So everytime I give 100% throttle from 3k-4k it hits a wall. So it makes it hard for me to get wideband readings to tune my safc2. I decided that I want to buy an EcuFlash cable and set the boost limit to 319 to get rid of it, if im correct. Id like to be safe and make sure nothing will go wrong by removing the boost limit. I'm running 23psi tapering to 21ish. So will removing the boost limit cause any problems, or is it just a dumb mitsu device???

 

If you buy the cable, sell your safc because its better to tune in the ecu then on that. And ya, you can just raise your boost cut it wont hurt anything.

 

Boost cut is a misnomer - it doesn't exist. What we have is fuel cut, and that is where the ECU cuts fuel when our airflow (MAF HZ) exceeds a certain value. Yes, you can raise this value to remove the fuel cut. When you get EcuFlash, don't just use it to remove fuel cut - use it to tune your car, because it makes the SAFC completely useless.

I'm curious, though. How do you know you are running 23psi tapering to 21 if you hit a brick wall at 4k rpm every time? We normally hit fuel cut at 5500rpm or higher, because airflow volume is MUCH HIGHER at higher RPMs than lower rpms, even though the boost is a little lower. It's very unlikely to hit fuel cut at 4k unless you are majorly overboosting.

Are you sure it's fuel cut and not a plug issue or IC pipe that is blowing open under boost?

 

i ran at the track in sunday with a conservative safc tune and it didnt hit fuel cut. but since it's getting colder, when i tune from 3k+ i start to get it.

 

That doesn't make sense. It should not hit fuel cut at 3-4k...it should only happen up top.

 

now im confused... well at least i got my question answered. thanks.

 

Fuel cut tends to happen in that range because the load is jumping very quickly during spoolup. if you lay into a 3rd gear pull at 2,000 - 2,500 you will go from a load of 80 - 260 in the space of less than 1000 rpm.

Several of us using ecuflash have run into it. You will hit your highest load value right around peak torque, so it is not just a relation to maf hz reading, I think it references a ve table as well so 1,300 hz at 4,000 rpm will be a much higer load value than 1800 hz at 7500 rpm.

 

You have a few options with ecu flash, you can up the boost limit or up the boost cut delay timer. and as War said, it is not really boost cut it is fuel cut triggered by exceding the max load value defined in boost limit table.

 

interesting... well i dont hit fuel cut at 4k, when i start 100% throttle from 3k it hits around 4-5k. well hopefully ecuflash can fix it. thanks for the help.

 

You initially said you hit a wall at 3-4k. Now, you say it hits around 4-5k? We need to know EXACTLY where it hits. 1000rpm is a large range...it should be about the same RPM each time as long as you stay in the same gear. Tell me what gears it does it in (try all 5) and at which rpm in each gear.

 

Maybe a dirty MAF sensor?

 

okay, if i floor it at 3k, itll hit around 4k if i floor it at 4k itll hit at 5k all happening in 3rd gear and probably in 4th and 5th.

 

could it be because my honeycomb has a few dents?

 

Thats a bad thing.

 

thats nice to know