I posted this over on a local E-Body forum, figured I'd share here too just in case there are some people on the hump of going EFI or not!

It's been awhile since I posted (crazy busy with work, house, getting married, etc.) and I ended up keeping my Challenger with a Eddy headed 408 small block. A few years back I was seriously considering selling it but couldn't do it. I've had it since I was 16. Anyway, I'm now in the process of modernizing and restoring the car. I've already switched to 1970 style bumpers and brackets and a dual exhaust valence. The rest of the body/paint will be done at a later date.

Engine wise, I ditched the Edelbrock 800 carb and Air Gap intake for a Super Victor EFI manifold, Edelbrock 4 hole throttle body, and some 44lb Venom Injectors in port fuel injection configuration. It's all fed from a tank mounted Aeromotive Phantom Stealth 340 pump.









Controlling everything is a Megasquirt 2 ECU that I built and modified myself. This thing is awesome, and I would do it all over again in a heartbeat. It is extremely universal and configurable, both from a hardware and software standpoint. It controls the following:

fan
PWM IAC
Injectors in Bank Batch fire
A/C Compressor
Ignition Coil
fuel pump relay
tachometer output

This winter I'll probably ditch the distributor entirely and fit a crank trigger and coil packs instead. The wiring and Megasquirt modifications are already in place for it. I also plan on adding a knock sensor.

I ended up building a harness from scratch since virtually everything else in my car is not stock after installing a Painless Wiring 18 circuit harness and a ton of other modern conveniences. I use a pair of 35 pin Ampseal connectors on an aluminum bulkhead plate I fabricated and mounted in the stock location. The black one is for the chassis wiring and the blue for the EFI system. The Megasquirt is located behind the glove box.



All I can say is, wow! I wish I had went EFI sooner. With minimal tuning I have this car running far better than it ever did with a carb. It'll idle in closed loop baby smooth at 800RPM despite the cam, and idles up on cold start or when the A/C is on like a new car. She fires up instantly and doesn't stumble or buck at all if driven cold. It is almost odorless now when idling, where as before it was smelly! It has built in rev limiter (can be set up to vary with engine temp, so lower rev limit when cold) and launch control functions. Here are some screenshots of the tuning and datalogging software. It's pretty powerful stuff and I've done calibration work for late model engines at the OEM level with Engineering level calibration software.





Cruising is incredible too. This car will run as lean as 16.5-17.0:1 without an issue, and I am still playing with advance to see how much I can squeeze out of it. I've already noticed a huge difference in MPG. Throttle response and part throttle are incredible as well. I need to get it on a dyno to really dial in the WOT and spark tables still. I'm running a wideband in each bank and pull crank signal off of the VR sensor in the locked out MSD distributor. With a few mods (shaft collar on the distributor shaft and chain tensioner) the timing is actually pretty steady.

Admittedly, I'm not a carb tuning pro, but I'm not that bad either.

Last week, I installed a Vintage Air A/C system. It works incredibly well and I'd recommend it to anyone. The fitment is pretty good, the box is tiny in comparison to the factory stuff, and it blows like ice. I did not use their compressor kit since I have a March serpentine drive, so I fitted a compressor to that instead. It makes the car much more usable since I no longer have to wait for the perfect day to cruise in it without being baked alive. Low speed cooling is an issue if I idle for a long time, but that rarely happens so I don't think I'll be doing anything about it. The HHR fan cools quite well for the most part.





This car is infinitely more enjoyable now, and I cannot wait to get the body/paint done so it looks as good as it drives. I'm planning on going to modern suspension, brakes, and a 6 speed too. If I can get low to mid 20's MPG out of this thing I'll drive it daily!

Way cool!

You will have to either drive it at artificial areas than "normal" to get the auto-tune to hit all the cells - or just smooth it out afterward by averaging it some. It basically "tunes" the fuel table in a stair step fashion since it's tough to hit all the rpms at all the different loads and still actually drive it at the same time. There are probably many areas of the fuel table that you'll never ever hit.

Yeah, VEAL works pretty well. Just punch in a target AFR and it adjusts the VE tables until it is where you want it to be. Widebands are pretty much mandatory as far as I am concerned unless you do it all on a dyno or have tons of time. I have neither.

I have a decent base map so I am now beginning to tune each bank independently. That made a huge impact on idle quality. Even a slight AFR difference from bank to bank can make all the difference between a solid idle and a rocky one.

I'm running MS3X on mine with the sequential injection and I couldn't be happier with how it all works.

The only tuning I did on the dyno was for some WOT pulls to try and dial in the timing better. Even at that - it still had to be changed because the dyno couldn't replicate the additional load of the wind resistance. I have thoroughly enjoyed the entire process of dialing it in.

Not bad for a box of resistors and caps! Welcome the MS club!

I really enjoy getting mine dialed in, and nice to have it run better every time you are out.

The only place I can't get perfect on mine is the accel enrichment. at 25ms pulsewidth it's still lean on 2 injectors. But not enough to detract from driving unless you need to mash on it!

Great stuff. Tunabilty is key with this. Same with the coilpacks. Excellent info. Is rf noise making the graphs read like that?

Awesome,

I have an MS3X unit built and running on stim boards, next step is to convert the car after drag week. I really don't have any carb problems, car gets good MPG for an 11.20 car(13-14 highway) and I don't have any drive ability problems.....I just want to be able to tune with my lap top.

I am going to try and do a jeep cam sensor like redmist did on his big block, I am not sure if it can be done on a small block or not but I will find out soon.

No, it's zoomed in a lot on that screen shot . Zoomed out its actually relatively smooth, for the cam duration. It's very steady off idle.

I am going to build one as well. Are you thinking about moving to sequential injection?
Hate to say it, but my budget may only allow for TBI for now and get a new intake later.
A/C conversion is underway now. Then the Megasquirt 2 kit and STIM board will be next.
Craig

I have to ask... is this in the right section.. talking
A/C ... as far as I know, race cars dont run A/C..
at least my junk doesnt
EDIT
I understand the injection.. I'm installing it now

Quote:

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I am going to build one as well. Are you thinking about moving to sequential injection?
Hate to say it, but my budget may only allow for TBI for now and get a new intake later.
A/C conversion is underway now. Then the Megasquirt 2 kit and STIM board will be next.
Craig

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No, sequential only really applies to low RPM's and idle quality. I'm very happy with the way mine idles and with the gearing it doesn't spend a lot of time at low RPM either. I'd have to upgrade to MS3/MSX which would cost me another $500 with harness, case, etc, and it'd simply be overkill for my build since I'd never put a dent in all of the inputs and outputs it has. I'd have to cut a new hole in the firewall and build another bulkhead harness too.

That said, my MS2 is maxed out right now so I'll only make the jump if I absolutely need to.

My build with everything was the same cost or less than one of the TBI packaged setups that are becoming quite popular, and it is far more capable than any of them too.

Quote:

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I have to ask... is this in the right section.. talking
A/C ... as far as I know, race cars dont run A/C..
at least my junk doesnt
EDIT
I understand the injection.. I'm installing it now

---

Race cars don't run EFI most of the time either. If there were an Engine ONLY forum, I would have posted there. But this is called Engine AND Race Tech.... Didn't realize it had to be both to apply.

I'm interested in the bulk head connectors you used. any chance of getting some pics of those and part numbers. I'm looking at doing the same thing with my car since the wiring harness needs to be updated anyway.

Same here on the connectors.

I am going to clean up the wiring on my MS3X setup, and get my engine "Plug and play" with some connectors like that.

I was originally looking at some cannon style plugs, but those look great also!

Riff Raff, your a/c would need to be for somebody sitting in your bed, holding on to the cage !!

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My A/C is still 2/40.. 2 window down at 40mph...I
will put A/C on my 38 Ply... thinking about changing
that 440 out for a gen 3 and maybe twin turbos along
with a 518 trans... gotta see how things would package

They are 35 pin "Ampseal" connectors.




http://www.digikey.com/catalog/en/partgroup/ampseal-series/27450

http://www.digikey.com/product-detail/en/776164-5/A105102-ND/2327367


They're pretty neat; they are sealed on the backside with a solid silicone barrier and the pins crimped onto the wires puncture holes in them so they automatically seal as they are installed. There is no need for a seal crimped onto the wire nor a plug like on other weatherpack connectors. They do make plugs to seal holes in the backside if one is depinned or punctured on mistake.

The male connector body has a silicone seal and the connector header also has a perimeter seal to seal off whatever you bolt it to. The lock tab is quite sturdy and there is no chance of these ever coming undone on accident between that and the silicone seals.

Ironically the sealed MS Pro and Microsquirt units now ship with these connectors and they can be submerged. I was using them before they were cool! I bought mine online from Digikey. They are very inexpensive, less than $10 each per side and a bag of 200 pins was like $8. They are color coded and keyed differently, so there is no chance of plugging them into the wrong headers. I bought black (chassis), blue (MS2), and grey (eventually for the MSX if I upgraded).

http://www.google.com/imgres?imgurl=http...=88&ndsp=26

http://www.google.com/imgres?imgurl=http...t=0&ndsp=18

http://www.google.com/imgres?imgurl=http...t=0&ndsp=18

Assembly is straighforward; crimp the pin to the wire and put the connector in the "service" position. The red lock on the front side is basically slide forward slightly but not removed. You then insert the pins through the back seal. When they are all installed properly the red lock is pushed back into place and the pins can no longer come out.

To remove a pin, the lock is moved and you simply twist the wire slightly to get it to pull out.

The OE crimpers are crazy expensive, but I was able to make do with generic weather pack crimpers and I also soldered them to make sure they never come loose.

I soldered and heat shrunk the wires to the header on the interior side of the firewall. Pro tip: Crimp pins onto the wire on this side and they will slide snugly onto the header pins making it MUCH easier to solder. Use large heat shrink or a zip tie to provide some strain relief, and anchor the harness bundle with a little bit of slack within 6" of the header with a P clamp or similar.

DigiKey has a pretty detailed catalog and PDF's you can download for everything you want to know about these.