Jeff, what kind of motor are you running and where does the car see most of its work? Dual purpose, dedicated track, street hot rod with some track work?

I spent just around 3k for the Jenveys (tb's, air horns, manifolds, linkage, filter plate, itg filter, tps) but I also opted for the taper bore setup. The top of the throttle body housing is 48mm and the base of the manifold comes in either 38mm or 40.5mm. If you went with straight shot tb's you would save some money I suspect.

As far as which ecu you choose thats up to you. I read plenty on everything available, I got a lot of info from the RX7 forums, one of the members posted a huge run down of each system, how it is setup and what it is capable of doing for you.

I have heard nothing bad about DTA, looks like a very good quality piece, not certain on their customer support. This being LA (hot rod central or so it seems) I was able to find a good number of shops (not porsche) that have installed and setup almost every kind of ecu. Im not trying to sell you one way or another, just show you to process I went through when choosing. If you want to go with Motec because someone close by has experience with it take a look at this: http://www.capa.com.au/prices_capa_performance.htm#capa_motec

Under 2k for 4 different models of brains. The problem with Motec is that you must pay to unlock options such as wideband lambda, igntion upgrade, sequential so on and so forth so the price adds up fast. Motec or not you still need sensors and ignition hardware.

Here is a list of parts similar to mine:
Crank pulley with trigger disc or magnetic trigger
Crank sensor & mount
TPS depends on throttle bodies (some come with it)
Air temp sensor
Intake air temp sensor
Map sensor
Oil temp sensor (if fan is controlled by brain or for logging data)
Injectors
Coilpacks (in my case 6 firing two plugs each)
Bosch coil ignitor modules (6 for total control of ignition, autronic at least)
6 14mm plugs
6 12mm plugs
12 plug wires

brain, ecu of your choosing
wire harness (most come with)
software
pc link cable

wideband 02 sensor, (autronic requires corrected output from the o2 sensor or it wont work in autotune. lm1's can be used as well as some other, the autronic piece is quite expensive and you really only need that if you do this a lot)

money, patience, help, support, you will need it all to put it together and get it running. I tell myself I can put the motor together, wire it all up, get it ready then I am gonna freak when I try to start it after the ecu has been synced with all its sensors, outputs and so on. Then I need to plug in a base map to start it for idle to check things over. It all adds up in a hurry and you start wondering why dont I just buy a different car that has all this stuff already or makes tons more power on a close to stock setup, then your remember you drive an old school porsche, you have molded the car to yourself and yourself to the car and those other cars dont compete anymore.

Best of luck in whatever decision you make. As soon as I have all my parts and start wiring in the brain and putting the motor together I will post pictures and comments and offer any little hints that I can.

Ryder

I am not sure what you mean.

The DTA has some glitchs that I have to work around. The idle control isn't that good. Same with the lambda. I haven't found a setting for the lambda to get a stable signal. The software isn't the best. Other than that the DTA has been great. I would think that all brand of ECUs have there downsides. It is a hard choice.

Tuning on a dyno I found very hard and stressfull. There is so much info coming at you that you have to pick the important stuff out of it and read and react to that. Plus I was paying $150 per hr and I wanted to get done. I didn't. And I didn't want to blow my motor up. Tuning on the street is not hard except for not crashing.:eek:

How are we doing so far to convice you?;)

Ryder, my motor is a 10.5:1 twin plug 3.4. DC44 cams and 1 5/8 exhaust. 3.2 heads. Dual purpose car.

Dean, most of the dyno shops here tune carbed hot rods. The one that the racers use specializes in MOTEC, I don't feel like shelling out the dollars for a MOTEC.....

Hmmmmmm

Cheers

Convincing me is comming along just fine! My big fear is firing the motor up for the first time. It will be fresh, never run and I need a good mixture to aid in the break in. Don't want to screw that up.

Jeff I know exactly how you feel. I am building a motor somewhat similar to yours so firing it up for the first time with an efi setup will be a bit stressful. 3.3 litre short stroke 100mm bore, 10.5:1 cr, twin plugs, mod s cams on 108 lobe centers from John, 993 heat exchangers, heads port matched to Jenvey intake and 993 exhaust, M&K muffler. Should be fun, just worried about that first start up and the break in and tuning.

DO IT!!! You will love it later on. Like Dean said regardless of brand I am certain every aftermarket ecu has its own idiosyncrises that make the learning process trying at times. I cant wait to give it a shot though, its very exciting stuff even though the technology is somewhat old.

FWIW I have heard more and more horror stories about Electromotive from this board and others as well as people at shops. The SDS while nice is still a long setup, DTA, Autronic, Haltech (seems like a fancy electromotive), Motec, EFI Technology would be the group I would choose from. If you think Motec is expensive look at the EFI technology stuff. Pretty much meant only for racing, nice but pricey, overkill in this situation.

Best of luck, btw, which way are you leaning now?

Leaning to going the EFI route..... Any one want to buy a twin plug HPV-1 set up??

Cheers

Most likely the Motec shop will tune any ecu you want. It only takes a few mins to learn a new EFI software. It is the running the motor on the dyno that take exp.

I understand your fear better now. You could have the dyno guy break your motor in for you. Do the Motec guys have an engine dyno or a chassis dyno? Is there anyone in your area that has converted to EFI?

Only a chassis dyno around here. And I am forging new ground up here on this conversion as far as I can tell. That goes for the whole car actually! :)

Is 795cdn a good deal for a 9 hr day on the dyno??

Cheers

Jeff - do it! I see guys with way less knowledge than you able to get a basic EFI system going on their 911. It's not as difficult as it seems. There is nothing like the precision from dialing in a map value in a fuel/ignition table that carbs just don't give you. The knowledge you gain will carry you forward into all cars you work on in the future, and in the long run, you'll be much more satisfied with the state of tune of your motor. With a carbed 3.4 drinking gas faster than you can say 'fill er up', vs. a twin plugged EFI controlled 3.4 capable of achieving 350-400 miles per tankful, your pocketbook will thank you later.

Use a LM-1 to dial and fine tune your base fuel maps - it will save you a lot of unnecessary time on the dyno. To program some base ignition tables - a good start would be something similar to the Bosch Motronic ignition tables as shown on my site, or like the 964 or 993 tables, or contact me and I can provide you some data tables and guidance. With that your car should start. All the other tables are usually trim values for fine tuning cold starts, idle, etc.

Motec has some good info in their manuals that you can download applicable to all EFI tuning that you should go over. When you are done road tuning and everything is running smoothly, then go to the dyno and spend your time dialing in for maximum power.

You know what might be trick? Ever examine an E46 M3 motor? Six ITBs sucking through a large common plenum which breath through a big snorkel with a Bosch HFM sensor. Wouldn't it be something to do the same with a 911 motor using an MFI airbox/filter on top of a set of ITBs, also breathing through a single snorkel with a HFM sensor.

Thanks Steve, I am sure I will badger you some for timming info etc...

Educate me on the singe HFM sensor idea.... I can fab the housing up in either FG of CF with out to much trouble once I get a mold made. What would the benefit be? Better vacuum signal I guess? How big would the hfm need to be? How much closer to the poor house would the hfm put me, I have no idea what they cost. I could do the plenum/airbox pretty cheap, not much material, just time.

Any downsides? Throttle response better or worse? Hmmm, now this could be interesting.....

Cheers

It's an idea that popped into my head after reading your post. Compared to Alpha-N, throttle response may be similar, with the edge probably going to Alpha-N. If your ECU provides the option to transition from Alpha-N to a MAP sensor, you could substitute a HFM5 sensor in place of MAP.

Except for the fabrication of the plenum, it's probably not much more complicated than the Alpha-N/MAP combination, although if you try this, you’d be venturing into new territory in the aftermarket, as I haven’t heard of anyone except the OEMs such as BMW-M do this. Most EFI sensors are basically 0-5 volts, a HFM5 sensor no different. Most likely some type of low pass filter would have to be placed on the output signal to even out the signal from the sharp intake pulses.

The E46 M3 HFM5 sensor is about $150 or so. On the M3, the measuring tube is built into the plenum snorkel, and is about 4" in diameter, and probably 6" long. Its response is very fast (for the ITBs of the M3), much more immediate than the old Ford hot wire sensors as used by some aftermarket kits. Within it are five terminals for power, ground, voltage signal out, and an air temp sensor. Since MAF measures air by mass and not by volume, compensation for changes in barometric pressures and air temps are automatically accounted for. The separate air temp sensor is used by the ECU to trim other variables, such as ignition timing etc.

Here’s some pictures of a system on a M3. The ITBs on the motor, a picture of stock vs an aftermarket German airbox plenum, and the trumpets inside.


http://forums.pelicanparts.com/uploa...1143407485.jpg

http://forums.pelicanparts.com/uploa...1143407517.jpg

http://forums.pelicanparts.com/uploa...1143407568.jpg

Steve, pretty neat idea I must admit. Wouldnt be "too" hard to implement as long as you dont mind fabbing up the parts. By chance do you do any dyno tuning for aftermarket setups or only for your chips?

Jeff, any news on what you are thinking and heading towards?

Just Motronic for now. Bosch Motronic is actually a very refined and robust EFI system, exceeding the quality and capacity of many aftermarket systems. It is only unfortunate that the programming software and code details are unobtanium to the public and a lot of the recoding has to be done by individuals reverse engineering the software.

Seems as if those days spent at Loyola have treated you well in the long run. Class of '02.

I just cant wait to put this project together and see if all the time and questions will have lead me to something nice in the end.

Okay, so I just talked to one of the dyno operators here and it turns out he is very familiar with Autronic and is a big fan. He says I can bring the car to them and they do all the programming for the initial start up and then all of the tunning on the dyno as well..... This is getting interesting. He says he does not use the autotune feature as the tunning process is not really that hard once you know what you are doing.

Another system he spoke very highly of is one I had never heard of. He had good stuff to say about Microtech. www.microtechefi.com He claims they are very easy to use and quite affordable. He also recommended another shop very close to me that is very experienced in dyno tunning this set up. Sooooo, funds permitting it looks like I am going the EFI route...

Steve, I think I should just get this thing running before I venture in to some "new ground" I would be interested in possible fabbing up the "hard parts" (plenum and such) for your idea at a later date, but you would sure have to help me with the electronic end of it!!! :)

Thanks again to all who have taken the time to contribute to this thread.

Cheers

Great thread, learned lots even though my move to EFI is still a ways away (this work thing gets in the way of Porsche's!). All I have engine wise at the moment is a core engine and a brand new '84 case.....no serial number even!

A question, I truly hate spark plug wires and was going to use Coil on Plug's instead of the coil packs typically used. I checked with Electromotive to see whether they could support 12 CoP's (two per cylinder), and they got back to me and said TEC-3's couldn't do it.

I haven't done an exhaustive check, but so far no EFI seems to be able to support CoP's....anyone have any experience with them on air cooled 911 engines?

In terms of mechanical install, the Bosch or Visteon units seem pretty good and easy, although modifying the valve covers is necessary (particularly on the plugs whch extend beyond the cover) will take some engineering...

Thoughts anyone?

Dennis

Dennis:

DTA's newest offerings and Motec M600 both support coil-on-plug ignitions and we are working on a valve cover specifically made for such systems,...:)

Whoo hoo.....when can I buy some of the valve covers?

Another way to look at this problem.
Carbs- Time to running engine, 1 hour, time on dyno, 2 hours. Done.

EFI- few hundred hours more. Many more dollars to get all the extra parts. Additional performance, minor if any. Hobby factor, 10X the carbs and its Really Nice to know how newer cars work.

I was going to say some well known guy was almost shamming me into the EFI route!!! :)

The coil on plug idea is a cool one, any idea if they can take the "weather" down on the lower valve cover?? Steve, we need to talk some more.........

So, I have mentioned a couple of systems that I am seriously considering, but I am also considering Steve's complete package featuring their manifolds and linkage and a DTA set up. Pricey, but sounds good....

Snowmam, thanks for checking in on this. However I am not sure what you are saying?? Carbs, easy but EFI a little more cool? Have I got that right?

Cheers