a very nicely performing Mondial t cab or a very expensive and time consuming way to learn about EFI. Let's hope it's the former.

 

Dyno'd the Mondial this afternoon with the PowerChipGroup chips on the same dyno as last month.

The Good News:
1. When looking at the raw data from the runs, we are seeing between a 9-12% increase in HP and torque from about 1600 rpm to 4200 rpm when comparing the best stock chip run to the best new chip run. This is quantitative data, not hunches. (But see Bad News below...)
2. Cold start is easier. It's 35 degrees in NY/NJ and she started after <1.5 seconds (one one thousand, two one th.....start!) after sitting outside for 5 hours. This is coldest she has ever been. Idle was smooth with no sputtering or missing. I have Redline in the gearbox and a naturally less-notchy tranny so the entire cold start experience is almost....non-Ferrari-like.
3. Seat-of-the-pants? Feels slightly better. Third gear pull is stronger.

The Bad News:
1. The raw data and the graphs don't jive. In particular, the raw data on some runs today vanished (N/A instead of real values) yet there is a JPG graph for the run up to 7000rpm. No clue what's going on there. I have to talk to the dyno shop.
2. The stock chip run was done 62 deg F, humidity 52%. The new chip run was done at 51 deg F, humidity 21%. So, today's run had a much drier, somewhat denser air mass. I can't get a good grip on the SAE correction in the data emitted but I suspect that I'm not comparing true apples-to-apples.
3. Still am leery of the A/F. The dyno shop concedes their sensor is weird when transitioning from idle to load, and it looks like although I'm richer in the low end, I'm still not hitting 14 until 5250 rpm AND -- get this -- I'm now actually leaner above 3750 rpm.

Next steps: Installing the K&N filter and the even more aggressive chips and doing this again.
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Bad news indeed.

First, I was comparing corrected and uncorrected power info. I "uncorrected" the stock chip run and then applied a consistently calculated correction factor to ALL runs. I used a great Javascript page at http://www.csgnetwork.com/relhumhpcalc.html to get a correction factor precise to 3 digits beyond the decimal point and it includes elevation in addition to temp, pressure, and humidity -- and it takes English units as inputs, which is great when that's what the DynoJet dyno is putting on the data export!

Second, the reference run from the first set of pulls in Jan had the highest HP and torque but is actually NOT the strongest of the pulls between 1500 and 3000 rpm.

We are now seeing only a 2-4% increase in torque from 1500 rpm on up. There is still some possibility for error if the reported DynoJet SAE correction factor is truncated (i.e. .97 reported but .97942 used internally for calcs).

Attached is an Excel spreadsheet with all the gory details.
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Yep. They said try the more aggressively timed chips, about 2-3% more timing advance than the previous set.

I won't be able to do another run for a few weeks but I'm done with the one-change-at-a-time approach. Next time we'll have the K&N filter, aggressive chips, and 94 octane fuel. With luck we'll see about 6-8% improvement.

 

No, the 93 octane chips. I want to run with 94 octane as a little extra insurance against preignition.

 

They claim the regular chips are 2-3% timing advanced over stock, and the aggressive chips are 2-3% more advanced over the regular chips. A/F tweaks are the same for both.