Lancer Evo 4G63 - Spark Advance Lump (not following the map) after 7400rpm WOT

Hi all,

We have a Lancer Evo Group H in Romania. The car is multiple times no.1 in National HillClimb Championship.

Cause we're fighting for the title and the other competitors improved their cars we had to move from E85 to race fuel 120 octane.

Now the fun begins. We've put the car on dyno today and a weird phenomena is happening.

Suddenly after 7400rpm WOT the ignition timing climbs very steep without respecting the map.

I'm waiting your advices, tomorrow we'll be a long day on dyno. I'm curious what's all about.

Best regards,

Adrian.

First of all in my own experience on the 4G63 I've seen zero improvement moving from E85 to some of the specialised race fuels - In particular we did back to back tests on a 580 kw atw engine running 38 psi boost and we actually saw about 3 kW more power on E85. I can't say that holds true for every race fuel but certainly in the case of Q16 there seems to be little in it.

I'm not sure I understand specifically your question - Are you saying that you need to advance the timing exponentially to achieve MBT once you go past 7400 rpm? That certainly doesn't sound right. Again in my experience if you're moving from a map that's optimised for E85, you should find minimal differences in the timing map. In my earlier example there was around 2 degrees difference between the timing map at 38 psi on E85 and Q16. Has anything else changed in the mechanical configuration of the engine? Are you simply changing fuels and nothing else? Have you confirmed with a timing light that you're actually seeing the timing that the laptop is reporting?

Hi Andre,

The engine has been measured on dyno with E85 doing 500kw.

Without any changes we've changed to Q16 and increased the turbo pressure to about 34psi. We haven't changed yet the ignition timing map, we left it like that for the first trials.

The problem that appeared was that the wastegate (40mm) couldn't cope to discharge the turbo. We are thinking that the MAP senzor could have experienced some peak bangs and now is defective giving wrong signals. We couldn't find anything on the logs but tomorrow we're back to read real-time values while ramping up.

What we see is that after 7400 rpm the spark advance doesn't respect the ignition timing map. Suddenly increases significantly above the set values in the map. It has to be something related with compensation or correction but we couldn't see anything on the logs. We're running Motec ECU.

I will try to give you some values tomorrow.

Thank you Andre, I hope that we'll find the guilty one :P

I forgot to mention, we've lost 15kW till 7400rpm and we were expecting to gain at least 30kW at 8000rpm only from fuel so you're right...not such a big deal.

Second thing, already have got the second wastegate in order to correctly and smoothly control the turbo pressure.

I haven't check the timing with the lamp, I will start with this operation tomorrow. It passed through my mind that could be a deviation from speed sensor reading. I'll post tomorrow some updates.

Thanks a lot.

My comparison was against Q16 which is an oxygenated fuel and as I mentioned the results were almost identical. If you're running on a non-oxygenated race fuel then I wouldn't be surprised for you to lose 15 kW. I don't believe that a gain of 30 kW is realistic just from that fuel change unfortunately.