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Gonna build a megasquirt
https://www.slantsix.org/forum/viewtopic.php?t=6463		 Page 3 of 4
Author:  welly225 [ Thu Aug 14, 2003 5:37 am ]
Post subject: 
Thanks for the support. I showed the website to a friend of mine who seems to think that the assembly wouldn't be too hard so we're doing some more research on it. He's also got a laptop (bonus). The engine build is still in the planning stages and the car is still in the body shop (not even started yet) so I don't need to rush out and do this tomorrow or anything. I just want to start with a solid plan.
I'm definitely on-board with the EFI page idea.
If I get into a bind I may take you guys up on your offers.

Thanks
Author:  jedimaster [ Thu Aug 14, 2003 5:49 am ]
Post subject: 
Bob D.
Could give me a run down on all the parts and specs you may have.
You said your running a
3.8l GM Thottle Body(off an NA or turbo car),
GM ECU Is the ECU and NA or Turbo one and what did you do about the programming of the ecu?
GM Turbo injectors and MAF,
Are you running an intercooler?
What ignition are you running and how did you go about boosting the fuel preasure, rebuild your tank and use an inline high preasure pump?
Also have you had your car on the dyno, or run it in the 1/4?
Have you done any other engine mods, cam, crank, pistons, valves, rods, port n polish etc...
Author:  Bob D [ Thu Aug 14, 2003 6:47 pm ]
Post subject: 
Jedi asked:
1) Could you give me a run down on all the parts and specs you have?
You said you're running a 3.8L GM Throttle Body (off an NA or turbo car)?

TB is from a NA 3.8L '85 Olds.

2) Is the ECU NA or Turbo and what did you do about the programming of the ecu?

NA ECM (Serv. No. 1227065) original EPROM, no re-programming. MAF sensor is self-calibrating (to a point).

3) GM Turbo injectors and MAF?

Yes, both from a '84-'85 turbo Buick

4) Are you running an intercooler?

No

5) What ignition are you running and how did you go about boosting the fuel pressure, rebuild your tank and use an inline high-pressure pump?

SL6 electronic distributor with vacuum and centrifugal advance disabled, GM 7-pin ignition module, ESC with knock detector, MSD 6A.
Adjustable fuel pressure regulator.
Stock fuel tank with 3/8 inch sending unit.
Inline high-pressure fuel pump

6) Also have you had your car on the dyno, or run it in the 1/4?

No

7) Have you done any other engine mods, cam, crank, pistons, valves, rods, port n polish etc.?

No
Author:  kesteb [ Thu Aug 14, 2003 11:10 pm ]
Post subject: 
The SDS site is http://www.sdsefi.com . You should read the tech section. Most of the problems with the megasquirt seems to be syncing the computer with a tach signal. If you use a MSD this is not a problem.

From the figures that I have seen, each injector requires 6 amps. This would be 36 amps just to trigger the injectors. Now you know why new cars have 100 amp alternators.
Author:  Dart270 [ Fri Aug 15, 2003 10:30 am ]
Post subject: 
Kesteb,

That 6A/injector must have been for low impedance MPI injectors, and even in that case, that seems mighty high for an average current draw given that peak-and-hold modulation should be used for those injectors. That is probably a peak current rating, and does not figure into power budgeting (average power) since the battery provides a reservoir of energy over short times.

A MPI 6cyl with high impedance injectors (standard on most production cars, 12-16 Ohms each) would have roughly 1A per injector at 100% duty cycle, or less than 6A total when the car is at WOT at high RPM. Normal usage (cruising, lower RPMs) will be much less than this, and you can run slightly bigger injectors to keep your duty cycle lower if you wish.

The MS computer only uses about 2-400 mA total, and the fuel pump uses another 3-5A or so, so the total budget is around 10A at max load, and closer to 6A under cruise conditions.

I did run my main power wire (injectors, ECU, pump) directly to the alternator with a fuse, so the cars original wiring does not play in, only the alt capacity.

My TBI system currently has 3.6 Ohms/injector, and thus has about the same current draw as the MPI I just described. On the highway I run less than 20% duty cycle, which is around 1 A total (average) current draw. I was running my stock 40 A alternator with no problems, and I just went to a later model supermini Denso alt at 50A, and have noticed no charging problems.

Just some food for thought...

Lou
Author:  Chuck [ Fri Aug 15, 2003 5:33 pm ]
Post subject:  Donor Cars
I just did a junkyard run yesterday looking for donor cars for a TBI system. Here is what I came up with so far:

Furd used a TBI on many '84 to '87 3.8L V6 engines. This looks like a good donor for a 2bbl system. We will need an adaptor plate. I like this size because it would match up well with the 225 (3.7L) and run OK in open-loop mode, so if the feedback sensors get goofeed up, it should still run.

I found an '87 Tempo that had a 4 cyl engine that used a TBI but it had been removed. I verified that the bolt pattern on this TBI was a perfect match for the SL6 1 bbl manifold. Unfortunately, I couldn't find any markings on the engine indicating the engine size, and it was the only car like it in the yard. We may be able to get a larger injector for this unit to up-size it for the 225.

I didn't see anything from Chebby that looked as good for a donor. There were very few Mopars in the yard, and the one V8 I saw with a TBI didn't look good for a donor either.
Author:  Pierre [ Fri Aug 15, 2003 6:25 pm ]
Post subject: 
Chuck, tempo engine was most likely a 2.2 or 2.3L. 94 2.3L tempo is the family car here, but that is port injection.

Are you sure you want a throttle body that small though? It would be as restrictive as a holley 1920 would be I assume. Now two of those on a dual offy manifold would be a nice setup. GM has a 1 barrel throttle body common in the late 80s to early 90s as well. I'd rather have two of those instead of one bigger one.

The dual barrel GM throttle body I am using now has plenty of air flow, but I suspect it causes a bit of turbulence because the clifford manifold has a 1/2 circle in the side of the flange facing the motor and this cuts into the airflow path of the throttle body. Also because of that curve the plate to manifold gasket has less then 1/8" room to seal.
Author:  kesteb [ Fri Aug 15, 2003 10:46 pm ]
Post subject: 
When I have done a power budget in the past, I have used the rated ampreage on the back of the equipment. This is standard practice for sizing UPSs for computer rooms. The equipment may never, ever use the rated amperage, but you need to have the excess capacity for "just in case". The last thing you need is a power outage and then exceed the UPSs capacity. Some rather interesting things can happen. Frying $100,000 computers is one of them.
Author:  shiftless [ Sat Aug 16, 2003 9:15 am ]
Post subject: 
Dart: You're correct, the MS uses a peak-and-hold method of controlling low impedance injectors (the ONLY way they can be controlled without frying them). Six amps are applied for a couple milliseconds, at which point the current drops off to a holding current of around one amp. Since the 36A is only being drawn for around 2ms, and the average current draw is much less, it would be safe to use a 30A alternator (with solid-state regulation of course).
Author:  Chuck [ Sat Aug 16, 2003 12:24 pm ]
Post subject: 
Quote:
Chuck, tempo engine was most likely a 2.2 or 2.3L. 94 2.3L tempo is the family car here, but that is port injection.

Are you sure you want a throttle body that small though? It would be as restrictive as a holley 1920 would be I assume. Now two of those on a dual offy manifold would be a nice setup. GM has a 1 barrel throttle body common in the late 80s to early 90s as well. I'd rather have two of those instead of one bigger one.

The dual barrel GM throttle body I am using now has plenty of air flow, but I suspect it causes a bit of turbulence because the clifford manifold has a 1/2 circle in the side of the flange facing the motor and this cuts into the airflow path of the throttle body. Also because of that curve the plate to manifold gasket has less then 1/8" room to seal.
Pierre,

My reason for the smaller TBI is to make a bolt-on conversion for the 1 bbl user. I don't know what the CFM rating is on the 1 bbl or the Tempo TBI, but the TBI may be greater because it doesn't have a venturi. I am thinking that we may be able to put in a larger injector so that it works OK with a 225 slant. I just think it would be nice to have a bolt-on unit that could be set up easily. I know 2 bbl manifolds are getting hard to find, so this setup would be for the 1 bbl user who just wants to get rid of the old carb setup with a minimum of hassle and expense. Just my personal take on it. For myself, I already have a Super Six manifold, so I want to check out the 3.8L TBI.
Author:  jedimaster [ Tue Aug 19, 2003 9:21 am ]
Post subject: 
Thanks bob thats a big help. Were you saying the GM Throttle body you are using will not work with the Megasquirt controller? I am going to be compiling data for Slant six EFI projects in the near future, and if anyone wants to have there info or not have there info posted on it lemmie know, I'll be sure to accredit anyone that submits information.

I was figuring on about 10 amps for the entire Batch fire Multiport conversion using a megasquirt.
I am up in the air with the Throttle Body
1) BMW 3.8l Throttle Body from the early 90's
2) Similar aged Ford 5.0l Throttle Body

Both are similarly priced(cheap) both have compatible TPS and IAC, both have already been documented and used in Mega Squirt Projects. I like the BMW one for its exoticness. But I don't know what the bolt pattern will be and how easy/hard it will be to machine it onto my intake. The 5.0 ford will likely win out as I can just buy an adapter for it. Any thoughts or anyone have any CFM rating for either one?

I was thinking of using Fuel Injectors from a 22RE Toyota Engine as they will be enough for up to about 200 HP according to the chart on the Mega Squirt site. Also I have access to them for cheap or maybe free. :) Or I was thinkning of using Fuel injectors off of a 3.8l Chrysler minivan as they flow an extra 23cc more at 223 cc and should do to nearl 250hp. They should also be plentiful at most any Junkyard as lots of them vans are gettin dumped. :)

As for the Fuel pump Issue I was thinking of using the design on the sds website for a surge tank, as I have seen several that are very much the same as that one and I want to avoid running a new fuel line and modifing my existing tank. I was planning on buying a new aftermarket external fuel pump as I don't know any car that comes stock with a suitable fuel pump.

As for the electronics, I am planning on gutting every wire out of my car and re wiring everything as much of it is getting pretty brittle, so when that happens I'll upgrading to a newer Alternator(likely one off of a later model 5th ave, as thats what I am taking the front brakes off of). Currently I am running an electronic distrib off of a late 70's slant, with a dual ballast resistor, new voltage regulator, 5 pin ICM, Accel Superstock coil, Superstock Wires, Wells Gold cap and rotor. I figure I'll have to switch to an MSD Coil of some sort to get a better ignition signal, Can anyone point me to the least expensive one that will get the job done, and what things will I have to change off my current setup to make the MSG coil and newer alternator work? Also I plan on gutting the entire instrument panel system and using an aftermarket setup for all gauges.
Author:  jedimaster [ Tue Aug 19, 2003 9:28 am ]
Post subject: 
Just a quick one, Now the MSD 6A Multipark Ignition, that is something you add on in addition to the existing coil right? What outputs does the 6A have on it and will it be compatible with everything I currently have and will have. Changing the alternator shouldn't altar the the function and components of the ignition system I have right?
Author:  welly225 [ Tue Aug 19, 2003 10:59 am ]
Post subject:  Ultra Mega Squirt
http://members.shaw.ca/megasquirt/UMS.htm

This is a link to Ultra mega squirt. A friend of mine forwarded it to me. It is an ugrade planned for fall by the sounds of it. Seems to include provisions for ignition control, a wide band O2 sensor and also semi assembled kits (for wussies like ME who are too chiken to solder themselves).
Author:  Dart270 [ Tue Aug 19, 2003 11:53 am ]
Post subject: 
Jedi,

The 6A has a dedicated "tach" output that is basically a 12V square wave and will work well for triggering the MS ECU. Also, I just bought a 4.6L Mustang TB off ebay that I will use on my first MPI setup. You can get almost new take-off ones for < $40 with TPS.

Welly,

I would not hold my breath for the UltraMS system in early fall. It is likely worth waiting for (and I will probably upgrade when it comes out), but I wouldn't be surprised if it takes quite a bit longer to get into kit form.

Lou
Author:  jedimaster [ Tue Aug 19, 2003 12:38 pm ]
Post subject: 
Yah I was reading about the ums, by the time I get around to doing the MS portion of the Fuel injection setup it may be out and ready to build. :) So you are going to use a 4.6l mustang throttle body, off a '96 and newer? I have seen a few of them in the 5 - 20 dollar range. How are you plannig to fit it to the manifold?
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