Thread:

My EFI twin turbo build

Originally Posted by ap67et10

are you data logging all of the running its doing? even if it doesn't plane, data log that so you can go back and make changes to the tune in the areas where the issues are occurring. Post up your data logs, this could be a good little thread with some real life info on tuning efi. Have you ensured all your constants are set correctly? have you verified the timing on a timing light with what the PCM is saying it is? Start with the basics, verify timing, verify all your constants are correct, now that you have it starting and idling properly, will it free rev? can you rev it or does it stumble real bad? if so, that needs to be changed before you should try actually accelerating. Also, make your timing a constant value and not a full customized table. have idle be low, in the 10-12 range and everything above idle should be 23-25 degrees, just block the whole thing out (kinda like a locked dist would do) this will give you a safe constant setting so you can focus on the fuel table. you should be in 100% open loop and slowly beginning to modify the VE table based on your data logs and how the engine is responding in relation to what you are seeing on the wideband. don't immediately jump to trying to drive the boat or WOT. go slow, as soon as it stumbles back out of it, shut it off and check your datalog to make the necessary changes, then retry. Tuning EFI is a time intensive process, especially if its your first time, and you want to ensure your first time tuning doesn't end in disaster. Be patient! One change at a time, and datalog EVERYTHING.

Andrew

Lol, Yeah or put one of these on there then go straight out & enjoy your boat!

Originally Posted by 79centurion

Hass, I dont know where that will bolt on to my intake Andrew. I did not get into any data logging yet. I was fighting the rain over the weekend. Boat got idled out, checked everything and went to slowly acc. It would just fall on its face. Timing is set at 0 under 400 rpm to start, 17 from 800-1500 rpm, and 28 degrees, with pulling it down to 24 under boost. I will change to a "lockout" table. I will get some data logging hopefully next week as work is crazy right now. As for free rev, it free revs well, just a little fat. We had the laptop hooked up the whole time to watch everything on the fly.

Dan

Hey Dan, you have a really nice setup there. With a little perseverance you will get it handled and it will be a great runner and make great power. I just had to point out one of the inadequacies of efi. Just like Andrew knew that I would have problems logging rpms with a mag I knew that there would be a huge hill to climb initially to setup the efi with a proper tune. Be careful, go slowly and sneak up on the tune so you dont blow the thing up while trying to get it right. Mind the boost guage and start off real low on boost and dont expect it to do exactly what you think it will till youve verified that you have control. With a turbochaged engine you can make eight really expensive ash trays out of your pistons or torch the head/block in just a couple seconds of wfo with the tune being off. Good luck, keep us updated , Hass