Best piston for turbo engine.

[dovlet]

Hi gents, what do you which piston is best for turbo 15-20psi? M50 M52 M54? Drag racing daily driving. Block is m50tu.
Please put with comments why you think it is better than others?

[Yother]

You need to define what your application is to answer this question. Street, race? Daily driven, rarely driven? HP /Torque goals?

[milKt]

Brand?

Compression?

Flat or Dished?

Fuel?

PSI?



You might ask your tuner.

[dovlet]

You need to define what your application is to answer this question. Street, race? Daily driven, rarely driven? HP /Torque goals?

Updated

- - - Updated - - -

Brand?

Compression?

Flat or Dished?

Fuel?

PSI?



You might ask your tuner.

Updated

[dovlet]

Ok gents, looks like best one is m50 non tu pistons. It has thick top and thick shoulders between compression rings. It is even bigger than in 2jz.
M50 & m50tuSmartSelectImage_2018-01-08-01-05-13.png

[someguy2800]

Every piston that ever came in any M5X motor is perfectly suitable to make 500 whp. You are way overthinking this.

[dovlet]

Every piston that ever came in any M5X motor is perfectly suitable to make 500 whp. You are way overthinking this.

Here in my country we have bunch of m5x engines and almost no s5x.

[someguy2800]

Here in my country we have bunch of m5x engines and almost no s5x.

That is not a problem. The only "S" part in my motor is the intake cam. Everything else is m50 and m52.

[dovlet]

That is not a problem. The only "S" part in my motor is the intake cam. Everything else is m50 and m52.

Bro, we have superbad gasoline. It is very important for me to have thicker pistone. I burnt 4 engine with m62b44tu pistones. Many times i faced with that. That is why i want to be in safe range.

[JimsR]

I would consider a lower compression forged piston.

[someguy2800]

Believe me I've been there, not everything on this side of the world is sunshine and lollipops. We don't have people on every street corner giving away M3's and our gas isn't any good out of the city either. You can get 93 octane in the city but the best we get out here is 91 which sometimes acts like 91 and sometimes acts like 87. Lucky we have ethanol now in some places but I still have to drive an hour to get it. When I used to run gas 91 octane from some places would detonate at 17 psi, and from other places I could only run mabey 13-14. I eventually got tired of it and started mixing 25% race gas in and then switched to E85 which I understand is not an option for you.

If its detonating the strongest piston in the world won't save it. A forged piston will last longer due to the differences in metalurgy but it will eventually just destroy other things. The M50 NV and M50 TU pistons are a simple cast piston with small steel struts cast into the skirts. You can tell this because if you have a very powerful magnet it will attract slightly to the sides of the piston. The M52 and up pistons are all cast with a hypereutectic alloy which has a very high silicon content compared to a normal alluminum alloy. This makes the alloy have a much higher tensile strength and so the cast in steel struts are not needed. You can't tell the strength of a piston by just the looks, they are cast with different alloys and have different load bearing designs. None of the M5X or S5X pistons are significantly stronger than the others and none of them will tolerat detonation for any length of time.

Many of us have been through this and have the blown up parts to prove it including myself. You have to do something on the tuning and fuel side of your combo or your just going to do the same thing as with your M62. The only viable option I see for you is a water alcohol injection system. They are easy to build and will work with any form of methanol or ethanol you can find locally and water. Most people here use windshield washer fluid which is 40-50% methanol and water. Even Vodka as you suggested in another thread would be perfect. I live out in the middle of nowhere in small town, there are no BMW parts or support available here. You have the same internet I do so you can either start coming up with solutions or keep repeating excuses for why you can't do things that others already have. I'm not trying to be condescending, I'm just saying your not at a huge disadvantage, its just going to take some creativity to find a fuel solution that will let the motor live and make power.

[gdavid]

Assuming this is for your stroker build, unless you are using a custom connecting rod length, the only piston you listed that will fit is the M54b30, the others will stick out of the block, assuming you are using the M54b30/S52 crankshaft and 135mm rods.

Maximum allowable height 210 mm.
Height = Stroke/2(89.6/2) + connecting rod (I'm assuming 135mm) + piston height.
Max piston height = 30.2mm
M50B25 = 38.2mm ; M50TUB25 = 32.55mm ; M52B28 = 31.82mm ; M54B30 = 28.32mm.

Some builders have milled down the top of a taller piston to make them fit but I don't see any advantage to this over the M54b30 other than cost savings. The M54b30 piston would yield in a higher compression than the m52b28 stock engine so you would need a thick head gasket to get your compression down. A good alternative may be using the M52b28 crankshaft with the M54b30 pistons.

I have been following your threads because you project sounds interesting. You may get better and consistent advice if your project topics are kept together on one thread. Just my opinion.

[someguy2800]

Assuming this is for your stroker build, unless you are using a custom connecting rod length, the only piston you listed that will fit is the M54b30, the others will stick out of the block, assuming you are using the M54b30/S52 crankshaft and 135mm rods.

Maximum allowable height 210 mm.
Height = Stroke/2(89.6/2) + connecting rod (I'm assuming 135mm) + piston height.
Max piston height = 30.2mm
M50B25 = 38.2mm ; M50TUB25 = 32.55mm ; M52B28 = 31.82mm ; M54B30 = 28.32mm.

Some builders have milled down the top of a taller piston to make them fit but I don't see any advantage to this over the M54b30 other than cost savings. The M54b30 piston would yield in a higher compression than the m52b28 stock engine so you would need a thick head gasket to get your compression down. A good alternative may be using the M52b28 crankshaft with the M54b30 pistons.

I have been following your threads because you project sounds interesting. You may get better and consistent advice if your project topics are kept together on one thread. Just my opinion.

This is correct

[dovlet]

If its detonating the strongest piston in the world won't save it. A forged piston will last longer due to the differences in metalurgy but it will eventually just destroy other things. The M50 NV and M50 TU pistons are a simple cast piston with small steel struts cast into the skirts. You can tell this because if you have a very powerful magnet it will attract slightly to the sides of the piston. The M52 and up pistons are all cast with a hypereutectic alloy which has a very high silicon content compared to a normal alluminum alloy. This makes the alloy have a much higher tensile strength and so the cast in steel struts are not needed. You can't tell the strength of a piston by just the looks, they are cast with different alloys and have different load bearing designs. None of the M5X or S5X pistons are significantly stronger than the others and none of them will tolerat detonation for any length of time.

Many of us have been through this and have the blown up parts to prove it including myself. You have to do something on the tuning and fuel side of your combo or your just going to do the same thing as with your M62. The only viable option I see for you is a water alcohol injection system. They are easy to build and will work with any form of methanol or ethanol you can find locally and water. Most people here use windshield washer fluid which is 40-50% methanol and water. Even Vodka as you suggested in another thread would be perfect. I live out in the middle of nowhere in small town, there are no BMW parts or support available here. You have the same internet I do so you can either start coming up with solutions or keep repeating excuses for why you can't do things that others already have. I'm not trying to be condescending, I'm just saying your not at a huge disadvantage, its just going to take some creativity to find a fuel solution that will let the motor live and make power.[/QUOTE]
A very interesting things i know from your inputs above. Tqvm. For sure i will be go with pistons i have now.

[dovlet]

Assuming this is for your stroker build, unless you are using a custom connecting rod length, the only piston you listed that will fit is the M54b30, the others will stick out of the block, assuming you are using the M54b30/S52 crankshaft and 135mm rods.

Maximum allowable height 210 mm.
Height = Stroke/2(89.6/2) + connecting rod (I'm assuming 135mm) + piston height.
Max piston height = 30.2mm
M50B25 = 38.2mm ; M50TUB25 = 32.55mm ; M52B28 = 31.82mm ; M54B30 = 28.32mm.

Some builders have milled down the top of a taller piston to make them fit but I don't see any advantage to this over the M54b30 other than cost savings. The M54b30 piston would yield in a higher compression than the m52b28 stock engine so you would need a thick head gasket to get your compression down. A good alternative may be using the M52b28 crankshaft with the M54b30 pistons.

I have been following your threads because you project sounds interesting. You may get better and consistent advice if your project topics are kept together on one thread. Just my opinion.

Ok, will follow it and should check what will be cr with my current config with m52b28 crank. My rod is 140mm

[gdavid]

Ok, will follow it and should check what will be cr with my current config with m52b28 crank. My rod is 140mm

So 210-140-42=28mm Max piston height. I don't think that rod length will work, especially with your turbo and octane considerations.

[NOTORIOUS VR]

What ECU are you using and do you have knock control correctly setup and working? Sounds like you will need it along with a very good tune.