What the hell just happened!
Thread Starter
Evolving Member
Joined: Nov 2011
Posts: 357
Likes: 17
From: Australia
What the hell just happened!
Hi all
Was just running some 2000 to 7000 wot runs in 3rd in my slightly modded Evo 9. Had done maybe 3 similar runs in 10 min (setting up a grimmspeed 3 port) when I thought I just blew my motor.
I was at a load of 235 at 6500rpm when I've had a massive drop in load to -7 followed by a spike back up to 240 with a huge knock (22). The car kinda felt like it stalled (maybe the knock dropping the timing?)All this at 100% throttle. AFR was 10.5 going to 9.95 during the spike. Boost was at about 22psi (eyeballing the gauge)
I went straight for the clutch and slowed to a stop. All seems ok but what just happened. Other mods are a Litespec catback, Walbro 255, suction pipe and k&n filter. Running 93 fuel (aussie 98ron) Any ideas?
Not sure if this is a Ecuflash thread thing, was just using it to tune the car at the time. Logging was with evoscan.
Was just running some 2000 to 7000 wot runs in 3rd in my slightly modded Evo 9. Had done maybe 3 similar runs in 10 min (setting up a grimmspeed 3 port) when I thought I just blew my motor.
I was at a load of 235 at 6500rpm when I've had a massive drop in load to -7 followed by a spike back up to 240 with a huge knock (22). The car kinda felt like it stalled (maybe the knock dropping the timing?)All this at 100% throttle. AFR was 10.5 going to 9.95 during the spike. Boost was at about 22psi (eyeballing the gauge)
I went straight for the clutch and slowed to a stop. All seems ok but what just happened. Other mods are a Litespec catback, Walbro 255, suction pipe and k&n filter. Running 93 fuel (aussie 98ron) Any ideas?
Not sure if this is a Ecuflash thread thing, was just using it to tune the car at the time. Logging was with evoscan.
Last edited by Fireescape; Feb 24, 2012 at 12:51 AM.
Thread Starter
Evolving Member
Joined: Nov 2011
Posts: 357
Likes: 17
From: Australia
Hi
Thanks for your ideas guys, I checked my boost cut table, it is set at 240 to 5500, 225 at 6000, 215 at 6500 (where the spike was) and 210 at 7000. Not sure but this seems ok, any other suggestions?
Thanks for your ideas guys, I checked my boost cut table, it is set at 240 to 5500, 225 at 6000, 215 at 6500 (where the spike was) and 210 at 7000. Not sure but this seems ok, any other suggestions?
You were at 235 load at 6500 rpm and your boost cut is at 215. There's your problem. Increase boost cut to ~240-245 at 6500. If your load goes over the value in the boost cut table for more than a certain time (specified in the boost cut delay table), it will cut boost, which is what you experienced. So adjust the table so that it doesn't happen under normal conditions.
In the first post you mentioned that right before the situation you got 235 load @6,500 and you have 215 @6,500 in the Boost Cut Load table -> here is the situation.
If your load exceed value in the Boost Cut Load table at given RPM for predetermined period of time (there is another table for this) -> you'll have quite rude cute. Increase the values in Boost Cut Load table if you plan to run the boost as it was during your run. The value in the table should be 10-15 units higher than your actual load during WOT runs, so that you do not hit the cut, but always have the failsafe in case something goes wrong (this table won't let it overboost too much for too long).
PS oops, we've been writing simultaneously
as Raptord said 
If your load exceed value in the Boost Cut Load table at given RPM for predetermined period of time (there is another table for this) -> you'll have quite rude cute. Increase the values in Boost Cut Load table if you plan to run the boost as it was during your run. The value in the table should be 10-15 units higher than your actual load during WOT runs, so that you do not hit the cut, but always have the failsafe in case something goes wrong (this table won't let it overboost too much for too long).
PS oops, we've been writing simultaneously
as Raptord said
