Ecumaster forum

Hi, have this issue wherein the behavior is that at 2nd gear during WOT, it would feel the car just hit a wall and then the rpm drops a bit losing boost and rpm. Only happens at 2nd gear before the fuel cut.

My fuel cut is 7300rpm while soft rev limit is set to 7000 rpm. I know when I hit soft rev limit it feels like it is misfiring, but fuel cut Im not sure. But then again it happens way before fuel cut and soft rev limit. I have had 2 instances on the log attached on the last 2 passes as I was trying to work on boost per gear, engine protection rev limit set to 105 degrees. What could be causing this? Any other area, section, map I can take a look at possibly causing this? Attached are the logs and EMU project.

HI
Sort out your VE map

Yeah I havent interpolated it yet, is it just VE doing it you think>? Probably too rich at the next cell?

Too lean mixture? 12.8/13 lambda values. I have seen your logs and your ignition and fuel maps are very different to mine (3rev 3sgte). High lambda value and low ignition angle values. Instead, if your speed sensor config its correct, seems like your car is very fast, 9" 100/200km/h its really good time. What mods have your engine?

woa your VE is a big mess, try equalising the large jumps atleast

rockyboist wrote:Yeah I havent interpolated it yet, is it just VE doing it you think>? Probably too rich at the next cell?

You need to do a lot more than just interpolate............

1. The jumps have been fixed
2. Not adding that much ignition until I get a good knock monitoring tool
3. The actual lambda in the graph has been adjusted since I havent mapped equally the voltage settings of the Innovate MTX-L and the EMU settings. I will have to connect the Innovate software to change the voltage values in the controller. The minimum and maximum voltage range EMU allows is a bit shorter from what Innovate has by default. Hence I had to adjust the lambda targets to get good values on the gauge, it actually is 11.4-11.5 in the gauge.
4. Speed sensor is correct that's a quarter mile run from a dig, and actually more than a quarter as I went through the end of 4th gear

Update: We went and change the headgasket as it was leaking and overheating during boost, going up to 104 Celcius at 1 bar and 108 cat 18 psi. Replaced with ARP headstuds as well. That's the only mod and the external mods are:

GT3076r turbo
1000cc ID injectors
MSD digital 6AL ignition system
AEM 320 lph fuel pump

It's a 2nd gen 3sgte.

Went back to the strip and tried 20 PSI, it pulled hard and liking it but the issue is still there (though CLT is ok now not overheating anymore). We think it was the fuel pump failing as it was still running on old wiring and old relay. As when we tried to directly wire it to the battery and ground was the trigger, it didnt have the issue but I only made a single run then we found I broke the manifold collectors welding so I had huge exhaust leak. I'll get the welding fixed and try again maybe next week with a new wiring and relay for the fuel pump. Will keep you updated. Here's the new EMU map, Ve and IGT tables updated.

UPDATE: So it was the Fuel Pump wiring. I have replaced the pump (AEM320) with a new one and still experienced the issue. I directly wired the fuel pump from the battery with thicker wires (12 gauge if Im not mistaken), and it fixed it. Now I can get past 7k rpm with no choking issues and drop in fuel. But a new problem came, it was misfiring at 22 psi. So I pulled boost back to 20 and it was all good. I may have to re-gap my spark plugs was I wanted to run 22PSI.

You can try to slightly increase the dwell time

What spark grade and gap do you have?

I have bkr8, it was gapped to .035 now it is down to .028. All good now. Did 321whp at 18 psi.