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Re: BMW M50 NV Tuneing. Also MAP vs TPS for load.

Posted: Thu Apr 05, 2012 8:36 am
by Jon K
You're running a VR6 though! Much different setup. I am running the standard setting with good results.

Also on the M50 its VERY hard to see the timing stuff. There's nothing to line up at all, actually.

Here's a trick. Use a mirror to set the timing to tdc. You can see the TDC mark between the crank pulley and thermostat housing. Then, go below and use White Out or paint or whatever and make a reference mark on the oil pan and crank wheel. Then, highlight the one tooth over - each tooth is 6 deg on a 60 tooth wheel.

I run 100 lb/min injectors at 13.5 - 14.0:1 AFR at idle.

This is an M50 non vanos 2.8L stock cams with 1000 cc/min injectors in full sequential (fuel and spark):

http://vimeo.com/27073018

Re: BMW M50 NV Tuneing. Also MAP vs TPS for load.

Posted: Thu Apr 05, 2012 9:15 am
by VR6Turbo
I know, but it's the same principal. Large injectors need more careful tuning at low duties.

13.5 AFR idle from 100lb injectors is good, but still very rich for such a light load. Still, if that's what your engine likes....

You're firing your COPs in firing order? I run mine in twin spark with 0 offset, so wasted spark essentially. What's the advantage of firing the cops sequentially?

Re: BMW M50 NV Tuneing. Also MAP vs TPS for load.

Posted: Thu Apr 05, 2012 12:45 pm
by Jon K
It'll honestly over like 14.0 - 14.2 at idle, but my fan comes on and off and it can swing the AFR a little.

Yeah I am sequentially firing my coils. I think your coil pack is a waste park coil right? Mine is coil on plug and there's really no benefit other than less electrical noise and at high RPM you won't be stepping on your toes w/ dwell and such.

Re: BMW M50 NV Tuneing. Also MAP vs TPS for load.

Posted: Thu Apr 05, 2012 1:47 pm
by stevieturbo
13.5 may be called rich at idle. But it's only rich from the point of view of emissions and economy.

But you can bet it will give you a nice strong idle. So if it's happy at that, and you're happy there isnt much wrong with it.

As for end angle. Ideally you need a gas analyser to determine what's best at low rpm's and idle etc.
But basic theory is adjust end angle until it reads richest as this should mean all the fuel getting injected is getting burnt properly.
You may need to monitor hydrocarbons as well though. Ive never tested this myself, although would like to try. I have only tested briefly on a car at idle using the wideband and the end angle can make a fair bit of difference to AFR yet making no changes to actual pulsewidth

Re: BMW M50 NV Tuneing. Also MAP vs TPS for load.

Posted: Thu Apr 05, 2012 2:55 pm
by Jon K
I should play with injector angle and my dynobox at idle

Re: BMW M50 NV Tuneing. Also MAP vs TPS for load.

Posted: Thu Apr 05, 2012 4:57 pm
by troy
I am running a intake cam in the exhaust side, and im not sure it is timed perfectly well. I am going to adjust cams while on the dyno. Maybe this is why it likes to idle rich.

I am going out to the car today, I will change my sensor angle to 84 degrees and play with injection angle.

Re: BMW M50 NV Tuneing. Also MAP vs TPS for load.

Posted: Thu Apr 05, 2012 6:11 pm
by stevieturbo
So you dont know ignition timing. You dont know if cam timing is anywhere near sensible and then you are going to spend money going to a dyno ?


I cant quite make any sense of that. Generally you ensure the car is in a fit state with all basics covered before going near a dyno.

Re: BMW M50 NV Tuneing. Also MAP vs TPS for load.

Posted: Thu Apr 05, 2012 6:56 pm
by troy
I am not going to the dyno today.... I have confirmed igniton timing is fine, inlet cam shaft timing is fine. The only question is the exhaust cam timing (jon will know what im talking about, with the cam swap on m50 engines)

Re: BMW M50 NV Tuneing. Also MAP vs TPS for load.

Posted: Thu Apr 05, 2012 8:33 pm
by Jon K
Did you swap in dual intake cams? Yeah I know all about that. That sucks lol. Its a pain in the ass because the timing blocks no longer line up. Honestly I would get it running with the stock exhaust cam so the cam timing is easy. There's no degree markings and so its kind of a "flying blind" thing. Some guys mod S50 cams to go in. What is the total setup like? Is it an NA or turbo motor?

Re: BMW M50 NV Tuneing. Also MAP vs TPS for load.

Posted: Fri Apr 06, 2012 12:26 am
by Roverdose
dti on the follower not an option? i dont ever use timing marks on a non std cam to time it up.

Drew