CIS to EFI kit

[RickM]

Quote: "How do people feel about having to drill a hole in the pipe just before the muffler?"

Would it be more accurate if you tapped in before the cat?

[1fastredsc]

Actually, 30lbs should be plenty, that isn't all that big. Stock 951's have 33lb injectors and handle just under 300 hp before needing replacement.

[tbitz]

Would it be more accurate if you tapped in before the cat?

Absolutely. O2 must be placed on the intake side of the pipe (CAT)before the muffler.

With SSI or backdated headers there is no CAT, so no problem. In turbo applications, the O2 sensor must be after the turbo, cause readings are affected by both temperature and pressure.

Stock 951's have 33lb injectors and handle just under 300 hp before needing replacement

Are you sure they are 33lbs? If you do the math 4 injectors at 33lb/hr at 100% duty cycle only give 240Hp. Is the fuel pressure at the 3bar standard, or is it bumped up to get more flow?

Cheers,

Tony

[Wrecked944]

Tony, I'm excited to see you are "weaponizing" your EFI conversion. I wish you great success. I think it's gonna be a killer app (as we say in the software biz) which could be serious competition to PMO. I'd gladly buy one from you but my 911SC...ummm...blew up...so she is no more. So I'll have to live vicariously through you !!

[cowtown]

Originally posted by tbitz
In turbo applications, the O2 sensor must be after the turbo, cause readings are affected by both temperature and pressure.

Tony, can you clarify this? I am running an O2 sensor directly to an AFM gauge on my K-basic 930 engine (no cat). The sensor is mounted on the wastegate pipe, between the exchangers and the turbo. I think this is the factory location on later cars that use lambda.

Would be more accurate if mounted after the turbo, at the muffler, and why is this so?

Thanks,
Colin

[tbitz]

Originally posted by cowtown
Tony, can you clarify this? I am running an O2 sensor directly to an AFM gauge on my K-basic 930 engine (no cat). The sensor is mounted on the wastegate pipe, between the exchangers and the turbo. I think this is the factory location on later cars that use lambda.

Would be more accurate if mounted after the turbo, at the muffler, and why is this so?

Thanks,
Colin

Don't want this thread to become a debate on where to put O2 sensor, but, if you have it on the wastegate pipe (which is before the turbo) the O2 sensor is exposed to the back pressure caused by the turbine. This increase in pressure causes O2 readings to be off. How much? I dunno. I can't remember if higher pressure reads leaner or richer. I'd have to look it up.

Also note, stock O2 sensors only tell you your above or below stoic mixture. Don't try and interpret AFR from a stock (narrow band) O2 sensor.

[jkb157]

Tony,If you can sell as a kit for 1400.00 I buy one in a second. thanks JB




79 911 sc

[cowtown]

Originally posted by tbitz
Don't want this thread to become a debate on where to put O2 sensor, but, if you have it on the wastegate pipe (which is before the turbo) the O2 sensor is exposed to the back pressure caused by the turbine. This increase in pressure causes O2 readings to be off. How much? I dunno. I can't remember if higher pressure reads leaner or richer. I'd have to look it up.

Also note, stock O2 sensors only tell you your above or below stoic mixture. Don't try and interpret AFR from a stock (narrow band) O2 sensor.

Thanks for the reply Tony. I'm aware of the limitations of the narrowband sensor.

Just wanted to know why the placement was critical, and what you say makes sense. I'll take this into a new thread after I dig around a little.
Colin

[1fastredsc]

To tell you the truth dude, i don't remember although 3 bar (45psi) sounds low.

[Guy Chiattello]

Toney,

I too am interested in your kit. I have been reading the MS sites and am very intrigued. I am planning a turbo conversion on my 82SC. Since I have installed a C2 electric tail I have no room for a intercooler so am considering two small turbo's off of my SSI's and then running compressor output to intercoolers in rear wheel wells (will install 73 oil tank).

I will want to get rid of airbox and pick up ambient air nearer to the turbo's. My question is, can you do your MS installation with no air box? or do some kind of workaround??

Guy Chiattello
82SC Black Coupe

[Bob Goding]

Tony , good luck with the project--I followed it eagerly,as you published http://www.geocities.com/tbitz/cis_to_efi.html
Questions--did you publish anything after Feb?-- How has the car performed since you got it running.- In other words, how about an update.
Regards Bob

[diy83sc]

Tony,

I have an 80SC that want's to show me what a 3.0 can really put out! Keep me in the loop as your beta kits develop. I have another car to drive...

Tony

[tbitz]

will want to get rid of airbox and pick up ambient air nearer to the turbo's. My question is, can you do your MS installation with no air box? or do some kind of workaround??

With the CIS gone, the air no longer must flow through the CIS airflow metering plate. You can just put air filters directly on the turbos intake and feed the turbo output directly to the throttle body. You still use the stock airbox, with CIS parts removed.

How has the car performed since you got it running.- In other words, how about an update.

Car has been running all summer and fall. Runs great.

Would your system supply adequate fuel for a twin-plug setup? What about larger displacement with twin-plugging?

Based on my calculations above with 30lb/hr injectors, the system would be good to supply enough fuel for 280Hp with injectors running at 85% duty cycle. You can always go with bigger injectors if you want more power. There is a limit though, then the fuel pump, regulator, fuel lines can't cope. Also large injectors cause problems at idle.

[Zendalar]

I am building MegaSquirt currently. 60mm throttle body, intake runners from 2.7 CIS. The megasquirt will be with MegaSpark software, so the fuel injection box will also handle the ignition advance/retard. After i get this running I will install a turbo.

I will propably use 30-33lb/h injectors.

Total cost so far has been under 200$. Already have the MS box and the intake manifolds. The sensors are not very expensive.

Oh yeah, the engine is 2.4T


I think the MS is the best/cheapest way to go, it is cheap and very versatile.

[jhelgesen]

Would the stock 3.0 injectors be capable of working with the system, if the plumbing were changed? Do they have the capacity?

[Tim Walsh]

John.
From what I've seen CIS injectors work on the same principal that MFI injectors use. THey open at a certian pressure and close at that same pressure. So by varying the pressure you know when your injectors are firing. The EFI injectors are electromechanical, not opened by pressure.

I'm not 100% on that but That's my impression.

[1fastredsc]

That's true, they open when the coil in them are given current, kind of like a relay closing a connection. And as already stated, cis injectors respond to fuel pressure, not electrical pulse.

[jhelgesen]

Okay, learn something new every day

[911ctS]

Zendalar------Please keep me posted on your progress with that 2.4T motor. I also have a 2.4 in my car and i am curious how yours turns out with the FI setup, 2.7 CIS manifold, and then the turbo. Good Luck!!
Clint

[tbitz]

Guess what I've been doing over the holidays





The above parts are one of the key pieces in the CIS to EFI conversion puzzle. They allow you to simply remove the existing CIS injectors and bung and pop these in place. Then fit a standard Bosch type EFI injector in the stock CIS intake runners.

I have redesigned these parts from my original ones. These parts now feature O rings to perfectly seal the bung in the intake runner. No need to weld, or epoxy these in place. Just push them in and your done.

I'm still working on the other parts. Subscribe to this thread to stay upto date with the kit.

Cheers,

Tony