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I’m looking to turbo the b230f in my ‘90 740 and I’ve read that the stock ecu can handle 7 psi of boost before something goes wonky. So I’d like to put an aftermarket thing in it. Is there any good write ups anybody knows of? And is there any recommendations for ecus? I’ve a novice at this kind of thing at the moment... thanks!
Goldenblock here!!!
my experience is the earlier non white label ecu will be the best choice.
Open it up check for a double cpu board inside.... That is the one you need!! Usually early 90 or 91
Goldenblock here!!!
my experience is the earlier non white label ecu will be the best choice.
Open it up check for a double cpu board inside.... That is the one you need!! Usually early 90 or 91
the B230FT engines had higher flow injectors, higher flow main fuel pump, they had a completely different air path with an intercooler on the radiator, the air filter box on the right side, and the battery relocated to the left side of the car. they used a different ECU, they had an additional fitting on the engine block for turbo oil return, the oil filter was relocated via an extended oil cooler arm. they had lower compression as the turbo boost adds effective compression, they had different exhaust mainfolds and down pipes, and they had a AW71 transmission which is a beefed up version of the AW70 used on non-turbos. Later B230FT turbo engines had additional oil squirters inside the engine block to lubricate and cool the piston skirts to prevent "piston slap". 1992+ turbos had a larger radiator, which is a good thing, as the additional power the turbo develops generates significantly more heat.
a 1990 740 may well be a Regina system, which is completely different from the Bosch LH2.4 system used on 1990+ B230FT turbos.
oh yeah, and B230FT engines get awful fuel economy, my 1992 turbo 740 got at best 16 MPG around town, and *maybe* 24 MPG on a long road trip on the open highway. it was pretty easy to get significantly less than 16 MPG around town.
the B230FT engines had higher flow injectors, higher flow main fuel pump, they had a completely different air path with an intercooler on the radiator, the air filter box on the right side, and the battery relocated to the left side of the car. they used a different ECU, they had an additional fitting on the engine block for turbo oil return, the oil filter was relocated via an extended oil cooler arm. they had lower compression as the turbo boost adds effective compression, they had different exhaust mainfolds and down pipes, and they had a AW71 transmission which is a beefed up version of the AW70 used on non-turbos. Later B230FT turbo engines had additional oil squirters inside the engine block to lubricate and cool the piston skirts to prevent "piston slap". 1992+ turbos had a larger radiator, which is a good thing, as the additional power the turbo develops generates significantly more heat.
a 1990 740 may well be a Regina system, which is completely different from the Bosch LH2.4 system used on 1990+ B230FT turbos.
oh yeah, and B230FT engines get awful fuel economy, my 1992 turbo 740 got at best 16 MPG around town, and *maybe* 24 MPG on a long road trip on the open highway. it was pretty easy to get significantly less than 16 MPG around town.
1992 turbo 740
I have all the parts to do the turbo swap, I was just wondering about the ECU. Since a turbo one won’t just swap in.
Yeah, I don't think there's any such thing as a turbo Regina system. the manifold air pressure goes positive when you have boost (normally its negative but it goes towards zero as you increase the throttle and RPM). and I doubt the Regina MAP sensor and ECU can cope with this. that and I doubt the stock regina fuel pump and injectors can provide enough fuel, under full boost, my 92 740T wagon could easily drop down to 6-8 MPG momentary at medium-high RPMs, thats a lot of gas, 2X more than a NA car can possibly ever burn.
oh, another minor detail. turbo cars, since the manifold pressure can be positive rather than negative (vacuum), all vacuum fittings require clamps, and systems like the power brake booster, and the HVAC air control, need a vacuum storage bottle fed via one-way valves, or things like power brakes, and the ventilation controls stop working under sustained boost, such as climbing long freeway grades in the mountains.
Yeah, I don't think there's any such thing as a turbo Regina system. the manifold air pressure goes positive when you have boost (normally its negative but it goes towards zero as you increase the throttle and RPM). and I doubt the Regina MAP sensor and ECU can cope with this. that and I doubt the stock regina fuel pump and injectors can provide enough fuel, under full boost, my 92 740T wagon could easily drop down to 6-8 MPG momentary at medium-high RPMs, thats a lot of gas, 2X more than a NA car can possibly ever burn.
oh, another minor detail. turbo cars, since the manifold pressure can be positive rather than negative (vacuum), all vacuum fittings require clamps, and systems like the power brake booster, and the HVAC air control, need a vacuum storage bottle fed via one-way valves, or things like power brakes, and the ventilation controls stop working under sustained boost, such as climbing long freeway grades in the mountains.
I know there’s not a turbo Regina system. I’m asking about after market ecus. I have a turbo intake manifold and I think it has that vacuum storage thing you mentioned. I also read that the Regina system with a turbo can handle around 7 psi before it starts having issues. I read a write up on turboing a Regina car and they just swapped the turbo stuff in, nothing about a vacuum storage bottle. They left the intake manifold alone.
there are no aftermarket ECUs for Regina. Heck I'm not even sure there are any for Bosch LH that are plug and play.
now, sure, you can rewire the whole engine to use something like a megasquirt, and spend weeks tinkering with custom fuel-air maps trying to achieve a decent balance of drivability and power and efficiency. best done with a gas analyzer, and a dynometer stand.
but if you have a write-up that says it can be done, then you either trust the author and follow their instructions exactly, or you're on your own. me, I don't think the regina system can deliver enough fuel for 7 PSI boost, thats 1.5 BAR (0 psi boost is the normal 1 bar at sea level), so you'd need 1.5X the fuel delivery at any given RPM at 7 PSI boost.... if you don't deliver enough fuel, the engine runs lean.... lean burn at high power outputs can burn valves and pistons.
oh yeah, valves... B230FT turbos have sodium filled exhaust valves, and they have different cams, too. I forgot that in my previous summary of the differences.
there are no aftermarket ECUs for Regina. Heck I'm not even sure there are any for Bosch LH that are plug and play.
now, sure, you can rewire the whole engine to use something like a megasquirt, and spend weeks tinkering with custom fuel-air maps trying to achieve a decent balance of drivability and power and efficiency. best done with a gas analyzer, and a dynometer stand.
but if you have a write-up that says it can be done, then you either trust the author and follow their instructions exactly, or you're on your own. me, I don't think the regina system can deliver enough fuel for 7 PSI boost, thats 1.5 BAR (0 psi boost is the normal 1 bar at sea level), so you'd need 1.5X the fuel delivery at any given RPM at 7 PSI boost.... if you don't deliver enough fuel, the engine runs lean.... lean burn at high power outputs can burn valves and pistons.
oh yeah, valves... B230FT turbos have sodium filled exhaust valves, and they have different cams, too. I forgot that in my previous summary of the differences.
for fuel delivery, couldn’t I use larger injectors and a performance fuel regulator? The guy in the write up used just a fuel pressure regulator upgrade. Wouldn’t the o2 sensors in the exhaust correct for lean running if the fuel system could deliver?
the O2 sensor and lambda loop has a very narrow range of latitiude, the base value without it has to be in a close range.
i'm still unsure that the MAP, which Regina uses instead of an MAF, is capable of reading positive pressure aka negative vacuum.
increasing the fuel pressure would increase the amount of fuel by a constant ratio, but I'm not sure the resultant effective modification of the fuel-air map is accurate across the board. for instance, at idle, with no boost, you would NOT want to increase the fuel amount or you would have too high of a fuel-air ratio.
the O2 sensor and lambda loop has a very narrow range of latitiude, the base value without it has to be in a close range.
i'm still unsure that the MAP, which Regina uses instead of an MAF, is capable of reading positive pressure aka negative vacuum.
increasing the fuel pressure would increase the amount of fuel by a constant ratio, but I'm not sure the resultant effective modification of the fuel-air map is accurate across the board. for instance, at idle, with no boost, you would NOT want to increase the fuel amount or you would have too high of a fuel-air ratio.
From what I understand sensors can read positive pressure. 0 volts on the sensor is 100% vacuum and higher voltages are less vacuum and more boost. Also a fuel pressure regulator just increases the amount of possible fuel it can deliver. The fuel injectors will only be open as long as they need to to get the right mixture. With regards to the low latitude of the system, that is exactly the reason I want an aftermarket ecu, so I can have more control over it.
Edit: I did a tiny bit more research, map sensors use a 5v scale, I likely have a 1.5 bar MAP sensor, which would entirely explain why Regina systems can take only 7 psi of boost. I could swap it for a 2 bar MAP sensor which would just skew the linear relationship of the voltage and pressure/vacuum.
well, taht aftermarket ECU, like a Megasquirt, or whatever, is going to physically look nothing like the Regina ECU, and not have the same connector, so the first step will be to build a custom engine wire harness to connect it to all the various engine sensors. Most of these control injection *and* ignition timing so you'll also be removing the Rex ICU that is paired with the Regina ECU.
as I said earlier, if someone has documented this process, you should talk with them.
well, taht aftermarket ECU, like a Megasquirt, or whatever, is going to physically look nothing like the Regina ECU, and not have the same connector, so the first step will be to build a custom engine wire harness to connect it to all the various engine sensors. Most of these control injection *and* ignition timing so you'll also be removing the Rex ICU that is paired with the Regina ECU.
as I said earlier, if someone has documented this process, you should talk with them.
someone has documented a turbo Regina not MSing a Regina. There’s a write up for lh2.4 but mine isn’t lh2.4. I know there’s not a plug-n-play for b230s, I meant which is the best and easiest to set up, it sounds like you don’t know exactly.
11-20-2020, 12:46 AM
Best Stand-alone Ecu for Regina/Rex 740
