911S 1971 Standalone EMS conversion

[combatic]

Ahhh...THIS thread is what all the boys are talking about...can't wait to see the numbers on this system and get the long term reliability report! Nice work.

[davidcz...]

I dig this. Learning learning learning...

[daepp]

Great work sir!

[prebordao]

Bom trabalho Tiago !

[Tiago/Tecnomec]

Hello everyone, sorry for the long time, but I thought the topic had kind of "died"...

Glad to see it has not!

Hi island911, I opted to set it up on Alpha-N configuration (Throttle position/RPM) only, no MAP or MAF metering. The ECM does have a built-in MAP sensor, but because of the S cams (lots of overlap and late intake valve closing) AND the Individual Runners (one throttle plate per cylinder), the manifold pressure signal bounces and fluctuates a lot, rendering the MAP ssensor signal very unstable and not a good option here. If there was a common plenum with only one or two common throttle plates, the MAP correction would definitely be a plus.

Hey Luke, I am willing to try to hook up the MAP signal, just afraid of the reasons above. Maybe you know of some adapted EMS 911 with ITBīs and agressive cams to tell me if the MAP signal was too affected? I would love to hear about it and get some inspiration. Would definitely be a plus to the calibration finesse if the MAP works good despite the reasons above.

Thanks kenikh, combatic, Davidcz, DAEpperson, prebordao, for the cheering, it is a very good feeling to hear from other Porsche lovers that it looks good! Obrigado (means thank you).

I did some power pulls, got 143 WHP (at the wheels), that is about 175 hp on the Flywheel (ther is NO exact conversion from wheel horsepower to engine or Flywheel horsepower, only approximations), but that took some tweaking with timing, asked for 36 at 6600 rpm, which did not feel right. A/F ratio was spot on at 0.82 lambda on an Innovate WB, tried some more, some less, no gain above that.

Also torque was a little low, so I did a compression test and now I suspect the valves are too tight (being a while since the last adjustment, I am guilty as charged). I ordered the valve cover gaskets and as soon as they get here (dam* brazillian customs holding the goods forever), I will adjust the valves and retest on the dyno.

Albeit that, I have done a little driving and the behaviour is very good with excellent manners and throttle response. Still have to change the VERY old tires, and the old brake lines to have confidence and push the car to feel it better.

I made the ignition coil stands, very simple (made of SS tube and sheet), but I think it looks ok:






Hope you guys like it, itīs all done with little money, but with big love

Best regards from Brazil

Tiago

[MdR]

Originally Posted by Tiago/Tecnomec

Hope you guys like it, itīs all done with little money, but with big love

Like it? I love it

[Lukesportsman]

STILL waiting on my test stand to get here. Been most of summer! Then, I'll hopefully get the ITB engine off static stand and onto test stand to work through electronics. I'm still uncertain of ECU I'm going to use. I have SDIS, mulitsquirt and FAST in garage to decide between, but each use MAP to help....I thought I'd try to connect the runners to a common add on plenum to gain a more stable signal. I DON'T know how big it would have to be or if it would work yet.

[Tiago/Tecnomec]

Hi MdR thanks a lot!

Luke, those are some pretty great ECM options, I know SDS and FAST (although I never used them myself) but do not know multisquirt...

I think the common plenum solution would probably work, I just donīt have the guts to drill the original MFI throttle bodies to mount the fittings for that.

Unfortunately I also have no idea on the volume of it... hope to see it working soon!

See ya!

[al lkosmal]

Originally Posted by Tiago/Tecnomec

al ikosmal, thanks for that, I just want to maintain my beloved 911 running the best I can. Are there any of your EFI projects around the forum? I would love to see them!

Tiago,
I continue to follow your posts........Nice work.

here's a link to a few projects I've been working on

koz77911's channel - YouTube


regards,
Al

[Tiago/Tecnomec]

Al, thanks for sharing that, I already subscribed to your YT channel.

I loved that Triumph bike ITBīs conversion you did on the 2.7, that is very ingenuous!!

That bike has a 3 cylinder engine, right? Was there much (if any) cutting/welding/fabricating necessary to mount the ITBīs to the Porsche engine?

Everyone should check it out, it is very cool!

regards,

Tiago

[silverc4s]

Tiago,
Just came across this thread for the first time tonight. I am very impressed with your skills, although not surprised.
I lived in Campinas many years ago, mid 70s, and was fortunate to be able to buy a new SP 2 at that time. I drove it there for most of my stay, loved it, but could not get it back to the USA upon the end of my assignment. Started my love affair with ass-engined cars, and have been addicted to this day.
Currently am driving a 73 targa with a Carrera 3.2 Motronic motor, and I also have a 1970 S Coupe, fully restored, MFI and all. Small world..
Anyway, thought you would enjoy my story, and my encouragement to continue with your beautiful project.
BTW, where can you enjoy there? Traffic must be awful now...
Ciao from here,

[Tiago/Tecnomec]

Hi silverc4s, that is a nice coincidence, you have lived in Brazil AND have a 2.2 911S

And let me say, I think it has been a really upgrade of "ass-engined cars" (haha loved that), from a 4 cylinder 1.7 liter VW SP2 to a Porsche 911 Targa with a 3.2 AND a 911S! I like the SP2, but I think the Porsches are just WAY other league! Over here in Brazil, pple call the SP2 "Sem Potęncia 2" which means something like "no power 2" lol, mean but kind of true...

Thanks a lot for the kudos!

Traffic is really bad here indeed, but there is always the weekends, late nights and back-roads...

regards

Tiago

[bug man nrg]

I like what i see on this set up nice job

[Tiago/Tecnomec]

Thanks bug man!

Well, it has been a few weeks with the car, and no problems so far! The car always starts great, behaves very well in traffic, and has very good throttle response... I am very happy! I finally adjusted the valves, changed the oil and filter, and started to let her rip the way she likes!

Here is a video of the car on the dyno accelerating hard:



I think it sounds even better than before, the engine just seems so happy to rev and roar, I love those S cams and the ITBīs!

Thanks everyone for the support, best regards from Brazil!

Tiago

[al lkosmal]

Nice job Tiago....................clean install with some great details....and it sounds great too!!

regards,
Al

[Tiago/Tecnomec]

Thanks a lot Al, still curious about those Triumph ITBīs of yours! Very cool!

Regards

Tiago

[silverc4s]

Very nice result, Tiago. You make this difficult conversion seem rather simple...

Any thoughts to marketing a kit?

Anyway, congratulations are in order.

[al lkosmal]

Originally Posted by Tiago/Tecnomec

Thanks a lot Al, still curious about those Triumph ITBīs of yours! Very cool!

Regards

Tiago

Tiago,
If you are interested, search the technical forum, using "al lkosmal" as the user name, search term.....................you will find all of my posts regarding the Triumph Speed Triple conversion.

keep up the good work. That is one of the cleanest installs I've seen.
Did you program the ECU yourself??

regards,
Al

[Tiago/Tecnomec]

Hello, silverc4s thanks a lot again!

I have no intention of selling a kit, I just did the conversion for this one car. Would love to help anyone interested in doing it though.

Al, I just checked out some of those topics and dropped a few questions on one! great work!

Yes I did the programming myself. It was very straightforward, I basically used the factoryīs ignition curve (with some more advance on part-load and when cold, really improved drivability), and dialed in the AFR using my WB O2 sensor... I have some experience with calibration (we build some crazy alcohol burning turbocharged engines over here), so this one was relatively simple... The biggest fight I had was with the starting enrichment, there was a "pop" I couldnīt get rid of when starting warm (but not hot nor cold)... Had to end up using more start enrichment than I wanted on warm engine temps, but itīs always a quick and clean start now!

regards

Tiago

[Quickstep192]

Tiago,

I've read this post with great interest. I think what you've done is ingenious. I have a 1973 911T that was converted from MFI to Webers. I would love to convert it to EFI. Like you, I have the original throttle bodies and re-using them would save costs. Also, like you, I don't want to make any irreversible modifications in case some future owner wants to put it back to original. I have several questions for both you and anyone else who would be willing to contribute.


Tiago,

Since you don't intend to market this would you be willing to provide drawings so I could get the injector adapters, fuel rails and the stands for the direct fire coils fabricated here in the US?

Everyone,

If I were doing this in the US, what injectors could I use?
What ECU would be best?
What's a US source for the crank trigger and other sensors?

Like Tiago, I'd love to move to EFI, but I don't want to make any irreversible modifications and Tiago's solution does just that.

I appreciate any input.