Anyone here presently running CIS and logging afr, rpm, map (boost and vacuum), and cp. What is the max control pressures you've seen.

I am in the process of putting my hardware together to log afr, rpm, map and cp. I am using the LM1,
LMA2, Bosch wideband O2, 3 Bar GM Map (boost / Vacuum), 0-100 psi pressure sensor, RPM converter, and a LED display that displays vacuum in negative numbers and transitions to positve numbers for boost. I'm installing the LM1 permantly and will use LogWorks to map the data through my laptop. I,m interested in logging timing advance and retard also. Has anyone logged timing with the LM1?
Cole

Cole are you talking system pressure? If so that can be shimmed to about 110psi, maybe more.

Brian, I am rusty but I am not sure that bumping system pressure dose anything. It is the differential pressure that effects fuel deliver quantity. The CIS fuel head is a very elegant fuel pressure regulator. It self compensates for variances in any thing in the fuel system that may effect fuel flow at the injectors like a Fuel Pump thats pressure might vary depending on age or how cold it is our. Thus, bump system pressure and I believe the head self compensates and still delivers the expected fuel quantity. Change the tension of the internal springs around the internal orifices to effect the differential upper lower head pressures and you change the delivery quantity. Again, I am rusty on the fine details.

I believe they are talking about Control Pressure as set by the WUR that determines the movement of the metering plate/arm/pin.

Cole, high CP is off boost, low CP is on boost. Do you want to know how high CP goes, how low it goes, or both. These are both easyly tested at rest. You might be talking about the Digital WUR ranges. Sorry if this is not helpfull.

It would not be difficult to add a pressure sensor on the fuel head for an output to track CP of one wanted to. I put a VDO pressure gage on my head that stayed there full time.

:)

I did bump the pressure up in the thread below and it defo gave me more fuel up top!!...see link....second batch of pictures

http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/379783-digital-wur-27.html

stup.

I went back and looked at your snaps. Great info but did not know how to conclude that you may have more fuel after the adjustment.

It looked like you did some tunning after you shimmed the system pressure which would make the two sets of screens uncompilable I would think. Plus, the cross section's where at different RPM points.

Again, I am just not understanding the comparison.

If you have a before and after with the only change being the shim I would love to see.

Or, tell me what you see that lets you conclude it effected your AFR's. Did you find that at near redline with the same on boost control pressures you saw .5 lower AFR or somthing like that after the change?

I think, rasine the system pressure raises both upper and lower head pressures in a way they cancels out said change and thus deliver the same fuel quantity. But that is just an opinion and I could be wrong. It has been about 6 years sense I looked at that. I just remember when I did, I concluded it was not viable.

:)

System Pressure I think is the hurdle pressure the fuel pumps have to achiave for the fuel head to be sure it has enough fuel to operate correctly.

Increase this to much and the fuel pumps might not have the ability to support it.

If the fuel pumps can not deliver at a pressure above the system pressure setting, no fuel will blead off out of the valve you have shimed and then go back to the fuel tank.

I could be wrong. :)

You are right about the differential presssure being controlled within 0.1psi or so by the internal springs in the fuel head and remaining relatively independent of this system pressure value. Theory is that you are controlling flow WITH ONLY ONE VARIABLE THAT BEING ONLY by opening more area in the slits for the fuel to flow thu, eliminating flow changes due to any pressure differential that would arise without the internal springs. The CP does control the amount of travel on the plunger and thus fuel delivery. It is independently controlled of system pressure by the WUR. However, with higher system pressure I think the fuel injectors operate at higher overall pressure and thus flow more fuel. I am not sure but from what I have seen of exploded views of the Fuel head, this is how it seems to work.

I like what your doing. Very logical approach in a very organized test procedure. I am definitey interested in purchasingone of these spun plates, I just wonder how the profile of the plate will be developed? Someone mentioned a direct copy of the original which is a good starting point, but I wonder if a wedge or other profile is better?
Dyno testing or something that measures A/F control is a must.

With nothing else changed, adding shims to raise system pressure makes things run richer and removing shims to lower it leans things out across all rpms.

You can compensate the midrange and idle with the adjustable WUR, but lowering the system pressure will lean out the top end and the analog adjustable WUR can't compensate for that.

I know- I've tried it, and thats my experience.

I have Brian Leask's adjustable WUR, and the modified IA fuel head I have wants to run at 97psi system pressure. Any less and it will go leaner than 12.5:1 at 6000+ rpm.
Unfortunately whern at 97psi system pressure it goes to 10:1 or richer in the mid range even with the boost line disconnected.

CIS... it just plain sucks for anything other than a totally stock car or lightly modified car... Even then it's a compromise and never should have gone into production in my opinion since they already had L-Jetronic that was light years superior.
And the even earlier D-jetronic could be made into a very high performance system easily because it used no airflow meter to choke the motor of air.

whatever... it all came down to the american market and the EPA emissions mandates that ruined everything performance oriented.

Brian,

I want to monitor real time control pressure at the WUR and I will have a stand
alone system pressure gauge (like the one unwired offers for control pressure) in the engine compartment

Keith,

I wanted to know max. cp's so I can select a gauge that allows me to scale it for the best resolution.

Fred,

The velocity plate I have is the original and has the profile that was originally used
and that's the plate we will have tested. The profile of the plate was developed by Bosch and Mercedes on Mercedes CSI's. If it does pan out I will make sure it's available to anyone that is interested. I will make sure nobody gets ripped off on price.

I want to be able to tune my 930 as well as possible by myself. It's my passion and I enjoy doing my own work. I do not have a lot of money so I try to make sure I'm not going off on some tangent that is just another fad or sham and has no practical benefit.

I have picked specific objectives for the car. Maximize the cars potential with
affordable bolt on parts. And secondly; do it in a manner that does not destroy the engine.

I had to do a top end so I did install sc cams, while doing the heads we did some light smoothing. I added headers and a different turbo, larger IC, MSD, short gears, fuel head air mod, 964 bov, and I have a DWUR comming.

I investigated what will break the engine. Too much boost, overreving, detonation. The first two are easy a boost controller maxed at 1 bar with the engine updates to support 1 bar and a 6500 rpm chip in the MSD. The last and most important detonation. Poor fuel, lean afr's, temprature, big boost, timing, and
no control over those variables will kill you. Enter the LM1.

If you can real time map AFR's, Map, Temp, CP, RPM, and Timing you can control detenation and optomize power. AND REALLY HAVE A LOT OF FUN DOING IT !!!!!!

Cole

Found a reference on line also that seems to support that bumping System Pressure effects fuel at all points as you have found.

If we can fix the issue with the metering plate stalling out by doing the Rensport Systems metering arm pin relocation and or by adding windage to the top of the meteringg plate, it will not begin to stall untill the metering pin reaches fuell travel.

This will flatten the AFR curve which is important to make the stock head support more hp and to tame heads that have been adjusted for increased fuel. I like the ease of the substitute MP but suspect the RS/pivot has merit because it not only helps the pin reach full travel but also improves the rate the pin slows with changes in the metering arm angles relative to the pin (ie, flatter AFR curve).

Once this happens, one could readjust the WUR so modified heads can work properly. If a head delivers 15% more fuel every where we need to increase CP so the meteringg plate advances 15% less with ingresses in air flow. Same thing with CP on boost.

With out a method to keep the AFR's flatter this dose not work because the fuel flow would normal stall out and some of the increased fuel deliver capacity will not be achieved. I know because we tryed this with the first head that we had rebuilt for increased fuel flow that later became the IA head. We came up with the RPM boost clamp as a work around.

I believe it is possible to get one point better AFR out of the stock head because I have done so by dramatically reducing CP on boost using my own fueler based on the Andial fueler. With a flater AFR curve we can also the modified heads to work to near factory levels with out using electronics or a RPM boost clamp to delay enrichment.

Think about what the factory would do to support 450rwhp. They would probably change the cone around the metering plate to change the rate of advancment and ensure full range, change the WUR settings, and set up the head fo flow more fuel. ( Porsche changed the fuel pressure reg to a higher setting when they went from the Carrera 3.2 to 3.6 and reprogramed the CPR. Same thing.)

:)

Cole,

The Andial fueler is belived to have come from AMG.

Back then I do not think they were yet absorbed by Mercedes but almost the same thing as the MP.

:)

Cole, you mean a gage like this :


http://forums.pelicanparts.com/uploa...1236737223.jpg

911ST, what is your name, it escapes me.
The system pressure needs to be raised to 95-100psi for applications at or above 400whp in order to assure correct AFR at top end. This adjustment is also part of what allows the possibility of accurate full range AFRs without the use of the RPM switch. The flow rate over the entire range of function is increased to a level that will facilitate adjustability outside of normal parameters.

Brian,

Exactly !!!!!! some how I knew you would have one.

Cole

Agreed and accepted as to flowing more fuel.

An inexpensive HF head mod is seems.

Seems to add more fuel everywhere from what I am learning. Thus, should require recalibration of the WUR to work properly or AFR's between idle and redline WOT will be exaggerated.

If you get 10% more fuel every where you can readjust idle CO but need to slow the advancement of the metering plate about 10% for correction. Or do things like the RPM bost clamp I guess.

However, why not just access the fuel the stock head makes with an Andial fueler or using the reprofiled fuel plate first to retain more civil fuel delivery.

Of course, the Digital WUR can tame all bad behaver inherent in jacking the fuel deliver of the fuel head.

So many options. That is a good thing.

Keith ;)

How may ways can we deliver more fuel on a CIS system, let us count the ways:

Readjust the fuel head (IA or shim the head system pressure).

Increase flow of stock fuel head by adding windage to the top of the metering plate.

Increase flow of stock head by reprofiling and extending the cone that the metering plate rides in.

Increase flow of stock head by relocating the metering arm pivot (Steve W. Renn Sport mod).

Lower on boost control pressure using the Andial fueler or Digital WUR.

Lower on boost control pressure by using a 3.6 WUR or readjusting the stock WUR.

:)

Us a fuel head from a V8 and plumb on or two of the extra injectors in as an additional injector (s).

Add an additional EFI fuel injector. (Not recommended unless driven at 100% duty cycle or uneven fuel distribution per cylinder.

Keith, the core of the issue is to allow the complete system to utilize 100% of it's capacity.
Full travel of the fuel head piston and full adjustment of flow are what it boils down to. We concentrated on flow on the 400whp engine by adding a modded (out of spec) fuel head along with shimming. Result was 12.0-12.2 AFR at peak HP with good idle and fuel mileage above 20mpg on freeway.

keith...as we have now all confirmed,on one of my first runs i could not go near max rpms because i had a shortage of fuel,i shimmed head by 0.5 mm and then i had more than enough fuel up top.

Understood. But what did it do to the rest of the AFR curve?

If you got a full point at 6000rpm, you might have gotten another half point in the mid range.

Brian,

How did you ensure fuel travel of the metering piston? I suspect this and re-tuning the WUR with higer CP's is the key to getting this to work correctly but I am not seeing any evidence of this here. Relocating the metering pin like Steve W dose or using the high profile metering plate should be the better ways to do this. Lower control pressure (Andial or adjustable WUR) is another but that dose not seem to deliver 100% travel of the metering pin.

Otherwise the AFR curve usually goes very fat with boost onset. That leads to having to do the boost clamp to delay enrichment. It works but not a factory style nor the best solution.

:)

We did nothing with piston travel. Messing with the plate lever geometry looks tricky at best. Fuel volume was increased using an (over) adjusted head and shimming the fuel port.

Where can someone get some of these shims for trying to raise system pressure himself? This is something along with the metering cone that I see inmy future.
Like Cole alluded to, I am a working slob that eats spaghettios to support my turbo habit. I do all my own work and want bolt on as much as possible to make the mods I have installed already work better.
I do not have the cash for the digital WUR, and apparently it aint ready for release yet (am I wrong?) as I think this digital control is the most elegant solution in regards to tuning. However, playing with shims and the MP cone that he will produce possibly is an easy and inexpensive try to get started.
I plan to start tuning with LM-1 soon as well after I can figure out how to hook it all up. Still trying to figure where to tap an rpm signal off for the aux box.

Mr. Fred

Looks like the DWUR newest rev. is coming out mid April as posted here.

I ordered mine. I'm ether selling my dog or trying to convince my insurance
company the DWUR is a new improved defibrillator replacement.

You should be able t get a tach signal from the back of the tach or from the
CD connector. Go to the innovate motorsports forum and do a search. Good Forum lots of help there.

Cole

I forgot one.

Jack the duty cycle of the Lambda system on the later USA 930.

Cole930:
You can use the new Zeitronix 150psi pressure sensor to datalog
your fuel pressure for example.
Depending on your WBO2 system, you only need a 0-5V input.
Together with rpm, map/boost and AFR this would be usefull.


Falk

Falk.

Really appreciate your input. I'm going to take a look into it today
I'm also interested in getting some timing feedback. I think we do not
take advantage of what effect timing control can have on these engines.
It's amazing what can be done for pre boost throttle response, optimizing
torque, and preventing detonation.

Cole

Can't forget the poor injector, can we? ;)
It is also is one of the limiting factors in the quest for more HP. Contrary to popular belief, this device is not simply an orifice in which fuel is atomized. The pintel oscillates due to the way is delivered across the injector's metering valve. The number of oscillations per second and the size of the orifice determine the delivery capacity of the injector. Increasing the control pressure is going to reach a point of diminishing returns. Same principle as increasing the fuel pressure on a specific lb/hr efi injector.

http://forums.pelicanparts.com/uploa...1237040606.jpg

What you're saying sounds logical and I wonder what the differences are in Euro injectors and USA injectors other than a part number if there are actually any differences.

But, I have to say from actual experience that when I first put on the IA fuel head and adjustable WUR the boost enrichment was so insanely rich my innovate LC-1/G3 gauge went to around 9:1 AFR and the motor would completely stall out from too much fuel... It didn't buck and misfire from the over rich AFR, it completey put out the motor at around 4000rpms and the smell of unburned hydrocarbons was sickening.
...and that is with stock skinny USA fuel lines and injectors, so that tells me the CIS injectors are capable of flowing/squirting way more gas then you'll ever need unless you're running 1.5bar and race fuel at 6500rpms.

I should also say the car has new 964 cams, B&B headers and muffler, Garretson intercooler, K&N air filter, 1bar wastegate spring with a boost valve in the pressure line set at 1-1.1bar, Imagine Auto modified fuel head, Brian Leask adjustable WUR, and new Ultimate Motorwerks K27HFS turbo.. so the motor is pumping alot more air than stock.

You have the relationship of control pressure and AFR backwards... higher control pressure pushes the control plunger in the fuel head downwards covering up the metering slits and leaning out the AFR's.. anotherwords high control pressure means less fuel to the injectors.

"Oscillations" sounds like a description of an EFI injection system. With CIS, the C is for continuous. Fuel deliver is controlled by varying pressure instead of changing the duty cycle.

At some point the CIS injector could be limited by the 'system pressure ceiling. However, we seem to be a long way from that as evidenced by the fuel we can deliver by modifying the head. I have always doubted the usa or euro lines or injectors as being a limiting factor. If you look at the cross section of the USA lines and remember that it delivers fuel continuously, it is plenty large. As to the injector and the delivery capacity of even the stock head, I had a conversation years ago a respected tuner years ago the modified WUR's for profit (Rice Fueler). He said even after lowering on boost control pressure to get more travel of the metering pin, he could still flood the motor at WOT if he pushed the metering plate down with a long screw driver. That was on a heavily modified motor with a stock head with maybe shimming the system pressure.

I know I keep harping on this but if we can fix the operating range of the metering plate we could have access to more fuel. Instead we use work arounds like the Andial Fueler or readjusted WURs to achieve lower control pressure and still leave fuel on the table.

If we do this right, we can convert our WUR to trigger enrichment with first loss of vacuum instead of with .5 bar of boost. This would give us access to preboost acceleration fuel along with reduced effort to get the MP moving for less lag. On cruse / vacuum the MP would be pulled back into an economy range.

:)

I'd like to try or make my B.L. adjustable stock 1987 930 WUR work with vacuum sensing to lower control pressure right away when you open the throttle like you've been saying...
I don't think hooking a vacuum line from the intake manifold to the vent line on top will do that on mine though. If you think it will please say so, but I think it's an older design WUR from the late seventies that works this way. Do you know the part number of a WUR that works this way?
Here's an upside down pic of my WUR showing the numbers on it. Do you know if this one can do the vacuum sensing if I hook a manifold vacuum line to the vent hose fitting?
http://forums.pelicanparts.com/uploa...1237047372.jpg

If I'm cruising at 20 -30 mph, and I lightly or heavily step on the gas my AFR gauge actually goes from 14:1 to somewhere around 15.5: 1 or even leaner at first, and then after second or two it goes to around 13:1 and then the car slowly starts accelerating. I know there's lots of room for improvement there...

I recently bought a used black euro fuel head that sat on a shelf for years. I'm going to eventually install it and do the 6 seperate plastic bottles on the injector lines to flush it out and check/adjust the individual flow adjusters if they need it.

I think a digital WUR would probably fix all the over rich midrange AFR problems I'm having while flowing plenty of fuel for 6500rpms under boost, I just want to wait for them to upgrade or evolve it some more before spending the $ on it.

thanks.
Jim

"Oscillations" are the pintels of injector opening and closing. If you put a stethoscope on the injector, you will hear a high frequency sound of the pintels opening and closing. This pintel oscillation is what creates the spray pattern. With no oscillation, all you get is a stream. The "C" in CIS is for Continuous injection, meaning the injector is spraying for the entire 720* cycle engine operation. As you already know, EFI injectors operate only during the induction cycle.
Here is a link to the Bosch K-Jetronic theory of application manual.

Bosch K-Jetronic link

I think the CIS injector pintle only chatters between open and closed when it first starts to open and maybe at idle. During acceleration and at speed there is so much more fuel going through the pintle that it is held open by pressure and flow continuosly.
If it was chattering all the time then the fuel system pressure regulator in the head would also probably chatter open and closed all the time.
You can hear the pressure regulator in the fuel head sqweek a little as it chatters and equalizes against the fuel accumulator when first turning on the fuel pumps, if the engine is off and silent so you can hear it.

A garden hose nozzle makes it's conical spray pattern in exactly the same fashion as a CIS injector, and the adjustable pintle position in a garden hose nozzle is stationary while doing it.
A CIS injector may chatter open and closed a little at idle speed, but I'm sure it is open fully at higher speeds.

JFairman:
I have the same problem you described with the IA head and BL WUR. This is the advanced tuning part, I suppose. We have plenty of fuel delivery. Although I have SC CIS, it is the same as 930, more or less. I believe the WUR sees boost pressure on one side of the diaphram, and reference pressure on the top fitting, with reference being atmospheric in the photo of your WUR. Brian Leask's RPM solenoid switch cuts the boost signal to the WUR until a pre-determined RPM. Of course, where we get boost signal pressure from is another variable. You will get different signals from locations either before or after the throttle plate. I have had some discussions with BL regarding this, and I will have to find my notes. I think if you were to connect vacuum to reference, it would make the WUR believe it was under boost, as it would want to pull up on the top of the diaphragm, as opposed to bosst, pushing up on the bottom of the diaphragm.

I know, it seems that high intake manifold vacuum during deceleration would make things go way rich if you hooked it up that way...

I guess I could put a long vacuum line on the top air vent port on my WUR and hook it up to a mighty vac and watch my AFR gauge... and see what happens.

This is some dyno stuff before I put in the RPM solenoid switch. I think I was running a nominal setup on the BL WUR, which were way too rich. Also, it was before I installed the Tial wastegate, which works a lot better than my old one did.

Here is what I have found: I can get a really good street setup, but it will run like crap at the track. Conversely, I can get a good track setup that runs like crap on the street. That is the rub, the constant futzing around with the setup. Arrgh!

I am thinking about finding a 930 CIS setup and putting that on the car (I am also thinking PMO and Mod-S cams too, just to avoid the futzing, but I sure would miss the boost!)

http://forums.pelicanparts.com/uploa...1237055951.jpg

RPM solenoid switch removes the big valley from the AFR curve. Control pressure and boost pressure adjustments basically move the curve up or down on the vertical axis. The actual shape of the AFR curve pretty much stays the same, with the steep slope going towards lean as the revs increase. That is the part of the curve that is the sand in the vaseline, so to speak. The Bosch WUR tends to give a saucer shaped curve, just the nature of the beast. My setup is a bit deviated from that, because I have the only setup in the world like it, and it is a massive PITA to get it right.


BTW: here is a link to Brian Leask's WUR. You can see the WUR AFR curves on it better than in my chart.
http://members.cox.net/930wur/

Jim, I have not done the vacunm sensing mod my slef. I guy named Lee Rice was famous for this years ago and it was called the Rice Fueler. Howver, I have talked to others that have converted there WUR them selves. There is not change in how the WUR is hooked up. What I belive is done is to modify or remove the spring that has to be pushed to triger the boost enrichment. Then vacunm holds the WUR in cruse / idle mode. Then when vac is reduced or goes away the enrichment cycle is trigered.

The AFR's are a curve because the metering plate dose not advance in a liner manner with changes in air flow. Work to correct this and gain full travel and you will not need to lower CP for more fuel. There are three ways to effect this. One is to relocate the metering arm pivot so with smaller changes in the metering plate position, the pin progresses further keeping the MP more up in the cone. Another is to add volunm to the top of the metering plate so air flow dose not start spilling of the end of the plate toward the end of its travel. The third is to reenginer the cone the plate advances in. It is even possable if one wanted to go to the effort to have the AFR curve be straight or even invert to more fuel is added in upper WOT rpms instead of getting leaner, up to the flow capacaty of the head.

Euro v US head. If I had a good US head I would not change it. It is possable to buy a $330 controler to drive the Lambda valve on the head. This becomes a fueler. The duty cycle of the Lambda valve is usally kept arould 50%. You use this driver to just act as a fueler by setting it to 25% and reset you CO. Then based on load and rpm you can start increasing the duty cycle up to 75% to gain more fuel. If you do not need much more fuel, it can be used to actually tune the AFR curve taking fuel out of the fat area and putting it back up top. Cool stuf and actually kind of easy to accomplish and can give an advantage to the USA/Lambda heads. Kind of an IA on demand.

:)

Vacuum sensitive enrichment
 

On the topic of vacuum (or the lack thereof) triggering additional enrichment, I've got an idea that I can easily test out. First, some history: I've been running with an Andial system to enrich at boost (and recently modified to enrich at chosen rpm's instead). But, I just installed one of Brian Leask's adjustable WUR's and probably won't be needing the Andial anymore. But I'll leave it installed, just in case.

After reading your posts last night, my mind subconsciously worked on this all night and came up with an answer. Why not put a vacuum sensitive switch connected to a port on the intake manifold post butterfly (such as the line that goes both to the WUR and to the decel valve), said switch to have a normally open switch under vacuum....which will close in the absense of vacuum, and act as a ground to activate my Andial fueler? I had a spare pressure switch on hand and proceeded this morning to modify it to act under vacuum instead.

So, here's the deal: At idle, or at steady cruise when there is sufficient vacuum on the engine side of the throttle butterfly, the switch remains open. But as soon as you stomp on the gas and the vacuum goes away, the switch closes and activates the Andial fueler to richen things up. Of course this would lower the CP across the entire range while accelerating as well as on boost, so a person would have to dial back the WUR boost enrichment so as not to over enrich when on full boost.

Does this follow the logic of what you're trying to do...get more fuel at the onset of acceleration to improve torque and response?

You do not want the Andial to trigger with vac or loss of manifold vac. The Andial you want to trigger upon a given boost threshold. Typically something above .9 bar as the factory system often has enough fuel for such. If anything, adding a RPM delay switch to the Andial is more what would be of benefit.

Keeping a stock WUR and adding an Andial with a rpm delay gives two steps of enrichment.

A modified WUR with a rpm clamp gives you one step in enrichment. This works with a modified fuel head as it goes rich on its own.

Both systems should be capable of the same total fuel but the advantage goes to the Andial because of its tunability and it might even be able to achieve a lower CP.

Again, I replaced the Andial controller with a vac/boost (load) by rpm and was able to get near idle AFR's. 14's at idle and cruse, instant 13 on accel from idle or cruse, and 12/1 on boost to red-line. (Split Second AIC-1 with internal oscillator.)

Having send the new UltWUR, that should achieve the same thing in a more user friendly way.

:)

Yep, I understand all your points I have a couple options to choose from...keep the stock WUR and my "stock" rpm-triggered Andial, or my adjustable WUR with the rpm clamp. I have both ready to go.

But back to my original point...I'm not taking about using the Andial as it's originally designed for boost enrichment. Rather, it can be setup to react to loss of vacuum, for anyone who chooses to do so for early enrichment. It's just an option, vs. trying to get a WUR to react to vacuum, which is opposite and contrary to it's design.