Vehicle was on my dyno some time ago now when it made 452rwhp/465rwtrq on my Dynamite Dynanometer tuned on speed density (ANN off). Vehicle idled, drove and performed great and the customer was happy.
The vehicle has returned because the weather has been in the 90s-100s lately and the vehicle will die in gear changes (reverse to drive most commonly.)
I went through idle tables to see if it helped, no change. throttle body tables, either direction made it worse and began idle hunting and surge.
I've tried a few suggested changes found here in this forum and still dying between gear changes.
I am at a loss at this point on how to fix this issue when the vehicle dies in gear changes when it is hot only.
If anyone can point me in the right direction that would be awesome.
You know timing tables are different when the MAT is hot....Maybe start there but here is my tune you can go through and compare...I have a APACHE MAX which isn't to far off from that cam...
You know timing tables are different when the MAT is hot....Maybe start there but here is my tune you can go through and compare...I have a APACHE MAX which isn't to far off from that cam...
Can all be done with just the idle rpm tables. Here is the easy fix.
Car running, logging rpm and idle desired rpm, timing, tps, basically all normal stuff, go from park, then to reverse holding the car with the brake, then to drive still holding the brake, then back to park.
As you transition, watch the idle rpm and adjust your tune by how much your idle rpm changes. Forget the actual settings in the tune from this point forward. If it goes up rpms in reverse, lower your drive rpm commanded by half the rpm rise (so say it jumps up 30-40rpms, drop your drive idle rpm by that much).
Basically want you want is the car to feel almost like it is in neutral while you cycle the gears. you don't want it pushing on the brakes, then suddenly not.
Try it, small changes make a big difference. And also you should set your minimum rpm tables all about 25rpms lower than wherever you end up with the regular idle tables. The ECU has an O SHIT moment everytime the idle rpm gets near that minimum, its ok to go a little below commanded but you have it set so commanded and minimum are the same, that's going to cause issues.
In your log your rpms look to drop over 100rpms when you go from park to reverse. When you go from park to reverse, does the car push against the brakes at all?