Hello,
I have a 1973.5 2.4CIS engine complete and running.

What would I have to do to add a turbo charger to the motor?

My dad seems to remember people making a block-off plate for the Air box, and running boost through it.

I have a turbo, and the means to set it up, but would like to know more about what needs to be done. If it is just blocking off the air box, and running boost through the stock system, and the CIS does all the Air/fueling, then I got it, but I'm sure that you have to play with the CIS system to keep up with boost, right?

I would love to hear some advice, and experience with these older engines and turbo charging. :)

There was someone that did this recently on the same motor.

You might try a search or start another post requesting help. You will get a lot of help.

This thread is more about how to make a 930's set up work better.

The best.

In our quest for more fuel we often ship the FD reg in increase System Pressure. At some point the fuel pumps may become the limiting factor.

Here is a link to spec on different pumps that might be used to support such a strategy.

http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/522178-cis-fuel-pump-options-more-fuel.html#post5134395

Perfect CIS AFR's and programmable Boost control by RPM at a modest price see this thread:

http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/482246-electronic-cis-fueling-boost-control.html

This has so much potential to transform a CIS 930 using a special AIC from Split Second Timing, Plumbing from the Andial Fueler, and a boost control valve from AEM.

It also has an option through the AIC to monitor RPM, manifold pressure, and several other sensors if wanted on to a PC and only costs about $320.

I believe it can even monitor any wide band O2 sensor voltage output and graph it against RPM & MAP and other sensor data.

Yup.. I saw this also...

I am 50% there. I have an HKS-AIC hooked up already in my car-7th injector plumbed into the intercooler-shooting down , working well so far-(safety). If I was to do it, i would need some help. It doesn't look that bad to do.. I just don't have the patience and the electrical part I hate. MSD6AL was a pain enough to do. My mechanic would do it...But when do i get my car back...takes his time becuz i'm on the back burner/price.

You understand we are NOT using the AIC to drive a 7th injector!

It is generally accepted that this is a bad idea on a 930.

Some have gotten away with doing so but it is believed this makes for significant variations if AFR's per cylinder.

We are using the AIC to bleed control pressure off the WUR so we can manipulate our AFR's.

From rennlist:

"It uses a unit developed by auto edge and a fuel injection engineer, I am not sure of all the ins and outs but it is a laptop programable unit with a proper fuel map that controls the pressure across the CIS I do know that supporting 600HP with this setup and CIS should be possible as we were able to get A/F into the 9's with only 75% duty all the way to redline."


My K27 HFS results - Rennlist Discussion Forums

Auto Edge - Home

Nice results!

Did u change the cams?

Black Hat,

Please see if you can get a web site address for the Whipflash Laptop programmable jetronic fuel management system your tuner used.

I had to make my own some seven years ago and now we have the D-WUR. There is one or two others including the Unichip system that can do this but this if the first time I have heard of this.

Also, how about posting your dyno results. I can not open the Rennlist info. Here is a good place: http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/521544-ultimate-930-dyno-thread.html or maybe start a thread on your car. The head lights look interesting to.

Thank you in advance if you can help.


http://forums.pelicanparts.com/uploa...1270762417.jpg

sorry all
it is not mine
I thought you might find this interesting
the tuner that developed this is in
900 Wildwood Road - Mahtomedi, MN. 55115.
voice (651)777-6924 - fax (651)777-6281

here is the site
Auto Edge - Home

link to car build
Project Cars

Hi Guys this is my Car.
The unit is actually mfg by the shop.
We have since the last run added a boost controller to the unit and now runs 1 bar and 415 WHP, 11.5-11.8 across the map.
Mods are k27 HFS, whipflash cis, fab speed headers, fabspeed cat bypass,web 964 na cams, regeared box, removed air pump, an a bunch of unrelated stuff.
http://forums.pelicanparts.com/uploa...1270814315.jpg

here are a couple of pics
http://forums.pelicanparts.com/uploa...1270814820.jpg
http://forums.pelicanparts.com/uploa...1270814834.jpg
http://forums.pelicanparts.com/uploa...1270814846.jpg
http://forums.pelicanparts.com/uploa...1270814857.jpg
http://forums.pelicanparts.com/uploa...1270814872.jpg
http://forums.pelicanparts.com/uploa...1270814884.jpg

Very, very nice.

Do you know if the boost controller is built into the fueler and mappable by rpm?

Dose it use the O2 input?

Did they have the Fuel Distributor (fuel head) worked for more fuel?

Jonty,

You and your turner look to have built about the perfect CIS C2 turbo. I had a 91 C2turbo with all the same goodies except for the larger turbo. I had a larger core in my intercooler. I also did a mappable fueler to control the AFR's perfectly.

However, I really wished I could have re-geared the trany for a closer ratio 2-5 gear set to raise the average HP per gear and keep in on cam.

Your combo of build and transmission suggests you know your stuff or have found a rare tuner that really knows what he is doing with these old CIS cars.

I am not often impressed but well done!!! :D

Thanks, the boost controller is stand alone, no rework on the cis head as it isn't necessary, no O2 input but I do have AEM xwifi unit with a wide band and a EGT on each bank which works very well.
I had wanted 420 to the wheels and a close ration box, which I now have and will enjoy :)

Keith, do you remember what the system pressure was in your car?

Sorry I do not. It was converted to a euro Fuel Dist and lines before I got it and assunm SP was stock euro non lambda.

Just played with the control pressures.

Hey guys, I have an idea, maybe has been discussed before but, at least I have not seen it. CIS was an advancement in it's time but obviously it is not close to ideal. We are constantly thinking about alternatives to make it as close to ideal (comparative to a modern EFI).

My opinion is that there are too many variables that operate at a mechanical level which are difficult to manipultate, MP, WUR, FD, low chamber pressure, high chamber pressure, etc.... Like any formula, you change one variable and all the others are affected.

The real option is EFI....but I, like many others do not want to move away from the CIS, be it cost, originality, the challenge of making it work at high HP, among others.

Well my idea is eliminate all the variables..take away the WUR and MP (along with its pivot arm) and put a single injector EFI by keeping the FD with the mixture pin stuck open and just work as a fuel distribution block and controlling the fuel rate with a single 500 lb/min injector (Precision Turbo Domestic Performance Fuel Injector Top Feed - Double O-Ring: No Limit Motorsport). Just about any ECU out there from Megasquirt to MOTEC will be able to control this, may be able to get away with just using a split second injector controller but have not done the entire research. This would be as close as we could get with controlling fuel without moving to individual injection Electronic fuel injection and keep a stock looking engine bay.

Interesting.

Thought of this before but I did not know there was a single injector that would supply enough fuel. My thought was to use a bank of injectors.

The next question becomes if the EFI injector can handle the pressure it will have to operate at to make this work.

EFI injectors vary how much fuel they deliver by increasing there frequency (with rpm) and duty cycle.

CIS injectors can only vary there delivery quantity with changes in there supply pressure.

In EFI terms, it would be like they only come in one size and they can only operate at a 100% duty cycle so we have to vary fuel pressure to control how much fuel they deliver.

Thus, lets say you operate the EFI injector at say 60 psi at 1 bar boost at 100% duty cycle the CIS injectors become a restriction and might only deliver about 50% of the fuel intended.

Saying it another way to get enough fuel past the CIS injectors at WOT to support 400+ HP you will probably have to operate at something like 80-100psi.

If so, we probably only need a about a 300# injector but it needs to be able to operate at up the the system pressure the Fuel Distributor is used to working at.

Still, it seems to have potential if the right high pressure injector can be found.

The savings is in not having to re-plumb the whole car. You will still probably want most the sensors of a simple MAP EFI system. Still, a simple kit could probably be under $2k and take a week end to install.

Any takers? :D

ps: I sent them an email requesting the operating pressures it is rated for and if it can work at 100psi.

911st, I am in...I have used the MegaSquirt before and have some overall knowledge plus I love this stuff. I was thinking that instead of having the injector inject fuel, use it to return fuel to the tank instead to effectively control the system's pressure. I think this way the injector will work less at top rpm hence maintaining a a more steady pressure where we want it most and also avoid possible fuel delivery delays. Also thought about a Speed density setup to avoid a MAF.

What ever you need I am here to support this initiative.

Interesting thought!

Thinking out loud, I wonder if changes in system pressure can effect fuel delivery enough to give us the control we need.

If so this would be a simple plumbing job.

There are a couple of other ways we might approach this.

Another thought might be to put a spring under the control plunger pushing toward full open and use a frequency valve plumbed in place of the WUR to move the control plunger's position. At a low duty cycle pressure would build pressure above the control plunger and push it down, high duty cycle would let it rise.

Or as you noted before to use an injector to meter fuel instead of the control plungers position against the metering slits. This would probably be the most controllable and accurate.

Then the question is how do we get the injectors fuel to the upper chamber?

Or, how about a custom distribution block that replaces the Fuel Distributor totally and holds the injector.

Not sure about this as part of what the FD dose is equalize fuel delivery to each cylinder. Basically every injector supply has its own regulator built in that I think is self compensating for changes in fuel or system pressure. (why I am not sure controlling system pressure will work.)

Now, depending on the approach, will we still be living withing the same gross fuel deliver potential. That is if a stock FD and modified WUR can support say 450chp, will that be our limit and is that ok?

ps, I have been trading email as to if the injector you noted will work at near 100psi sustained.

Hello,
I seem to remember on my 300CE Benz, that the additional plate picture provided by another person(silver disc) was actually at the BOTTOM of the flat plate, which I found odd, but then it made sense as to smooth out the flow, instead of creating more vortices's/turbulence.

Aerodynamics is a very tricky, black art...glad someone else is thinking of this as well...would like to hear or see some results.

:D

911st, I think we are very much in synch, although I never thought of the spring under the plunger option and replace the WUR with an injector to manipulate the control pressure, I think the theory on this one is very clear and doable. We just have to make sure the plunger does not stay open when the car is shutdown. But this can be achieved pretty easily letting the pump run for a few seconds after shutdown to build up pressure that will overcome the spring. I have a 911 Carrera 3.0 I can use as the guinea pig before plunging into the turbo 3.6.

On the other hand, I need more details on the inner workings of the FD. I am craving CIS K-Jetronic info and have been reading all over the internet. I am gonna try and get a CIS system from a Junkyard for experimenting.

Back to your spring under the plunger idea, this does achieve getting rid of the metering plate and have a single point of control, the big fuel injector which combined with an ECU and the other signals (TPS, MAP, etc) should do the trick.

Update: http://www.porsche928forums.com/download/manuals/CISRebuild.pdf, all credit to it's author Richard Andrade. This certainly confirms your concerns on controlling fuel with simple plumbing and pressure, the FD is a little monster. I have yet to understand the function of the diaphragm and springs for every injection port. I will figure it out, unless someone already knows the answer and chimes in before I do :-).

I suspect one of the things the FD dose is compensate for the fuel pump should it go out of spec and even system pressure if it goes out of spec. That is the AFR's will be maintained to the best of its abilities. It is the upper lower chamber differential that determins how much fuel is delivered not system pressure.

I think raising and lowering system pressure might only effect things at the highest delivery rates. That is, if system pressure is down to 80psi, it might have solid AFR's until say 300hp and then go lean. But if you move SP to say 100psi it might deliver fuel just fine up to 400hp or such. (Not to be comfused with the metering plate stall at higher air flow.)


The spring idea could be with removing the metering plate and installing a spring on the lever, or removing the lever to and putting it right under the control plunger. This would push the control plunger it toward WOT delivery.

I to wondered about shut down. However on EFI when the injectors close, fuel pressure is maintained in the fuel rail so the residual pressure should ( I hope) keep the CP in the idle position.

The check valves at the injectors will retain pressure there. On top of that there is a dampener that helps keep the CIS ready.

I am just not sure how accurately we can move the CP up and down. Can we maintain a 14/1 AFR at idle. Move it for accell fuel and hold it at cruse without something without a feed back loop or reference system that knows the position of the CP at all times.

Changes in control pressure against the metering arm seems to be accurate enough to maintain constant AFR's w/o a feed back or reference circuit.

This also would not require much of a frequency valve or injector. We might just use a normal Lambda Frequency Valve or source an Andial FV. It could also operate at about the same pressures as the WUR or higher if we need more fedility or response time.

Also, a Lambda style CIS might work will as it will fine tune the AFR's at idle and cruse. The EFI might even take control of this for fine tuning and or accelation fueling.

I am out of town until Monday on a golf holiday. When I get back I have the 91 Turbo technical guide with pictures and description of the CIS I might be able to share.

Will give this all some more though.

Regarding the possible choices of FV, I'm interested in trying this - but how best to adapt an injector designed with a fuel rail top fitting and a manifold port below to a hose connector both ends instead?

What kind of pressures would this FV be seeing? If I'm understanding this correctly, I realise that the return bleed on the bottom isn't as high pressure as the supply/inlet side - but is that inlet getting CIS system pressure?

There's some older FI injectors with hose barbs on the top - but they aren't designed for 6.0 bar. And almost all the high-capacity injectors are of a more modern design.

The inlet is seeing System Pressure. Just before the fuel return on the FD there is basically a fuel pressure reg built in. Every thing between the fuel pump and there should be at system pressure or SP less the upper lower differential. The exception being the control pressure exit port on the top of the FD. I believe.

If you use a standard style injector probably have to make a manifold for it and it might hold the injector kind of like a D cell battery.

There are several Frequency Valves including the one Porsche used on the Lambda style FD's that have hose fittings on them. See post #73 on page 4 of this thread of a FV that I sourced from Andial for my programmable fueler.

As to what pressure it would see it depends on if it is on the system pressure side or for moving the control plunger up and down. And with that it depends on the spring tension we use.

OK, the vendor for that large EFI injector emailed me it would function at a steady 100psi if needed.

Cool!

I found a fitting which seems to go at least part of the way towards adapting a stock injector to provide hose end fittings http://www.electromotive-inc.com/efi_parts.html (Fuel Injector Boss, Cap and Assembly, at the bottom of the page).

Might be able to use the supply side fitting on the injection side instead of using the manifold bung as the O rings seem the same size.

http://forums.pelicanparts.com/uploa...1285124741.gif

Then the question is how are we going to get fuel in to the upper chamber via the injector?

One path is through the metering slots?

One way would be to come in from the top of the Fuel Distributor. However this would probably require modifying the F D with a larger hole in from where the Control pressure fitting goes. And modifying the control plunger so fuel could get down from the top

Another way would be to come in from the bottom of the FD via a replacement for the Control Plunger that blocks the lower chamber supply source and leaves an open path to the upper metering slots. This might be more of a bolt on and not require taking the FD apart. It would require a fitting to enter the metering housing. Could bring it in the arm pivot.

I am thinking we cold make a fitting that replaces the control pin, and has O rings on it to seal off the lower chamber supply and deliver fuel to the upper chamber.

What would really be cool is if we could hide/house the injector inside the metering housing.

http://forums.pelicanparts.com/uploa...1236365567.jpg

I got it, we remove the control plunger, use the lower chamber's system pressure to supply down the control plungers hole, to the injector, put the injector in the bottom of the metering housing, and feed the upper chamber up the center of the fitting we replaced the control plunger with.

Simple, no external supply fittings or clues except a couple of wires going in side of the back of the metering housing.

To cool!!!

So you are saying, connect the bottom of the FD with plunger removed to the input of the injector and the output of the injector to the top of the FD? Could you explain a little deeper I think I may not be getting it right. The control pressure is controlled by the FD integrated pressure regulator? Without the plunger, there would be no upper and lower pressure and the pressure would be equalized. Is this then exploring the path of controlling the overall pressure of the system rather than pressure differential? Sorry I was away...was on a trip..I am very interested in a solution like this.

I still think there is some merit in removing the whole air flap and arm, then controlling the plunger directly with a stepper motor, actuator, servo, or some device that will give direct control over the plunger. It could be hidden in the housing. Then you could remove the WUR, start injector and various other components.

The way the FD works is Supply Pressure enters at the bottom of the control plunger area, goes up its side and as the metering slits are uncovered flows into the upper chamber.

We would have to remove the control plunger and replace is with a manifold that slips up into the FD. It would have two sections sealed off with O rings. One would seal above and below the supply ports. The other section would be to the area above the supply ports to the metering slits/ports.

Fuel would come down the manifold to supply the injector. Then be returned up the center of the manifold to the metering slit port area.

Said manifold would have to be sealed off above the metering ports to cap off the control pressure circuit that is tied in to the bottom chamber.

Thus, the manifold that would occupy the space of the Control Plunger would have three O ring seals. Bottom, mid, top with two passages. One to the bottom half to acces SP and one to the upper half to feed the upper chamber.

It might be easyer to just make a simple manfold that just blocks the lower ports and get fuel off the supply conection.

Stepper Motor.

Yes, this is workable and it could be concealed inside the metering housing. We just need to replace the control plunger valveing with some other type of valving.

Both approaches would probably remove the metering plate, arm and the WUR. If one wanted they could just leave the WUR in place even if it is not functional.

It just seems that it is easyer to adapt almost any EFI driver to run an Injector / Frequency Valve based system.

Which ever is used we do have less air flow restriction and better tailoring and adapting of fuel and ignition to varying operating conditions. We would get much of the benefits of an EFI conversion except maybe expanded gross fueling without all the heavy plumbing modification and a bit less electrical work.

Ok, I am inclined to work on the servo motor, I think it will provide more control than the frequency valve. I think the frequency valve will be a lot more challenging to get it to work within acceptable margin of error in an open loop mode. Obviously, this is just speculation, I have not done any scientific process to prove this. Just that the stepper motor will not violate the original CIS design in terms of how the pressure differential is controlled (plunger). I have started doing research with the designs used for fly by wire throttle body control. There is readily available documentation of people using PIC microcontrollers for a to d conversion and using a PWM signal which is probably the logical signal to use from the EFI ECU.

The stepper motor system could work very well.

To me the challenge is on the software side and finding a suitable driver. There are systems that will drive a steeper motor but I suspect not for the application planed. I could be wrong on this but looking into this might be a good next steep.

With a Frequency Valve we can probably use a normal EFI system. w/o modification.

Pull the WUR and block off the CP to the fuel head so the plunger has the most freedom (least resistance) to move. Remove the arm and plate, then drill and tap the bottom of the plunger for connection to the stepper. Then build a mount for the stepper. That would be the cheapest approach.

Now all you need is the stepper motor and the control electronics. Something open source like MegaSquirt could be adapted with a change in the source code. And it already has the basic input devices covered like MAP, IAT, RPM. We need an EE to step in!

I've had this rolling through my head for years, just never did anything with it, and don't have the EE skills to dig deep into the MegaSquirt.

My thoughts exactly, keep it as original as possible, but change the control elements slightly.

That was my next thought, to keep things simple, just build an outboard stepper motor driver that accepts the PWM signal from the ECU. If all works well, then implement the stepper motor driver internal to the ECU.

FWIW I built a MegaSquirt I and play with it using the STIM and my o-scope. Haven't done anything else with it. I might be tempted to donate it to the cause.;)

Here's a good source for all things MegaSquirt:

DIYAutoTune.com Megasquirt Kits / Assembled Engine Management Systems, Wideband o2 Sensor Systems and tuning products