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Tuning the BMW M50 / M52 engine

BMW tuning - Your guide to tuning the BMW M50 / M52 engine

Below you will find a guide for tuning the BMW M50, M52, and M54 engine. It is a guide where the tuning parts you need, and what typical errors you need to be aware of are reviewed. However, you are always welcome to contact us if there is anything that needs to be corrected or added.

This is how we can best help you!

Many people would like to know if they have all the parts they need to put a new turbo in their car, and if in doubt you can do the following:

Create a login on the website - So you are created as a customer

All the items you expect to use or are in doubt about if you need, you put in the shopping cart.

Send me an email with questions from the email you created the account with- Then we can see the parts you have questions for or see if you are missing something, as well as add parts if I think you are missing something.

 

Decide how many horsepowers you want BEFORE you start tuning

It is always a good idea to decide how much horsepower you want before you start rebuilding your car. Do you want, for example, 250 or 350 hp. ? - There can be a big price difference between the two.

It is especially important with the M52 and M54 engines to decide before you start as they are not as durable as eg the M50 engine. I recommend a max of 350 hp. on the M54 / M52 engine as it is an aluminum block - This is with reinforced Athena top gasket and ARP bolts on min. 2.5L engine. However, it must be said that others have achieved power up to 450 hp. with pistons and connecting rods, you may also be lucky to get the same result but we can unfortunately not recommend it when there may be a risk of the block cracking. Note that on the M54 the bolt on the oil pump comes loose, staple it with a welder, or gives it a corneal dot. The thread in the block on M52 / M54 can not be tightened several times, the thread will be torn to pieces, therefore you must use support bolts from eg ARP. The crank in the M52 / M54 is good and can also be used in an M50 engine for very high power.

Below you can see the intake manifold on an M52 on the left and an M50 on the right. There is much more flow in an M50 intake that you can easily transfer to your M52 engine. And you can also see a flow test.
.............. M50 .......... M52
cyl 1 ..... 284cfm ..... 188cfm
cyl 2 ..... 276cfm ..... 191cfm
cyl 3 ..... 288cfm ..... 201cfm
cyl 4 .. ... 288cfm ..... 195cfm
cyl 5 ..... 276cfm ..... 194cfm
cyl 6 ..... 284cfm ..... 191cfm

We have a specially made intake manifold for the BMW M50 engine. It is made with the extra good flow with funnels inside the plenum chamber.

BMW intake manifold - High flow

An M50 engine with reinforced cylinder head and bolts allows you to go for 1.1 bar charging pressure without a problem, ie around 420 hp. The M50 block is a really good and stable choice as a power of over 1000 hp has been achieved on such a block. The block is made of cast iron.

Tuning Selection - Compressor Kit or Turbo Kit

You can choose between a compressor kit or turbo kit and there is an incredible number of opinions on what is best and here is our opinion. A compressor kit can be a super good choice if you do not want a lot of hp, they are typically easy to install. The compressor is driven by a belt and it obviously takes some HP. The advantage can then be that the charge pressure comes further down in the revolutions. But if you want something that is easy to assemble and disassemble, it is a nice choice.

A turbo kit can be somewhat more comprehensive to install, which must be made/installed, for example, turbo manifold, turbo, downpipe, oil supply and return to the turbo, pipes, and piping, etc. therefore, the power at the same charge pressure as a compressor will be slightly higher.
Do you need a lot of hp then go for a turbo kit, and moderate hp which is easy and cheap to install it must be a compressor kit. 


Below is a closer look at tuning with turbo:

Turbo manifold Selection

You can choose from several setups as we have cheap cast iron turbo manifolds where the turbo is located under the manifold at the back of the engine compartment - It is a fine manifold which has been used for a myriad of projects. It can be an advantage to use an oil return pump for the turbocharger as it sits very low and therefore can't easily get rid of the oil from the turbo. If you want to make a lot of hp. and want a turbo manifold that has an extra good flow, you can choose a top-mount manifold, it has a T4 connection to the turbo and must therefore use a large turbocharger. When mounting a manifold, we strongly recommend making a bracket between the flange at the turbo and into the engine so that it braces and reinforces the manifold so you avoid vibrations and thereby split the manifold. When fitting a new turbo manifold, we also recommend fitting new support bolts and nuts so that the manifold and turbo do not "shake" loose when driving or racing.

We also specialize in turbo manifolds.

Topmount turbo manifold - M50 - The Topmount manifold is a really good choice. Fits well with GT35 turbo.

Cast iron turbo manifold - Can be a little trickier to mount as there is not much space.

Oil return pump - Must use for the cast iron manifold.

Support bolts & copper nut for exhaust & manifold.

 

Turbocharger - Choose your turbo too big!

Normally many would recommend doing the math and looking at flow charts to decide which turbo to use. But the problem is that 99% of all cases you will want to have more hp. once you have achieved your first goal. Then it can be a little awkward to stand with a turbo that is too small. If you drive eg drifting, you also want to have many revolutions on the engine and power up in revolutions as this is where it makes the most smoke. Do you want eg 350 hp. I would definitely recommend a T3 / T4 turbo - It can deliver 400 hp. and then you have the opportunity to screw up a bit when the 350 hp is not enough anymore. To keep the heat away from the engine compartment, it is recommended to put a turbo hood on the turbocharger. It keeps the heat inside the turbo which also gives faster flushing on the turbocharger. If you buy a turbo from us, we have complete control over which fittings and oil hoses you need, we guide you through the purchase of this.

T3 / T4 turbo for 400 hp. This turbo is really good up to 400 hp. It has an internal wastegate

GT35 turbo for approx. 500 hp. - Fits very well with a 2.5-liter engine that should provide some power

T70 with T3 flange up to 650 hp. - Large turbochargers used for operation, 402 meters, etc.

Turbo hood - The turbo jacket for the turbocharger's hot side.

Oil hose feed line - Kit with feed line

Oil hose return - For topmount turbo

Water connection - Kit for mounting water hoses for cooling turbochargers

AN fittings - Make your own connection of oil and water system to turbocharger

 

Structure of Fuel System - Fuel injectors and Fuel Pump

It is important to build a Fuel system that can supply lots of Fuel, you must not make a system that can only supply eg 105% of the amount of fuel you need, then there is not much that needs to be a bit worn and bad before the system is'ent getting enough fuel. On the vast majority of BMWs, there is originally an internal Fuel pump that can deliver to approx. 300 hp. If you need to make more hp, we recommend that you upgrade to one of our 500 hp. Fuel pumps. The Fuel pumps I mention at the bottom of the link are incredibly easy to install, remember to buy a flex Fuel hose for installation.

Of gasoline injectors, we can recommend our 668 cc. injectors that supply enough Fuel for 120 hp. pr. PCS. which gives approx. 720 hp. at 6 pcs. They are high ohm injectors and can therefore be used for all types of engine controls. They are large and will often cause the engine to get a greasy mixture at idle and at partial load driving, therefore they are often used for drifting and motorsport. If you need some that can be used for street driving, you can use 504 cc. injectorss that deliver enough for approx. 540 hp. Both types of injectorss fit directly into the original BMW injectors rail.

If you want to save a little on programming/chip tuning of your BMW, you may. solve it by using an adjustable Fuel pressure regulator which adjusts the Fuel pressure sharply when charging pressure occurs. With the regulator linked to below, the pressure can be adjusted up by 14 x pressure - That's a lot.

At 500+ hp. it is recommended to use 10mm. Fuel hoses

Fuel pump - Choose between GSS340, GSS341, GSS342 or internal Fuel pump for 700hp.

Fuel injectorss - 668cc. if pollution to sight is not a requirement to be complied with.

Fuel hoses - Flex Fuel hose for mounting inside the tank.

Progressive regulator - Adjust the Fuel pressure sharply at charging pressure

Adjustable Fuel pressure regulator - For mounting directly in the injectors rail

 


Ignition System - Spark Plug & ignition coils

BMW's original ignition system is reasonably sensible. It can easily be used up to approx. 1 bar charging pressure, then there are many who "knock" the spark plugs together and thus the spark does not have that far to jump and therefore is not blown out of the thickness in the cylinder chamber. However, we recommend changing the ignition coils when you get up there because the bigger and more powerful spark at the spark plug you have the faster and better the combustion starts. By changing the ignition coils, you will be able to avoid the possibility of unstable ignition and combustion and thus also the ignition bank.
Also, remember to switch to cold spark plugs so that there is no "hotspot" on the spark plug which can make a pre-ignition that starts the combustion.

Turbo spark plugs - Cold spark plugs for an engine with charge pressure

BOSCH TFSI ignition coils - Really strong ignition with REALLY good spark

 

Top gasket and ARP top bolts - Up to 1.1 bar charge pressure

You can drive with charging pressure up to approx. 0.6 bar charging pressure on a standard engine. You can drive with 1.1 bar charge pressure on a standard motor with ARP top bolts and a cutting ring top gasket or a Cometic steel top gasket. I myself am mostly for cutting ring top gaskets as steel top gaskets in some cases can become leaky if the block and the top piece are not 100% straight. With Athena cutting ring gasket, you may be lucky not to have to flatten the block and cylinder head, however, it is recommended!
Some have also been lucky enough to run more charging pressure on their engine without changing more, however, I would not recommend this if you are not ready for the engine to break down.

ARP top bolts - Stronger top bolts are needed as the originals stretch.

Cometic steel top gasket - It is often used to use between 2-3.5mm. steel top gaskets.

Wiseco steel top gasket - Wiseco has made a super good 2mm. cylinder head for BMW M50 at a canon sharp price!

Athena cutting ring top gasket - When choosing a 2mm. as it lowers the compression ratio slightly.

 

Exhaust & Downpipe

No complete systems have been created that just fit plug and play together.You have to make your own downpipe as it is relatively complicated to make so it fits both BMW E36 and E46. Remember when you make eg downpipe it is important to give it power wrap before you mount it, it keeps the heat inside the pipe and keeps the engine compartment cold.

GT 35 flange - If you want to build your downpipe yourself, you can use this flange

Exhaust - Build your own exhaust, middle pots, pots, rear pots.

Simons Catback exhaust - Really good stainless steel exhaust for BMW at the right price

Stainless pipes - If you build the exhaust and pre-pipes yourself, you can use our stainless steel pipes.

Y-piece - Use to drive from downpipe to original exhaust

Custom made exhaust - We build an exhaust that fits your car

Powerwrap - It is strongly recommended to use power wrap to keep the heat out of the engine compartment.

 

Intercooler & intercooler pipe

There is typically plenty of space to mount the intercooler and lead the intercooler pipe. I would recommend an intercooler of a good size. Choose one that fits approx. to the power you need to drive with. Both intercoolers below can be adjusted relatively easily on the BMW E36 and E46.

Intercooler for 400 hp. - Efficient intercooler that is easy to place on a BMW

Intercooler for 600 hp. - Super good intercooler which is a little bigger and requires something more space.

Silicone hoses - Find everything you need for silicone hoses

Stainless steel pipes - Find cheap stainless steel pipes for building intercooler pipes

Stainless steel clamps - Stainless steel clamps for mounting silicone hoses

 

Suction Hose & air filter

The turbocharger must have air through a silicone tube and an air filter. I can recommend a 90-degree silicone bend at the turbocharger where you then mount an air filter. If you choose a T3 / T4 turbo you will need a 3 "connection and with the GT35 and T70 turbo, you will need a 4" air filter and silicone hose.

Silicone hoses - Find silicone hoses in different sizes

Air filter - KN Air filter, HKS Air filter & Apexi Air filter

 

High-quality sports clutch and racing clutch

When you are getting good power with your turbo kit for your BMW, you also need another clutch. Original coupling lasts for approx. 300 hp. Therefore, we have some really good options for upgrading your clutch. You can browse. choose a clutch kit from Sachs performance, here you can get the clutch with organic material mixed with zintermetal, it allows you to disengage "normally" - that is, where it does not take hard as a racing clutch made with eg 4 point zintermetal. However, pure zintermetal holds for somewhat more effect.

Racer clutch & sports clutch - Sachs performance clutches in really good quality for tuning

PMC Motorsport - Here you will find almost everything for your driveline. Clutch, flywheel, and adapter if you need to drive with a different gearbox.

 

 

Heatshield - Away with the heat in the engine compartment!

We can only recommend keeping the heat away from the engine compartment, the colder you can keep the engine, etc. the more power and durability you have in the engine. Among other things. it is a really good idea to use a turbo hood to put over the hot side of the turbocharger, it is close to the bonnet and sits not far from the turbo intake. Powerwrap is a very good idea to use on the downpipe as it also sits up in the engine compartment with a top-mount manifold. If there is anything else you need to have screened off, you can use tape and cover wrap.

Turbo blanket - Turboblanket which is placed on the exhaust side of the turbocharger

Heat Shield Tape - Tape for shielding heat, put on the cold part

Heat Shield Cover Wrap - put on hoses that go up from hot parts

Powerwrap - mounted on downpipe and exhaust

 

Chiptuning & programmable motor control

When tuning the BMW, there are several options, you can either choose a programmable engine control or chip tuning. Chip tuning can be selected for projects with eg T3 / T4 turbocharger as original motor control can not be programmed for too high effects. If you are good at making some wires and installing engine control, you can use a universal engine control from Vems. It may be a good idea to use one of our wiring harnesses that we make for cheap money. However, Vems has also made a plug and play system which is incredibly easy to install - Can definitely be recommended.

Vems engine control - Universal motor control which is a super solution

Wirering - Wirering for universal engine control

Vems PNP - Plug and play motor control for BMW M50 engine.

Below you see a picture of setting up the ignition output on a BMW M50 where the cam sensor is not set. It runs with a "wasted kick". If you want to mount a VEMS engine management on your BMW, we sell a cheap Config file (setup) for the engine control, so you can easily get started and start the car without any problems.

When the wires are properly plugged in, start the engine and check that cylinder 1 turns on approx. in "top" (+ -15 degrees) - Test with an ignition gun. No injectors connector fitted.
If it does not turn on at the top, you can change when it turns on by pressing "Shift Up" or "Shift Down"

 

Charge pressure control - Boostcontrol with several steps

With electronic charge pressure control, you can drive in several steps. Ie. you can have a program where you run with eg 0.7 bar charging pressure and a step where you run with 1.1 bar charging pressure. You can do this in several ways. If you drive with original engine control, you must have retrofitted an electronic boost controller, they are simple to install and set up. But if you drive, for example, with Vems motor control, the option is built into the box and the software and you can make it control the charge pressure, you just need a charge pressure valve.

Electronic charge pressure control & charge pressure valves - We recommend an Autogauge boost controller for mounting!

 

Engine oil - Remember additive is a really good idea

If you drive a race or just fresh driving for everyday use, we recommend that you use good and thick engine oil. We have made a lot of engines with turbo and have in this connection use a 10w-60 oil. Such a viscosity is used when you want to be sure to have a high butter pressure even when the engine is hot. Has your engine run many km. it can also be an advantage to use slightly thicker engine oil, then the oil will not flow so easily / get through where the engine is worn. By using 10w-60 engine oil, you can lose a little bit of power, as the oil does not flow as easily, but power loss is not large compared to driving with oil where you are sure of oil pressure and lubrication effect.
I would also strongly recommend using the Danco oil additive (Tec2000) - It is used to pour into the engine oil and gearbox. It's not just some sales ploy! Just try doing a few searches on google and you will see that it is actually a product that works really well.

Motor oil - Find our cheap motor oil & amp; gear oil at really good prices

Oil filter - Optimize oil lubrication, with a high flow oil filter

10w-60 oil - Engine oil that is very thick when the engine is hot

Tec 2000 - Additive that protects engine & amp; gearbox absolutely fantastic

 

Oil cooling - Electronic gear pump with simple installation

It is usually not super easy to find a cheap solution for an oil cooler for a BMW M50 / M52 engine, this is because these engines are not originally made with oil cooler. However, you can use an oil cooler console from an M3 engine, but that costs a lot. We found a solution that is simple and easy to install. You get an oil cooler kit that comes with an electric oil pump (the gear pump changes the engine oil twice a minute), reinforced oil hoses, an fittings, oil cooler, working relay, etc. Super grease kit for little money.

Electric oil cooler - Oil cooler for BMW M50 / M52, etc. can be used on all models.

 

Engine Parts - Forged pistons, connecting rods & amp; Turbo-crackers

Need more hp. than 420 on the M50 engine (Max 350 hp std. 52 / M54) you must have the engine separated and have forged pistons and h-profile connecting rods in the engine. We have good experience with JE stamps, Wiseco stamps. We have found a supplier who delivers really good connecting rods at incredibly good prices, you get them both in 130mm. and 135mm. for the connecting rods, we can clearly recommend SPA bolts which are really strong and just hold.

If you need a 2.8 liter crank in a 2.5-liter block, you can use 2.5-liter pistons and 130mm. connecting rods.
The hose length of 2.5 liters is 75mm. and 2.8 liters is 84mm. - Difference of 9mm. that is 4.5mm. each end. So the compression will be a little lower if you do not get the planet block or the top piece.

H profile connecting rods - rods and bolts in great quality

BMW K1 connecting rods - Original connecting rods from K1 in top quality

Forged stamps - Find forged stamps for BMW and other car brands

Turbo camshafts - Race camshafts for BMW with turbo up to 800hp.

 

Pictures and installation instructions

Below is a small overview of what the turbo kit will look like. The picture is with our GT35 turbo, top mount manifold, and AN fittings / AN hose for oil supply and return.

The downpipe goes close to the valve cover and it can therefore be an advantage to use power wrap to put on the outside of the downpipe as well as a turbo form for the turbo's hot side. If this is not enough you can use Heat shield tape. If you choose to make the downpipe yourself, you must be aware that it must go very close to the turbo manifold in order to be there for the body. Again you can see a delicious way to make oil inlet hose, AN fittings, and AN hose.

 

The top mount manifold is made really nice, there are not many joints on it, and is bent in the machine. The assembly on all the pipes is made as 6 - 1 and gives a really good flow. You can also see the outlet for the wastegate which has a flange for it. A 40 or 44mm is used. wastegate.

Remember to use good studs and locknuts/copper nuts when mounting the turbocharger and downpipe. If you do not use the right ones, it shakes the turbo and downpipe loose, and the gaskets break.

The return run must be above the oil level. We made it by drilling a 19mm. hole in the engine block, sanded a little in the castings around so that the nipple can be there, and then cut 1/2 "thread. In it, you can put an An nipple (1/2" - AN10). A very good and nice-looking way to make it.

Return made with Blue / Red AN fittings - AN10 which is approx. 14.5mm. It is the right size for oil return. Do not use smaller.

The return line is seen from below where you have a turbocharger and manifold.

Turbo oil can be taken where the oil switch is located. We have an adapter that is inserted in between where there is an outlet with a 1/8 "-27 NPT thread. In it is a nipple (1/8" -27 NPT - AN4) with an AN4 hose connection with a 180-degree bend. As you can see in the picture, you have to be a little careful when tightening AN fittings :) You can put black insulation tape around them to help you tighten them or you can use the right tools we also sell.

 

The turbocharger uses a nipple that fits in the turbocharger (see which one to use with the turbo you choose) and then you can use a 105 degree AN4 bend.

Below you see that there are approx. 3 cm. up to the bonnet of a BMW E46

Below you see a BMW E36 fitted with our GT35 turbo, top mount turbo manifold, and 44mm. wastegate.

On the dyno curve, you can see it makes 509 hp. and 610 nm.

Below you see a BMW E36 with an M50B32 engine. 0.7 bar charge pressure.