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Discussion Starter · #21 ·
So ive been doing a bit of research ive found some places do 1000w 48v alternators is that enough? i also found out that many cars with 48v systems use a dc to dc converter for charging but i didnt find any info on the alternators themselves but i expect they are probably 48v alternators which are used to charge both the 48v battery and the 12v.

also i foumnd an original audi battery and here isa picture from the sticker so we can see what its specification is. battery doesnt look tall but i would like to know how long and wide it is
 

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So ive been doing a bit of research ive found some places do 1000w 48v alternators is that enough? i also found out that many cars with 48v systems use a dc to dc converter for charging but i didnt find any info on the alternators themselves but i expect they are probably 48v alternators which are used to charge both the 48v battery and the 12v.

also i foumnd an original audi battery and here isa picture from the sticker so we can see what its specification is. battery doesnt look tall but i would like to know how long and wide it is
You still must have a BMS (battery management system) to control charging and be matched to the type of batttery chemistry and battery spec. You must NEVER allow an overcharge to happen to a Li-ion battery because it will go into meltdown (catch fire)

A DC-DC converter will be needed to charge the 12v battery AND supply all the 12v electrics, if the only alternator is the 48v one.

(a 12v alternator rated at 70amps is 1000watts, so 1000watt 48v one should be about the same size, but only rated at 20amps, so the DC-DC converter will need to provide 12v (14v) at potentially 30amps or more for all the 12v electrics)

So in a nutshell, you will need:
1) 48v battery
2) 48v alternator
3) BMS matched to the battery
4) DC-DC converter with charging controller
5) PWM controller for the turbo
6) Interface between the engine ecu and turbo controller.
 

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Discussion Starter · #23 ·
You still must have a BMS (battery management system) to control charging and be matched to the type of batttery chemistry and battery spec. You must NEVER allow an overcharge to happen to a Li-ion battery because it will go into meltdown (catch fire) obviously yes you dont go messing with li-ion or li-po or any other one without doing it properly. fires that have happened in electric cars have demonstrated that is very important.

A DC-DC converter will be needed to charge the 12v battery AND supply all the 12v electrics, if the only alternator is the 48v one. yes of course, i have a feeling thats what the audi has is a 48v alternator. They use a dc to dc converter to charge the 12 v battery (i think). it was clear from the diagrams it showed these components. the only thing it didn't say was if the alternator was 12v or 48v but im fairy sure it is probably 48v.

(a 12v alternator rated at 70amps is 1000watts, so 1000watt 48v one should be about the same size, but only rated at 20amps, so the DC-DC converter will need to provide 12v (14v) at potentially 30amps or more for all the 12v electrics)


5) PWM controller for the turbo
6) Interface between the engine ecu and turbo controller.

Not sure on this part thats my brother's department thats going to me processes closer to the end


so the system is looking fairly simple at the moment which is a good thing because if someone else wants to copy it they can. and if someone wants my brother to fit the same to another vehicle he should be able to do it easy enough.
 

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So ive been doing a bit of research ive found some places do 1000w 48v alternators is that enough? i also found out that many cars with 48v systems use a dc to dc converter for charging but i didnt find any info on the alternators themselves but i expect they are probably 48v alternators which are used to charge both the 48v battery and the 12v.

also i foumnd an original audi battery and here isa picture from the sticker so we can see what its specification is. battery doesnt look tall but i would like to know how long and wide it is
At £1,500 and only 20% more capacity than the Fiesta one I'd suggest it's not worth pursuing.
The Audi charging system remains 12v with a DC : DC step up to charge the electric turbo battery. Note Audi also do "mild" hybrids that use a 48v motor/generator but those are only "greenwashing" in a vehicle that weight.
 

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M57N2 would be a far better way to spend your money.
Yeah, bigger lump that drops in would be a better idea, but not as much fun from a troubleshooting / solving way.
 

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yeah, i dont really get the premise tbh. The stock engine has a variable vane turbo and hits full boost extremely quickly already. Sure, it doesnt make much below 1500rpm, but why are you ever trying to request full power that far down the rev range? Select the correct gear and your at 2500-3000rpm and response is instant. Its also modifying something where the solution already exists, and in the case of the E90 that solution is the 330d, or 335d for even more go.

One thing the bigger engine does, is makes the lower RPM range more flexible, simply by virtue of 50% more capacity and thus 50% more power even without any boost. If you do find yourself in the wrong gear it doesnt matter as much.

Maybe its just an age thing. I remember when i was younger, modifying cars, and always wanting to "do something different".... I did daft engine swaps that looking back now i can see made zero sense. My brother had a 320d, and we did various bits to it including injector upgrades and larger turbo etc. Most folks on the BMW forum pointed out we should have just bought a 330d. Somehow we thought we knew better... Some time later i bought myself a 330d, and immediately realised that indeed they were right. It was just better in every possible way. Not only did it make more power in a much nicer way, it had a wider power band, it was smoother, it sounded nicer etc etc. A completely stock 330d was better than that tuned 320d ever could be, and ofcourse, the 330d could easily be remapped for even more. He eventually stripped the 320d for parts because he couldnt sell it for what it was "worth" and having learned theres no replacement for displacement, bought a 130i.

Eventually i realised the common approach that i rubbished when i was younger was common because it worked and people had gotten to that point by iterating thru the other options and finding the best one.

Given how difficult its been for OEM's to get electrical turbocharging working and viable (they've been working on it for at least 20 years) I think the idea that your going to bolt such a system to an existing engine, and somehow have it work properly, is just nuts. Especially when the intention is only to provide a tiny bit of boost below 1500rpm, where you basically never should be anyway... Maybe you find the process of building the thing fun, but again, with time i've realised that jumping into something that Just Works has its benefits. If the thing you want doesnt exist, then sure, build it. But in this case, you could either fit the larger engine, or if for some strange reason you want to keep the nasty 4 cylinder, grab the twin turbo arrangement from the 123d, and get that working on your E90. At least someone with millions of pounds has engineered a solution that does actually work, and you just have to tackle the challenges of making it work with your particular car.
 

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yeah, i dont really get the premise tbh. The stock engine has a variable vane turbo and hits full boost extremely quickly already. Sure, it doesnt make much below 1500rpm, but why are you ever trying to request full power that far down the rev range? Select the correct gear and your at 2500-3000rpm and response is instant. Its also modifying something where the solution already exists, and in the case of the E90 that solution is the 330d, or 335d for even more go.

One thing the bigger engine does, is makes the lower RPM range more flexible, simply by virtue of 50% more capacity and thus 50% more power even without any boost. If you do find yourself in the wrong gear it doesnt matter as much.

Maybe its just an age thing. I remember when i was younger, modifying cars, and always wanting to "do something different".... I did daft engine swaps that looking back now i can see made zero sense. My brother had a 320d, and we did various bits to it including injector upgrades and larger turbo etc. Most folks on the BMW forum pointed out we should have just bought a 330d. Somehow we thought we knew better... Some time later i bought myself a 330d, and immediately realised that indeed they were right. It was just better in every possible way. Not only did it make more power in a much nicer way, it had a wider power band, it was smoother, it sounded nicer etc etc. A completely stock 330d was better than that tuned 320d ever could be, and ofcourse, the 330d could easily be remapped for even more. He eventually stripped the 320d for parts because he couldnt sell it for what it was "worth" and having learned theres no replacement for displacement, bought a 130i.

Eventually i realised the common approach that i rubbished when i was younger was common because it worked and people had gotten to that point by iterating thru the other options and finding the best one.

Given how difficult its been for OEM's to get electrical turbocharging working and viable (they've been working on it for at least 20 years) I think the idea that your going to bolt such a system to an existing engine, and somehow have it work properly, is just nuts. Especially when the intention is only to provide a tiny bit of boost below 1500rpm, where you basically never should be anyway... Maybe you find the process of building the thing fun, but again, with time i've realised that jumping into something that Just Works has its benefits. If the thing you want doesnt exist, then sure, build it. But in this case, you could either fit the larger engine, or if for some strange reason you want to keep the nasty 4 cylinder, grab the twin turbo arrangement from the 123d, and get that working on your E90. At least someone with millions of pounds has engineered a solution that does actually work, and you just have to tackle the challenges of making it work with your particular car.
You can adjust the vane linkage so the vnt makes more boost a low rpm, and with a decent remap you can hit max boost well below 2000rpm. If the remapper knows his stuff, he can also raise the boost pressure and alter the map calibration so the ecu is happy with the new boost profile.

If the performance below 2000rpm is very poor, the maf needs changing. (or the remapper can eliminate it).

The BMW 2L in the 75/ZT could be remapped to 160bhp from 113 and that engine didn't have a VNT turbo. The same engine in the Freelander TD4 which does have a vnt has reached 178bhp.
In both of those cases, I'd worry about the drive train longevity.
 

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Discussion Starter · #29 ·
At £1,500 and only 20% more capacity than the Fiesta one I'd suggest it's not worth pursuing.
The Audi charging system remains 12v with a DC : DC step up to charge the electric turbo battery. Note Audi also do "mild" hybrids that use a 48v motor/generator but those are only "greenwashing" in a vehicle that weight.
hmm interesting well my alternator is 150a, even the bigger engined ones use the same because its based on charging the size of battery.
M57N2 would be a far better way to spend your money.

Easy isnt worth anything.

330d 335d boring! there are no challenges in those you just buy it and tune it or buy it put readily available modifications on and map. its too boring.

also the 320d handles a lot better.
 

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So ive been doing a bit of research ive found some places do 1000w 48v alternators is that enough? i also found out that many cars with 48v systems use a dc to dc converter for charging but i didnt find any info on the alternators themselves but i expect they are probably 48v alternators which are used to charge both the 48v battery and the 12v.

also i foumnd an original audi battery and here isa picture from the sticker so we can see what its specification is. battery doesnt look tall but i would like to know how long and wide it is
Can't but think you are on the wrong forum, hint this forum is for EVs.
 

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hmm interesting well my alternator is 150a, even the bigger engined ones use the same because its based on charging the size of battery.
So 150A @ 14v is 2.1kW max - we are back to the duty cycle question again - how long is acceptable between electric supercharger uses to recharge the battery? Assuming that you use all 0.8kWh it'll take 24 minutes to recharge with no losses, other loads etc. Is that good enough?
 

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So 150A @ 14v is 2.1kW max - we are back to the duty cycle question again - how long is acceptable between electric supercharger uses to recharge the battery? Assuming that you use all 0.8kWh it'll take 24 minutes to recharge with no losses, other loads etc. Is that good enough?
Is there going to be any kind of electric propulsion motor on this wacky car? Sorry it's just the "wrong" forum.
 

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Discussion Starter · #34 ·
yeah, i dont really get the premise tbh. The stock engine has a variable vane turbo and hits full boost extremely quickly already. Sure, it doesnt make much below 1500rpm, but why are you ever trying to request full power that far down the rev range? Select the correct gear and your at 2500-3000rpm and response is instant. Its also modifying something where the solution already exists, and in the case of the E90 that solution is the 330d, or 335d for even more go.

One thing the bigger engine does, is makes the lower RPM range more flexible, simply by virtue of 50% more capacity and thus 50% more power even without any boost. If you do find yourself in the wrong gear it doesnt matter as much.

Maybe its just an age thing. I remember when i was younger, modifying cars, and always wanting to "do something different".... I did daft engine swaps that looking back now i can see made zero sense. My brother had a 320d, and we did various bits to it including injector upgrades and larger turbo etc. Most folks on the BMW forum pointed out we should have just bought a 330d. Somehow we thought we knew better... Some time later i bought myself a 330d, and immediately realised that indeed they were right. It was just better in every possible way. Not only did it make more power in a much nicer way, it had a wider power band, it was smoother, it sounded nicer etc etc. A completely stock 330d was better than that tuned 320d ever could be, and ofcourse, the 330d could easily be remapped for even more. He eventually stripped the 320d for parts because he couldnt sell it for what it was "worth" and having learned theres no replacement for displacement, bought a 130i.

Eventually i realised the common approach that i rubbished when i was younger was common because it worked and people had gotten to that point by iterating thru the other options and finding the best one.

Given how difficult its been for OEM's to get electrical turbocharging working and viable (they've been working on it for at least 20 years) I think the idea that your going to bolt such a system to an existing engine, and somehow have it work properly, is just nuts. Especially when the intention is only to provide a tiny bit of boost below 1500rpm, where you basically never should be anyway... Maybe you find the process of building the thing fun, but again, with time i've realised that jumping into something that Just Works has its benefits. If the thing you want doesnt exist, then sure, build it. But in this case, you could either fit the larger engine, or if for some strange reason you want to keep the nasty 4 cylinder, grab the twin turbo arrangement from the 123d, and get that working on your E90. At least someone with millions of pounds has engineered a solution that does actually work, and you just have to tackle the challenges of making it work with your particular car.

its not extremely quickly, furthermore there are no swirlflaps because they get taken out so as not to end up in the engine which makes the low down torque worse but it's a sacrifice people make to save potentially killing the engine. the plan is to have instant boost not have to wait for the revs to build up so the electric turbocharger will do that then the normal turbocharger will take over after that.

330d or 335d isnt a solution for me thats too boring!! anyone can buy one of those and put pre made stuff on it and boom you are done. thats very boring there is no challenge!

bigger engines make more power but the whole system is heavier. much heavier drivetrain as a whole, heavier engine etc etc.

dunno about an age thing but ive always been like this (im 43 now) i prefer to try do different things rather than copying everyone else my brother is the same. Prime example he has a 320d that is faster than any stock 330d and 335d its even faster than most modified 330d and 335d's. you can get 300hp 600+nm out of a 320d without even opening the engine but he's gone further than that. he did consider the electric turbocharger however, his 320d is a drag racing car and it would have added extra weight. when he runs that he pulls away in second gear.

i can tell you about 330d and 335d as my brother is a tuner and he specializes in them, most of his tuning work is on these so ive driven and been in many of them data logging and 9 out of 10 of these that come in for tuning have some issues that need rectifying which is a mich higher figure than 320d's. yes they go fast but as i said before its quick and easy and boring. also, those cars suffer from a hot cylinder number 6 very common because the routing of the coolant isnt good. they almost always come into my brother and the vac lines immediately need changing because they are often perished and these can cause a number of problems. there are many other little problems that these have as well which contribute to having losses in power on the top end. the 320d M engines are a far more reliable system and easier to work on.

let me tell you another story the 2.5 sounds the best better than 330d and 335d also as a side note a 320d is louder. but anyway back to the 2.5 lump, since my brother sold me this 320d he's onto his next project to drive as a daily so he has a 118d he's pulling the engine out and building a 2.5 build which as expected what his plans are is not something others have done in a 1 series. there are 130d's that were made by enthusiasts though I saw one a couple weeks ago at my brothers on the dyno that thing was savage lol.

i like the challenge and thats the main reason im doing what im doing and the fact that people get all pissy about it in some cases amuses me because they're all like just buy a 330d and im like no thats boring lol. the original aim was Volvo power pulse which has its similarities to this but it would be far more work. to put it simply compressed air gets pumped into the turbine for instant boost but that would require more space more weight more complicated system.

i am used to driving a diesel with swirl flaps and it gives that pleasing low down torque and its a very nice driving experience. but in the bmw im not prepared to run swirl flaps because it could kill the engine. so I need a better solution. while an electric turbocharger may seem crazy or whatever its a challenge which is the whole fun part of doing something like this. and because no one else has done this before as a retrofit so to speak.

as for twin-turbo from a 123d the problem still remains if I went that route I still wouldnt have the low down torque im looking for, exhaust gasses still need to spool the turbo

also as a final thing we are well into electric cars hybrids and what not so instant boost will become a standard practice I predict in the next 5 to 10 years. consumers will expect it. anything with a battery and an electric motor these days be it a fully electric vehicle or a combination of an electric side and a combustion engine side they all have instant power. and i believe this is why companies are trying to move forward like the audi sq7 theyve realized they need to compete with this sort of thing and it makes sense they first try it on a large engined more expensive car because people like to see fast cars do these things, and eventually it will get into more vehicles as time goes on.
 

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Discussion Starter · #35 ·
You can adjust the vane linkage so the vnt makes more boost a low rpm, and with a decent remap you can hit max boost well below 2000rpm. If the remapper knows his stuff, he can also raise the boost pressure and alter the map calibration so the ecu is happy with the new boost profile.

If the performance below 2000rpm is very poor, the maf needs changing. (or the remapper can eliminate it).

The BMW 2L in the 75/ZT could be remapped to 160bhp from 113 and that engine didn't have a VNT turbo. The same engine in the Freelander TD4 which does have a vnt has reached 178bhp.
In both of those cases, I'd worry about the drive train longevity.

correct to a point you can adjust the linkage if its a vac operated turbo it has to be done on the map if its electronic. mine is electronic so its a faster response compared to a vac operated one there are tradeoffs for this sort fo thing so it depends on the individual and if they are prepared to accept them.

once the car starts spooling about 1500 rpm on mine it will spool up and rev very quickly i have a hybrid turbo as well, also it doesnt have a maf that has been mapped out it runs what it needs to off the map sensor. in any case a maf sensor has its limitations so while its useful its only upto a certain point.


many 2.0 turbo diesel bmws often badged for example 116 118 316 318 those are the same engine as the 120 320 520 variants in many cases the difference is a detuned ecu and they also run different turbo and injectors. so if you were to upgrade those to 320d versions or even better those will tune exactly like the X20 variants. my brother bought a 118dfor his project and the reasonthats a good choice even for people who want to just tune that engine is theyve had an easier life with less power. :)
 

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Discussion Starter · #36 ·
Can't but think you are on the wrong forum, hint this forum is for EVs.

im in the right place i was recommended to come here the main reason for being here if you haven't figured it out is to get more information about batteries and charging systems for what im planning to do and this is one of the best places to do so. also im pretty sure there is probably some people here converting cars to electric also so that is useful as well
 

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Enjoy your ICE whilst you still can, they are very much time limited. If you want instant low down torque perhaps the Nissan e-power concept might interest you?
No, I thought not. ;)
 

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Discussion Starter · #38 ·
So 150A @ 14v is 2.1kW max - we are back to the duty cycle question again - how long is acceptable between electric supercharger uses to recharge the battery? Assuming that you use all 0.8kWh it'll take 24 minutes to recharge with no losses, other loads etc. Is that good enough?
yeah well i need to find that out. i hoped someone may have been able to at least estimate some things here given that ive provided the battery info from the original vehicle and i am told that the car runs on a 12v alternator but i guess whoever could do that hasnt seen this yet.

i cant really say what is good enough and what isnt i know very little about batteries and charging and discharging i was hoping to find out some more info here if not then iwill need to look elsewhere. i could try to get hold of valeo who make the turbocharger as a last resort but they might not want to give me the information. i can only ask i suppose but im waiting for the turbo to get here first so at least then i have it in my hands
 

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Discussion Starter · #39 ·
Enjoy your ICE whilst you still can, they are very much time limited. If you want instant low down torque perhaps the Nissan e-power concept might interest you?
No, I thought not. ;)

That is quite interesting! except for the gasoline part lol. maybe something for the future though! i mean i probably got the room for a system like that im sure
 

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Discussion Starter · #40 ·
Is there going to be any kind of electric propulsion motor on this wacky car? Sorry it's just the "wrong" forum.
only the electric turbocharger. once the car is up the rev range it has a lot of power nothing phases it even a 16% grade hill just put your foot down its almost like its not a challenge
 
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