Tuning CIS -using a wideband controller

[ny_fam]

Here is a short report on a CIS upgrade I did a few months ago and it turned out very well so I figured I'd share the results.
If you Don't want to go all the way to megasquirt you can go half way - keep CIS and add computer controlled tune-ability. For less than $300 you can add a wide band controller to your CIS Lambda setup(k-jet). Then you can use your laptop to set the CIS fuel ratio(s) to find the best tune. I've found this to be the best bolt on I've done to my GTI yet. This mod really made all the other upgrades work very well.
You'll need a Innovate MTX-L with O2 sensor controller $199 from DIY Autotune(or similar PLX unit) and about $50 or so in wiring connectors and 2 auto relays. I'm not the first to do this upgrade done back in 2005 by a guy that seems to work at Innovate Motor Sports http://www.innovatemotorsports.com/f...ead.php?t=1520

http://www.diyautotune.com/catalog/i...844-p-467.html
Gauge fits perfectly in the GTI console gauge pod in place of the redundant clock.


Note where NA motors make the most power(generally speaking more compression will use more fuel). The stock GTI lambda fuel ratio tends to run around 10:1 at WOT. I have found and others confirmed that 13.2 -13.5 is where these VW NA engines make the most power. So the Stock Lamba at WOT is wasting fuel, and not making as much power as it can.

Installed

Cheers
ny_fam

[ziddey]

Am I remembering correctly that this doesn't work right for cis-e if you're to use the wot switch to switch from a stoich/lean afr to rich signal? It causes the ECU to disregard lambda for a few seconds or something like that? I wonder if actually tripping the WOT switch and bringing it to open loop for a split second while the output is changed would solve this.

I'd imagine a good mod would be to use a TPS or otherwise have the switch triggered at say half throttle to switch from lean/cruise mode to enrichment instead of at WOT.

[ny_fam]

I can't speak for CIS-e, but does work for CIS lambda. We modified our WOT switch so it is switched when the larger secondary throttle plate starts to open, so its more like you describe.

I know that others have used a similar setup for CIS-E but I don't know the details, I'm aware of CIS-E for racing applications where a WOT switch may not be used any more.

[Danger1523]

I believe I have CIS-E so I don't know how this would apply to such. How could you alter the compression ratio up without changing pistons and head etc. Thanks

[ny_fam]

There are after market head gaskets that can bump the compression a 1/2 a point.

[Road Boss]

I need to keep this in mind once I had my charger to my CIS.

[ellocolindo]

i have cis-e motronic in my 91 passat now. i am boosting it; and gather all the CIS system form a volvo 240t to use. will the volvo set-up fall in the CIS-lambda definition?

[ny_fam]

If the fuel distributor uses a frequency valve then yes.

[ellocolindo]

yes it has a frequency valve. i do not know if i will use it...

[spddemon313]

well i have a few quesitons if you all don't mind helping out a noob to engine tuning. i just got my car up and running after an extensive 3 1/2 year rebuild. i'm hoping to eventually switch to carbs so i can clean up the bay. i'll be on stock CIS-lambda for a little while though, at least until the break-in period is over for my engine.

so i've been looking at all sorts of engine tuning threads and tool and tips and these wideband controllers kee surfacing. first off, would you mind telling me how you hooked up your wideband to your car...as in which wires go where? i know one goes to a laptop for datalogging and tuning, but do the others all hook up to the O2 sensor control until under the glove box?
also, if i do end up switching to carbs, that means the entire o2 control unit is deleted, will i then just run the wires from the wideband into the passenger compartment to the gauge?

second question, what can a wideband do that a simple gauge on the stock single wire o2 sensor can't? other than instant tuning off your laptop of course.

just trying to figure out if it's worth the $209+tax+shipping to go with a wideband if this is only a daily driver...yes i want good results and performance, but this isn't a race car

thanks for reading, easy on the slams i'm new to this tunign bizz

[ny_fam]

The controller gets programmed by the laptop, then in normal operation you don't need the laptop connected. The controller will allow you to set the fuel mixture where you want, something you can't do with CIS- lambda (K-Jet).
Once your on carbs you use the wideband as just a gauge to tune the carbs.
The innovate MTX-L is both the gauge and controller in one. So you just need to find a place to mount the gauge. The wiring isn't that complex to setup, easier to install. You'll need power, ground, switched power, a 3/8" hole in firewall for wires to pass through. Send me a PM about the wiring details.
For what its worth - a properly tuned 8v on CIS should be able to make in the range of 110-120 hp, with just bolt ons and a good tune. I believe this is part of that good tune.
Cheers

[spddemon313]

The controller gets programmed by the laptop, then in normal operation you don't need the laptop connected. The controller will allow you to set the fuel mixture where you want, something you can't do with CIS- lambda (K-Jet).
Once your on carbs you use the wideband as just a gauge to tune the carbs.
The innovate MTX-L is both the gauge and controller in one. So you just need to find a place to mount the gauge. The wiring isn't that complex to setup, easier to install. You'll need power, ground, switched power, a 3/8" hole in firewall for wires to pass through. Send me a PM about the wiring details.
For what its worth - a properly tuned 8v on CIS should be able to make in the range of 110-120 hp, with just bolt ons and a good tune. I believe this is part of that good tune.
Cheers

sweet! thanks for the info. if i'm understanding correctly, the wideband will replace the current lambda sensor...does the wideband have the wire to hook into the oxygen sensor control unit like the old lambda has? certainly it must right? because you're making changes on the laptop so the engine performs differently.

last question...would you say it's worth it to get a wideband if i'm switching to carbs? if all i'm doing is reading the A/F ratio, can't a narrowband gauge on the old lambda do the same thing and save me some money? i understand that the widebanda is a much finer tuning and readout of the o2s sensor, but is it necessary?

[ny_fam]

Yes the wideband controller replaces the O2 sensor of the CIS setup, and plugs into the CIS system via the O2 connector of the K-jet computer.
The controller doesn't come with any of these connectors you'll need to make a wire harness or buy one.

Is it worth it, I think its a very worth while mod but you have to decide if its worth while for the time you'll be using CIS.

[redpig]

any literature on how it wires up

[ny_fam]

Follow the innovate link at the top of the thread or send me a PM for details.

[booested4door]

this is bad a**! the innovate link up top stopped working though. id love to read it.. def. thinkin this is a must do. notice better gas mileage?

[ny_fam]

We'll be making a the wiring harness to make this work. I may have the content from that link stored away here, We'll see if we can get some version of it back online. The Innovate forum may just be updating etc..

[booested4door]

really?! how much will that run and what will it entail? please dig this info up man!!! ill prob. be doing this as soon as i get my rabbit back......need as much info as you have please

[ny_fam]

PM sent.

[mr sarcastic]

The link to the innovate write up is dead! I'd really like to do this, anyone got a write up for it? I have my wideband and I'm ready to make it happen.

[Hummdog]

Im looking to do the same if there is an updated link, or anything similar out there.

[noizze]

I've been using the LC-1 in my cabby for about 4 years now. The ability to tweak the Lambda switch point and adjusting the transfer rate is what makes it all worthwhile for me. For those of you who are try to race an old CIS car, one of these will help you make more power.

[Mark0ne]

Sorry if this is a stupid question. So the tuning capabilities wouldn't work on a cis basic car... Right?

[nbvwfan]

Basic with out Lambda, it would not work, though on a pure basic setup, you could manipulate the heating strip in the WUR.
From what I gather in this someone is writing about sending a signal to manipulate the frequency valve duty cycle (lambda valve), in order to regulate upper to lower fuel cahmber pressure. In theory it will work, applicationally, it will take a lot of trial and error, especially if you are dealing with a boosted application.
I know because I am, although I am doing it to a CIS-E platform (K-Jetronic), with the DPR, taking the Lambda's place and enhancing it with faster and finer response.
Though applicationally, my setup is a crude hodgepodge of a Hobb switch and playing with a fixed signal to effect the DPR (future plans are a MAP and TPS). All this while using my wideband as a "window" into the running conditions so I don't melt pistons.

[ps2375]

CIS does a good job of holding the AFR that you set it to. The WB is a good way to see where the AFR is at and then adjust it. Unless you get close to the systems limits, a good functioning CIS is hard to beat for what it is.

When we swapped the 16V into the Scirocco (which had CIS-Lambda), that is what we did, as trying to feed the lambda controller the signal from the WB did nothing but make it go lean, no matter how we programmed the WB. We just disconnected the frequency valve's power and set the mixture with the 3mm allen and had solid AFR's from idle to redline.

[nbvwfan]

That is because a signal to the lambda causes a lean duty cycle, as in IIRC, opening lower chamber flow, increasing the lower chamber pressure and restricting the flow that is allowed to be metered out the upper chamber ports.
Did you try switching the voltage?
That is what I am doing on the DPR, but in that the DPR is a magnetic coil that can accept positive and negative current, the lambda cannot as it is a valve that is switched on.

[ps2375]

We had the WB set up to output a NB signal in place of the NB O2 sensor. And yes, once the Frequency valve was unplugged, the system goes lean, then you just adjust the mixture screw to set the mixture(AFR) and that is pretty much where it stayed. We did have the WUR mounted up where the battery used to be, so as not to change the system pressure and therefore the the mixture.

The Lambda system has a controller (under the dash) along with the NB sensor along with the Frequency Valve on the Fuel Distributor.

[teknikALLEN]

http://www.innovatemotorsports.com/products/MTS.php