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| The 130mm tip fits nicely in the rear bumper opening. |
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| With 5 degrees of timing removed from the areas of the map where knock was detected, the knock count has fallen to one or none. Note that the actual logged timing advance does not look that different from the previous log. This is because the ECU is no longer removing timing to save the engine. The log is closer to the actual timing map. Mitsubishi's ECU starts removing timing at 3 counts of knock. |
To be conservative, Naji reflashed the ECU pulling about 4 degrees of timing out of the ignition map. This immediately reduced the knock count to 0-2 which is very conservative and safe. Naji told us that this is standard procedure for an Evo X with lean spool and that he has frequently seen high knock counts in newer Evo X’s with bolt on mods and lean spool enabled.
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| The exhaust in place. |
This was not tuning for power, just to be conservative for safety. We did not see any reduction in power with less timing. Detonation causes a loss of ring seal and misfire due to extreme cylinder pressure fluctuations so it is typical to not lose power or even gain power with less timing. So as a warning, if you have a 2010 or later Evo X with bolt on power adders and you are forced to run crappy 91 octane gas, you should see a reputable tuner and check your knock count! Naji will tune our Evo for power in the near future and he will probably disable lean spool, add some transitional fuel and up the boost at higher rpm.
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| The Greddy RS exhaust made 11 more peak hp and 9 peak lb ft of torque on our Evo X. You can see that the turbo spooled a little faster and the peak boost was slightly higher. The most marked change is the air fuel ratio during spool up, look how much leaner the engine runs during spool up. This is one of the reasons why 2010 and later Evo's need some tuning to avoid detonation with bolt ons. |
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| To date our mods have gained us 30 hp and 24 lb/ft of torque more than stock, not bad for some simple work! |
In short we found the Greddy RS exhaust to be well made, delivering some solid power gains even against a pretty efficient stock exhaust. In our next installment we will be pairing this exhaust with an AMS big mouth turbo outlet and downpipe which should hopefully free some more power. We will also turn Naji loose to see what some simple tuning can do for the 4B11 engine even with some very minor mods. Stay tuned we are already working on this segment and will have results shortly.
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