If there WERE a reflash available...
Feb 5, 2009, 02:05 PM
#31
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^So you propose the "scalability" of the MAF system is enough to compensate for variances in individual cusomers' setups (i.e., airflow, effected by both differences in turbos as well as BOV reactivity)?
What sort of variances in individual customer's setups would you be able to program for? Put differently, what components would/could you take into effect for the flash? Would each customer send you a list of their setup and you program what you load to the ECU accordingly?
minor hijack...FWIW, there is some inherant scalability in the stock ECU in regard to fuel delivery. Prior to having a piggyback installed, I had my turbo hardware all bolted up and WRX 440's in my car. I of course stayed out of boost, but in normal vacuum conditions, AFR worked toward 14.7 per usual. However, once it got colder outside (maybe 40F or colder), I started to stall out at idle. There were no vacuum leaks, etc. Perhaps it couldn't compensate enough to the temperature change. There was a CEL, but for the high-flow cat...not system too lean/rich. Having a piggy subsequently installed and tuned didn't solve the problem; I ended up going with the 5th injector route and the stock 4 primarys w/ no stalling at idle since...hijack over
What sort of variances in individual customer's setups would you be able to program for? Put differently, what components would/could you take into effect for the flash? Would each customer send you a list of their setup and you program what you load to the ECU accordingly?
minor hijack...FWIW, there is some inherant scalability in the stock ECU in regard to fuel delivery. Prior to having a piggyback installed, I had my turbo hardware all bolted up and WRX 440's in my car. I of course stayed out of boost, but in normal vacuum conditions, AFR worked toward 14.7 per usual. However, once it got colder outside (maybe 40F or colder), I started to stall out at idle. There were no vacuum leaks, etc. Perhaps it couldn't compensate enough to the temperature change. There was a CEL, but for the high-flow cat...not system too lean/rich. Having a piggy subsequently installed and tuned didn't solve the problem; I ended up going with the 5th injector route and the stock 4 primarys w/ no stalling at idle since...hijack over
Feb 9, 2009, 12:45 PM
#32
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The scalability of the MAF system is actually pretty good. If the sensor itself proves insufficient then I simply machine a slightly larger MAF housing for the sensor element. Since a larger tube allows more airflow per unit of measure it will also allow a larger total amount of air to be measured.
Assuming stock sensors, there are 2 things that are outside the ECU's control that will need to be made consistant. Fuel injector and fuel pressure. The 440cc WRX injectors did not work very well because the factory ECU was able to trim some of the fuel out and run a large negative long term fuel trim. When the vehicle is not using that fuel trim (crank/startup/cold warmup) you're pretty screwed and injecting like it had stock injectors inside which will quickly flood the engine.
Little details like that wreak havoc on piggyback computers and that's part of the trouble for us in the Northern climates. The manufacturer designs and tunes the vehicle to start in up to -40C weather so the factory program gives me the ability to scale the injectors so they also work under those conditions. When I set about designing a piggyback to take all these things into account it quickly became evident that I was really designing a complete standalone fuel ECU. Outside the budget.
Assuming stock sensors, there are 2 things that are outside the ECU's control that will need to be made consistant. Fuel injector and fuel pressure. The 440cc WRX injectors did not work very well because the factory ECU was able to trim some of the fuel out and run a large negative long term fuel trim. When the vehicle is not using that fuel trim (crank/startup/cold warmup) you're pretty screwed and injecting like it had stock injectors inside which will quickly flood the engine.
Little details like that wreak havoc on piggyback computers and that's part of the trouble for us in the Northern climates. The manufacturer designs and tunes the vehicle to start in up to -40C weather so the factory program gives me the ability to scale the injectors so they also work under those conditions. When I set about designing a piggyback to take all these things into account it quickly became evident that I was really designing a complete standalone fuel ECU. Outside the budget.
Feb 9, 2009, 02:13 PM
#33
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^During warmer months, my car started, idled, and ran just fine. Once it got colder, in the initial open loop startup times, the engine continued to start and run just fine...it was just after the sensors were warm and I was in closed loop that it would stall out.
...however, moot point...
So, just so I understand, the requisite information you would need from a customer is fuel injector size and fuel pressure? That info, plus my stock ECU and $500, and in return I get a setup that is able to control a turbo system, regardless of componentry (aside from the aforementioned)?
Tempting. The RRM/SS units are at least that much. Though you can make adjustments to the 5th injector's output and timing curves, many people don't have the knowledge to tune it themselves beyond the base map, or the funds to have it fully tuned at a shop.
...however, moot point...
So, just so I understand, the requisite information you would need from a customer is fuel injector size and fuel pressure? That info, plus my stock ECU and $500, and in return I get a setup that is able to control a turbo system, regardless of componentry (aside from the aforementioned)?
Tempting. The RRM/SS units are at least that much. Though you can make adjustments to the 5th injector's output and timing curves, many people don't have the knowledge to tune it themselves beyond the base map, or the funds to have it fully tuned at a shop.
Feb 9, 2009, 03:32 PM
#34
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Hey just a heads up to you guys the new openecu ECUFlash program now supports the H8 processor. The H8 Family is why our 69's were so uncrakable we are currently working this and testing it in the 4g community
