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.