CIS to EFI kit - Page 18

tbitz · 07-29-2004, 07:14 PM

I really don't fiddle much with the O2 switch point. I set it to run a bit rich which is the way the 911 engine seems to like to run.

There is work being done by the designers of MegaSquirt that will allow you to enter a desired O2 switch for each VE entry in the table. This way the O2 switch point will vary depending on driving load.

No inputs for EGT/CHT on MegaSquirt .

Eagledriver · 07-29-2004, 09:05 PM

I don't think you'd get much use out of an EGT on a car. I had one once when I was experimenting with an adjustable jet on a carb in my old Plymouth Valient. The only time you can use the EGT is at a steady cruise on level ground. It would give no data on accelleration or full throttle conditions since the EGT will be constantly changing during those times.

-Andy

KobaltBlau · 07-29-2004, 10:37 PM

abisel, the way to go for you might be the TWM throttle bodies that fit on weber manifolds. you could use CIS parts (intake manifolds and plenum) with Tony's kit, but if you're really going for an RSR type motor (read: cams) I think you will need individual throttle bodies.

Doug Steinel · Doug Steinel's Garage

Abisel,

exactly how could you "trick the ECU with a pot"? Would this pot vary the current sent to the ECU by the movement of a knob? I would like to rig up such a system to my Lambda CIS system. Any idea how to do it?

abisel · 07-30-2004, 07:58 AM

Quote:

Originally posted by Doug Steinel
Abisel,

exactly how could you "trick the ECU with a pot"? Would this pot vary the current sent to the ECU by the movement of a knob? I would like to rig up such a system to my Lambda CIS system. Any idea how to do it?

From what I remember from several years ago, the O2 sensor has an output voltage range of, I believe, 0.5 to 1.0 volts. This range of voltage to the ECU tells it either a rich or lean condition and the ECU compensates accordingly. By manually varying this voltage, you "trick" the ECU to thinking one thing when you want it to do another. I am not sure of the O2 voltage output voltage range or which is lean or rich. Maybe Tony could shed some light here.

magic930 · 07-30-2004, 08:10 AM

I think the voltage is 0 -1volts, unless its wide band which provides 0-5 volts.

tbitz · 07-30-2004, 09:26 AM

Yes you could do the pot idea as abisel indicates. It does defeat the "closed loop" operation though. I don't think it is required though, as you can program the VE table to whatever AFR conditions you want to begin with.

audiofilius · 10-16-2004, 03:01 AM

just think...
Lean=Low(voltage)

ohecht · 10-16-2004, 03:32 AM

I am still using CIS, but I am using the Innovate LM-1 (WBO2) to send a precise voltage based on the mixture into the lambda computer. I also used the stock CIS WOT switch to change to a 12.8 switchpoint at WOT while using a 14.7 switchpoint for all other conditions. This has made the CIS much more reliableand predictable across a wide range of engine and ambient temperature conditions. The idle and throttle response are noticeably better.

I also put CHT sensors on all 6 cylinders a few years ago, and I have noticed that cylinders 1 and 3 are running slightly hotter than the rest lately

Olivier

350HP930 · 11-21-2004, 07:16 AM

Hey guys, I just wanted to subscribe to this thread by adding that I am going the EFI route on my 930 project.

Right now I am just trying to decide if I will fab my own injector blocks or purchase some from one of the existing vendors.

tbitz · 11-21-2004, 07:57 AM

350HP930,

This is 930 EFI conversion thread Here .

Driving season is just about done here in Ottawa. I'll be parking my 911 and get cracking on the turbo addition.

RickM · RickM's Garage

Ay word on a Megasquirt version which will control ignition?

bigchillcar · bigchillcar's Garage

any word from anyone on their own installation of the kit on a 2.7? i read earlier in the thread that one was planned...
ryan

cowtown · 11-21-2004, 10:36 AM

Quote:

Originally posted by tbitz
350HP930,

This is 930 EFI conversion thread Here .

Driving season is just about done here in Ottawa. I'll be parking my 911 and get cracking on the turbo addition.

tbitz, do you mean you are going to put a MegaSquirt 930 EFI kit togther like the one you have for the NA 3.0? That would be great....

tbitz · 12:35 PM

Quote:

Originally posted by RickM
Ay word on a Megasquirt version which will control ignition?

MegaSquirt in conjuction with the stock distributor and an external HEI module can control timing for the 911. I haven't implemented that yet, but I will do so when the turbo is installed.

There is also an add on module coming soon that will plug into the existing MegaSquirt and convert it to MegaSquirt II. MegaSquirt II will have many new features like a larger VE table (12x12), Dual-tables for VE and AFR target tables, and more....

No plans right now for me to develop a 930 EFI kit.

klatinn · 11-21-2004, 05:59 PM

Hi,

FWIW, there is another DIY EFI system available:

http://www.vems-group.org/wiki/index.php

It uses a different processor, but is (tuning) software compatible with the megasquirt. It's programmed in 'C', not in assembly as megasquirt. Also does sequential injection and ignition and controls up to 8 coils for a COP setup. Substituting waste-spark coils for COP coils you can also run it with a double plugged setup.

Regards,
Klaus

swackdog · 02-21-2005, 06:47 PM

Tony,

Like may others, I think this is an excellent idea. Many of us would like to dump our CIS for a EFI system. Price range sounds good and should generate alot of interest. Also, as others have said, the more complete the kit the better. FYI -- concerning some of your competition. Pat Williams Racing in Memphis has an EFI kit for 930s and is developing a kit for NA 911s. Price is estimated at $3,500-4,000 so your pricing looks very attractive. There was an article on PWR's kit in the February issue of Excellence on p 163.

safe · safe's Garage

Has anyone used this system with hot cams like early S cams yet?

TOO RUF · TOO RUF's Garage

Let me know when the Megasquirt 2 is available. Complete unit.
Thanks

KobaltBlau · 04-04-2005, 09:44 AM

Magnus, the issue becomes the shared plenum single throttle body configuration, even with CIS->EFI, you're not much better off than a carrera 3.2 if your goal is running hot cams. this problem is mostly poor response at lower RPM (because the pulses in the shared intake are screwing everything up), is solved by individual throttle bodies like those made TWM, and can still be used with the same control system, i.e. megasquirt.