Quote:
Originally Posted by beast37185
Ok so I've just became a member, so here it is.
I have a 1992 5sfe I'm building - its bored 20 over, getting the head shaved, port and polished, and custom built cams, turbo kit, stage 3 clutch, HKS bov. So my question is do i need a whole new engine management system or can i have my ecu flashed and tuned or are there any other ways than buying the $1700 management ems. What obd is this car too?
ALSo I dont know what size injectors to buy how can i figure that out. And if you can think of anything else i would need to make this build succesful please im open to your input...............OH and for you who think that its a waste of time to build a 5sfe save you fingers from wasting key strokes.
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What turbo and how much boost will you be running? What are your goals and are you going to move the red line up?
Since you are going turbo I would not shave the head except to clean up the mating surface. Also since you will be putting new pistons in make sure you gap the rings to 3sgte specs. The 5sfe specs only allow you to go up to about 250rwhp before you risk binding. Since you have a 92 5sfe you do not have a knock system. This changes what you can use for tuning because you will either need to add more fuel or pull some timing in the mid RPMs.
You can't flash the 5sfe ECU and no one is providing ROM tunes for them. So you either can trick it with a piggyback or completely replace it with an EMS and you will need to do one of these two things to run lager injectors to have enough fuel. What kind of engine management you need depends on how much power you are going to make and how closely your torque curve matches the stock one. For instance you can use a 3sgte ct-26, stock cams, 315cc injectors, gen2 3sgte Map sensor and a simple fuel only piggyback to go up to 10psi and about 180rwhp. You will also need an upgraded fuel pump. You then have the AFRs tuned to keep you running a little rich during the transition to boost in the mid RPMS and then a safe AFR on full boost. If you had a 93+ with the knock system you don't even need a piggyback for that setup. The danger, as it is with all NA engines that are turboed, is that you can never over boost because you don't have fuel or maps to safely go there.
If you use a larger turbo or go more boost then you have to do more tuning and also will need larger injectors. Injectors of 400cc and bigger start to become a problem with piggybacks because you can't adjust enough at idle and cruise to keep it from going rich. 400cc should be good for about 240rwhp. You can get away with 460cc RX7 injectors and a piggyback if you are willing to accept running rich at idle and cruise. Those will cover you up to 300-320rwhp but I wouldn't do it unless you have the knock system or the ability to tune timing with a smarter piggyback or EMS.
Forum for every generation Toyota MR2. Including the AW11 and SW20.
1992 MR2 5sfe HELP PLEASE!!!
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