Conversion from Carbs to CIS to EFI, Using BITZ racing kit to convert to EFI Options

[bfrymire]

Hello everyone,

This is my thread to cover my conversion from Carbs to EFI. I will be using the Bitzracing CIS to EFI conversion kit, to replace the webers on the motor now, which is a 2.7l six. (And before anyone asks, I am not selling the carbs, yet. (IMG:style_emoticons/default/smile.gif) Want to make sure it works better before I unload the carbs.) (http://www.bitzracing.com)

Ok, I am sure someone will ask why. Well, I autocross the car every month, and drive sometimes on the street. The carbs, due to sitting, tend to gunk up and require regular maintenance, and because, I am hoping the car will idle better, and just in general be more well behaved street driving. (Hey, it may even polute less. One can hope.)

First step is to take it and have it tested on the dyno for a benchmark before any changes. (http://www.dynospotracing.com)

The kit is fairly complete with good instructions. (You have a few parts to source yourself, easy to get.)

As I go, I will provide more part numbers and details.

Here's a picture of the parts kit including parts I sourced myself.

[Dr Evil]

Thanks for chronicling this (IMG:style_emoticons/default/smile.gif) I am interested.

[shoguneagle]

Agree with the "Good Doc Evil". very interested since I have a spare 911 2.0 sixer engine without carbs setting in the garage. I prefer injection since I live at altitude and carbs are a problem when I go to sea level.

Question: Does it meet CARB (California Air Resource Board) requirements and approval?

Thanks,
Steve Hurt

[bfrymire]

Thanks for chronicling this (IMG:style_emoticons/default/smile.gif) I am interested.

Not a problem there... I was / am very interested to see which wins as far as HP and driveability.

So, I will be doing a before, initial install and tuning dyno runs. Tony is using the megasquirt and has basic maps for it. There is also a self-tuning mode with the software to get it closer without the dyno.

There seems to be mixed results. Some people report more hp than carbs, and one guy (on youtube) reported less hp. Well, I will be posting charts and doing a lot of tweaking, as I want this to work well.

-- brett

[bfrymire]

Agree with the "Good Doc Evil". very interested since I have a spare 911 2.0 sixer engine without carbs setting in the garage. I prefer injection since I live at altitude and carbs are a problem when I go to sea level.

Question: Does it meet CARB (California Air Resource Board) requirements and approval?

Thanks,
Steve Hurt

no. It's going on a 1973, so, does not need bi-annual inspection/test. If I ever need to smog it again, this will pass better than the carbs anyway. (and I do have a fall back plan, if it comes to having to smog it again. In other words, EFI is easier to convert to propane, which will classify the car as an alternate fuel vehicle and smog exempt.)

-- brett

[Gint]

Cool! What do you plan to use for induction, fuel rails, etc...? Which kit is that? What are they using in that kit for an ECU? Thier own, Megasquirt?

[wobbletop]

Subscribed. (IMG:style_emoticons/default/biggrin.gif)

[turboman808]

Why can't webers be converted to fuel injection? You can mount the injectors in a spacer between the webers and the head or mount the injectors above the webers pointing in. Seeing this setup with injectors mounted inside air filters alot lately.

Then figure a way to mount a TPS to the webers and program it up.


Wanted to switch to an AEM setup this winter but once you add it up it's gonna cost at least 3 grand. I will use the haltek for now.

[bfrymire]

Cool! What do you plan to use for induction, fuel rails, etc...? Which kit is that? What are they using in that kit for an ECU? Thier own, Megasquirt?

The kit is from Bitzracing, www.bitzracing.com, and includes everything except parts that are from normal supplies, like injectors, fuel pump and regulator. If you look in the photo, the fuel rails are wrapped in plastic. (I should have taken them out for the photo.) The ECU is a megasquirt with maps developed by Bitzracing.

Lots of details on their website. They developed it for the 911, and there isn't much for the 914 as far as specifics. Tony has been quite helpful.

-- brett

[bfrymire]

Why can't webers be converted to fuel injection? You can mount the injectors in a spacer between the webers and the head or mount the injectors above the webers pointing in. Seeing this setup with injectors mounted inside air filters alot lately.

Then figure a way to mount a TPS to the webers and program it up.


Wanted to switch to an AEM setup this winter but once you add it up it's gonna cost at least 3 grand. I will use the haltek for now.

Cost mostly. I looked for a kit that did individual throttle bodies and the it was mega bucks.

Also, the R&D has already been done and it works. I think the only way to get the webers to work, is to gut them, and just use them as throttle bodies. You could then drill and create a boss to mount the injector. Just sounds expensive.

The only real custom part on the Bitz racing kit is the fuel rails. Fairly straight forward and simple install.

-- brett

[GeorgeRud]

Yes, please continue to chronicle your progress. I also have a 2.7 with Webers that I have been thinking of converting (it should be happier with what passes for gasoline these days). I think the Bitz conversion would be a very cost effective way to get started on EFI without too much trouble.

I'm currently running an Electromotive crankfired ignition, and was hoping to be able to get both fuel and ignition control eventually. I understand the Megasquirt systems do have that capability, but not in the Bitz conversion kit (yet?).

[turboman808]

I was gonna say mount em like this but I think they only work at WOT. Makes sense since you wouldn't want to spray fuel on the butterflys I imagine.

(IMG:http://www.twminduction.com/ThrottleBody/ThrottleBody.imgs/3006_throttles_kit_lg.jpg)

[bfrymire]

Yes, please continue to chronicle your progress. I also have a 2.7 with Webers that I have been thinking of converting (it should be happier with what passes for gasoline these days). I think the Bitz conversion would be a very cost effective way to get started on EFI without too much trouble.

I'm currently running an Electromotive crankfired ignition, and was hoping to be able to get both fuel and ignition control eventually. I understand the Megasquirt systems do have that capability, but not in the Bitz conversion kit (yet?).

There are a couple of people on the yahoo groups (bitzracing) that have done the crank fire with the megasquirt. Tony doesn't support that yet. (Do a search on the yahoo groups for bitz racing.)

-- brett

[bfrymire]

I was gonna say mount em like this but I think they only work at WOT. Makes sense since you wouldn't want to spray fuel on the butterflys I imagine.

(IMG:http://www.twminduction.com/ThrottleBody/ThrottleBody.imgs/3006_throttles_kit_lg.jpg)

Wow. That looks expensive! Hum. Jake Raby just posted something along the lines of this. His contention is that for low HP motors, it doesn't make much difference where the fuel is injected. (Look for the thread on individual throttle bodies.)

I am going to be using the CIS factory setup as the starting point. So, I will be using that throttle body, and runners.

-- brett

[bfrymire]

Ok. Here's a picture in a 911 of what the finished conversion should look like. (I pulled this from Tony's site, after getting permission.) Tony also knows about this thread, and we may see some comments from him.

-- brett

[number6]

For those who didn't catch it, there was an Excellence article about this kit not too long ago. The author converted his 911 and commented on all the major steps, including tuning. I'll see if I can dig it up and at least post the issue date.

Brett, good luck with your project. Can't wait to follow your progress.

[shoguneagle]

Would appreciate at least the date of the issue and then I can go back and locate it.

Thanks
Steve Hurt

[wobbletop]

Could it be...

#167 Sep 2008
How to Add EFI to Your Early 911

[bfrymire]

Status update:

Went and did the Dyno thing today. Hum.. Not good. I knew the 914 was not running as well as it used to but...

I made about 100hp at the wheels! And it barely rev'd to 6000rpm.

Well, the baseline is a bust, but I am going to move forward with the conversion.

The reason for the poor running was due to the carbs needing cleaning/rebuilding. It appeared to be leaning out at high RPM. (I used to have no problem reaching 6800. )

Well more to come as I start the conversion.

-- brett

[rktmn247]

Progress? Very interested in this. Thanks for taking this on.