Today we did a remap for a Speedster with stage 1 Compcams camshafts. After the camshafts were fitted the idle of the car wasn’t very good and the engine didn’t have very much power. So the owner came by Peter for a remap. I brought my exhaust gas tester with me, because the exhaust gasses weren’t up to spec to make the MOT.

After flashing the ECU with Peter’s software we made some initial adjustments.

Before changing the idle settings for the engine we did an exhaust gas test on idle and 2500rpm. The results look like this:

Idle
CO: 0.01% vol
HC: 165 ppm
CO2: 6.95% vol
O2: 11.40% vol
Lambda: 2.106

2500 rpm
CO: 0.00% vol
HC: 172 ppm
CO2: 15.42% vol
O2: 0.07% vol
Lambda: 0.999

Lambda at idle is way off. So Peter started to ajust the idle tables and raising the idle RPM. In the end we ended up with a 1200rpm idle. Then we put the ECU into learning mode and the owner went for a drive to get the ECU calibrated. After 1.5 hours he returned. After finalising the ECU settings we did another exhaust gas test. This time the values were within MOT boundaries.

Ide (1200rpm)
CO: 0.04% vol
HC: 251 ppm
CO2: 14.70% vol
O2: 0.74% vol
Lambda: 1.026

2500 rpm
CO: 0.03% vol
HC: 248 ppm
CO2: 15.25% vol
O2: 0.00% vol
Lambda: 0.993

Then Peter and the owner did a final calibration run to set the target AFR to optimal. Just like with all the other cars, 12.9 seems to be optimal. When deviating as little as 0.2 you loose power as can be seen in the graph below (lower curve is 12.7 target AFR).

Still the results were pretty disappointing. The car as a 2.4 inlet manifold (the correct one) and a good airfilter (original exhaust). So it should be at least the same power as Peter’s car when he still had his original exhaust. But when comparing the graphs this isn’t the case.

Something doesn’t add up here. With the higher lift cams power should be higher. And it doesn’t make sense that idle is so way off compared to normal. Also HC is still high even after calibration. Might be that the cams aren’t installed correctly and the timing is off.

To be continued..