VEMS on a 1.8T 20V

[lorge1989]

Found this site via a FB recommendation, hoping to bring some diversity here since nearly all of the builds are with 5 cylinders. But I will be sticking with the old Audi theme, don't worry.

Currently running a built 2.0 20v, 5858 Comp turbo, 870cc and an early Chris Tapp AEB tune in a B3 90. I want to upgrade the management and always wanted a standalone project, I just need some help picking all of my components!

I bought the car with the harness already swapped, I've done a lot of re-wiring and cleaning up but ultimately I want to ditch the stock AEB harness all together, I am not interested I making an adapter to mate to the VEMs ECU.

First things first, speed density will be easier but I would like to run a MAF eventually. What MAFs are common with VEMs?

Off the shelf VW/Audi components I will be using:
Cam sensor (Hall)
Crankshaft Position Sensor
Fuel injector harness
VR6 DBC Throttle Body (Built in TPS)
Knock Sensors - I won't be using this right away but hopefully I can use this as a safeguard eventually.

Other sensors:
Water Temp, IAT - Stock most likely. Hopefully I can plot the output by measuring resistance by hand. I think both of these are not a simple 0-12V output.
EGT - Have that.
O2 - Have that as well.
Fuel Pressure Sensor - Going to use a universal solution with a 0-12V output.
LS1 Style Coils - what trouble with I have here? Pretty easy to wire up?

Those are the majority of parts I can think of. Fuel pump with always be on, unless I can find a PWM solution.

What about wiring in a level sensor for coolant and oil?

What are the chances I can retain my tach/speedo?

I've done a lot of research on the tuning aspect of things so I think I will be OK there, I just want to make sure I get the setup 100% correct the first time so I don't have trouble down the road.

Thanks!

[All_Euro]

Welcome - looking forward to seeing this unfold

[chaloux]

Welcome!

It should be pretty straightforward I think. There are a few here running 4 bangers! Zerb is on VEMS if I'm not mistaken. It seems like if you're interested in doing all the wiring over again, pick up a VEMS econoseal unit. You could even have Marc make you a harness for it or at least send you a flying lead harness that you can finish off.

Why do you want a MAF? Your tach should be fine. I think.

[alxdgr8]

Welcome!

It should be pretty straightforward I think. There are a few here running 4 bangers! Zerb is on VEMS if I'm not mistaken. It seems like if you're interested in doing all the wiring over again, pick up a VEMS econoseal unit. You could even have Marc make you a harness for it or at least send you a flying lead harness that you can finish off.

Why do you want a MAF? Your tach should be fine. I think.

+1, Marc's flying lead harness for $400 is a great deal and doesn't need much work to finish.

[lorge1989]

Welcome - looking forward to seeing this unfold

Thanks!

Welcome!

It should be pretty straightforward I think. There are a few here running 4 bangers! Zerb is on VEMS if I'm not mistaken. It seems like if you're interested in doing all the wiring over again, pick up a VEMS econoseal unit. You could even have Marc make you a harness for it or at least send you a flying lead harness that you can finish off.

Why do you want a MAF? Your tach should be fine. I think.

Didn't Zerb move on to a VR? I thought he was running lugtronics, which is VEMS if I remember right.

I was just planning on getting this:

http://www.efiexpress.com/catalog/produ ... 5950a11103

I have a few junk harnesses of of newer VWs that I was planning on recycling to make it happen. I can get a lot of the connectors off of these with wires already attached. I like the thought of doing it all myself, just so I am super familiar with everything if that makes sense.

I just wanted a MAF to explore different tuning angles so to speak. Speed density is easy to set up but getting those VE tables perfect is something that will take some time I assume (I've never done it....). Using a MAF is just totally different but can be a more precise tool setup properly. To be honest, I just want to keep my options open, and if there is a decent solution out there I would probably wire it in just to record how much air I'm flowing even if I was using speed density.

Another reason for a MAF is because of an opinion of a friend. Hes an engine calibration engineer and he has been feeding me info over the past year or so leading up to this. Its helped open up my mind to a lot of things which is nice. I know he likes using a MAF and I'm sure has a much more technical response to why than I could give you as to why.

Hopefully putting in my order in for the ECU and other stuff within the next month!

[SEStone]

A MAF allows fewer assumptions to be made about the air flow into the engine...for example, air temperature measurement becomes nearly irrelevant. However, it opens up the problem of intake tract leaks, PCV flow causing error, etc.

That being said, modern cars are going away from using MAFs for cost savings reasons. Modern Bosch engine management actually converts a MAF signal back to units of speed density (IE, manifold pressure) to account for air flow. Getting rid of the MAF sensor and just using pre/post throttle body MAP sensors results in the exact same calculation without requriing a $200 sensor.

Sam

[my2000apb]

A MAF allows fewer assumptions to be made about the air flow into the engine...for example, air temperature measurement becomes nearly irrelevant. However, it opens up the problem of intake tract leaks, PCV flow causing error, etc.

That being said, modern cars are going away from using MAFs for cost savings reasons. Modern Bosch engine management actually converts a MAF signal back to units of speed density (IE, manifold pressure) to account for air flow. Getting rid of the MAF sensor and just using pre/post throttle body MAP sensors results in the exact same calculation without requriing a $200 sensor.

Sam

how does one integrate with dual MAP sensors?

[SEStone]

There are two or three sensors depending on the application, I believe. In boosted cars, there is a baro sensor, a pre-throttle body sensor for boost control, and a map sensor for actual load measurement. Essentially taking the same measurements as we are with any of our speed density systems. If we had a true load-based ecu, the pre-throttle body sensor may be more important.


Sernt frrrerm Terrrperrterrrk

[lorge1989]

Right. On the surface the MAF is a more straightforward way to go about it. Easier to tune, IF you have all your ducks in a row, meaning no leaks and all the other stuff like you said. I've never seen two MAP sensors used for tuning purposes on a factory car, or even common tandalone setups.

On factory VW/Audis with late 1.8Ts they use the MAF, MAP, IAT, CLT and wideband O2. On the early cars, AEB, they only have a MAF, IAT, CLT and narrowband O2. This is the type of setup I am moving away from. With VEMS, at least the universal ECU, there is only one MAP sensor. You have to have this on the manifold side simply and obviously because pre throttle body there is no vacuum. I can see the usefulness of putting another pressure sensor pre-tb just for boost control, but most likely if you need that then you have bigger more restrictive problems on your hands.

A barometric pressure sensor could also be useful but really only necessary if you are pushing the limits of the car in varying elevations. A good example would be the cars that run pikes peaks etc. I would think that a factory ecu would adapt to changing conditions like that without the need of another sensor.

[SEStone]

A baro sensor is handy if you live in changing elevations. Even though someone said it shouldn't make any difference...my car runs leaner and leaner on speed density at higher elevations. Driving through southern CO/northern NM where you hit about 9000ft, my fuel trims were running about 9% richer than normal.

I've never tried it, but I see MAF tuning on a standalone system like this as being very tricky, just because of how the maps are setup. The way the MAF input is used, and the way load is calculated using a MAF (or MAP) signal is very different in something like Motronic, which is setup for it to begin with and is relatively straight forward. Since VEMS probably (I've never tried myself) doesn't break the MAF signal down into load, tuning would be a challenging target as you'll be moving diagonally across your maps (assuming maps are laid out as RPM vs. mass air signal) in a steady-state load condition.

[lorge1989]

A baro sensor is handy if you live in changing elevations. Even though someone said it shouldn't make any difference...my car runs leaner and leaner on speed density at higher elevations. Driving through southern CO/northern NM where you hit about 9000ft, my fuel trims were running about 9% richer than normal.

I've never tried it, but I see MAF tuning on a standalone system like this as being very tricky, just because of how the maps are setup. The way the MAF input is used, and the way load is calculated using a MAF (or MAP) signal is very different in something like Motronic, which is setup for it to begin with and is relatively straight forward. Since VEMS probably (I've never tried myself) doesn't break the MAF signal down into load, tuning would be a challenging target as you'll be moving diagonally across your maps (assuming maps are laid out as RPM vs. mass air signal) in a steady-state load condition.

If you live in the moutains or frequent them I can defintely see why you would want one. But for me, NY is not that mountainous, especially near Buffalo.

The whole load based convo and how each map is setup in different system is something I know very little about. I just assumed because it was advertised that you could use a MAF on VEMS that there was different ways to setup maps depending on the route taken. At this point it seems that I won't be considering using a MAF at all for tuning.

Down the road if I figure I need one for any reason I can tackle it then, when I am more familiar with the whole thing.


Recently found a cool little item that will help me with what I want to do.

http://www.leashelectronics.com/Pro-Str ... PS2012.htm



My car is not a daily, not even close to it. So I always wanted to, lets say, 'half gut' it. Meaning if I could replace the factory body harness with something like this to just work the lights and a few other accesories that would be great. I have had a few electrical gremlins with this car already, so I want to re-do all the wiring and make everything as simple as possibly so I don't have any of those issues again, and also it will save me some weight.

I have planned on getting rid of the heater box/controls, radio etc. I also plan on ripping the whole car apart for paint so I want to just do everything at the same time.

Thoughts on this? I know its slightly off topic.

I'm just not sure how things like the power windows and sunroof will work. I'd like to just do a manual swap on the windows and delete the sunroof but I read manual windows are tough to find.

[Mcstiff]

I've thought about how I could use something like this http://www.isispower.com/products.html? ... =ISIS2BOXZ

[lorge1989]

Complete overkill for what I'm doing, cool piece though.

[ads]

I had a painless kit in my car but still had to run an additional fuse panel and relay panel. I really didn't like what I had done so I bought one of the leash electronics boards, couldn't be happier with it. Super easy to wire up, and they clean everything up a lot. They are also very compact and easy to hide, I would recommend one if you plan on redoing your chassis wiring.

[lorge1989]

Thanks for input, makes me decision easier.

I wondering if I can incorporate the power windows into it somehow. I'm not sure if all I need to do is supply the panel with power and thats it or what. Just seems that manual windows are not going to be found easy, if at all.

Any other input on the whole sensor problem I described in my original post? All of you 5 cylinder VEMS guys just use all stock sensors?

[ads]

Yes you can wire it up to your power windows. They have nice heavy duty 70 amp relays. I powered my power windows and mirrors off of one relay.

As for sensors, I used all stock sensors but I used the plug and play aan ecu, not sure if its any different to wire it up to the econo seal unit. The only thing I would really worry about would be shielded wire like the knock sensors and crank sensors. I have heard that coiling bare copper wire over your primary sensor wires works for reducing emf but have only done it once myself and it wasn't on a sensor. Im sure someone who has used the econo seal unit would know what to do better than I

[vt10vt]

Any other input on the whole sensor problem I described in my original post? All of you 5 cylinder VEMS guys just use all stock sensors?

The PNP VEMS ECUs use the factory sensors so *I would guess* you should be fine with an econoseal. My suggestion for wiring is to pillage a factory harness for the VR and Knock sensor wiring (if you're using that too) They're really nice, heavily insulated and individually wrapped and just so happen to be the right length to reach a convenient ECU mounting point!

[boost_addict]

I would recommend buying the V3 harness vems sells for $280. it is almot a full harness. u basically push it through firewall then cut to length, crimp stock vw.audi plug pins on and plug it in.. the relay pack is extra online, total harness and relaypack is about $325. The relay pack is a bit big however it has everything to run anything u could want engine wise and remove any of the unused relays/fuse slots you dont need, it also has good quality relays/sockets/ fuse block/ and econoseal plugs.. and BENEFIT that if you did a painless main relay panel or one similar pictured above it only makes wiring the 2 together that much easier

V3 is made with gxl grade wire which is far better then the typical automotive wire or the stock wiring. I ALWAYS SAY to make your own injector harness. The inj harnesses they sell are long/bulky and come with that cheap plastic wire loom crap, the V3 engine harness is all done in quality shrink tube so why they change to the plastic junk on their injector harnesses is beyond me. i also like to put boost valve in with that 8 pin supplied plug as well since it uses the injector power/flyback wires.

I found it was WAY easier for people who were new or unsure on building a harness from scratch to go this route.. it has all the grounds tagged together which is great piece of mind as vems is very picky about grounds and will fry the ECU if not grounded correctly.
so the important grounding/shielding/flyback/communication plug is all taken care of. and they give u a nice wiring diagram with color-coding to make an easy install.
i spend more then double in materials to make a custom race harness from scratch and it takes me 30-40 hours, The vems harness i can have installed in a car and start tuning in ONE DAY.

Hope this helps some.. i have a custom harness i made in my coupe, however in the mk4 vrt 6262 GTI that i daily i have a vems v3 harness in that car and i love it. almost wish i did the same for the coupe


i might actually have one on my shelf i could sell. I bought it at the end of last summer for a friend and he never ended up taking it.
ill cut u a deal and i think i put a couple more ends on for him too. send me a pm if your interested. the only thing i don't like about the v3harness is the communication cable is really short so I lengthen them for my guys

if you have any other questions feel free to ask.

heres a pic of the single trigger v3 harness.. they also make a dual trig harness. they do have differences between the single and double.(removable injectors harness on one not other. relay packs are different. and the shielded wire for the trigs is a different wire.. i think the single trig wire is much nicer then the dual trig harness shielded trig wires

[lorge1989]

I would recommend buying the V3 harness vems sells for $280. it is almot a full harness. u basically push it through firewall then cut to length, crimp stock vw.audi plug pins on and plug it in.. the relay pack is extra online, total harness and relaypack is about $325. The relay pack is a bit big however it has everything to run anything u could want engine wise and remove any of the unused relays/fuse slots you dont need, it also has good quality relays/sockets/ fuse block/ and econoseal plugs.. and BENEFIT that if you did a painless main relay panel or one similar pictured above it only makes wiring the 2 together that much easier

V3 is made with gxl grade wire which is far better then the typical automotive wire or the stock wiring. I ALWAYS SAY to make your own injector harness. The inj harnesses they sell are long/bulky and come with that cheap plastic wire loom crap, the V3 engine harness is all done in quality shrink tube so why they change to the plastic junk on their injector harnesses is beyond me. i also like to put boost valve in with that 8 pin supplied plug as well since it uses the injector power/flyback wires.

I found it was WAY easier for people who were new or unsure on building a harness from scratch to go this route.. it has all the grounds tagged together which is great piece of mind as vems is very picky about grounds and will fry the ECU if not grounded correctly. So the important grounding/shielding/flyback/communication plug is all taken care of. and they give u a nice wiring diagram with color-coding to make an easy install.
i spend more then double in materials to make a custom race harness from scratch and it takes me 30-40 hours, The vems harness i can have installed in a car and start tuning in ONE DAY.

Hope this helps some.. i have a custom harness i made in my coupe, however in the mk4 vrt 6262 GTI that i daily i have a vems v3 harness in that car and i love it. almost wish i did the same for the coupe


i might actually have one on my shelf i could sell. I bought it at the end of last summer for a friend and he never ended up taking it.
ill cut u a deal and i think i put a couple more ends on for him too. send me a pm if your interested. the only thing i don't like about the v3harness is the communication cable is really short so I lengthen them for my guys

if you have any other questions feel free to ask.

heres a pic of the single trigger v3 harness.. they also make a dual trig harness. they do have differences between the single and double.(removable injectors harness on one not other. relay packs are different. and the shielded wire for the trigs is a different wire.. i think the single trig wire is much nicer then the dual trig harness shielded trig wires

Thanks for this awesome reply. Where is that harness and relay setup you were talking about, I don't see it on EFI-Express.

In this whole process I was fortunate enough to pick up an MS3 unit from a friend, so I in fact won't be running VEMS. Still, I needed a harness. I'm going to be using a stock AEB harness with updated coil connectors, for FSI stuff and some other things being deleted. EVAP, MAF etc. I will probably be helping a friend put VEMS in another 1.8T powered B3 sooner or later so this is good stuff to know.

This is basically what my friend was running in his A4 that this ECU came out of. He also supplied me with a little adapter to go from the MS3 to the stock harness. All I need to do is put in a relay/fuse box for power going to the injectors, fans and coils. There might be one other thing, but I can't remember at the moment.

Another thing is I still have the option of incorporating a knock sensor but so far no one I know of has gotten the stock Audi knock sensors to work. I won't be tackling this right away, but it is something I would like to try down the road.

[boost_addict]

he may not have it listed as he makes custom harnesses at efi express. (im sure marc @ efi can get these too)
this is a harness that VEMS makes and sells.
you can see it on the vems webshop at http://www.vems.hu

[Marc]

I'm bad at listing all the stuff we have. I'll add the harness stuff next week. in the mean time, call us or email the shop for a quote.