Starting this thread as a place for those of us who are thinking of installing, are installing, or have installed a VEMS ecu system in their 928, and have questions, or would just like to share info.

 

Adding some useful RL links:
Brett
Sny928
Kingwildh - Installation and Set Up
Gulpilen COP
951 Install

 

Thank you for starting this thread kind sir.
I think it is realistic to say VEMS doesn’t come with a lot of technical support available so this will be an invaluable resource for me at least.

My supercharged 86 track car was converted two years ago. I don’t know if IB would be cool with direct links to another forum. But PM for details.

 

We did a Vems PnP install on a 1991 Audi 200 Quattro Turbo we did a turbo and other upgrades on. I was excited for this build since I've been debating on getting the PnP Vems for my 81 (converted to 85 EuroS LH / EZF) since Shark Tuning those computers is a real PIA. This would save me from having to re-wire the car (again).

My tuners initial reaction when looking over the coding was a glorified MegaSquirt which we 100% refuse to touch anymore due to how many issues we've had with that platform. After a few teething issues with the ignition setup, the car is running great, made good power and so far only one issue where the car randomly shut off while the customer was driving down the highway. I've been been driving the car to try and recreate the issue, so far no go if anyone has some input on that type of issue. Already checked all the connections, grounds etc... No idea.

I'm still pondering the Vems for my 81, boils down to my tuner agreeing to touch it (he's also my boss and friend of 20+ years). I told him it's either this or the ST1 with ribbon cables and chip burning. I'm already putting a Motec M130 on my 79 race car, don't really have the budget for two of them unless I swap ECU's back and forth.

Assuming that I do, and keeping with the nature of this thread. What is on the list for upgrades along with the Vems on the 84/85 EuroS platform? Coils, sensors etc... When we do a stand-along install here (95% are Motec) we always have failsafe's built in with oil pressure / temp, coolant temp etc... How many channels are in these Vems ECU's for such things?

Thankfully it's not up to IB. As long as such a link isn't just blatantly advertising a product, I don't have a problem with it. Anything to help the community the better.

From the other thread:
Talking with my tuner about various stand-alone options (that's all he does, 6-7 days a week is tune. He was recently in Germany with the BMW factory superbike team helping them improve their program). I asked about the 100 tooth timing ring. To make a long story short, he said many platforms flat out do not support that many teeth and those which do, he's skeptical on how accurate it will be.

My solution is going to be installing 60-1 ring form an 87+ automatic on any 928 I install a standalone ECU on. My design team has an 85/86 flywheel on the project shelf and has the initial design drawn up. If this pans out we may do a small run of flywheels that will work with the stock clutch and have whatever tooth pattern we want.

 

Thanks Hacker, there’s plenty of frustration in the thread so it’s barely an endorsement and certainly not advertisement

https://forums.openroad.site/viewtopic.php?t=3845

The only time I have seen VEMS ECU shut down mid drive was in fact a grounding issue for me.

The lower tooth count flywheel would be the way to go. You can enter 99 teeth in VEMS set up but it gives you a caution icon. It will not accept tooth width proper (3.6), and will only accept 3.5 as closest value.

 

It's a gray area and I'm known to wear red iridium sunglasses

@Mark Anderson what's the going rate / availability of 87+ flywheels from automatics?

I recall 25+ years ago installing an 85/86 clutch into an S4 the "trick" was to sweat on the timing ring from an 87+ automatic in place of the 100 tooth unit. That seems like the easiest solution to this issue, assuming the rings are not stupid expensive.

Note - the 78-84 L-Jet / CIS flywheels are like 1% smaller than 85/86 LH flywheels. You cannot sweat any of the timing rings onto them. That was a frustrating evening when I thought I'd be firing up my 81 for the first time with LH / EZF installed. My 81 has literally been parked for several years since I got frustrated tuning the LH / EZF (and I bought a few more 928's.....) I'm very very antsy to get that car back on the road and seeing so many going the VEMS route is really pushing me over the edge. Hopefully once I pull the trigger and get Luke even more familiar with it, I can help figure out some of the issues.

How does cruse control work with Vems?

 

I wish I read that thread before I started tearing into my car. Makes me think I won't be bringing it to Rendezvous.

 

Hey guys, cruise control good question. My CC deleted so I can’t speak to it. Grepin might have insight on that.

I don’t want to sound anti VEMS, it’s a substantial upgrade to platform, especially with forced induction. My issue was as a beginner, it would have been better to have had active tech support. The software can be glitchy, and others can speak on the autotune feature, I found it lacking

Anyway, with trigger issue. There is an advanced filtering option that could be explored. Probably there is a path to success with some trial and error.

Hans looked at trigger log and:

“Looks like you are saturating that input, and need to put a padding resistor in there to dampen the signal.”

 

CC is one of those things often given up when going to stand alone. So if lost here, it's not a unique issue. That's why a true PnP setups cost so much for modern cars. They incorporate all the can bus data along with the engine tuning.

In the tuning world, autotune is for getting the car started, run through a couple of heat cycles to check for leaks, check timing, etc.... then off to the tuner to fully tune the car. That's not unique to VEMS. We bench tune ECU's all the time just so folks can get their new engine started, check all the easy stuff before bringing it to the dyno. The last thing we want is a car trailered in that's never been started, that once up to temp blows a coolant line due to a loose hose clamp. It's a mess, wastes everyone's time.

I talked to Mark A, he has four 87+ automatic flywheels on hand. He used to have a pile of them but Carl bought them all........nice huh?

I'm buying two of them. One for my 81 and the other for my 79. IMO this seems like the best / easiest fix. Twin turbo Todd might have a couple of them on hand too, he's checking his parts cache.

 

I have a pile of them here too. Wanted to verify timing location off multiple wheels.

I won't need them shortly, so that will free up some more inventory.

 

Installed my VEMS, but couldn't get the built in bluetooth to connect. Good news is the car started immediately, although idle was lumpy. What I found is that one of the connectors for the bluetooth module popped off, by chance does anyone have a pic of inside their VEMS unit

showing where the orange wire gets connected?

 

Here you go;-)

 

Thank you! Hooked up the connection, reinstalled the unit, and it connected right up to bluetooth!

 

I spent a couple days trying to get my VEMS to connect to Bluetooth only to find that there is no Bluetooth if you ask for an SD slot. Apparently, you get one or the other per Peep.

 

You can buy a separate Bluetooth adapter, and connect it to the serial connection...and switch between bluetooth and serial cable...I have the same setup.
And yes I have also have a spare VEMS in my parts box;-)