M50 turbos and reality check

[Coyote_ar]

Its easy to start throwing out really large numbers, but its hard to relate that to car performance if this is your first turbo build.

Is this just me, or it happens to anyone else?

Yap, so it's better to start off with 300-400hp, because after couple of months you'll be wanting more. Then it's much easier to go from 400hp to 600hp than from 600hp to 800hp.

It will happen to everybody, there just isn't such thing as "enough power". It's weird but that's how things are.

yeah the problem with wanting more, is if you can really use more?

i mean, drag racing aside, 400+ seems to be more than what any e30 can use.

for sure traction should be an issue, even with the wildest tyres you can fit on the back.
and for high speed ... well a 400+ e30, with overdrive box + long ratio diff should be able to get close to 300km/h. and theres no way a e30 is able to be under control at such speeds (at least not without HUGE ugly wings).

so really, is there a point in going for 400+ HPs for any car not intended for drag racing?

[Phill172]

Was speaking to a guy over on E30tech, who is running standered management, cant run a M3 MAF on a non vanos 2.5 M50 but i believe it does work on a 403 ecu, i will double check have it written out somewhere!!

Standered M50 2.5 non vanos MAF puffs out at about .3/.4 bar, iv just been looking into it all loads for the past 6 months and for me to do it properly (not all out) so its realiable and doesnt blow up in competition use, its about double the price for me to a V8 in.....

however, heres the info and a vid of the guy I have been talking too




Hi, i'm glad i can help you. HX35 is perfect turbo for M50, i promise, you will like it
E85 is ethanol/alcohol based fuel. 85% alcohol and 15% gasoline. Google for more info, few main advantages are high octane number, someting 104-110 and lower burning temps, etc. You can achieve more power with E85, also high CR is not a problem.
My friends M50 is without vanos too, the MAF is "enlarged". He is also on 98 octane at the moment. In my optinion standart MAF maxes out arrround at 0.3-0.4bar or so. We had fuel-cut everytime at 4500-5000rpm with 0.5bar pressure with original MAF

Hi, is your m50 without vanos ? if yes, then m3 MAF will not work, unless you are planning to use only its housing (pipe itself).
What are your power goals ?? Up to 350hp i would not lift the head, maybe even for 400 or more with E85. But thats me .. I don't think if stock thicker head gasked is a good idea.
1. It will not help to reduce CR a lot.
2. It's weaker (thicker paper gasket = easier to blow).
ARP studs are welcome. Do you have E85 in your place ? Then you have not to worry about high CR.
HX35 with 12cm^2 housing or similar size modern turbo will spool crazy fast with right setup (right exhaust manifold, right WG routing, right ecu tuning, no leaks, etc).
For M50 ECU tuning i use WinOLS, Tuner Pro, Ostrich2.0, Innovate LM2 wideband + SSI4 4ch. logger and their software LogWorks3, also external 250kPa MAP sensor. EPROM programmer and UV light for chip programming.
Soon i'll retune the ECU for new setup. More agressive ignition timing and slightly higher boost. This time additionaly i'll hook up Vipec Knock Amplifier for knock sensing and logging, and probably EGT sensor right after 6th cylinder exhaust valve. Exhaust manifold backpressure testing is also on the list, but i'm 100% positive it is in the right place with that size turbo.
About turbo sizes, you don't need BIG turbo, you need CORRECT turbo. You can't put nissan 200sx or skyline turbo, because M50 engine is more efficient (more N/A power). To small turbo = high exhaust manifold pressure = high temperature = bad for engine. OK you will get faster spool and higher low end torque, but you loose high rpm power. "high rpm torque = good horsepower", this is what you need. Also it's better for clutch and drive train, they hate everything breaking low rpm torque, you are not building m50 diesel engine right ?
Here are two examples:
Lets say you have small turbo setup. And your powerband is 2.5-5.5k rpm. Or big turbo setup with powerband 3.8-7k rpm and very acceptable spool up time. I prefer second example i can say so, only because i've driven them all, and tuned also. In the end owner of 2.5-5.5k powerband is not happy, even if he achieved his goal "fast spool", but the car actualy is pretty slow comparing to high rpm powerband setup.

Hope this helps,
Laimis




And this is the full set up of the car in the vid.......hope it helps!

cant find the youtube one

http://www.laimisbmw.com/temp/kolikas.zip



- 100% stock M50B25 NV, #403 ECU
- Custom made MAF, core element in larger diameter pipe (IIRC, 84mm inner),
the MAF is "after turbo", between IC and TB, almost like in stock place.
- 380cc@3.5bar injectors from 2001 Volvo C70 2.3 20v Turbo.
- Custom built semi-tubular exhaust manifold, T3 twin-scroll and dual WG piping divided up to - WG valve (for better engine VE, faster turbo spool, etc.).
- 95'-00' generation KKK K27 turbo, 57mm inducer, 19cm^2 exhaust housing, it came from Iveco 7-8 liter diesel truck. The turbo is very similar to Holset HX35 in size when i compared them, but K27 got larger exhaust wheel and housing, and a little older tech than HX series. But still i'm pretty statisfied with this particular K27 performance.
- HKS 50mm WG replica routed to the atmosphere.
- 76mm downpipe, 60mm exhaust (resonator + rear muffler).
- Small IC from previous setup. Waiting at the moment for big ic to arrive.
- M52B28 flywheel and pressure plate + 6 puck Clutchnet sinter disc.
- Some uprated fuel pump
Hm, i guess thats all Fuel 98 petrol, boost pressure 0.5-0.6bar, 7* retard at torque peak and safe AFR - 12.5 dropping to 11.3 or so at the rev limiter. But as i wrote earlier, waiting now for big IC, also the clutch is on the limit, probably he will buy Sachs racing pressure plate, and then i try to rise the boost until injectors will max out (arround 360-380hp), that would be 0.9-1bar.
Now i guess it have arround 280hp, maybe more, maybe less, hard to say. After big IC is fitted, we will bring the car on the dyno.

Temps are OK, but i recommend for you at least larger water radiator, my friend is using one from e36 325tds, and if you intend track-race use, oil cooler is also recommended.
Also, today i rised idle to 900rpm, for better oil/water distribution and better fan cooling (when hot).

By the way, e36 m3 3.0 injectors are ~300cc with M50 FPR at 3.5 bar, so they are enough up to 300 hp.

[Jonsku]

yeah the problem with wanting more, is if you can really use more?
i mean, drag racing aside, 400+ seems to be more than what any e30 can use.
for sure traction should be an issue, even with the wildest tyres you can fit on the back.

Easily, after all 300hp isn't very much. Sure it spins the tires when you launch it in first gear but that's it - no bigger drama. And this is with 245/35 cheap rubber, when using quality tires a bit wider it’s no problem to do full throttle accelerations with 400hp (though first gear will spin).
I’d say traction will be issue after 500hp, because very good rubber with proper suspension will handle lower power in E30 quite well.

and for high speed ... well a 400+ e30, with overdrive box + long ratio diff should be able to get close to 300km/h. and theres no way a e30 is able to be under control at such speeds (at least not without HUGE ugly wings).
so really, is there a point in going for 400+ HPs for any car not intended for drag racing?

I’ve done 260km/h in E30 without any wings, just normal bodykit and good suspension (and brakes). It wasn’t scary, could’ve done more with minor modifications. Though same (or actually bit higher) speed in E36 M3 was much more convenient..
After all it’s not question of the top speed, but for example acceleration from 100km/h to 200km/h. That’s something you’ll use more often.

[Jon_Bmw]

So its been tested for 15,000 miles then...
Some people will think that isn't that far, but i think that is pretty good going for a 'standard' engine.

Also, that is good power considering the boost level, maaaahooosive turbo?

[GeoffBob]

'Spent part of today studying that video of the E30 M50 speedometer in the original post.

For fun, I logged (as best I could) the vehicle speed as a function of time in order to calculate vehicle acceleration. The driver clearly starts out at around 85km/h in 3rd gear, shifting to 4th and then 5th, before backing off. I estimated 1300kg for the E30 with turbo'd M50 + driver. I then assumed an area-drag coefficent for the E30 of roughly 0.65m^2 at standard atmospheric temp and pressure (this is reasonable).

Using this data I was able to calculate the drag force on the car (as a function of speed) as well as the force required to accelerate the car (Newton's laws). From there is was fairly simple to convert this linear force on the vehicle to the wheel torque (assuming a typical wheel of 570mm diameter.

Despite the video not showing the tacho it seemed fairly reasonable to assume a red-line of 7000 rpm. From there it was a few steps to determine what gear ratios were at work. It was then possible to plot wheel torque and power as a function of engine speed.

Here's the result:



Keep in mind the following:
1) This is wheel torque and power (referenced to the engine), so you can expect flywheel values to be greater than shown.
2) I have assumed WOT.
3) If I were able to read the video to any greater degree of accuracy the dots would fall closer to each other.
4) The trend lines are approximations only. You get the idea.

From the above I would estimate that this is a roughly 300kW (400whp), 400Nm (290 lbs-ft) engine, measured at the wheels, at an engine speed of around 7000rpm.

FYI, acceleration values in 3rd, 4th and 5th gears were 0.51g, 0.38g abd 2.80g respectively.

[E30BeemerLad]

Geoff, do you work for the South African division of NASA?

[Gunni]

'Spent part of today studying that video of the E30 M50 speedometer in the original post.

For fun, I logged (as best I could) the vehicle speed as a function of time in order to calculate vehicle acceleration. The driver clearly starts out at around 85km/h in 3rd gear, shifting to 4th and then 5th, before backing off. I estimated 1300kg for the E30 with turbo'd M50 + driver. I then assumed an area-drag coefficent for the E30 of roughly 0.65m^2 at standard atmospheric temp and pressure (this is reasonable).

Using this data I was able to calculate the drag force on the car (as a function of speed) as well as the force required to accelerate the car (Newton's laws). From there is was fairly simple to convert this linear force on the vehicle to the wheel torque (assuming a typical wheel of 570mm diameter.

Despite the video not showing the tacho it seemed fairly reasonable to assume a red-line of 7000 rpm. From there it was a few steps to determine what gear ratios were at work. It was then possible to plot wheel torque and power as a function of engine speed.

Here's the result:



Keep in mind the following:
1) This is wheel torque and power (referenced to the engine), so you can expect flywheel values to be greater than shown.
2) I have assumed WOT.
3) If I were able to read the video to any greater degree of accuracy the dots would fall closer to each other.
4) The trend lines are approximations only. You get the idea.

From the above I would estimate that this is a roughly 300kW (400whp), 400Nm (290 lbs-ft) engine, measured at the wheels, at an engine speed of around 7000rpm.

FYI, acceleration values in 3rd, 4th and 5th gears were 0.51g, 0.38g abd 2.80g respectively.

Definitely not going to be 400nm´s of torque. That would suggest the NA capacity of the engine to produce only 160nm torque. And that is hardly going to be possible on a engine that used to be 240nm or so.

Very close on the 300kw wheel power

As seen on his dyno chart his peak torque is in a very short range so he´d have to start well before 4k for you to make a good analysis.




On the calcs.

[GeoffBob]

[N00b]

@ Gunni.
Forgive me if I've missed the answer to this one, but why do you clearly favour the M50 2.5L over the M52 2.8L? Is the M50 inherently the stronger of the two with engine strength being more important than the extra capacity of the M52?

[Gunni]

[Jonsku]

@ Gunni.
Forgive me if I've missed the answer to this one, but why do you clearly favour the M50 2.5L over the M52 2.8L? Is the M50 inherently the stronger of the two with engine strength being more important than the extra capacity of the M52?

I'm not Gunni but still i'll give my opinion

The M50's are much cheaper to come by and have stronger block (M50 iron, M52 is aluminium) so they're better for turboing.

[GeoffBob]

On his website http://www.schub-karre.com/

Thanks, I’ll have a look at that.

It says M50 gearbox and they came in two fashions
0.81:1 final with a 3.73 or so rear and then 1:1 with a 3.25 final drive.

I’m not familiar with that first box Gunni. Can you please tell me in which M50 engined car I'd find one in, or is this possibly a M20 box to which you refer?

stock E30 sizes say 7000rpm with the 1:1 and 3.25 is 255kmh So he must be running a taller diff for sure.

Agreed. I was quite surprised when I saw that top speed figure on his dynograph of 280km/h.

”¦. On the 2.8 m20 turbo I made on the lowest boost setting of about 0,45bar I still made 430flywheel NM torque.

This is partly my point Gunni. What I am showing is not the flywheel torque, it’s the wheel torque normalised to the engine. In other words I have simply taken the wheel torque (calculated from the acceleration demonstrated in his video) multiplied by the assumed gear and diff ratios. Since I have no way to estimate (from the info shown in the video) his transmission losses, this is the best that can be done.

It’s quite a useful exercise to undertake on your own car, BTW, and can be made a lot easier by fitting an accelerometer and a few other instruments with a cheap lap-top based data acquisition unit (that way you don't have to study the video). The value of a system like this is that it tells you how much of what your engine is producing is actually making it to the road (contributing to acceleration and overcoming aerodynamic drag), and how much is lost (contributing to heating diff and gearbox oil, heating and wearing tyres etc).

[rob0r]

This thread really makes me think about turboing my M50 NV! What exhaust manifolds are people using as this for me is the deal breaker. I can weld to a certain degree but a custom manifold is going to be beyond me...

I've seen the M50 turbo manifolds on Ebay, which I've heard can be flipped and modified to become a top mount manifold, but that's about it. Has anyone got any experience with this manifold or similar?

[Gunni]

They don´t work for E30´s.

but I might be able to organize these




24v top mount E30 manifolds

[rob0r]

That looks like a nice manifold... costly?

How come the ebay ones don't fit E30s? My M50 is actually in an E21!

[Gunni]

Cause the placement of turbos in E36´s is so much more in front then E30´s so it doesn´t work .

[Rav335uk]

That looks like a nice manifold... costly?

How come the ebay ones don't fit E30s? My M50 is actually in an E21!

Is that Actually finished now Rob?

[town325i]

On his website http://www.schub-karre.com/

Thanks, I’ll have a look at that.

It says M50 gearbox and they came in two fashions
0.81:1 final with a 3.73 or so rear and then 1:1 with a 3.25 final drive.

I’m not familiar with that first box Gunni. Can you please tell me in which M50 engined car I'd find one in, or is this possibly a M20 box to which you refer?

Some very early m50 e34's came with over drive gear boxes i think danthe told me before he has one stashed away

[rob0r]

Is that Actually finished now Rob?

Selectively unfinished! I could of had it done by the end of this summer but I didn't see the point with winter around the corner. I'll finish it at my leisure, hopefully with a roll cage, over winter.

[GeoffBob]

It says M50 gearbox and they came in two fashions
0.81:1 final with a 3.73 or so rear and then 1:1 with a 3.25 final drive.

I’m not familiar with that first box Gunni. Can you please tell me in which M50 engined car I'd find one in, or is this possibly a M20 box to which you refer?

Some very early m50 e34's came with over drive gear boxes i think danthe told me before he has one stashed away

Thanks town325i for the info.

[ShonkyBob]

That can be done on the stock ecu even with the stock MAF as well.

So you´ll need

injectors (anything above 32lb will do it fine), the ecu can be adjusted for larger injectors

rest is normal turbocharger stuff.

Manifold, turbo, pipes, intercooler, hoses, clamps, oil feed and drain and so on.

So your saying it can be run safely on stock managment, interested

Yes it can as long as the MAF can measure the air coming it it´s not that hard. But you do need someone who has access to the important bits of the ecu to actually change it for bigger injectors and then sort out fuelling and ignition on a dyno.

This sorted and it will work just fine. I think the stock M50 maf runs out at 300hp or so, but few tricks can make it last just a bit higher

Would you recommend anyone in particular in the UK to map the standard ECU?

[raj1vad]

hey man ive newly signed up, a loving e34 520i m50 owner, and gonna get it beefed up with some turbo loving soon,


just wanted to say this thread was a lovely read, thanks gunni.


ps: my plans are m50b20 bored out to a 2.5 (making is a m50b25 in essence), put a m50b25 head, lower compression slightly, ARP bolts, uprated headgasket.

and a turbo on about 1.0bar, all controlled by decent management.


im sure seom more experienced members can shed some light on my plan, cheers people.

BMW FTW

[chu346]

Don't think to can bore it out that much mate, and if you could you shouldn't if you want to turbo it. The 2.5's have a longer stroke, so you will need custom pistons and the space between the bores will be too small. You should just put a 2.5 in if that's what size you want.

[raj1vad]

oh ok, cheers 4 ur help, i was advised by a few bmw tuning firms that it can be done, and that they have done it before, well im not at the stage where im putting money on the table, when i am i shall look into the matter further.


appreciate it, ps: ur engine bay in u sig looks badass

[eko]

Would this turbo be suitable for an M50 running on standard management?
Too big,small?
School me please

[Cook318IS]

Would this turbo be suitable for an M50 running on standard management?
Too big,small?
School me please

link?

[eko]

Doh its been a long day

http://cgi.ebay.co.uk/742730-5018S-New- ... 19c0167262

[staley_turbo]

That's a derv turbo. Will never work properly

[eko]

That's a derv turbo. Will never work properly

See,ive got a lot to learn

[RichIS]

some thing along the lines of a holset hx30 would be ideal for a low boost std management setup i would of thought ?

[Gunni]

some thing along the lines of a holset hx30 would be ideal for a low boost std management setup i would of thought ?

It would be perfect for a 300hp setup with excellent low end.

[eko]

some thing along the lines of a holset hx30 would be ideal for a low boost std management setup i would of thought ?

It would be perfect for a 300hp setup with excellent low end.

What injectors would be needed to go with this and what car from?
Also is it best to buy a ready made kit for the oil feed/returns pipes or are custom bits needed?

[Rallyprep_UK]

Awsome thread !

MMM I really want a M50 2.5 NV engine....

[DanThe]

That's a derv turbo. Will never work properly

See,ive got a lot to learn

Isnt it more about the capacity derv engine the turbo is designed for? A similar capacity derv turbo will run out of puff too soon because the engine does not rev as high as a petrol, but if you chose a turbo from a 5 litre derv for example it wouldnt run out of steam as early, right?

[Gunni]

some thing along the lines of a holset hx30 would be ideal for a low boost std management setup i would of thought ?

It would be perfect for a 300hp setup with excellent low end.

What injectors would be needed to go with this and what car from?
Also is it best to buy a ready made kit for the oil feed/returns pipes or are custom bits needed?

oil feed will be based on what turbo you use, also custom can be cheaper then ready made if you know where to shop (hydraulic supply shop)

I think 32lbs injectors should do just fine and a bit more, you can find them in all kinds of applications.