[hassmaschine]

yeah, I can't believe that you could successfully turbo an N52 for less than just buying a 335i. I think an N54 swap would be simpler, and honestly, cheaper.

I'm willing to bet tuning alone is at least $1k, if you can even accomplish it. At best, you'll be able to run 6-8psi, and have an engine that sorta runs right, I'm sure with unforeseen issues. At worst, you push too far and have a blown up engine.

I'm not saying turboing an N52 isn't possible. I just don't think it can be done on a shoestring budget and not end in disaster.

[TheSt|G]

Originally Posted by 135Pats

Hrm yes let's take a magnesium block that was meant for NA operation and add boost to it.

Seems legit.

Folks, if you want a BMW I6 which plays nice with boost get a factory boosted motor (54,55) or an S54. Otherwise you should have a spare N52 longblock for when you throw a rod out the side of your current motor.

Honestly I have never seen a group of folks with such a great NA motor, so utterly driven to ruin what makes it a great motor. The 52 wasn't meant for boost. Don't boost it.

Absolutely spot on. The issue is that there are a large number of people in this section who own a N52 not because they value what it is good at, but because they could not afford something with the N54/55.

[mmmnot]

Originally Posted by 135Pats

Hrm yes let's take a magnesium block that was meant for NA operation and add boost to it.

Jesus. I'm glad one person here understands physics and different metal standards.

Faith has been restored and for that, I thank you.

[hassmaschine]

Well, it's really a composite block. but honestly, the block is probably the least of worries when trying to turbo an engine that has 0 aftermarket turbo support.

[Jashley73]

Honestly, I can see the merit. If someone didnt' want the direct-injection hassles of the N54/N55, then it makes a little sense to try and go this route, but on the whole I agree with the majority of you, that this just doesn't make much sense at all. Economic, practical, and so on...

The block probably isn't too much to worry about. I'd be most concerned with the aluminum head-bolts, and what happens when they start to stretch... And the rods - do we know what they're made of? Die-cast aluminum probably?

[rhombus]

Originally Posted by Jashley73

Honestly, I can see the merit. If someone didnt' want the direct-injection hassles of the N54/N55, then it makes a little sense to try and go this route, but on the whole I agree with the majority of you, that this just doesn't make much sense at all. Economic, practical, and so on...

The block probably isn't too much to worry about. I'd be most concerned with the aluminum head-bolts, and what happens when they start to stretch... And the rods - do we know what they're made of? Die-cast aluminum probably?

Head bolts are not aluminum. Only the valve cover bolts are. I checked into it some time ago.

The main issue I see is the lightweight rotating assembly and increased peak cyl pressures with a turbo. Plus, a turbo will have more backpressure than a SC and will have higher EGTs. A turbo will also have a higher peak cyl pressure at peak Tq because boost comes on full once the turbo is spooled. The SC does not hit peak boost until redline so peak cyl pressures are lower. This is also partially because at high RPM there is more valve overlap which lowers cyl pressures.

The midrange tq that everyone loves about the N54/55 is what will kill the N52. Midrange TQ is where cyl pressures are the highest and also where the engine is most likely to detonate. The detonation can be kept in check but having high TQ in the midrange through boost stresses the lightweight assembly which will cause it to cry and give up; aka throw a rod. The N54 has a strong bottom end, which is evident by the TQ numbers they can sustain. The N52 was designed to to be the lightest production I6 produced. It has a very light rotating assembly which gives a great driving experience.

Tuning wise, it would be best to lock out the valvetronic and do a standalone if going turbo. All of that done, you end up with none of the advantages of valvetronic (fuel economy, variable lift) yet still have the heavy valve springs to deal with when revving the engine high. IMO, its alot to spend and still not be able to push the motor more than the SC already reliably does.

[135Pats]

Originally Posted by Jashley73

Honestly, I can see the merit. If someone didnt' want the direct-injection hassles of the N54/N55, then it makes a little sense to try and go this route, but on the whole I agree with the majority of you, that this just doesn't make much sense at all. Economic, practical, and so on...

The block probably isn't too much to worry about. I'd be most concerned with the aluminum head-bolts, and what happens when they start to stretch... And the rods - do we know what they're made of? Die-cast aluminum probably?

The only drawback to Piezo DI is the complexity of standalone tuning, and the injection window limitations. The former is accommodated by retaining the DME, the latter easily accommodated by adding PI which can be driven by several different piggybacks (not ideal but it's not rocket science to sequential fire).

IMO that's not even close to being compelling enough to risk a factory motor over. PI was like $1.2K, and you are all set from a fuel standpoint. Obviously, an N52 is going to be a bit more expensive to replace.

I wouldn't trust the block but agree that fastners would be the first to deform under pressure. The rods are an alu cast IIRC.

[631twentyeighteye]

You're gonna blow the welds on the intake. Make sure you secure your floorboards.

[hassmaschine]

The head bolts are not aluminum (meaning, the bolts that actually seal the combustion chamber).

there are aluminum bolts at the front of the head casting, but they would be more like timing cover bolts if it were a separate casting.

the rods are definitely NOT aluminum. they are forged steel/cracked rods. where do people get this stuff? I don't think BMW has ever made an engine without forged rods, and not many other manufacturers either.. cast cranks, sure, but never rods.

[135Pats]

Originally Posted by hassmaschine

The head bolts are not aluminum (meaning, the bolts that actually seal the combustion chamber).

there are aluminum bolts at the front of the head casting, but they would be more like timing cover bolts if it were a separate casting.

the rods are definitely NOT aluminum. they are forged steel/cracked rods. where do people get this stuff? I don't think BMW has ever made an engine without forged rods, and not many other manufacturers either.. cast cranks, sure, but never rods.

You are totally right on the rod material, I wasn't thinking straight. Cracked cap rods, as is the case on all modern BM motors.

Regardless, the 52 is poorly suited for boost on any number of fronts.

[CobraMarty]

N52 with 6-7.5 pounds of intercooled boost will live. No more than that amount of boost and definitely not without an intercooler like the ESS SC kit.

What did ESS break on their blown 128? Most likely had charge IATs well over 200* at ?10psi and detonated and popped a head gasket or blew a hole in the top of the piston or broke a ring land.

PI is not a bad idea for tuning a N52.

And why keep a spare N52 shortblock? Keep a N54 shortblock and bolt on the N52 head. I'm sure it can be done. Then all the benifits of the 335 without all the drawbacks- DI and crudded up intake ports.

[SDemetris]

Originally Posted by CobraMarty

N52 with 6-7.5 pounds of intercooled boost will live. No more than that amount of boost and definitely not without an intercooler like the ESS SC kit.

What did ESS break on their blown 128? Most likely had charge IATs well over 200* at ?10psi and detonated and popped a head gasket or blew a hole in the top of the piston or broke a ring land.

PI is not a bad idea for tuning a N52.

And why keep a spare N52 shortblock? Keep a N54 shortblock and bolt on the N52 head. I'm sure it can be done. Then all the benifits of the 335 without all the drawbacks- DI and crudded up intake ports.

Im not saying its impossible, People have made DOHC M20s. But still you'd have to have some serious balls to attempt that, with no real benefit. Its not like there is a specific racing class that would make it fit in or anything to drive people to do it. it would be just for fun

[CobraMarty]

Originally Posted by SDemetris

Im not saying its impossible, People have made DOHC M20s. But still you'd have to have some serious balls to attempt that, with no real benefit. Its not like there is a specific racing class that would make it fit in or anything to drive people to do it. it would be just for fun

And that is why to do it. Street fun.

No racing, no specific class, no insurance hike,...
No real benefit? The Goal is 6-7.5 pounds boost which will add around 100hp, about 330-350hp, yes just a little more power than a stock 335.

Is it 'worth it' NO, but I still want to do it.

For example, Used take off 335 N55 turbo and catted downpipe $1000, take off 335 intercooler $100, There are plenty of N54 and N55 'take offs' for hand me downs.

[E82IsTheWay!]

do it, its a 1000$ car.

[SDemetris]

Originally Posted by CobraMarty

And that is why to do it. Street fun.

No racing, no specific class, no insurance hike,...
No real benefit? The Goal is 6-7.5 pounds boost which will add around 100hp, about 330-350hp, yes just a little more power than a stock 335.

Is it 'worth it' NO, but I still want to do it.

For example, Used take off 335 N55 turbo and catted downpipe $1000, take off 335 intercooler $100, There are plenty of N54 and N55 'take offs' for hand me downs.

It seems like you would know about take offs.

... but anyways.. nobody that COULD do it would, and anybody that would want to do it wouldnt be able to

[CobraMarty]

But others have done it or are doing it. ESS, VF, Active.

I'm not sure what the jab is about 'take offs'. There are plenty of 335 guys that have taken off perfectly good OEM parts and replaced with 'upgrades'. These parts have plenty of life left in them. Perfectly good for a 328 300-325hp project. One man's trash is another man's treasure.

A 328 with M3 brakes from a guy who upgraded to bigger brembo brakes. M3 control arms on a 328, wheels, etc. Plenty of 'take-offs'.

[Mike.]

so any ideas on who would be tuning this?

why not just get the sc kit, have your 290 at the wheels, wait until they figure out the other problem they have..and upgrade accordingly

[CobraMarty]

There are many options for tuning.

The front runner is to leave the stock injectors and DME tune as is. Perfect starting, idling, cruise, nat. asp. running as BMW designed. Add a secondary injection system PI with a separate controller for it and only add fuel under boost. It would have it's own MAP sensor and turn on when boost. It can also have boost timing retard also only under boost.

[chris82]

Originally Posted by CobraMarty

And that is why to do it. Street fun.

No racing, no specific class, no insurance hike,...
No real benefit? The Goal is 6-7.5 pounds boost which will add around 100hp, about 330-350hp, yes just a little more power than a stock 335.

Is it 'worth it' NO, but I still want to do it.

For example, Used take off 335 N55 turbo and catted downpipe $1000, take off 335 intercooler $100, There are plenty of N54 and N55 'take offs' for hand me downs.

330-350 and you're looking at a blown motor most likely. ESS blew a N52 with their supercharger when they got it to 350 so they lowered the boost. I think turbos are a littler harder on the engine given the rapid increase in pressure where a supercharger is more linear, I think that's how it works ...



Anyways, to OP, just sell the damn car and whatever you get for it, put it towards a 335i. If you got it for $1000, then it shouldn't be hard to make a profit .....

Another route to go. If you got it for $1000, strip it and go full race car. Even that makes more sense than turboing a N52

[Riley1524]

The OP has stated numerous times that the title is salvaged. Hence, that's why he paid so little for the car. Its very hard to sell a car with a salvaged title. If he wants to try, let him try.

[CobraMarty]

ESS blew at 350hp with no intercooler and iffy tuning/fueling between 7-10 pounds boost.
It's not the HP level that is the limit, but tuning, charge IATs, timing, etc.
7-7.5psi intercooled with proper AFRs and boost timing retard under boost will live.

Turbos can make the same power as the SC with less boost as they cost very little power loss to produce the required boost where as the SC will require about 30 hp to produce 7 pounds boost. For example, the SC will need to 'make' 380hp -30hp to dyno 350hp. The turbo needs to make 355hp - 5hp to dyno 350hp.

So one 'blown up' engine and the sky is falling. They haven't even said what the damage was.

[Mike.]

But don't you think it says something that the major brands have not taken the endeavor on? I'm all for this btw and the progression of the n52 but it's going to be a process