MSD Suggestions....

[vetteboy86]

Looking to mount an MSD on the vette. Any mounting suggestions, or pictures of an install?

 

[rascal_rascal_99]

The best place you'll probably find to mount an msd box is going to be under the headlight on the passenger side. Mounting it may take a little creativity on your part depending on how you decide to do it. I think a lot of people who put them there remove the horn and mount an L shaped bracket there in it's place that the msd box can be bolted to. What I did instead was drill two holes through the metal strip that holds the air spoiler in place under the front end. I did have to use two very long bolts to do this so that I could shim up the back end of the msd box a few inches. The front of it I packed foam around to cushion it and help hold it in place but it's not bolted. I'd imagine you'll want to go with a msd6AL box, although I'd suggest calling msd and talking to them if you're not sure. Their wiring harness will make the job easier too if you haven't thought about it, and if your running something other than stock copper top plugs, you'll probably want to do a plug change when you put the msd box in.

 

[vetteboy86]

I actually was able to get some questions answered over on their forum. I am going to go with the msd 6AL box, but was worried how the stock rev limiter would work. I am going to get the in cap style coil they offer to go back to a stock type look . Did you use the harness? I was wondering if they could give a data sheet on how that harness actually plugs in. I am worried about the EST wire and also the tach drive wire. I wanted to try to mount the box somewhere close to the battery. I doubt however there is enough room.

 

[rascal_rascal_99]

I don't think you'll find room near the battery...good luck though, maybe you'll find a spot I missed! lol It will probably be better to get it closer to the coil than to the battery though since you'll have more wires running to it instead. Just run a nice heavy wire for your hot wire going to the battery and it should be fine...and as I'm sure you've already heard, make sure you've got very good connections anywhere you're tying in wires. When I was putting in mine a couple of years ago I tried the msd forums and found some help with installing, but nothing about where to put it. Since I was working on a 92 LT1, we're talking about putting it into a little bit different beast here, so I know the basics of how it will go in but don't know of anything much more specific to your car that you'll have to consider much. I do know there is a ton of wiring diagrams at msd's website, if you have trouble finding what looks like the right one for you I'll see if I can help you scare up the correct one if you want. I used their wiring harness with my vette, I've put them in race cars quite a bit in the past and have done some without the harness...the harness makes it much easier, especially if the msd box fails, just a couple of plugs to swap and it's running again if you use the harness. Basically you're looking at unplugging the coil wire from the coil, plugging it instead into one end of the wiring harness, the other end of the harness plugs into where you just removed the coil wire, and you'll have a T/pigtail coming out of the middle of the harness that you'll run to the wires coming from the msd box. One guess on the rev limiter is that I wouldn't expect it to be a problem, which ever one is set lowest is simply going to kick in and the other won't matter...I don't know anything about the stock one or how it works, my personal preference would be to try to get things programmed so that you're hitting the msd rev limiter instead. Are you using the stock tach or an after market added in? If your running off the stock tach, you may not have to worry about the tach wire coming from the msd box at all. If I remember correctly, that's mainly for if you have an aftermarket tach added on and need somewhere to plug it into? On race cars I've used it, on street cars I don't think I've had to unless it was an aftermarket tach added on. Have I helped making anything clear as mud yet?

 

[vetteboy86]

Thanks, I will let you know how it is going as I get closer to the install.

 

[Chris Kennedy]

Thanks, I will let you know how it is going as I get closer to the install.

I used to have one of these MSD units in my old '81, and watched a friend of mine who is a professional mechanic fuss over installing one of these in a C4. It can all get VERY complicated, and the unit in my car failed and shut down the car (don't know if this would happen in a C4 installation). On top of that, the unit did NOT give an improvement that you could feel. So......this is a long way of saying that if you haven't installed it, you may be best off returning it and using the money for something else. You end up spending lots of time and effort getting frustrated on putting it in, and then when it doesn't do anything you can feel you are too embarassed to admit it, and you have just complicated-up your ignition system to boot! When I had the engine rebuilt in my '81 I simply left it off.

/s/ Chris Kennedy

 

[vetteboy86]

I appreciate your reply. But not all of your advice is correct. I had good advice when I installed my msd system. I am experiencing a miss above 4700 RPM's or so. I think it is either ignition or fuel. So a guy at work who has built several motors and currently runs his 9 second car regularly suggested the MSD. I do have electrical background with schooling and my current job, however this install was not a problem at all. MSD makes a wiring harness just for the GM incap Coil HEI system. There is absolutely no cutting or splicing of the stock harness. The MSD harness simply runs from the MSD box, to the coil and then the wires that plug into the coil go into the MSD harness. The good part is that if the box ever did fail, I can unplug the harness and hook stock wiring back up and drive away. I would recommend this install to anyone. If anyone is interested, I could provide part numbers.

 

[Chris Kennedy]

Sounds good! Glad it worked out for you.

/s/ Chris

 

[vetteboy86]

Thanks!

 

[tdr1919]

I appreciate your reply. But not all of your advice is correct. I had good advice when I installed my msd system. I am experiencing a miss above 4700 RPM's or so. I think it is either ignition or fuel. So a guy at work who has built several motors and currently runs his 9 second car regularly suggested the MSD. I do have electrical background with schooling and my current job, however this install was not a problem at all. MSD makes a wiring harness just for the GM incap Coil HEI system. There is absolutely no cutting or splicing of the stock harness. The MSD harness simply runs from the MSD box, to the coil and then the wires that plug into the coil go into the MSD harness. The good part is that if the box ever did fail, I can unplug the harness and hook stock wiring back up and drive away. I would recommend this install to anyone. If anyone is interested, I could provide part numbers.

Vetteboy,
How are you? I just failed my inspection on emissions, the mechanic suggested installing the MSD unit, that it would reduce the CO emissions and also give me better gas mileage. You still feel the MSD unit is the way to go?
Thanks,
Tom

 

[lex luther]

Had mine mounted directly behind the alt. over the discolored valve covers on the passenger sides. I like the fact that it covers up some of the valve cover and it looks flush behind the alt. No problems in 7+ years with this location, including Houston summer heat.

 

[lex luther]

Meant, drivers side.

 

[tdr1919]

A mechanic told me he's seen them l mounted inside the car on the passengers side (up above where your feet go) and run the wires thru the firewall.
I cant see a good place in the engine compartment to mount it and still keep the wires relatively short.

Vetteboy, did you install it yet , and where did you mount it?
Thanks,
Tom

 

[rascal_rascal_99]

A mechanic told me he's seen them l mounted inside the car on the passengers side (up above where your feet go) and run the wires thru the firewall.
I cant see a good place in the engine compartment to mount it and still keep the wires relatively short.

Vetteboy, did you install it yet , and where did you mount it?
Thanks,
Tom

Unless being stuck down there muffles the noise more than what I would expect, did he say anything about the buzz/humming noise from the box? MSD boxes actually aren't quiet under power, I'm sure you could drown it out with the radio...lol...but knowing the noise they produce is part of why I stayed in the engine compartment.

Lex, would it be possible to see a pic of yours? I'd like to see it if it's not too much trouble. Thanks!

 

[Rowdy1]

Worked For Me

A mechanic told me he's seen them l mounted inside the car on the passengers side (up above where your feet go) and run the wires thru the firewall.
I cant see a good place in the engine compartment to mount it and still keep the wires relatively short.

Vetteboy, did you install it yet , and where did you mount it?
Thanks,
Tom

That's where mine is, passenger side, to the right of your feet with the wires nice and short.

 

[jmrl98]

I think he has it mounted already, but just for option purposes, mine is under the driver's side headlight, wires run along fender well.

 

[Hilmarbjorn]

Here´s where I mounted mine:

I think the 6AL is a little taller than the Digital-6 so it may not fit in this location.

 

[tdr1919]

That's where mine is, passenger side, to the right of your feet with the wires nice and short.

Rowdy1, is it noisy?

Tom

 

[rascal_rascal_99]

Rowdy1, is it noisy?

Tom

I had the pleasure of meeting Rowdy1 (briefly) at cruisefest and hearing his car...which I think it's normal rumble may drown out the sound from an msd box...lol. I'd be curious to hear from someone with a non convertable that's mounted a box inside the car somewhere to tell us how noticeable it is.

 

[lex luther]

Rascal

Unable to take picture, and even if I could it would not provide the info you are requesting for mounting. It is very slick, immediately behind the Alt. and you can not see the mount from the top. The person that did it is Rick L of Corvette Techniques, and I believe he is now with Corvettes of Houston (Service). He might be able to turn you on to the mount he used.