BMW, VANOS and Megasquirt

froej25 · Post by **froej25** » Wed Aug 10, 2005 11:07 pm

Well, I was curious about this, and plan to do a turbocharged BMW 3 series down the road, so I did a little research. There does not appear to be any people on the forum running MS on VANOS equipped BMWs, and not many questions about them, so maybe I'm answering a question that no one wants answered. However, I find this odd; BMWs with single VANOS are coming down a long way in cost, are excellent platforms, and have prohibitively high costs for extensive modification (Active Autowerks turbo costs $10,000!). It makes little sense to buy a $6-9k vehicle and spend $10k on a turbo; I assume that since these are premium vehicles with a low volume, these manufacturers feel justified in charging a premium for performance enhancements. The stereotype of the average BMW driver is certainly not exactly the hands-on, DIY type. But I digress; the point is these engines have potential, and MS may be the key to unlocking it at a reasonable cost.

I should mention here that I am NOT a BMW or MS expert; hopefully once we get out pole barn built I’ll be able to go my hands dirty again, I’ve been out of the garage for far too long. Rather, my purpose in writing this was for my own knowledge and to raise other’s awareness of a possible project.

I should note that these BMW’s used distributorless ignition, so it may be a good idea to use MS for ignition as well as fuel control. The costs of buying BMW parts would quickly become ridiculous; using MS for ignition control from the beginning will probably save a lot of money down the road.

The most likely subject of MS modification would be an inline 6, probably a M50 or M52. The displacement on these varies from 2.0 liters to 3.0 liters, with horsepower ranging from 150 bhp to 240 bhp. This may not sound like much, but the dyno graphs indicate a power / torque plateau, not a peak; these engines develop flexible power. They are also quite light, around 300 pounds. This may make them a candidate for engine swaps, $1200 for the engine alone (1996 2.8 liter from www.car-part.com), $650 for a 5-speed manual transmission (same source).

VANOS is BMW’s version of variable valve timing, and exists in two forms. Single-VANOS varies the cam timing on the intake cam only. Dual- VANOS varies cam duration by up to 12 degrees and increases lift by 0.9 mm. Since this technology was introduced on 2002 M3s (I believe), I find it unlikely that anyone will be trying to use MS to control it; additionally, so many variable are processed that it may be beyond MS’s capabilities to regulate well (I know, blasphemy, but true). For these reasons, I will focus on single- VANOS.

Single- VANOS controls the intake cam’s timing by altering its relationship to the crankshaft; a secondary timing chain from the exhaust cam (which is driven directly by the primary timing chain) drives the intake cam. The VANOS device is complex internally, but externally requires little input; oil for pressure to mechanically actuate it and an electrical input to energize a solenoid that controls the pressure. When the solenoid is energized, the cam advances 12.5 degrees. The cam is at 0 degrees advance at idle and above ~5000 rpm; it is advanced 12.5 degrees from idle-5000 rpm to “improve cylinder filling” in the midrange. So this should be fairly simple to implement with MS; just like VTECH (solenoid switch) but at two points, and if you’re willing to sacrifice a rough idle, one point would be possible (5000 rpm).

Anyway, no flaming please. I'm simply throwing this idea out to gauge interest and see if anyone has thoughts or input on the concept. There is a lot of details that would need to be worked out- specific sensors to use, how to integrate the MS with the factory BMW ECU, etc.. But it does seem doable; I'll try to get around to it, but if anyone else would like to jump in first...

M50/M50TU (S50US?) I6, DOHC 24V single VANOS; basic engine 1989-1998, E36 320i/325i, E34/39 520i/525i, early E36 M3; 299 lbs; 2.0 liter 150 bhp, 2.5 liter 192 bhp, 3.0 liter 240 bhp
Maybe 1992+ 5 series, 3/95+ 3 series

M52/M52TU (S52US?) I6, DOHC 24V, 1996-1999
Iron block in US (308 lbs), alloy block in Europe (260 lbs)
I think most are Single-VANOS, exception being 3.2 liter used in later M3
E39 520i/523i/528i, E36 323i/328i, E38 728i
2.0L 150 bhp, 2.5L 170 bhp, 2.8L 193 bhp, 3.2L 240 bhp

Links:
VANOS
http://www.bmwworld.com/technology/vanos.htm
DME (ECU)
http://www.bmwworld.com/technology/dme.htm
SCC
http://www.sportcompactcarweb.com/edito ... hnobabble/
Not sure if correct on double VANOS, says no lift adjustment
http://www.ukcar.com/features/tech/Engine/vv/vvt_3.htm
BMW engine specifications
http://www.bimmerforums.com/engine_faq/

Background:
Car designations:
1st digit: car platform (3, 5, 7)
2nd & 3rd digits: engine displacement (liters, add “.” Between numbers (23=2.3L))

Exx designation- I have no idea here, not sure what it means, just that all members of a certain platform share the same one- i.e., E36 is the 1991-1998 3-series (I believe).

Engine designations:
1st digit: M=?, S= solid lifter, N=?, W=?
2nd digit: 4= I4, 5= I6, 6= V8, 7=V12
3rd digit: evolution of previous engine?

efahl · Post by **efahl** » Thu Aug 11, 2005 6:32 am

My nephew has an E36 with a single VANOS M52 in it, so I've gone through the mental exercise of specing out an MS for it. The VANOS is no problem, turn it on or off, it's just a digital signal. The trigger wheel is no problem, just grab the 60-2 and decode it with James's already working code. Fuel is, of course, trivial. Ignition is problematic, since we are missing two parts for a 6-cyl COP: 1) six drivers; 2) cam sync on trigger wheel decoder. There are solutions for both of these either in the workshop or on the road, but they are not available to the general public yet, so you'll have to wait a while (or come up with an independent solution for these problems) before you can use MS as a generic implementation on these motors.

Eric

froej25 · Post by **froej25** » Thu Aug 11, 2005 11:02 am

Would it be possible to use Ford's EDIS system for this application? It would lose some of the BMW engineering, ditching the COP, but wouldn't it be cheaper and possibly easier to use in the long run? And since it is a wasted spark system, it would not be necessary to sync the ignition event with the cam. Glad to see there's at least one other nut out there who's been contemplating this...

Oh yeah; "So, humans have weak knees? My people will find this very interesting. Muhahahahahhahaha."

boost junkie · Post by **boost junkie** » Thu Aug 11, 2005 11:05 am

Even easier might be to use the BMW 60-2 crank trigger decoded by MSnS-E use the spare outputs to fire a ford EDIS-6 coil pack.

froej25 · Post by **froej25** » Thu Aug 11, 2005 3:39 pm

Yes, the MSnS apparently can decode this signal. I didn't realize it before, but it makes sense, since BMW uses Bosch components. Then have it drive the EDIS-6... Only loss is the COP, and like I said before, I don't see that as much of a loss at all; I haven't seen any evidence that COP is that great of a benefit (but that may be ignorance talking). I believe the BMW uses a 60-2 configuration; there may be a better way to do it, using a Bosch unit from another 6 cylinder, if someone wanted single spark instead of wasted spark. Additionally, should be more reliable, since it would utilize the factory setup instead of a retrofit. Yet another thing to look into I suppose...

efahl · Post by **efahl** » Fri Aug 12, 2005 6:47 am

My inclination would be to retain the COP just because all the wiring is already there, you just need to have (logic-level?) drivers for each coil, plus the cam sync, and you're ready to go.

But, you are right, a wasted spark solution would work quite easily today. As boost junkie says, just put use a 6-cyl coil pack and wire that directly to the MS board, probably with coil drivers on the MS like Ryanpzz uses on the Mazda V-6 motors. Available now, very easy, well proven.

Eric

milesinfront · Post by **milesinfront** » Fri Aug 12, 2005 4:37 pm

It is commomly believed in the BMW community (myth prehaps?) that the VANOS system is infinately variable. Could the single soleniod which switches the oil on/off be PWM to vary the amount of oil pressure and therefore the amount of advance?

My brother was looking into MOTEC for his M52 and the local MOTEC guys were very weird about controlling VANOS. They said it could be done, but we know a guy that spent a fortune with MOTEC and it still wasn't right.

Surely MOTEC could control an on/off situation if that's all it was....

I guess we need to put the VANOS solenoid output on a scope???

froej25 · Post by **froej25** » Fri Aug 12, 2005 5:25 pm

Looks like wasted spark would be the way to go, at least for a beginner like me- and honestly, the main thing I'm looking for is a good motor to swap into a '69 Opel GT, the BMW I6s look like the way to go. And as a bonus, the car would stay all German! Really though, I have a lot I'd have to do; its quite possible the I6 would be too long, and not sure if the I4 would be worthwhile...

Rickmilesracing... I am not an expert on BMWs, far from it, but if you look at the links I included at the bottom of my initial post, the sources I read indicate that single-VANOS is a simple on/off deal, dependent solely on rpm. In the US at least, the only dual-VANOS system that was offered on a M52 was the one used in the 3.2 liter E36 M3. It may be different in Australia, but in the US single-VANOS is (as far as I can tell) a very simple setup- either the intake cam is advanced 12.5 degrees, or it is not. Dual-VANOS, however, is infinitely variable (within a range) on both intake and exhaust cams, and also can add up to 0.9 mm of lift. That system requires input from many sources and is beyond the scope of MS, or probably any aftermarket system, for the foreseeable future. MS could possibly manage a second set of injectors- but I think the DME (BMW ECU) would be confused once the additional fuel was added. Not sure how it would respond, but I bet it wouldn't be pretty

Jon

milesinfront · Post by **milesinfront** » Fri Aug 12, 2005 5:33 pm

Sounds like the answer I was looking for!

Cheers!

eliotmansfield · Post by **eliotmansfield** » Sun Aug 14, 2005 2:27 pm

Just bought my dads old e36 93' 325 se to see out its twilight years for my missus. Once she's done with it, would be fun to MS & turbo it!

fraatti · Post by **fraatti** » Mon Aug 15, 2005 11:02 am

Bmw m50 has very good potential.. it can hold up to 500hp with orginal pistons with some money it could look like this..

http://www.pure-pf.com/phpBB2/viewtopic ... &start=210

check other pages also there is very nice pictures..

few motor pics..
http://www.pure-pf.com/phpBB2/viewtopic ... sc&start=0

http://www.pure-pf.com/phpBB2/viewtopic ... c&start=75

m52 aluminium block holds about 0.65bar..

I have m52b28 motor and m50tu block waiting.. =)

froej25 · Post by **froej25** » Mon Aug 15, 2005 3:39 pm

Looks nice- but I'm more concerned about performance than looks. Although, I did like the comment in the post under the pictures: "gibberish (to me

) bling bling gibberish". "bling bling". *sigh*. American culture marches on I suppose... Still, I am glad to know that the engine is fundamentally strong; most things I have read were positive, saying it has a very strong crank for an I6, and good flowing heads. Although, I am curious about how VANOS will work with the turbo; guess I'd have to play with it, see what point would be best for swtiching over, just set the VANOS control on a toggle for the dyno runs. Really, I won't be looking for too much power anyway; an Opel GT doesn't weigh that much, the main concern will be fitting the engine (may need to use a 4-cylinder).

milesinfront · Post by **milesinfront** » Mon Aug 15, 2005 3:44 pm

Our untested theory on choosing when to switch on the VANOS is to do 2 dyno runs, one on, one off. Overlay the two runs and find the point where the power curves intersect. That should be your switch point....

This is WOT only, and may not be the best switch point for other loads....

addissimo · Post by **addissimo** » Mon Aug 15, 2005 8:37 pm

m52 engines from 1999-on are double vanos... Its also known as the m52tu. The m50 engine came as a non vanos engine in 1991-1992, and the m50tu is the single vanos variant 1993-1995. I have an m50tu in my 88 325 and it flies with the stock engine management. I'm planning on turbocharging soon so ms is the cheapest engine management route.

Vanos doesn't have to be used if were going standalone. It does however give a noticeable boost of torque, and if one were to look at dynocharts from www.aatuning.com, you'll see that vanos definately doesnt get in the way of big power from turbochargers.

For those of you looking at the aluminum blocks, they come from 1997&1998 z3 2.8s. You dont want a 1999-2000 block- its double vanos, and alot more difficult to do things like camshafts etc.

Speaking of cam shafts. If you're looking to sticking n/a, a good option for the m50tu is to use m3 cams, you'll be in the 230 hp range assuming you're using custom exhaust and eliminate the AFM. Keep in mind though that because of the vanos system, replacing cams is about a 13-15 hour job, and requires you to rent or make two special tools. There is info about this at www.pelicanparts.com in the tech section.

I'm excited that there are finally other people interested in setting up an m50.

froej25- The m42 and m44 are both wonderful engines. They're based on the same technology as the m50, just with two less cylinders. They're cheap as hell, and you can boost them pretty well with as little as a head gasket.

If you want big NA power out of a 4 cly. go for an s14, its a bad-ass high-revving engine. The stock us-spec s14 makes 189hp with the standard motronic. Chips allow a redline of 8200rpm, making it a very peaky motor. Rebuild one and make it 2.5 litre and youre looking at the 280hp range. Unfortunately, they're very expensive, and its a rull race engine, you'll need to know what you're doing when rebuilding, and maintaining. If you want more info on how to make a high power s14 checkout a few websites:

www.turnermotorsport.com
www.vacmotorsports.com
e30m3performance.com

The top two are retail sites that have tons of parts, the last one is an all around guide to e30 m3s as a race car.

Hope this helps, and I'll be seeing you all arround shortly.

-Addis

gielamonster · Post by **gielamonster** » Tue Aug 16, 2005 7:48 am

I think someone needs to fab up a couple turbo manifolds on the cheap and we can all have at it! I know my '93 325 would love to huff a little boost, it doesn't like getting passed.

addissimo · Post by **addissimo** » Wed Aug 17, 2005 2:07 pm

gielamonster wrote:I think someone needs to fab up a couple turbo manifolds on the cheap and we can all have at it! I know my '93 325 would love to huff a little boost, it doesn't like getting passed.

I'm working on it... But i'm working on a bi-turbo setup. If you look around single turbo manifolds can be had for about $500. I think i'll be able to get the bi turbo manifolds going for about $250-300.

-Addis

addissimo · Post by **addissimo** » Wed Aug 17, 2005 10:30 pm

When setting up the ignition, you were talking about using the stock 60-2 wheel and outputting to an edis system. Would you need the edis controller, or just the coil packs? How would you go about connecting everything through wasted spark? Would it just be easier to mount the 36-1 wheel and use that with the full edis system?

thanks-
Addis

milesinfront · Post by **milesinfront** » Wed Aug 17, 2005 11:32 pm

Read the FAQ page on the enhanced code. It explains how you can use 3 separate outputs to control 3 coils via 3 external ignition transistors....

All using the stock wheel and sensor....

addissimo · Post by **addissimo** » Thu Aug 18, 2005 9:48 pm

So thats where the wasted spark comes in... If you were to use ms'n'edis, it'd single spark though wouldnt it?

sorry- i'm a n00b to ignition and stand alone efi.

-Addis

milesinfront · Post by **milesinfront** » Thu Aug 18, 2005 10:34 pm

EDIS is also a 3 channel setup, but only requires one output from MS...