How much boost can I run now???

[ogbimmer]

I started off with a 2.5 m50 that I was going to turbo with some hardened stock rods, a hardened crank, and a set of nice 8.5:1 forged pistons.

then I got the m3 and decided I want to to make a 3.2 out of my m50 so I bought a 3.2 s52 crank which is forged so at this point I have to buy different rods since my compression ration is different..

I'm thinking might as well get some nice forged rods so I can have a fully forged bottom end...

How much hp is the s52 crank good for? How much boost should I be able to run after tuned on e85? I looked for these answers for a while and didn't find much so If anyone has an experience with a forged bottom end with a forged bmw crank I would like t here it :)

[BMWZ318is]

ive seen videos on youtube from hp freaks and with the stock crank with forged rods and pistions they are running 1000hp you should look up the videos

[ogbimmer]

ive seen videos on youtube from hp freaks and with the stock crank with forged rods and pistions they are running 1000hp you should look up the videos

linksss

[BMWZ318is]

http://www.youtube.com/watch?v=XRAnB...feature=relmfu here is part one

[ogbimmer]

IVARS 1500HP BUILD USED A BMW M54 CRANK... thats pretty awesome :)

[BMWZ318is]

yah i was amazed how much hp they made

[ogbimmer]

dude I'm thinking with e85 I might boost 30 psi and see what I get :D

[BMWZ318is]

that would be sick you would have so much power what are you going to put the motor into?

[ogbimmer]

my white m3 lol

[BMWZ318is]

dang you might tear the back end out of it with that much power lol

[Mprudent]

that is a huge deal of stress on the crank, so tuning is is a huge part. it may last a short while on a crap tune but you will need to have a decent amount of progress on the fuel maps and timing to make this last. even then its a hit and miss on durability. I applaud them for making that much power and hope it lasts as they are pros for sure.

I wanna throw their setup in a 320i. nuts.

[ogbimmer]

anyone actually boosted with a m52 crank, s52 crank, or any other oem forged bmw crank??

[einstein57]

IVARS 1500HP BUILD USED A BMW M54 CRANK... thats pretty awesome :)

IIRC the m54 crank is the same as the s52. s50b30 rods are also supposed to be forged as well.Not sure about s52 rods. But i'm useing eagle rods because i was given an offer i could not refuse.

[The Humjet]

The stock rods tend to fail first on m5x/s5x most sometimes they find themselves coming out of the side of the block. A lot of guys on bimmerforums use h-beam rods.
I think you'll be ok with the stock crank. As long as the engine is balanced and assembled correctly and tuned the motor should last many moons under some boost.
Also E85 is also a good idea to get your car set up on. There are many advantages you get when you run on that stuff especially with the power your power goals.

[ogbimmer]

The stock rods tend to fail first on m5x/s5x most sometimes they find themselves coming out of the side of the block. A lot of guys on bimmerforums use h-beam rods.
I think you'll be ok with the stock crank. As long as the engine is balanced and assembled correctly and tuned the motor should last many moons under some boost.
Also E85 is also a good idea to get your car set up on. There are many advantages you get when you run on that stuff especially with the power your power goals.

I am most likely going to buy forged rods anyway I just wanted to know how strong the forged oem s52 crank is.