MS on my 72 Chevelle SBC... A few questions?

[RacnJsn95]

I was wanting to do a 5.3/6.0 swap complete with GM electronics, but my Dad convinced me that being times are hard, I should try to keep as much money as I can in the bank... I want the car to be streetable, yet still fast, and I want EFI for better mpg... I've been collecting mics parts and pieces over the past 3-4 years picking up pieces as I come across sweet deals, and I've pieces together this:


injectors not pictured

The setup consists of, a Prof. Products Super Hurricane+ EFI manifold, what I think is a 1000CFM progressive linkage 4v throttle body, fuel rails off some other setup that just happened to work on this manifold, and I now have a set of 26# injectors from an 04 gm 6.0... Rather than buy a whole new engine, I'd like to put this stuff to use with the help of a MS system. I am semi familiar with MS, and have wanted to put it on several cars in the last 7-8 years, but have never pulled the trigger.

At the moment I have 2 questions that I have not been able to find the answer for...

1) Camshaft... How big is TOO big? I know too much overlap, and it seems duration also makes it hard to tune... The cam is currently a 521/508 lift cam (w/ 1.6 rockers in the intake side), 234/244@.050" duration on 112 LSA. I can't find the exact IVO/IVC/EVO/EVC specs any more as the cam grind seems to have been disconued within the last year or so that I've looked it up last. Is this runable? Or should I swap in something else?

2) Firing the MS off the tach signal... I've seen it mentioned several times that the MS can be triggered from a tach output signal? Although I haven't been able to find anything successfully running on like that... I've got an MSD 6AL box with an MSD Pro-Billet distributor... While at the moment I'm not too concerned about using the MS box to control ignition, I would like to retain them both, and was thinking if I could trigger the MS box off of the tach output from the MSD box, that would be super cool, and most likely the easiest way to go... Can anyone confirm or deny this?

Thanks!

[Matt Cramer]

The setup consists of, a Prof. Products Super Hurricane+ EFI manifold, what I think is a 1000CFM progressive linkage 4v throttle body, fuel rails off some other setup that just happened to work on this manifold, and I now have a set of 26# injectors from an 04 gm 6.0... Rather than buy a whole new engine, I'd like to put this stuff to use with the help of a MS system. I am semi familiar with MS, and have wanted to put it on several cars in the last 7-8 years, but have never pulled the trigger.

Looks like a decent starting point.

At the moment I have 2 questions that I have not been able to find the answer for...

1) Camshaft... How big is TOO big? I know too much overlap, and it seems duration also makes it hard to tune... The cam is currently a 521/508 lift cam (w/ 1.6 rockers in the intake side), 234/244@.050" duration on 112 LSA. I can't find the exact IVO/IVC/EVO/EVC specs any more as the cam grind seems to have been disconued within the last year or so that I've looked it up last. Is this runable? Or should I swap in something else?

Factory ECUs with factory tunes may be thrown by big cams, but when you've got full tunability like with a MS, this isn't as big an issue. MS has been run on some pretty crazy engines.

2) Firing the MS off the tach signal... I've seen it mentioned several times that the MS can be triggered from a tach output signal? Although I haven't been able to find anything successfully running on like that... I've got an MSD 6AL box with an MSD Pro-Billet distributor... While at the moment I'm not too concerned about using the MS box to control ignition, I would like to retain them both, and was thinking if I could trigger the MS box off of the tach output from the MSD box, that would be super cool, and most likely the easiest way to go... Can anyone confirm or deny this?

Thanks!

Confirmed. The MSD box's tach output will trigger a MegaSquirt RPM input, usually without any trouble at all.

[RacnJsn95]

Ok, I'm gonna try it... I ordered a MegaSquirt Stimulator v2.2 - unassembled kit from you @ DIY AutoTune, ordered a soldering station, and some supplies... If I can't put the stimulator together myself, I have no business trying to assemble a MS box of any kind and I'll just have to order it assembled.

[RacnJsn95]

OK, I received the MegaStim v2.21 kit shortly after ordering it, but no such luck on the soldering station showing up fast. It finally showed up today, so I started to assemble the MegaStim kit. The soldering station I'm using is a Weller WTPCT unit, with the TC201T pencil iron. I started using a 1/32" conical tip @ 600 deg, but couldn't even get stuff hot enough to make a joint. About to give up, I decided to try the tip that came with the station which was a 1/16" screwdriver tip @ 800 deg (I think, and it may be too hot?), then I was able to solder stuff...

When I first started I noticed the stripes were "burning" off the resistors and one had a blemish, I figured because the tip was too hot, but I was only leaving it in place long enough to get the solder to melt. As I got used to the tip, and the soldering procedure I had less problems, but I still think the tip may be too hot for temp sensitive components... So I'm going to order some 700 deg tips... Below is a picture of the completed stim kit, with a close up of the problem resistors, and one burn spot I had over a trace on the back of the board... The burn spot it not all the way through the trace, so I think it may be ok, but I'm wondering if I will need to replace the resistors? I wish there was a way to test this thing without the MS board.



Keep in mind this is my first time attempting to solder electronics on a real board... I think the most important thing I've learned with electronics soldering so far is that EQUIPMENT MATTERS! I've tried making stuff on proto boards with a harbor freight iron, and couldn't for the life of me figure out how people could even do this stuff, lol! I'm going to order the relay board kit, and try that then decide if I should try to tackle the MS system itself...

[trakkies]

First, what solder are you using? If lead free - throw it as far away as you can and get 60/40 lead stuff. You'll likely need to go to a proper supplier like Digikey. Best size is 0.03" diameter, RA. The tip should be about twice than, with an angled face. Temperature about 650F.
When making the first joint of several, clean and tin the tip. And do so each time you start on as new component. You don't need to when doing several joints one after another, but must each time the iron is left for more than a short time.

[RacnJsn95]

I am using Qualitek RA300 Rosin Core .032" dia solder... Apparently it is lead free I was under the impression that I just had to use a rosin core solder when soldering electronics, never read anything about specific lead contents. I can get 60/40 rosin core .032" at Radio shack. So I should switch solder before attempting to assemble anything else? Will the stim work or is it junk?

You're saying 1/8" tip? That seems big for such small stuff... I already ordered some 1/32" "screwdriver" tips in 700 and 800 deg today. I'll have to look into other tip options...

[trakkies]

Lead free solder is the spawn of Satan. ;-)

1/8th inch tip would be 0.125" I was suggesting one more like 0.06 which would be about 1/16th. Basically one small enough not to bridge adjacent tracks, etc.

I didn't understand the relationship you give between tips and temperatures. But Googling your iron suggests the temperature isn't user set. Which seems a retrograde step to me. However, 650F is about right for 60/40 solder. Lead free needs higher.

[8974Ollie]

I am using Qualitek RA300 Rosin Core .032" dia solder... Apparently it is lead free I was under the impression that I just had to use a rosin core solder when soldering electronics, never read anything about specific lead contents. I can get 60/40 rosin core .032" at Radio shack. So I should switch solder before attempting to assemble anything else? Will the stim work or is it junk?

You're saying 1/8" tip? That seems big for such small stuff... I already ordered some 1/32" "screwdriver" tips in 700 and 800 deg today. I'll have to look into other tip options...

The soldered joints should be OK, When you get the solder from Radio Shack, get the solder resin too.
Judging from your posted photos the solder joints look good. Nice cone shape.

[trakkies]

[snipped]
When you get the solder from Radio Shack, get the solder resin too.

Why, as a matter if interest?

I've only ever used multicore.

[8974Ollie]

the resin will help to keep the solder iron tip clean and help the solder stick to what ever you are soldering.

[trakkies]

the resin will help to keep the solder iron tip clean and help the solder stick to what ever you are soldering.

Right. I just wipe the tip on a damp sponge. Or use my finger - but that need practice.

[RacnJsn95]

Well I got my assortment of soldering iron tips, went and bought some 60/40 rosin core solder, and the relay board kit showed up so here is my next attempt at soldering electrical... stuff. I think it turned out really good, better than the stim. The 60/40 solder was probably helped the most. Used the 1/16", and tried the 1/32" blade screw driver tips in 700 deg. I don't think I could have asked for better results for my second attempt at anything like this. Awesome looking joints on this thing, and no board burns!



The only thing I'm questioning at the moment is whether or not to use the relay board or not... After doing some more reading/research on here and the mega manual, it almost seems like the relay board is more of a PITA than it's worth when it comes to the wiring in the long run... I'm half tempted to sell this thing on evilbay and try to recoup some money then Just buy the MS II kit, and 8' harness, then wire my own relays, and fuses inline; seems like it would keep the wiring effort more straight forward. I'm no stranger to wiring, just have never dealt with PCB stuff... Thoughts?

[trakkies]

My principle is to keep the number of connectors and connections to a minimum. My car already had EFI so I simply remade the engine loom using the original relays. One advantage of the relay board is that it makes probing circuits for fault finding etc easier. I have a breakout board which you plug between the MS and loom for that - but so far haven't needed it.

[8974Ollie]

I would keep the relay board. Makes for a neat instillation. You say you are inclined to get some relays and fuse holders and attach them in line. How will you mount the relays and fuses? Having them dangling on the wires will not make a tidy package.

[trakkies]

You can get relay plugs which clip to brackets. Or a mounting frame that takes several together. Fuses can be in a fusebox - they can be bought in various types. My preference is to mount such things inside the car - close to the MS. Rather than the hostile environment beside the engine.

But this is just my preference.

[RacnJsn95]

Ok, I think I will retain the relay board... Looking at wiring options now and mounting locations... I think I will mount the MS box itself under the dash on the drivers side, so I can easily access the DB-9 tuning port. I believe I will mount the relay board on the under the dash, on the passengers side in the cab.

Looking at the DIY Autotune wiring options, I could buy the relay cable (4'), and then would have to get a wire bundle... I think the 23" bundle would be too short, the 12' is obviously too long, and a waste of wire, and money... The relay board came with a male DB-37 connector and hood, so I think the most economical route would just be to buy an 8' harness from DIY, cut it half, solder the connector to the one end, and use the remaining 4' as my wire bundle... Took some rough measurements, it's about 4' from the drivers side mounting point of the MS box to the relay board mounting point on the pass side, and 4' inside the cab @ the relay board to the front of the engine. So 8' is the magic number. Anyone see a problem with cutting the 8' harness in half and doing this?

[trakkies]

Sounds good. I've no real idea of what you'd pay for the correct cable sizes and colours in the US by the metre. As what you're doing amounts to making a loom yourself.
The most difficult part of making this loom is fitting the DB37 connector.

[RacnJsn95]

Ok! Finally made the last "big order" for the MS stuff, sensors, wiring, fuel pump, and WB o2 sensor stuff today!

Only had one question at the moment. I bought the Innovate standalone gauge kit w/ LC1 & DB gauge (http://www.DIYAutoTune.com/catalog/inno ... p-152.html)... The car will have dual exhaust. I'm assuming since the car will be running a multi-port injection setup, that both banks will "in theory" read the same. So will I be ok with one o2 sensor, or do I REALLY need 2?

I had planned on welding the LC1 bung into the drivers side header collector.

[trakkies]

Ok! Finally made the last "big order" for the MS stuff, sensors, wiring, fuel pump, and WB o2 sensor stuff today!

Only had one question at the moment. I bought the Innovate standalone gauge kit w/ LC1 & DB gauge (http://www.DIYAutoTune.com/catalog/inno ... p-152.html)... The car will have dual exhaust. I'm assuming since the car will be running a multi-port injection setup, that both banks will "in theory" read the same. So will I be ok with one o2 sensor, or do I REALLY need 2?

I had planned on welding the LC1 bung into the drivers side header collector.

According the information I got with my Tech Edge unit, a wideband sensor can't stand as much heat as a narrow band one, so usually has to be mounted rather further downstream in cooler gasses.

Could you run a link pipe between the exhausts and fit the sensor to that? I don't think there is any power increase with twin fully separate exhausts on most V-8 configurations. But I'm not certain.