Making the right engine management choice
Posted by niphilimmaster@reddit | projectcar | View on Reddit | 19 comments
I've been planning my first project car on almost all point and i basically know quite anything i'll do to it on the long term. Excepted one thing that I have a hard time understanding deeply enough to be sure of my choices, the engine management. Does i need to just use a piggy back like an apexi or do i need a full aftermarket ecu and make a custom engine loom? does modern piggy back are good enough or the money spent on a aftermarket ecu would be worth it, since i'm going from NA to turbo i guess its heavier than simple tweaks to the ecu.
To give context the project is a at200 celica wich gonna be built to be a tarmac rallye car, I'll also build a 7agte to go in it. So basically not the usual model for rallye and a even less usual engine, i really wanted to make something that you won't really see somewhere else and found all the parts i need to buy exepted the above part so i hope you guys will help me find out what are the pros and cons of both thing or if there is alternatives that are even better i dont know.
HSLB66@reddit
The first step in this decision is: Who is going to be tuning and how do I make their life easier so they want to tune my car well?
The second step in this decision is: recursive back to the first.
All of the features in the world don't matter if you have to go 200 miles out of the way to find a tuner.
niphilimmaster@reddit (OP)
Do you thinks i could be my own tuner if i take me time to learn ans use not too hard plateform or its very hard having something working with a beginner level in engine tuning ? It would change my perspectives because if i really need to make it tune by someone i would simply ask a trustable tuner wich plateform he like to work on so it would be nice to work on it for him
HSLB66@reddit
If you have to ask, I'd discourage it. Sorry not trying to be a dick or rude, but it's a very complex process to get right and a very expensive problem to get wrong.
niphilimmaster@reddit (OP)
No problem as long as it is argumented its ok, thats specifically the part of the process that i know the less for building my car so beeing humble is the least. thanks for taking you time to answer also !
RPE10Ben@reddit
You’ll need to consult forums specific to your vehicle to see what off the shelf options there are and what their limitations are. If there’s none, then yea you’ll need to go aftermarket. If you can find a wiring diagram of the electrical system (and preferably the OEM ECU’s pinout), you can modify the OEM harness for your aftermarket ECU. I put a Speeduino in my car with a custom harness I made and I’ll warn you. The learning curve is extremely steep and painful. Ultimately worth it though.
niphilimmaster@reddit (OP)
Il check rusefi's ecu, I didnt thought there would be a good alternative to speeduino if i make a custom harness. That would certainly be the kind of work that i would be proud of once achieved even if 99% of the process i hated it
devilpants@reddit
It’s crazy to me that people are still using the same piggyback stuff that we were using 20+ years ago when technology has changed so much and a better solution should exist.
I remember the apexi stuff being hard to use and kind of junk back then and thinking in 10 years how amazing the replacement computers would be.
I would look into stand alone but it stinks they aren’t better and cheaper and easier to use today- they really should be but oh well.
niphilimmaster@reddit (OP)
I agree that piggyback stuff is outdated but i do not agree for the cheap part a least in France, here i can get a apexi power FC for 300euro for exemple. Even a speeduino dont fit in that budget since you have to make a loom to make it works. Thats why Im trying to find if that money and Time is worth that kind of engine build or not so much
juwyro@reddit
I would just go aftermarket ECU.
niphilimmaster@reddit (OP)
any strong reason behind that or just that piggy back aren't that good ?
juwyro@reddit
Older ECUs are tunable but they're not as good as a standalone. You get a lot of flexibility and safety for whichever way you want to go with the car.
niphilimmaster@reddit (OP)
Safety is definitly something i didnt thought about that much, i guess i have to look a that too thanks!
juwyro@reddit
Way more control over boost, by gear, traction control, etc
phate_exe@reddit
There are two factors I would be looking at when it comes to engine management:
For the first issue, your life gets a whole lot easier if the car doesn't have to get plugged into a scanner for emissions testing since you can run a standalone. If you do have to plug in, your solution will have to involve the stock ECU in some way.
For the second issue, I'd feel better about running "worse" engine management expertly set up by a good tuner than I would about the best engine management system set up by someone that's learning.
niphilimmaster@reddit (OP)
Emission testing would not be a problem so i can go fully aftermarket if i want. Also i try to build it as much as i can myself so maybe if its achievable i woud learn the whole tunning process too or at least make it run to the tuner without ruining the engine, i don't know any tuner currently so i couldn't say if any platform would be better than the other. If i have to do it myself wich one would be the easiest to learn ?
ThePotatoPie@reddit
A piggyback can work going from NA to turbo but it's always a compromise.
How high boost are you running? Are you swapping to larger injectors and are you planning on running coil on plug etc
niphilimmaster@reddit (OP)
The engine build will be in two phases, Firstly putting a turbo on a 7afe wich will keep the standard ignition system and gat just bigger injectors, 20psi max will be run on that setup. Then once i find one, swapping the head with a 4age 16V head wich will get coil on plug and higher boost pressure.
ThePotatoPie@reddit
Hmm 20psi on a piggyback is a gamble. I've had engine ecus throw codes when trying to retard timing with piggybacks especially enough to run 20psi.
Have you looked into standalones at all? They're getting quite affordable
niphilimmaster@reddit (OP)
up to how much pressure you think i can go with a piggy back? I have looked at standalone and they are pretty neat ( maybe a megasquirt or someting under 1 grand) and my biggest problem with them is that there is no standalone that come with premade loom compatible with my particular engine, I don't think it would be that hard to make but i start from 0 for making my own loom so I don't really know how much work it is and if its worth the pain.