m20b25 turbo

[e30timmy 0]

i was thinking about turbing my m20 but am not sure of where to find parts? Any info aswell would be great

[topcat 11]

i was thinking about turbing my m20 but am not sure of where to find parts? Any info aswell would be great

thats awesome,the search button is your best friend

[charles28 136]

www.millerperformancecars.com

For some of the stuff needed, ie, Injectors etc

[No name user 379]

i was thinking about turbing my m20 but am not sure of where to find parts? Any info aswell would be great

what would you like to know

[nipe 1]

what would you like to know

Subscribed

[polley 916]

what would you like to know

Cheap, hory, and reliable

[oscar90 0]

Subscribed

+1

[e30timmy 0]

what would you like to know

were id be able to find parts, and how do you go about the oil feed and return lines as im new to bmws and havent had time to pull the motor out yet. i know im going to need it to be rebuilt before i even consider bolting a turbo on but i was wondering if anyone had a few suggestions on a few set ups like turbo, injectors. also what diff would i need

[No name user 379]

were id be able to find parts, and how do you go about the oil feed and return lines as im new to bmws and havent had time to pull the motor out yet. i know im going to need it to be rebuilt before i even consider bolting a turbo on but i was wondering if anyone had a few suggestions on a few set ups like turbo, injectors. also what diff would i need

You dont need to do too much to the motor but also depends on what you idea of a rebuild is?

You can get away with stock compression and pistons depending on the power leave your after 200ho isnt hard to do, a good mls head gasket and caps screws for head bolts pull them down to 65 ft/ib you can use the stock cam without an isssue.

As for the exhaust manifold "j" pipes work well and cheap to do the chinese manifolds work ok also Scarles carry them, keep with the stock intake for ease of the throttle etc change the vacuum valve for the booster their a pain in the butt and leak use one off a late model japper doesnt need to be turbo.

Change pump to a evo 1-3 or any aftermarket also change to a larger fuel filter easy job repco carry a good selection, as for injectors if you use the ones from a m42b18 they are lucas high imp 240cc and x6 will support 300hp and will drop straight in.

You can keep the stock ecu/dme and afm to which you can suck through or blow thru the easiest would be suck thru they will also voltage cut at 4.8 volts you can put a bolt stop inside then and set it to 4.7, no need to touch the ignition they dont run a lot of advance so need to retard it for up to 10psi which is over a 50% gain in power.

to control the injectors use an apexi AFC works great easy to use oil feed tee's off the oil sender switch oil return can run around the front of the motor to the high side of the sump use a -3an line and 19mm return.

If you chose to intercool its whatever you can fit into the front doesnt need to be massive anything at this power level is better than nothing keep the piping to 2-2 1/4 inch's for response sake, its easier to use a turbo with a built in waste gate like a evo 2-3 or GTST RB25/20 due to the room issue and external makes things hard.

This a brief over view of ones ive done on a budget if you intend to spend more then aftermarket ecu etc adds to the cost but you should be able to do the whole turbo setup under 2k.

You dont need a bunch of power in the car to wake it up my m42b18 e36 admittedly has good stuff inside the motor but still runs a stock ecu with a mapecu3 piggy back and makes a lazy 270hp and makes fools out of m3 e46 ( well it did the other day the owner got a bit p.i.s.s.e.d was bloody funny) i can add much much more but most like the basic stuff hope thats some sort of help.

[Ace Of Spades 51]

You dont need to do too much to the motor but also depends on what you idea of a rebuild is?

You can get away with stock compression and pistons depending on the power leave your after 200ho isnt hard to do, a good mls head gasket and caps screws for head bolts pull them down to 65 ft/ib you can use the stock cam without an isssue.

As for the exhaust manifold "j" pipes work well and cheap to do the chinese manifolds work ok also Scarles carry them, keep with the stock intake for ease of the throttle etc change the vacuum valve for the booster their a pain in the butt and leak use one off a late model japper doesnt need to be turbo.

Change pump to a evo 1-3 or any aftermarket also change to a larger fuel filter easy job repco carry a good selection, as for injectors if you use the ones from a m42b18 they are lucas high imp 240cc and x6 will support 300hp and will drop straight in.

You can keep the stock ecu/dme and afm to which you can suck through or blow thru the easiest would be suck thru they will also voltage cut at 4.8 volts you can put a bolt stop inside then and set it to 4.7, no need to touch the ignition they dont run a lot of advance so need to retard it for up to 10psi which is over a 50% gain in power.

to control the injectors use an apexi AFC works great easy to use oil feed tee's off the oil sender switch oil return can run around the front of the motor to the high side of the sump use a -3an line and 19mm return.

If you chose to intercool its whatever you can fit into the front doesnt need to be massive anything at this power level is better than nothing keep the piping to 2-2 1/4 inch's for response sake, its easier to use a turbo with a built in waste gate like a evo 2-3 or GTST RB25/20 due to the room issue and external makes things hard.

This a brief over view of ones ive done on a budget if you intend to spend more then aftermarket ecu etc adds to the cost but you should be able to do the whole turbo setup under 2k.

You dont need a bunch of power in the car to wake it up my m42b18 e36 admittedly has good stuff inside the motor but still runs a stock ecu with a mapecu3 piggy back and makes a lazy 270hp and makes fools out of m3 e46 ( well it did the other day the owner got a bit p.i.s.s.e.d was bloody funny) i can add much much more but most like the basic stuff hope thats some sort of help.

Crunchy..... I would just like to say your the f***ing man!

Wish i could be this knowledgeable. Was also considering doing this and that is everythingish i need!

[No name user 379]

Crunchy..... I would just like to say your the f***ing man!

Wish i could be this knowledgeable. Was also considering doing this and that is everythingish i need!

i wouldnt go that far but it is very general i can add a ton more but it comes down to your wallet

[328FTW 0]

I've always been of the stance that "shortcuts" with stock ecus are what blows things up. Full standalone is usually always the way to go even with engines that use a volume type of metering (AFM) rather than speed density. Fuel you can dump it in till it's running out the tailpipe but unless the timing is well controlled the motor dies a sad death. I've never really see many pull it off without true standalone, at least not for a decent period, only takes a short period of leanout on an ecu that isn't monitoring a wideband or what have you and the motor is toast. Plus it means you're not maxing out the trim settings on things that control fuel only, they are different in their limitations but they are usually just that, limited.

The exception to using standard ecus to me is if you change injectors then remap a chip in the stock ecu to compensate timing etc. Which is basically going back to having control of your criticals. Stock ecu turbo setups are usually very mild for what is put into them and the gains in my mind are "not as fun" as n/a power adders due to that cut timing and less responsive feel, till you get to the 300+hp turbo realm then they really come into their own.

I'm not too specifically clued up on these motors but looking at them and their compression it appears easier than most. As for parts, I make everything usually, putting the turbo on is the easy bit.

[No name user 379]

I've always been of the stance that "shortcuts" with stock ecus are what blows things up. Full standalone is usually always the way to go even with engines that use a volume type of metering (AFM) rather than speed density. Fuel you can dump it in till it's running out the tailpipe but unless the timing is well controlled the motor dies a sad death. I've never really see many pull it off without true standalone, at least not for a decent period, only takes a short period of leanout on an ecu that isn't monitoring a wideband or what have you and the motor is toast. Plus it means you're not maxing out the trim settings on things that control fuel only, they are different in their limitations but they are usually just that, limited.

The exception to using standard ecus to me is if you change injectors then remap a chip in the stock ecu to compensate timing etc. Which is basically going back to having control of your criticals. Stock ecu turbo setups are usually very mild for what is put into them and the gains in my mind are "not as fun" as n/a power adders due to that cut timing and less responsive feel, till you get to the 300+hp turbo realm then they really come into their own.

I'm not too specifically clued up on these motors but looking at them and their compression it appears easier than most. As for parts, I make everything usually, putting the turbo on is the easy bit.

the main thing it comes down to you have to know what your doing even with a stand alone you can still screw it up setting safety limits on things even n/a you can still get it wrong you need to go back though time ( im showing my age here ) but all we had to deal with was bolt on's using stock ecu in fact many turbo jap cars came out stock turbo with a AFM ( no speed density )ive pushed stock ecu's way past 3x their stock power levels and never had an issue.

The mapecu for a piggy back is sold all round the world including cars like the R35 gtr to which no aftermarket ecu can allow the car to run all its functions and still make power this fits the bill nicely, ive tuned many types of aftermarket ecu's in the last 30 years the reason ive done the piggy back is most say "you cant do that" and i love proving them wrong my little m42 makes 270hp and a daily driver/work hack isnt treated well even from a new motor now done 3500km runs great.

A history would show it companies like Apexi,Trust, HKS etc made lots of wire in units for trubing n/a in fact the worlds quickest HKS GTR at the time used a stock ecu with wire on goodies and for those who dont know ran 7's for the 1/4 mile, adding fuel and changing timing isnt a hard thing to do if you know how and thats the key to making it work.

Now do keep this in mind theres a ton of people out there with little money and want to play thus as yourve stated running a few pounds boost isnt an issue they dont want a 5000hp toy they know what it costs and are more than happy doing it how they can afford it, thats what the country is known for DIY and that gets my interest more than a big dollar build i do those every day but people that can think outside the square get my attention.

Peoples attitude towards things is what brings success not a mind set ! and prof of what they can do and i can give a very long list for that one

In saying that is it a case of "you cant do that" or the person just doesn't know what their doing? my answer spend less time trolling the net and get out into the real world.

Edited November 10, 2012 by crunchy

[e30timmy 0]

You dont need to do too much to the motor but also depends on what you idea of a rebuild is?

You can get away with stock compression and pistons depending on the power leave your after 200ho isnt hard to do, a good mls head gasket and caps screws for head bolts pull them down to 65 ft/ib you can use the stock cam without an isssue.

As for the exhaust manifold "j" pipes work well and cheap to do the chinese manifolds work ok also Scarles carry them, keep with the stock intake for ease of the throttle etc change the vacuum valve for the booster their a pain in the butt and leak use one off a late model japper doesnt need to be turbo.

Change pump to a evo 1-3 or any aftermarket also change to a larger fuel filter easy job repco carry a good selection, as for injectors if you use the ones from a m42b18 they are lucas high imp 240cc and x6 will support 300hp and will drop straight in.

You can keep the stock ecu/dme and afm to which you can suck through or blow thru the easiest would be suck thru they will also voltage cut at 4.8 volts you can put a bolt stop inside then and set it to 4.7, no need to touch the ignition they dont run a lot of advance so need to retard it for up to 10psi which is over a 50% gain in power.

to control the injectors use an apexi AFC works great easy to use oil feed tee's off the oil sender switch oil return can run around the front of the motor to the high side of the sump use a -3an line and 19mm return.

If you chose to intercool its whatever you can fit into the front doesnt need to be massive anything at this power level is better than nothing keep the piping to 2-2 1/4 inch's for response sake, its easier to use a turbo with a built in waste gate like a evo 2-3 or GTST RB25/20 due to the room issue and external makes things hard.

This a brief over view of ones ive done on a budget if you intend to spend more then aftermarket ecu etc adds to the cost but you should be able to do the whole turbo setup under 2k.

You dont need a bunch of power in the car to wake it up my m42b18 e36 admittedly has good stuff inside the motor but still runs a stock ecu with a mapecu3 piggy back and makes a lazy 270hp and makes fools out of m3 e46 ( well it did the other day the owner got a bit p.i.s.s.e.d was bloody funny) i can add much much more but most like the basic stuff hope thats some sort of help.

yea man thats a great help ae and yea just think might try just the basic 1st then when get more use to it might try more advanced stuff but thanks man much appreciated. just another thing what would you reconmend about the brakes?

[No name user 379]

yea man thats a great help ae and yea just think might try just the basic 1st then when get more use to it might try more advanced stuff but thanks man much appreciated. just another thing what would you reconmend about the brakes?

Get some certified brake lines as in braided new disc's get them slotted i can help there and some hawk race pads off ebay a ton cheaper than here even with the postage ive brought a few sets in now they work great plus some good fluid but again as its been pointed out theres many ways to doing things and for most its your wallet that controls what you do and hate to say it but around here its also a mind set that stops many.

Now if you wanted a big horse power setup i can give a shopping list on that also and for those reading this there's a good reason why people like Slatter and Delmount go so well they listen cause the more you talk the less you learn.

You can make reasonable power doing n/a but itll cost you more and you'll never make the same torque or endless topend from it than going forced induction each to their own.

[328FTW 0]

While I realise you can make power on stock ecus with the right touch I do often wonder why. It made sense maybe 10 years ago but today you can have standalone really really cheap. It's the tuning that kills you but you need to do that regardless so I'd rather go with the better system. I'm a fan of megasquirt, some people hate it but mine was fine right up till I sold it. Sure I blew up a couple motors with it but I've blown plenty more on stock ecus.

My prelude runs a LINK, antilag, launch control and features that are just in general not really easily possible on standard ecus. $700 off tardme. I mean that's nothing when you look at what the car can do. The car is unlike almost anything else. I find drag cars spend most time at WOT and they tune as such, my car being a rally car has a much much broader range of scenarios; road cars you don't want huge injectors drowning out any chance of good MPGs because it's only good for WOT and only has the flexibility to do that one thing well and the rest of the range is compromised.

To generalise doing turbo setups:

• Cheap stainless manifolds usually crack, they use lower grade stainless and the welds are often sub-par.
• Cheap turbos often die young, chinese quality control is sh*t and there is a lot of the time metal swarth from machining just left in the assemblies or bad tolerances on the bearings etc. Even pot metal wheels that explode.
• Tuning is your friend
• Widebands are your other best friend
• Psi and horsepower have almost nothing to do with each other, learn to at least partially understand turbo efficiency maps.
• Cheap intercoolers work fine
• Use good clamps on your pipes
• Expect it to cost more than you planned
• If you can't afford another motor or to have your car leave you stranded then don't try.

Probably more stuff but my suggestion is a big ugly steampipe manifold and something solid like a genuine garret t3/t4. Not because it's optimal but because it's solid. If you can spring for a good ball bearing turbo then go for it but they can't be rebuilt as a rule, 360 degree thrust bearing on a turd pusher t3/t4 of the right trim is an ok setup for most 6 cylinders and parts are everywhere. N/A built motors are fun as hell, I've driven a 300hp 2 litre and it had to be one of the most responsive motors I've even been behind but the M20b25 is too limited heavy and wrong kind of car to really benefit greatly. For starters the whole 2 valve per cylinder thing makes for throwing about heavy valves which on a revvy n/a motor is all kinds of wrong.

I just bought a nice tig welder and was kinda half considering getting into making some manifolds and what not. I can mig them up but most people recoil at my shitty looking welds spattery cause of the CO2 I run on it now. Steampipe is the bomb for turbos, stainless I like more for n/a cars that don't get the things red hot. A good stainless turbo manifold is $$$$ if they are using the correct alloy for it.

[polley 916]

Nothing wrong with chipping / piggybacks if done correctly and you dont need the more advanced features. That factory cold start and driveability...

If you keep blowing up engines youre doing it wrong.

[No name user 379]

Nothing wrong with chipping / piggybacks if done correctly and you dont need the more advanced features. That factory cold start and driveability...

If you keep blowing up engines youre doing it wrong.

+1

the end result of any job is the ability to make all aspects to work in harmony

[No name user 379]

Knowledge and wallet that decides what your going to do, the stainless Chinese manifolds work fine with some hand work the cracking has a lot to do with what you hang off it including no flexi in the system even a steam pipe manifold cracks in fact even factory cast turbo manifolds crack all manifolds crack at some point in their lives.

Stainless has down falls it doesnt retain heat well something that makes turbos more responsive its mainly used when running race gas or alky based fuels as it does corrode and flake m/s can also work well in the same situations provided its coated inside also cheaper to make purging isnt needed.

T3/4 means nothing its just the frame size it has no reflection to what it actually does theres more than 2500 combos you can have and their going up in cost, ball bearing turbos are alot more expensive cant be rebuilt ( well i do but i manufactor my own parts ) they are also only 5% more responsive than a plain bearing again a myth for those buying them, as for reading maps again they are dependent on what turbine and housing size is driving it useless info for most the sizing should be left up to those who do so for a living yes there generic turbos that work but as yourve pointed out far from ideal.

As for aftermarket ecu yes you can get some cheaper units but you still have to install so a good knowledge base on car electronics is a must or a mate that wont screw it up then you need to know how to drive it and tune which theres a tad more to it than a wideband a good knock monitor then understanding the engine characteristics from compression and sorry but boost has a big reflection on the effective comp ratio and its effect on the fuels BTU's to how hard you can lean on it and running rich isnt always a smart idea it may help cool charge air temps but can induce detonation again its a knowledge thing, tuning is black art not a science you either know how to do it or dont and reading countless books doesnt help every car is different from the next if it was a science how come dynos tuners get differant results from each other or are they screwing with the TCF factor to make themselves look good? thats another topic again.

You mentioned your honda to running all the bells and whistles and stock ecu cant? Not true Hondata do a plug in for most model hondas covering all the toys and some plus an Apexi power fc is also a plug in and if covers your model can be picked up for well under 1k in regards to injector sizes you MUST HAVE a fuel system that will support your power levels regardless road or race delivering "x" amount of ltrs per min, ive have plenty of customers running big hp setup road cars running 1200cc plus injectors that have better drivability and idle than stock due to injector design as for economy? dont expect to get 40 mpg from a 800hp toy for that i will say its hard to bet a honda for a work hack there great for that atleast.

The topic off n/a versus turbo or two versus four valve many things come into that equation its not hard to double a n/a power output with 10psi of boost but to achieve the same n/a is an expensive exercise thus two valve with a turbo reving to 6k like a m20b25 isnt an issue in fact makes for a friendly car to drive you don't need massive cams and head porting( mind you they do help ) nor does it need to be revved within an inch of its life to make the power plus the torque gain from a turbo is far greater than a n/a unless you start going to bigger displacement, like most things its a personal choose to what you want and how you go about it each to their own again your wallet decides what your going to do or you wouldn't have brought a MS or the link at a budget price to start with, what i put up for doing a basic turbo m20b25 falls well within someones budget to have some fun its not a race car but will put a smile on there face and theyll learn some skills along the way and thats not a bad thing youll have to admit BMW's are cheap to buy and play with so whats the harm lifes short do what makes you happy.

[328FTW 0]

I'm bias, when I say n/a power I mean gobs of it. Generally not very good street setups mostly because of cams. Boost is only useful if you know more info is what I was getting at, like when someone in a starlet quotes "run my car at 18psi, GOES HARD" 18psi means jack all by itself if someone says such and such motor takes X boost it's nice to know what is pushing that air.

I still stick by standalone being brilliant however the user and tuner behind it has a lot to do with that, it's not worth dirt if the user has no idea what they're doing.

Something I have zero idea about is on these cars you have basically 3 iterations of the motronic ECU with the M20 engines and even one jetronic unit and how they get on for one being easier than the other to mess with.

[No name user 379]

I'm bias, when I say n/a power I mean gobs of it. Generally not very good street setups mostly because of cams. Boost is only useful if you know more info is what I was getting at, like when someone in a starlet quotes "run my car at 18psi, GOES HARD" 18psi means jack all by itself if someone says such and such motor takes X boost it's nice to know what is pushing that air.

I still stick by standalone being brilliant however the user and tuner behind it has a lot to do with that, it's not worth dirt if the user has no idea what they're doing.

Something I have zero idea about is on these cars you have basically 3 iterations of the motronic ECU with the M20 engines and even one jetronic unit and how they get on for one being easier than the other to mess with.

agree im not anti n/a just for of power even 2psi makes a massive difference and when it comes your Honda especially vetec outstanding good engines the first motors in the world for a production car to make over 100hp per liter 91 civic i think was 170hp? there about

[actletpone 43]

Not sure if allowed to post links to other sites here? However if you google 'turbo e30 faq' you will find a write up which is a good starting point for information.

[No name user 379]

Not sure if allowed to post links to other sites here? However if you google 'turbo e30 faq' you will find a write up which is a good starting point for information.

I dont think anyone bothers to use this place anymore.....tumble weeds roll by

[Silver Fox 43]

some of us do still roll around...