I hope my new SDS PEFI system is half as good as their delivery time, I sent the group order in by snail mail and email last Monday. Exactly (almost to the minute) one week later I have it in my hands!

I wish I could install it right now, but I’m swamped for the next 2 weeks. I let you guys know how I make out when I do install my SDS. I might be able to do a couple of pre-install thingy’s before then, we'll see.


Everything looks good, the controller is a bit larger than I thought (I don't know where I'll put it) and Bowlsby would most likely say that he could make a more factory looking harness. Other then that it all looks to be pretty cool.

Just a tad bit excited

Mark

Nice to hear that.

Could you take some pics and show how the box and all sensors looks ??

Hey Timo

I don't have a digi cam, but the stuff looks exactly like it does on the SDS web site:
http://www.sdsefi.com/

I plan to take full pic's of the system, plus the install and I will post it with a full write-up of all the details.

I have only had it a couple of hours, but I've had it laid out and together on the floor, real easy. If I didn't have to make a crank trigger and TPS mount, drop the engine to fix some oil leaks, install my new 1.7 rockers w/ 911 adjusters etc, etc.... (oh-no, I have DWD!!!) I could probably install it in an afternoon.

If you can hook up a car stereo you can hook this up, it's all one-off connectors and labeled. The head temp sender looks like it's a stock 914 sender.

I don't think I will put it in the stock mounting spot, the SDS wiring will let me mount everything under the dash or in the console. They want you to keep the ECU dry so I think this is the best spot.

This thing is supposed to be rough programmed, we shall see real soon, but I have to pay some damn bills first!

Congrats Mark...keep us posted on how well the install and tuning goes. To my way of thinking both the SDS and Megasquirt FI systems lead the pack for replacing D-Jet.

I have considered making replacement harnesses for both, ready-made to take out another headache for anyone making the swap. If you are willing to loan me the harness you create I can duplicate it for others much easier.

Now that we see how much work the MS was (Dave Hunt) it will be interesting to see how smoothly the SDS goes in.

yes, I would really like to see how well it works and the benefits. time to throw it on the dyno! I'm looking at TEC's and stuff like that.

Mark,

The SDS site looks pretty cool and ignition with the FI is a real plus. I'd sure like to know the details of your system. Please keep us informed. I think you'll find it will be a lot of fun. It sounds like you get to jump into tuning pretty quickly since all of the sensors and the harness are included.

You mentioned mounting a TPS. The shaft in the throttle body turns the opposite direction of most cars so finding a TPS with an 8mm shaft and counterclockwise rotation was a problem. I finally took a Subaru TPS and drilled a hole in the back so I could mount it upside down which solved the rotation problem. I then used stove bolts to mount it to the steel plate from an old 914 TPS. Worked fine.

I noticed SDS mentions an Air/Fuel ratio Meter for tuning so I'm curios to hear your plans for tuning.

Dave

There isn’t much of a harness to create, the coil drivers need a switched 12v source but if I mount it within 18” of the factory coil that all she needs. The switched 12v for the ECU just needs a piggyback connector on the fuse box and I have to find a couple of grounds. The only wire I “may” have to splice is the power to the fuel pump, other than that it looks almost plug and play.

Jeff, the main things that you would do different is to shrink wrap it in all the right places and maybe eliminate the GM style connectors. I say “maybe” because of the way SDS has wired the harness, if you have to pull the engine all you do is undo the connectors. Sort of like disconnecting your trailer lights, when you unhitch you trailer, except it’s a half-dozen (or so) connectors. For example, there is just one connector for the injector wires, you leave the wires on the engine and the ECU in the car.

Dave, I bought a correct TPS with the system, I just have to make/modify a plate. I have a Haltech Af-30 air/fuel meter, it’s basically the same thing as the one SDS sells. I do know all about the wide band debate, but I have a lot of experience tuning carbs with this meter and my plugs always look perfect. They have rough programmed it already, so we will have to see how it goes.

It will take me way more time to mount everything and make it all look as sanitary as I want it. The crank trigger may be the biggest PITA.

The big debate is my engine. I have a 1.8 L-jet and the connectors are d-jet, I have all the d-jet stuff, but I’m not going to build my 2.3L engine yet, I don’t have the coin, maybe mid summer. If I can sell my ’67 bug I will have coin for the big 4 right away. I’ll use the d-jet injectors and the 2.0 TB/plenum.
Either I leave the longblock stock OR I stick in this Scat C-25 cam and big valve flycut 1800 heads that I have lying around and have a bit of fun with it. Remember I build engines, I have 7 T4 cores (2 are 2.0 914), and so this is totally no real big deal for me. As for dyno time, I doubt if I will dyno the 1.8 unless I really have to, I will dyno the 2.3L.

But first have to get 3 customers type 1 (beetle) engines out of the way before I can really start on this. Not to mention the fact that my Dad sold the farm and I have to move all my junk out of the barn by July 8th. Oh yeh… and I’m also helping my brother-in-law fix up his new Dojo, sigh, so little time.

Mark

Mark,

Sounds to me like you got it all set. Only 2 things I think you should consider (these were news to me). First the 2.0l injectors flow a lot of fuel, way more than you need. I would suggest considering smaller injectors. I think it would be easier to tune.

Second, the 2.0l injectors are low impedence. So, watch how much current they get. They need higher current to open then it needs to drop. To much current they get real hot.

Dave

Dave,
Yep, this system is real complete.

It has resistors in-line for the low impedance injectors.
If I do have a problem with the 2.0 injectors a friend said that he would lend me a set of 1.7 injectors to try out.

Which injectors are you using?

Mark,

I'm using the 2.0 injectors with resistors in series with the injectors. They work fine that way.

The fuel flow is a little different story. It was really difficult to flow a small enough amount of fuel on over run. I have it working but that portion of my fueling map was a lot of work. Before you use the 1.7 injectors check the resistance. I suspect they are low impedence like the 2.0 but I don't know for sure and with the resistors in series you may not be able to open them predictably if they are high impedence injector. Brad Anders has the specifics for the 2.0 injectors for sure and may have info on the 1.7s.

Dave

If you have problems flowing small enough quantities of fuel at light load with the stock injectors try a set of Nippon injectors from a Subaru 1.8 turbo (late '80's). They work great and have good resolution. $5 each at the local wrecker. Pull the mounting collars off and they are a drop-in replacement. (I'M TALKING TO MARK AND DAVE ONLY! DON'T DO THIS IF YOU ARE RUNNING D-JET)

Also, regarding the narrow band O2 meter - I keep hearing people say they are useless. That is just total BS (where did the BS smiley go?). Having this meter is a tremendous help when getting it all roughed in. I couldn't have done it without one.

Lastly, you'll love being able to set your ignition advance curve in software. This totally rocks. Making the advance curve temperature variable is the icing on the cake.

-Ben M.

Suggest you run the TPS off the end of the throttle shaft down at the pedal. It wont last long out back. I not found them to be very wasterproof.

How

I think that it would be hard to control the air/fuel ratio better than this (on a stock 2.0).

Ben, thanks for the Subaru 1.8 turbo injector tip, are they also low impedance?

I agree with the narrow band O2 meter statement, I've been tuning carbs with my Haltech meter since the mid 90's without a problem. They do lack sensitivity on the rich end of the scale, but that better than the lean end!

I thought for a long time about the programmable ignition option (or should I say the $400. price tag), but in the end I decided why should I go high tech on the FI and stay low tech on the ignition. It didn't make sense not to get it.

The only reason I'd go with the smaller injectors is due to cost...the factory 2.0 injectors worked fine (and still do) so why mess with a good thing?

Besides, if one starts to upgrade the motor (cam or turbo), I'd like to know that my injectors can flow enough fuel and not reach max duty cycle too soon.

I totally agree with you Mark, why go Hi-tech with the FI and not do the same with the Ignition??? Only if the rule books dictate would it make sense.

(megasquirt is an exception)

Yes, the Scooby injectors are low impedence. 3.5 ohm I think.
I couldn't find flow numbers for them, but that motor is 1.8 litre and 110hp. A pretty close match for a typeIV be it a 1.7/1.8/2.0

-Ben M.

You guys this may sound funny, even though the 2.0 Injectors are a good fit I don't believe they are perfect. The factory put a circuit in the ECU to turn them off and they added a decel valve to lean the air fuel mix at high vacuum. I believe those were compromises they came up with at least in part to deal with the difficulty of tuning these injectors. They will work and work pretty well and I chose to keep them in my setup. But, they puke some fuel out the exhaust at high vacuum and medium to low RPMs.

I'll live with that. I don't doubt that the Subaru injectors are a better fit but these cars have always been compromises and I kind of like that.

Dave

Dave,

To help overcome the richness, you can lower the fuel pressure as long as you have sufficient atomization...the max duty cycle for the 2.0 injectors is rated at a higher than normal fuel pressure.

I'm using 1.8 injectors which are okay for a normally asperated motorm, but once I finish the turbo, they'll be swapped out for 2.0 injectors (the 1.8 are rebuilt with only a few hundered miles on them if you know anyone looking for some )

I'm going to try the 2.0 injectors first for sure.

SDS has already programmed (rough) the system for these injectors.
It is supposed to start right up and then I have to fine-tune it from there.

I asked SDS about my 1.8 injectors, they didn't want me to use them.
They said pretty well all L-jet injectors are limited as far as engine mod's go. They told me to use the D-jet injectors.

Ah, is the glass half empty or half full? he he. You say the flow rate is quoted at a higher than normal fuel pressure, but I look at it the other way around. The injectors were designed to opperate at 35psi. THAT is their optimum opperating pressure. The 914 was set up to run them at a lower pressure.... BECAUSE THEY'RE TOO BIG!
But I agree, if you're headed for bigger jugs, or a turbo then keep the 2.0 injectors. Want to know the real reason I'm running the Scooby injectors? I had a stock injector spring a leak and would have had to park the car for a week while I had new injectors shipped out to me here in BFE. So I grabbed the Scooby injectors because They were $20 for a full set and I knew they were an appropriate fit. I was pleasanty surprised when I found I had a huge improvement in tuning resolution. Once I get the turbo* on the car I might go back to 2.0 injectors or something else, but for now they are fine.

-Ben M.

*might be a while. I got the car back together a few days ago and am just enjoying driving it. Don't want to take it apart again yet.

Hey Ben.......I was wrong, I was looking at a different table for injectors.
This info below is from "Brad" Anders site:

Yellow (1.7L) - 265 cc/min @ 2.0 Bar, 3V, 0.15 mm ± 0.05 mm lift
Green (2.0L) - 380 cc/min @ 2.0 Bar, 3V, 0.15 mm ± 0.05 mm lift

So the injectors are running at thier designed flow and pressure if at 2.0 Bar

I still say it's better to be too rich than lean and not to be able to do anything about it until too late

Very cool feature!

I’ve been reading my programming manual, the SDS has a rich/lean adjustment knob. When you’re programming at any given RPM you adjust this knob and find the “sweet spot”. Then on the controller you look up the value on the knob, add that value to your map and return the knob to zero. Then you go on to the next RPM level.

They say that this makes for fast adjustments, as you don’t have to change the mapping to see what works.

This is supposed to be very fast come dyno time, as you can adjust the knob during the pull to find the best setting.

Mark,

That adjustment knob sounds super. In my case with the MS its or , kinda like a game on the PC. Nothing hard but when you're paying for dyno time it was slow. The best solution for me was to do a pull at a steady load then make all the changes to that portion of the map at once, then another pull to see how it worked. Added up to about 2 hours of dyno time. Even with cost it was the best money I spent on the project

Mike is right about horsepower waiting to get out of theses injectors. Someone has to let all those ponies out. My duty cycles are very low. Most of the time, they are in the teens and low 20's on the road Idle is about 4% and over run gets below 2% and that is with the AFR at 12-12.5 %. If I try to lean that out anymore the AFR jumps around too much and the car bucks. Running rich like that is not the perfect solution but it is a small part of the fueling map and I can live with it. I need to do some real highway driving and keep track of milage. I suspect it will suffer a little.

That liitle problem was greatly improved with a special code that allows pulsewidth resolution down to .001 mille second. Overrun is much smoother and I'm satisfied with it now.

Dave

Hey Mark,

that feature with the knob is "trim"...my Haltech has it for fuel and ignition.

Basicly it's a 0-10k potentiometer (variable resistor)

It could be added to the Megaquirt or even the factory FI which some people do so that they can enrichen or lean out the motor (not too good of an idea to have it accessable all the time in the cockpit)

Mike, your right.

SDS says to remove this knob (trim) once programming is done and locked down. They don’t want you tweaking it all the time.

I was going to mount the controller, trim and meter but the manual says it is not necessary on a street car, once programming is done and locked you can just remove it all.

I don’t know if it works on the ignition, haven’t got that far yet.

Agreed.

Mike,
Although I do agree that SDS’s mixture knob is much like variable resistor, there is a bit more to it than just that.

The mixture knob gives you a real value on the gauge function to enter into your map. You use it to adjust each single RPM segment.

Just hooking up a variable resistor to MS would not be the same. Sure, I guess you could hook up an Ohm meter and through trail and error figure out what the values were, but it would hardly be as instant as the SDS mixture knob.

The 'tuning pot' feature of the SDS being described sounds really neat. I can see how this would really speed up tuning (BTDT). Speaking of 'trim pots' (as opposed to the SDS 'tuning pot'), These can be handy, and can indeed get you into trouble. My MIC3 ECU is set up with an ignition trim pot on the dash. I can use it to retard the advance curve incrementally. The idea is if you get some bad gas or have a tuning issue or something you can just retard the ignition a few degrees until you fix the problem or reprogram the ECU. Well last Satruday I spent 2 hours trying to diagnose an ignition problem. Crank sensor? Programming error? No, my 2yr old daughter had cranked the trim pot all the way around and shifted my advance curve 10 degrees across the board.

-Ben M.

LOL! Trim pot, tuning pot, trim, potentiometer, and variable resistor a thousand names for the same thing! I think that I will stick with mixture knob since that’s what it’s called in my manual.

Ben your “engine trouble” made me LMFAO, sounds like something my kids would do!

Mounting an ignition crank trigger on a T4, what a PITA!

I just realized that if I mount it to the front of the fan it will make belt changes a bitch and if I make a disk and mount it behind the fan housing, adjusting the sensor will be next to imposable.

Wooops.. thats the coil

This is the crank trigger, the plate is about 1-1/4"X 2"

The lyrics to "Hotel California" come to mind.
(all sounds nice until you get sucked in and find the devil in the details)
I feel your pain.
-Ben M.