MyE28.com

Hello there. I'm new here and I find a lot of useful information in that forum. I'm planning to make a project with the base of e34. The two motors that i could use are the M30B35 and the M powered S38. The difference in the price of the cars is about 2000 euro. I wonder what's better - to buy a 535i and turbo it with 2000 euro more for the project, or buy an M5 and tune it with 2000 less. I want a car that will have a big load of torque in the low end and even that high horsepower figures (around 500-600 whp). Also what I need to go with the S38 to these numbers? The aftermarket pistons are obligatory but are they the only thing that have to be upgraded in the motor? Thank you in advance.

fr3nzy wrote:I want a car that will have a big load of torque in the low end and even that high horsepower figures (around 500-600 whp...

I predict this will become a "classic" thread!

Game on!

Game Off!

Just let your budget decide. Lots of money, S38. Low money, M30. Your hp goal seems to dictate lots of money.

Russc

russc wrote:Game Off!

Just let your budget decide. Lots of money, S38. Low money, M30. Your hp goal seems to dictate lots of money.

Russc

Yeah it's obvious that the S38 is more expensive but leave this alone ... what internal upgrades are needed to hit the 500-600 whp (pistons, rods, valve springs, bearings ?!?!). I think that it would need much lower boost levels to achieve this marks than the M30 ...

Well,
If you believe the tuners, a 600whp S38 will cost at least $20k to build. YMMV.

I would rebuild with motorsports parts for that hp level. So $15k worth of parts sounds right. Check the thread with TCDs 17psi dyno run, were arguing this over there.

RussC

I'm staying out of this one.

fr3nzy wrote:Hello there. I'm new here and I find a lot of useful information in that forum.

Hello fr3nzy and welcome to the mye28.com board.

fr3nzy wrote:I'm planning to make a project with the base of e34. The two motors that i could use are the M30B35 and the M powered S38. The difference in the price of the cars is about 2000 euro. I wonder what's better - to buy a 535i and turbo it with 2000 euro more for the project, or buy an M5 and tune it with 2000 less.

Your reference to the price difference indicates it may be significant for you. 2,000 Euro (about $2,500 USD) will be lost in building either engine meeting the specifications you have outlined. It shouldn't, in my opinion, be used as a measure.

fr3nzy wrote:I want a car that will have a big load of torque in the low end and even that high horsepower figures (around 500-600 whp).

It's amazing how similar people are from different parts of the world when you get to know them.

fr3nzy wrote:Also what I need to go with the S38 to these numbers? The aftermarket pistons are obligatory but are they the only thing that have to be upgraded in the motor? Thank you in advance.

To achieve the 500-600 whp you desire, you will not "need to go with the S38 to these numbers" but if your budget will allow, you may want to. Your goal of "a big load of torque in the low end" meaning 400NM at ~2,000 RPM will be expensive with either engine. It will require a more complicated and exotic approach if you also want the 500-600 whp specified at higher engine speeds. "The aftermarket pistons" are only the beginning. You are asking these engines to put out a lot more power than they were originally specified for. This can be done, but it will take money.

M635CSi wrote:

fr3nzy wrote:Hello there. I'm new here and I find a lot of useful information in that forum.

Hello fr3nzy and welcome to the mye28.com board.

fr3nzy wrote:I'm planning to make a project with the base of e34. The two motors that i could use are the M30B35 and the M powered S38. The difference in the price of the cars is about 2000 euro. I wonder what's better - to buy a 535i and turbo it with 2000 euro more for the project, or buy an M5 and tune it with 2000 less.

Your reference to the price difference indicates it may be significant for you. 2,000 Euro (about $2,500 USD) will be lost in building either engine meeting the specifications you have outlined. It shouldn't, in my opinion, be used as a measure.

fr3nzy wrote:I want a car that will have a big load of torque in the low end and even that high horsepower figures (around 500-600 whp).

It's amazing how similar people are from different parts of the world when you get to know them.

fr3nzy wrote:Also what I need to go with the S38 to these numbers? The aftermarket pistons are obligatory but are they the only thing that have to be upgraded in the motor? Thank you in advance.

To achieve the 500-600 whp you desire, you will not "need to go with the S38 to these numbers" but if your budget will allow, you may want to. Your goal of "a big load of torque in the low end" meaning 400NM at ~2,000 RPM will be expensive with either engine. It will require a more complicated and exotic approach if you also want the 500-600 whp specified at higher engine speeds. "The aftermarket pistons" are only the beginning. You are asking these engines to put out a lot more power than they were originally specified for. This can be done, but it will take money.

Hello M635CSi, the prices of work here are different from the US and I will DIY almost all the work on the project so don't bother with $. The low end power will be made by a SC + turbo. All I need from the engine is to hold for an example 1.2 bar which are needed for my HP and torque targets. The complete rebuilt here is cheap and I want to know which parts from the engine need to be upgraded. I don't know if the stock con rods will hold. Do I need stronger valve springs to prevent valve floating and anything else that may 'crack' under boost ...
In Europe there are relatively fresh M5s (1994-5) which were daily driven so I won't have a big problem with corrosion on cylinder walls or anything too bad to fix. The engine will be managed by MS2 with WB O2 control so I will try to keep the AFR always in the safe zones.

Hey ... does anyone know which parts need to be upgraded??

Not really. Only people with deep pockets tend to take on s38 turbo projects, and they're usually reticent to reveal details. I don't think Dinan did anything for their s38 turbo kits aside from use lower compression pistons. The stock hardware is really quite stout. Some projects have gone ridiculously overboard and beefed up everything possible at very high cost, but nobody actually knows if the stock parts will hold up or what would go first AFAIK.

Nobody here knows what will go first on an s38 cause we're all trying to see where the weak points are on the m30. So far, it appears the ring lands and headgasket are the weakest link on that motor. Might very well be the same for the s38.

The Dinan kits were 500-600hp IIRC, and that was with old and currently quite dated turbo and engine management technology.

Jeremy

fr3nzy wrote:...the prices of work here are different from the US and I will DIY almost all the work on the project so don't bother with $.

fr3nzy, I think you underestimate the complexity and expense of this task you set yourself about. Please bear in mind, the people that will be "doing the work" must first understand the work. This necessarily means they are highly skilled and educated craftsman and automotive engineers or your results will fail to impress others. Also, the cost of the parts you will need, as Russ has so correctly pointed out, will be in the tens of thousands of euros.

fr3nzy wrote:The low end power will be made by a SC + turbo. All I need from the engine is to hold for an example 1.2 bar which are needed for my HP and torque targets.

Your approach sounds like something Alfa Romeo tried some years back... VERY complicated and it hasn't been heard much about since. I would suggest you use a supercharger for your application.

fr3nzy wrote:The complete rebuilt here is cheap and I want to know which parts from the engine need to be upgraded. I don't know if the stock con rods will hold.

The stock con rods will hold if the engine is tuned properly but I would replace them with stronger H beam connecting rods for safety.

fr3nzy wrote:Do I need stronger valve springs to prevent valve floating and anything else that may 'crack' under boost ...

The engine should be redesigned for operation under boost and blueprinted to exacting specifications. What this means is that each part of the engine will need to be inspected to determine whether it is suitable for service or needs replacement with a new or more appropriate part. With turbocharging and supercharging, you will not need as much engine speed to achieve your power goals; valve float will not be an issue. If you wish to overcome the effect of boost against the port side of the valve, you can shim the valve spring appropriately to compensate.

fr3nzy wrote:In Europe there are relatively fresh M5s (1994-5) which were daily driven so I won't have a big problem with corrosion on cylinder walls or anything too bad to fix.

Oh yes, you have the whole engine to fix for this project. The cylinder walls should be the least of your concern but they also will require to be fixed.

fr3nzy wrote:The engine will be managed by MS2 with WB O2 control so I will try to keep the AFR always in the safe zones.

You must also keep boost presure, charge air temperature, liquid coolant temperature, oil temperature and exhaust gas temperature in the "safe zone".

Jeremy wrote:Not really. Only people with deep pockets tend to take on s38 turbo projects, and they're usually reticent to reveal details. I don't think Dinan did anything for their s38 turbo kits aside from use lower compression pistons. The stock hardware is really quite stout. Some projects have gone ridiculously overboard and beefed up everything possible at very high cost, but nobody actually knows if the stock parts will hold up or what would go first AFAIK.

Nobody here knows what will go first on an s38 cause we're all trying to see where the weak points are on the m30. So far, it appears the ring lands and headgasket are the weakest link on that motor. Might very well be the same for the s38.

The Dinan kits were 500-600hp IIRC, and that was with old and currently quite dated turbo and engine management technology.

Jeremy

Stock Dinan Stg I S38 turbo was rated at 475hp crank.

RussC

It should be possibl to put a m30 manifold on a s38, this guy did it, he made an adapter: http://members.home.nl/karel635csi/bmwm ... wpage5.htm

he also putted a s38 head on a m30 block.

i've heard, he now has blown up his exhaust manifold and he's going to make one that fits directly on the s38 head.

Holy crap! I'll bet this thing is a monster!

accota wrote:It should be possibl to put a m30 manifold on a s38, this guy did it, he made an adapter: http://members.home.nl/karel635csi/bmwm ... wpage5.htm

he also putted a s38 head on a m30 block.

i've heard, he now has blown up his exhaust manifold and he's going to make one that fits directly on the s38 head.

The guy seems pretty ingenious. I think it would have been less work and certainly resulted in a better product to have either made a tubular exhaust manifold to fit the M88 cylinder head or connected the headers with a Y pipe collector and hung the turbo on that with the wastegate coming off the Y pipe.

Installing the M88 twin cam head on the block of their single cam motor is something BMW had in mind originally but installing one of their two valve exhaust manifolds on their four valve head was not...

Kyle in NO wrote:Holy crap! I'll bet this thing is a monster!

Yeah, but is the intercooler big enough?

I like the way the thread is going now

In my opinion if you have both the engines (s38 and m30) you will have to spend round about the same money for about 500 whp because the two engines are quite similar, only the s38 have the much better flowing head. Both the engines will have to be rebuilt and blueprinted. Only the s38 will need low CR pistons which the m30 has from the factory. I don't see much difference in the bottom end or anything else that will be much more expensive in the s38. I'm also curious what is the list of things that will make the $20k

Hey Kyle here is the Turbo Magazine article on that car:

Turbo e30 m3

Newer engines can run 10-15lbs of boost with 10-11:1 CR. If you look at the Audi 2.0T FSI engine, that's about what it is doing. It is amazing. I don't have a full understanding of what makes it possible, but i think it is a combination of

- FSI (direct injection)
- precise injector control
- precise ignition control
- good head design

i'm sure that redesigning a head for direct injection is not trivial, nor is fixing the shape of the combustion chamber. But i wonder, could you do it for $20k ?

Matt wrote:Newer engines can run 10-15lbs of boost with 10-11:1 CR. If you look at the Audi 2.0T FSI engine, that's about what it is doing. It is amazing. I don't have a full understanding of what makes it possible, but i think it is a combination of

- FSI (direct injection)
- precise injector control
- precise ignition control
- good head design

i'm sure that redesigning a head for direct injection is not trivial, nor is fixing the shape of the combustion chamber. But i wonder, could you do it for $20k ?

You left out the most important thing, the FI computer system. That is were the magic happens to make 10:1 CR run 12psi of boost. The timing and fuel system being manipulated by mulitple knock sensors is fantasitc.

RussC

fr3nzy wrote:I like the way the thread is going now

In my opinion if you have both the engines (s38 and m30) you will have to spend round about the same money for about 500 whp because the two engines are quite similar, only the s38 have the much better flowing head. Both the engines will have to be rebuilt and blueprinted. Only the s38 will need low CR pistons which the m30 has from the factory. I don't see much difference in the bottom end or anything else that will be much more expensive in the s38. I'm also curious what is the list of things that will make the $20k

I can't disagree more. If you build both from scratch, the S38 will take at least $15k in parts if you use Motorsports parts. Thats were the expense comes from. A S38 re-build here in the USA will cost a minimum of $9k w/labor. I dare you to go price out a 3.8l stroker crank for a S38, over-sized pistons, block, ect from BMW or anywhere else. You will be very suprised by the price.

A M30 monster can be build from scratch for ~$3k in parts and ~$1.5k in labor. You can't touch S38 parts for that here.

Sure, you can buy a used S38 for $3k-$5k and slap it in and pour 15psi of boost to it, thats easy and cheap, for sure. But most people who want to make 600hp from a S38 build from scratch so they know what they HAVE when they bump 15psi to it.

RussC

Matt wrote:Newer engines can run 10-15lbs of boost with 10-11:1 CR. If you look at the Audi 2.0T FSI engine, that's about what it is doing. It is amazing. I don't have a full understanding of what makes it possible, but i think it is a combination of

- FSI (direct injection)
- precise injector control
- precise ignition control
- good head design

i'm sure that redesigning a head for direct injection is not trivial, nor is fixing the shape of the combustion chamber. But i wonder, could you do it for $20k ?

Saab's Combustion Control (SCC) is interesting: "The secret to SCC is a combination of four key features: air-assisted direct fuel injection developed jointly with Orbital Engine Corp., featuring a novel spark plug injector from Delphi-Orbital; variable valve timing; a variable spark gap; and special piston-crown geometry." - Automotive Industries, Nov, 2000 by John McCormick.

It makes me wonder if the Saab spark plug/injector unit will be sized such that a retrofit to other applications could be practical with some machining.

The material an engine is made from is another factor that Influences the choice of compression ratio. Engines made from aluminum have the advantage over engines made from iron. Because aluminum removes heat more effectively than iron, detonation is reduced and a higher compression ratio can be employed. Which brings us to the question of why compression ratio matters other than as a design parameter. It would seem that as long as intake charge temperature in the cylinder is OK, then the compression ratio isn't too high. If it is not, lowering the compression ratio is one way of reducing it. But here’s the point; the compression ratio in and of itself won’t tell us what the intake charge temperature in the combustion chamber will be. And it's intake charge temperature in the combustion chamber that controls detonation, not the compression ratio…

russc wrote:

fr3nzy wrote:I like the way the thread is going now

In my opinion if you have both the engines (s38 and m30) you will have to spend round about the same money for about 500 whp because the two engines are quite similar, only the s38 have the much better flowing head. Both the engines will have to be rebuilt and blueprinted. Only the s38 will need low CR pistons which the m30 has from the factory. I don't see much difference in the bottom end or anything else that will be much more expensive in the s38. I'm also curious what is the list of things that will make the $20k

I can't disagree more. If you build both from scratch, the S38 will take at least $15k in parts if you use Motorsports parts. Thats were the expense comes from. A S38 re-build here in the USA will cost a minimum of $9k w/labor. I dare you to go price out a 3.8l stroker crank for a S38, over-sized pistons, block, ect from BMW or anywhere else. You will be very suprised by the price.

A M30 monster can be build from scratch for ~$3k in parts and ~$1.5k in labor. You can't touch S38 parts for that here.

Sure, you can buy a used S38 for $3k-$5k and slap it in and pour 15psi of boost to it, thats easy and cheap, for sure. But most people who want to make 600hp from a S38 build from scratch so they know what they HAVE when they bump 15psi to it.

RussC

Ohh I see now where the difference come. I know that the M badged parts are very overpriced. But I'm not so crazy to buy original motorsport parts. I don't see the point of buying a completely new block, stroker crank or oversized pistons:
1. I will order pistons with different design with lower CR which however are not supplied by motorsport.
2. I won't buy a worn-out car or engine that will need a new block, stroker crank and what else . The engines are not so fragile as the rebuilders tends to. They are making hell of a lot of money by replacing parts that will need for example only refreshment. But it is actually normal because one item or service cost what the customer is willing to pay, not the real value. Let me give you an example. When reparing one 'Sony' TV and one 'VelikoTurnovo' (very old Bulgarian shit TV) The price of the parts is equal and the work is also equal, but the Sony onwer pays $60 and the Veliko Turnovo owner pays $10. Let this example now alone.
3. In my poor opinion the only things that need to be changed with new motorsport parts are the bearings and the sealings. If someone tells you that you need new block, rods, crank and whatever new on a smooth running engine is a day robber for me. No offence.

We didn't start the fire
It was always burning
Since the world's been turning
(Billy Joel, 1989)

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