"Bubba" joins the stable; sorting out EFI issues

[70SWT]

Originally Posted by GaryR

Great story, but the PO may be confused/exaggerating a bit if he says he was doing PCA Club Racing in the 80's. PCA had Driver's Education events on track then (this is far from racing) and the only amateur "Racing" was with SCCA. The first PCA Club Race was at Summit Point in 1992.. It IS possible he ran Time trials at that time with PCA, that's another possibility.

As some follow up while I continue the project and await various new parts, including fresh EFI components - the PO was kind enough to provide a pic of some of his mementos from when he had the car (his name redacted by me to protect his privacy):



Looks like he had a blast with various events.

I'm glad to be the custodian of this cool 911. With so many mild regrets from the ones I've sold over the years, this one will be a keeper...

[911SauCy]

The attention to details and focus on a proper end result are admirable here...

However, do you have any idea how solid, consistent, and robust a properly installed/tuned CIS actually is?

This is a real Frankenstein EFI system. The mix of parts and aging of technology is going to leave you chasing your tail for a likely less than ideal result. It's also likely that if you find a tuner willing to take a stab at such a situation, they won't exactly know how to do it. FAST is the incorrect application in a Porsche.

Never mind considering the less than fluid airflow dynamics of that UIM, I guarantee a CIS would make more power as well.

Why not install a good working CIS and make the car run as intended?

There is an entirely complete one for sale (no affiliation) in used parts section now. Bolt-on and go...

[70SWT]

Originally Posted by 911SauCy

The attention to details and focus on a proper end result are admirable here...

However, do you have any idea how solid, consistent, and robust a properly installed/tuned CIS actually is?

This is a real Frankenstein EFI system. The mix of parts and aging of technology is going to leave you chasing your tail for a likely less than ideal result. It's also likely that if you find a tuner willing to take a stab at such a situation, they won't exactly know how to do it. FAST is the incorrect application in a Porsche.

Never mind considering the less than fluid airflow dynamics of that UIM, I guarantee a CIS would make more power as well.

Why not install a good working CIS and make the car run as intended?

There is an entirely complete one for sale (no affiliation) in used parts section now. Bolt-on and go...

Thanks for the input - sounds like you are strongly in the CIS camp. Yes, I have had a couple of CIS 911s. One ran pretty well, albeit with less than stellar throttle response, and the other required a lot of attention to run well.

I think the guarantee that CIS will make more power than EFI is unfounded. Things seem to go the opposite way, from what I am reading so far, with an improvement in throttle response as well with EFI. The CIS metering plate obstructing airflow is a known impediment to (at least) the latter.

I have the complete CIS system for this car, but will not be re-installing it.

As mentioned in a prior post, I agree, FAST is not right for this car and seems problematic in some applications. I have removed the FAST system and am moving to the Bitz Racing setup in order to use a simple system that is known to work in 911s, to have support from folks using it, and to generally take a clean-sheet approach.

Overall, this is a project for fun, and I will see what works best. If Tony's system also proves problematic, I will try other EFI options.

As far as what was intended, well, this is 2019, and CIS is 1970s technology - a number of old technologies were intended for air-cooled era 911s that we tend to upgrade. I'm not a purist, and am happy to introduce new technology into my cars. To each his own!

[911SauCy]

I hear ya.

Perhaps my CIS spoils me...

Touch key starts after weeks of sitting, solid running throughout rev range, it revs like a switch, easy to tune, better torque than ITB EFI (I know that's not the case here) ...

Zero CIS issues and 205whp, I can't complain...

As a part of the discovery and fun of the project. It would definitely be interesting to see CIS dyno numbers, hp and tq, versus the existing system. Of course, both tuned to same AFR, same dyno, relatively same ambient temp.

[scottrx7tt]

Not sure why you would want a Bitz EFI system when the Bitz ECU is just an MS1. Everything else is there. In fact, your current EFI ECU is more advanced than the Bitz ECU. If you want to go with megasquirt for the additional support, just buy a microsquirt, that way you can upgrade to spark/timing control down the line.

[Dr J]

Agree with Scottrx. Fuel is half of the equation. Spark is the other half.

If you ever do other mods to the car to increase power (quite a few have boosted them!) you can safely tune for that.

BTW, you already have that nice custom-made airbox which can handle any boost you may want to throw at it in the future. I have a very similar one.

The downside of the EFI is the tuning, but there are lots of guys here that can give advise on it. There are a few threads on some efi tables. For ex.

https://forums.pelicanparts.com/porsche-911-technical-forum/975423-official-efi-ignition-map-sharing-thread.html

https://forums.pelicanparts.com/porsche-911-technical-forum/788215-megasquirt-success-ve-ignition-tables.html

[70SWT]

Originally Posted by scottrx7tt

Not sure why you would want a Bitz EFI system when the Bitz ECU is just an MS1. Everything else is there. In fact, your current EFI ECU is more advanced than the Bitz ECU. If you want to go with megasquirt for the additional support, just buy a microsquirt, that way you can upgrade to spark/timing control down the line.

Yes, FAST should be substantially more advanced. But after working with it and interacting with folks on their experiences with FAST, altogether, I believe it is just not right for our engines. Will leave it at that.

So, my plan is to start with something that is clearly simpler but has been shown to work reasonably well on our cars. As it is inexpensive, if it proves adequate and reliable, great; if not, I will upgrade from there. Thanks...

[jpnovak]

I agree with the above.

Microsquirt is a fantastic alternative to the FAST. It is fully capable of fuel and ignition for our engines.

I really like Tony's kit but it could use some updating. Unless things have changed in the past few years you will have to solder components to enable the ignition output as well as run additional wiring through his existing harness. I have in the past bought his injector adapters and then installed my own system on top. This can be done for less than his kit but requires the skills to make the connections and build the wiring harness.

[trond]

I would go with bitz kit. If for any reason not entirely happy it will be easy to upgrade with MSnS firmware or even MS2 ECU. Bitzkit is an certain way to get running. It lacks some features that most don't need is all. And it works out of the box

Or JP made it work out of the box to be more precise. But I upgraded to MSnS and later to MS2 on my own. Easily. So a great starting point with almost guaranteed result.

[scottrx7tt]

Originally Posted by trond

I would go with bitz kit. If for any reason not entirely happy it will be easy to upgrade with MSnS firmware or even MS2 ECU. Bitzkit is an certain way to get running. It lacks some features that most don't need is all. And it works out of the box

Or JP made it work out of the box to be more precise. But I upgraded to MSnS and later to MS2 on my own. Easily. So a great starting point with almost guaranteed result.

$500 for a stripped down MS1(Bitz ECU) the only thing that is advantageous is the Bitz ecu works with the current fuel pump circuitry. The idle control isn’t even set up on this unit, you have to use the AAV from your old CIS. No TPS. I could understand buying the Bitz fuel rails, and injector adapters. That is a complete kit solution fromgoing CIS to EFI. Tony has a base fuel MAP to get your car going, but still needs fine tuning regardless.

Microsquirt V3 $399. Full MS2 with the ability to run a multitude of nice features including full ignition control. It only takes about 10 minutes to fix the wiring pigtail on the fuel pump relay if running microsquirt or MS2.
When I originally got involved in the EFI conversion, I went with the Bitz ECU, mainly because I was scared to do any tuning on my car, but quickly found out my car would not run on Tony’s pre loaded fuel MAPS. I had to fiddle for awhile to get it running good. Then if you had the key on for any length of time, the car would not idle due to the way the CIS AAV works. I quickly realized I was going to have to upgrade the ECU to do what I needed it to do. After inspecting the circuitry in the Bitz ecu, it was missing much of the circuitry to do an easy upgrade to MS1extra, or MS2. I’m not an electronics guy, so I was going to have to pay someone to do it. I just decided I would sell my Bitz ECU, and get into the Microsquirt, which is an extremely nice unit. Now I have more modern idle control, and full ignition control using EDIS(distributorless)
Not sure why Tony does not just upgrade to microsquirt with his kits. You cannot even buy an assembled MS1 ECU from DIY Autotune any more, because it’s rather outdated processor and the price being so close to microsquirt. Only assuming Tony is making a profit assembling the MS1 to fit the needs for his Bitz kits.

[70SWT]

Thanks, all. Yes, the Bitz kit should be a good way to "sneak up" on functionality while enhancing my EFI learning curve. If Tony gets me there more or less out of the box, great; if not, also great, I will follow the trail so ably blazed by others.

There is no real rush on anything, with cold weather coming (even here!), and I am doing a number of other things to the car.

[70SWT]

Originally Posted by Dr J

BTW, you already have that nice custom-made airbox which can handle any boost you may want to throw at it in the future. I have a very similar one.

I thought it was pretty cool as well. My plan is to close up all unneeded openings on it from the prior IAC etc. and have it powdercoated to dress things up a bit. This setup will never look as cool as ITBs, but I hope to improve things at least a little. Perhaps put a tasteful Porsche crest on the flat, upper rear aspect of the box once the holes are closed.

I saw a very similar box that was nicely done up in another thread, but can't find it again to save my life...

[70SWT]

Speaking of out of the box...Just received a package from some exotic place supposedly called "Canada" - sounds made up...



D@mn it, it's just some paper...no wait...



Ah, better!




Thanks, Tony...too bad I have about 20 things to do to the car before I can really check it out...

[jpnovak]

Awesome. Can't wait to see the install completed. You will be happy with it.

[wreckah]

have fun with the install.

the bitz kit takes the nerves out of the EFI conversion for newbies...even us guys with a bit of mechanical experience.
take your time and enjoy

If i'd do it again, i would go microsquirt immediately, but there is a learning curve, and tony's kit provides just that: an easy, proven entry into EFI world. The path is sometimes as important as the end result.

And the later upgrade to microsquirt/crank trigger to control ignition is almost for free...sell your CDI, dizzy, coil, you'll probably make a profit.

[jpnovak]

I will suggest that you add a wire to the harness in both Pin 27 and Pin 36 before you pull through the car. This will be much easier to enable ignition control in the future. Currently there is no ignition output wire on the existing harness.

having to fish a wire for ignition post-install is not fun.

[70SWT]

Originally Posted by jpnovak

I will suggest that you add a wire to the harness in both Pin 27 and Pin 36 before you pull through the car. This will be much easier to enable ignition control in the future. Currently there is no ignition output wire on the existing harness.

having to fish a wire for ignition post-install is not fun.

Thanks for the tip!

[jpnovak]

You should also look up idle air control (IAC) valves. There is a simple idle speed control that operates on one wire. There will not be a wire for this IAC in the harness. Tony's kit uses the stock CIS AAR bypass valve and it works well. However, your system has deleted this. MS can control the 4 wire GM IAC but you will need several modifications to the ECU PCB as well as the wiring harness to enable it. The single wire is much easier.

The point is... You have a different starting point than just replacing an existing CIS system. This means you need to do your homework now before you have to re-do the harness in the future.

[70SWT]

Originally Posted by jpnovak

You should also look up idle air control (IAC) valves. There is a simple idle speed control that operates on one wire. There will not be a wire for this IAC in the harness. Tony's kit uses the stock CIS AAR bypass valve and it works well. However, your system has deleted this. MS can control the 4 wire GM IAC but you will need several modifications to the ECU PCB as well as the wiring harness to enable it. The single wire is much easier.

The point is... You have a different starting point than just replacing an existing CIS system. This means you need to do your homework now before you have to re-do the harness in the future.

Yep, I have been debating what to do with respect to this issue.

I was thinking of adding several unused wires into the wiring harness for potential later use if more sophistication of whatever type is needed. For now, my overarching thought is to configure things as closely as possible to what Tony has intended here (using the AAR) to reduce the chance of an undiagnosable failure mode, while still using the aluminum airbox. (I could revert to his "clean" look approach to do so, but I don't want to butcher the stock CIS components, and will keep them for posterity).

So, is it possible to use the AAR on/in conjunction with this airbox...I have no idea just yet. I have been getting killed with regular work this week and have had little time to look at these things, but will be exploring all of this more by the weekend.

[70SWT]

A quick update: EFI-related work is on hold until I complete a bunch of basic maintenance and mechanical items. Time for the car has been tough to find due to a massive increase in work and travel obligations.