VEMS Community Forum

Members => Projects & Installs => Topic started by: Sam8888 on October 08, 2016, 10:06:24 am

Title: E21 With M20 N/A
Post by: Sam8888 on October 08, 2016, 10:06:24 am
Hi there!

I have a BMW E21 with M20B25 VEMS'd

Engine specs:
M20B25
ported cylinder head
headers
3 angle valve job on the intake
lighweight flywheel (around 4-5kg)
Carbon airbox (chinese BMC knockoff)
VEMS
Wasted spark
M50B25 green injectors with 3.5bar fpr (190cc)
Running on 100 octane fuel
Factory exhaust from the headers, which i think is very restrictive for the engine.

Sometime in the future i want these updates to the engine:
ITB's (from some bike)
build a M20B28 N/A

Here's my config (but i always find something to change):
https://drive.google.com/open?id=0B2LftYmTraGcWmIySmtzTDVvQms (https://drive.google.com/open?id=0B2LftYmTraGcWmIySmtzTDVvQms) <- any comments welcome

Engine bae:
(http://img1.indafoto.hu/7/9/11679_780261c4b9a55cd803080619d0cc3e11/24263825_bd18d56dd3030bf7ea35901d5c235ff6_l.jpg)

Engine harness is modified to the VEMS, i cut out everything that i don't needed.
(http://img1.indafoto.hu/7/9/11679_780261c4b9a55cd803080619d0cc3e11/23930010_a1b2ffbb78cbe9049f812297d87c9a80_l.jpg)

And here's some pics of my ride:
(http://img1.indafoto.hu/7/9/11679_780261c4b9a55cd803080619d0cc3e11/24480935_b3c00d1992d8ae1b543dfff09085ed02_l.jpg)

(http://img2.indafoto.hu/7/9/11679_780261c4b9a55cd803080619d0cc3e11/24480925_2cdee168df095dce6f1243ae2af30ae8_l.jpg)

And here's some launch control practice:
https://www.youtube.com/watch?v=ySLmMfz6Kec (https://www.youtube.com/watch?v=ySLmMfz6Kec)
Title: Re: E21 With M20 N/A
Post by: wersch on October 08, 2016, 04:30:26 pm
Realy nice car!  ;D
I noticed that the trigger settings are 2 degrees incorrect.
Should be 60 degrees if you trigger on tooth #4.
Title: Re: E21 With M20 N/A
Post by: Sam8888 on October 08, 2016, 05:29:06 pm
Realy nice car!  ;D
I noticed that the trigger settings are 2 degrees incorrect.
Should be 60 degrees if you trigger on tooth #4.

Thanks!  :)
Triple checked that with a timing light gun, and it's spot on with the 62 deg.
Title: Re: E21 With M20 N/A
Post by: wersch on October 09, 2016, 09:07:33 am
Maybe you need to turn around the +/- cables on the primary trigger then, because it should be 84 degrees trigger angle on standard M20 if you trigger on tooth #0.
You can see this if you make a triggerlog.
Title: Re: E21 With M20 N/A
Post by: Sam8888 on October 09, 2016, 10:19:12 am
Maybe you need to turn around the +/- cables on the primary trigger then, because it should be 84 degrees trigger angle on standard M20 if you trigger on tooth #0.
You can see this if you make a triggerlog.

My FTT is 4 (so the 5th tooth after the missingtooth), so that is giving me 62 deg. It's kind of the factory M20 setting in the VEMS, only adjusted 60 deg to 62 with a timing light.

Should i modify FTT to 0 and 84? Why? (i just want to know why is it better to have on 0 and 84)
Title: Re: E21 With M20 N/A
Post by: wersch on October 09, 2016, 10:50:31 am
60 deg. with FTT #4 will give the same setting as 84deg. with FTT #0.
As i understand the synchronisation is faster if you trigger on tooth #0.

I have done many ECU installations on BMW engines and both M20,M30 and M50 have 84deg. triggerangle.
Title: Re: E21 With M20 N/A
Post by: Kamuto on October 09, 2016, 11:44:44 am
just leave it how it is :)
Title: Re: E21 With M20 N/A
Post by: Sam8888 on October 09, 2016, 06:40:34 pm
Okay, i'll leave it like it.  ;)
Thoughts on the VE/ignition maps?
I guess my injector dead time isn't any good, because there's a valley in the VE table at idle.
Title: Re: E21 With M20 N/A
Post by: Sam8888 on October 16, 2016, 03:43:21 pm
I wonder about the sequential injection. I should just add a cam sensor, set up the 2nd trigger in VEMS, and engine setup odd fire and that's it? (ofc. when the injectors is individually connected)
Title: Re: E21 With M20 N/A
Post by: Kamuto on October 16, 2016, 11:35:48 pm
I wonder about the sequential injection. I should just add a cam sensor, set up the 2nd trigger in VEMS, and engine setup odd fire and that's it? (ofc. when the injectors is individually connected)
not odd fire :) but yes you are right
Title: Re: E21 With M20 N/A
Post by: Sam8888 on October 17, 2016, 09:06:05 am
Okay then i'll do it.  :D
I have a spare crankshaft VR sensor, i guess that'll be fine for camshaft sensor too.
Title: Re: E21 With M20 N/A
Post by: Kamuto on October 17, 2016, 01:14:40 pm
Okay then i'll do it.  :D
I have a spare crankshaft VR sensor, i guess that'll be fine for camshaft sensor too.
check what ecu you have, hall sensor connection may be much more easier
Title: Re: E21 With M20 N/A
Post by: Sam8888 on October 18, 2016, 02:26:21 pm
I did pictures from my Genboard back in the days. I have the 2nd LM1815 installed, and the wire that needed to be there, but unfortunately can't see the required solder blob (it's under one of the injector drivers). I have to disassemble it to check that.

Correct me if i'm wrong, but according to the pictures all i have to do is solder that blob at the back of the board (if it's not soldered already) and it's ready to accept the 2nd VR. (It's easyer to me because i have plenty of VR sensors at home)

Pictures:
(http://img2.indafoto.hu/7/9/11679_780261c4b9a55cd803080619d0cc3e11/24574377_bec82a41940dfc89a92bec79fddad211_l.jpg)

(http://img1.indafoto.hu/7/9/11679_780261c4b9a55cd803080619d0cc3e11/24574385_27bf4fc7f16de74f25513d893208932b_l.jpg)

(http://img2.indafoto.hu/7/9/11679_780261c4b9a55cd803080619d0cc3e11/24574387_d72c4f61c21f9a35b64bb2728c6f2599_l.jpg)
Title: Re: E21 With M20 N/A
Post by: Kamuto on October 19, 2016, 02:40:57 am
I see that you have sec trig vr installed on ec18-7 pin :) all must work out of the box :)
Title: Re: E21 With M20 N/A
Post by: jrussell on October 20, 2016, 08:03:49 pm
I think you mean ec18-12 pin for the 2nd VR. Pin 7 is at the far right of the pic.
Title: Re: E21 With M20 N/A
Post by: Kamuto on October 20, 2016, 11:34:38 pm
I think you mean ec18-12 pin for the 2nd VR. Pin 7 is at the far right of the pic.
yes you are right, sorry ;)
Title: Re: E21 With M20 N/A
Post by: Sam8888 on October 22, 2016, 02:17:15 pm
Developed the camsync plate, will see if it fits after the prototype is ready.  ;D
I guess it'll fit for M20/M30/S38 engines. We'll see how much it'll be to manufacture these.

(http://img1.indafoto.hu/7/9/11679_780261c4b9a55cd803080619d0cc3e11/24586031_330fc00c5e7979ed3a085fbf90df993d_l.jpg)
Title: Re: E21 With M20 N/A
Post by: Sam8888 on November 09, 2016, 08:54:45 am
If i'm correct, i should wire the injectors like this? It is confusing, because of Injgroup is arranged in the ignition firing order.
So if i set 1-5-3-6-2-4 and wire like this, it will be ok? Tryna search for this Injector group table, but didn't find any good explanation.

So if i'm correct, the injection will happen by the adjustable real cyl order despite of the confusing reverse Injgroup order? (Why is the Injgroup even there if so?)

(http://img1.indafoto.hu/7/9/11679_780261c4b9a55cd803080619d0cc3e11/24636712_6fca7fb0ed5dae97b5fb789e3896a776_m.jpg)
Title: Re: E21 With M20 N/A
Post by: gunni on November 11, 2016, 01:25:51 pm
That will be fine,
assuming it fires on no.1 to start with
Title: Re: E21 With M20 N/A
Post by: Sam8888 on November 23, 2016, 08:39:08 pm
Ok, my car is now running sequential injection. But here's one thing i don't get:

I wired my injectors as the picture above: output 1 to cyl 1, output 2 to cyl 2... and so on.

I made the cam snyc to happen before the 1st cyl at TDC, but after the missingtooth (around 8th tooth on the 60-2).

According to the configuration this seems to be 180 deg off, since if i power off injector 1, then shuts off cyl 6.  ???
Turned around the camsync pulse sender 180 deg, and now seems ok, but the 2nd trigger is now sent when the 6th cylinder is on TDC.
This is because VEMS resets the cycle at the next missingtooth event?

Here's a video.
https://www.youtube.com/watch?v=T9H9pWGijRc (https://www.youtube.com/watch?v=T9H9pWGijRc)
Title: Re: E21 With M20 N/A
Post by: gunni on November 25, 2016, 01:17:43 am
The injector outputs should be aligned with the firing ignition coil,.

I.e the top one being cyl1 should also be cyl1 on the ignition outputs table. That way you know that the injection timing is correct.
The problem is that the ecu doesn´t actually know which cylinder is which as there is no firm selection method of outputs to cylinders like most other ECU's.

The trigger point of the camsync sets the phasing of the engine, by swapping the disc around you are potentially moving the trigger point to the other revolution of the engine cycle.

If you have injector output 1 wired to injector 1 then turning that off will definitely not turn cylinder 6 off.
Title: Re: E21 With M20 N/A
Post by: Sam8888 on November 25, 2016, 03:35:10 pm
Yeah, i know that. If i set off 1st cyl injector, it shuts off 1st cylinder, so far so good now.

The problem i was talking about:
I made the cam sync signal to happen AFTER the missingtooth, but BEFORE the 1st cylinder TDC, because i thought it will reset the cycle immediately. But as it turned out VEMS managed to reset the sync only at the next missingtooth event, this confused me a littlebit. Ofcourse flipping the cam signal 180deg made the trick.

So the ideal cam signal position is AFTER 6th cylinder TDC, but BEFORE missingtooth!

V2 cam plate will be available soon, pm me if anybody interested. It'll be usable on M20, M30, and maybe S38 and M40 too, but these needs to be checked.

Couple pics, hence this is just the prototype, the final product will be prettier:

(http://img1.indafoto.hu/7/9/11679_780261c4b9a55cd803080619d0cc3e11/24672881_87ea726b83d67b975cd83f0b983b920f_l.jpg)

(http://img2.indafoto.hu/7/9/11679_780261c4b9a55cd803080619d0cc3e11/24672883_2bb5a974186d9b15ba53934770a3e1c0_l.jpg)

(http://img1.indafoto.hu/7/9/11679_780261c4b9a55cd803080619d0cc3e11/24672885_084acf4ba99935b8e4a43d09c1d94b89_l.jpg)