msd vs stock opti

**jAgZ28** · 03-25-2008, 10:54 PM

well i think my opti is going and i would like some opinions on which is the better choice pros and cons of each, stock and msd... i might as well also ask if what i am noticing is caused by the opti going bad. the car is stumbling at high rpm, it act as though it is misfiring but it doesnt misfire at all other than that. also when i get on the car i hear it backfire often after i let off. also i rarely have what i call bad starts, where the car wants to stall immediatly after i start it when it does this the rpms are really low and i have to stay on the gas just a bit to keep the car from staling until the car gets warm then this goes away. the plugs and wire are about 2 years old, the plugs i put in are platinum so i know thats still good. thanks for the help!

**jimmybling31** · 03-25-2008, 11:04 PM

well I don't know about if yours is going out, but you can retard of advance the timing more with the msd and the msd won't go out.

**Firebirdjones** · 03-26-2008, 07:44 AM

I'm not sure I would spend money on the MSD setup.

I love MSD parts, and run their ignition systems on a couple of old school hotrods, but for the LT1 I'm up in the air.

Yes you can adjust the timing 4 degrees in either direction,,,,but whether or not this can be accessed on the car after it's installed is another question. Since it's burried behind the water pump and a slew of other accessories in the way.

Quite frankly if I can't take a screw driver and change the setting at the race track between rounds (such as an MSD digital 6 box) Then this timing feature is useless to me. If I'm going to test it then it's going to happen at the track,,,,can it be accessed easily enough and changed with the turn of a screw

To be honest if I wanted to make timing changes I would do it in the tune anyway.

Other than that,,,,it's a nice piece, made a little better with a rotor button that can withstand high rpms without failure unlike the stock unit is prone to, has a nice billet housing with I believe a better bearing design, which is where alot of opti issues come from anyway.

If it were me I would just stop at your local dealer and pick up a stock GM opti for about $270 and be done with it,,,,go another 100,000 miles. Thats what I've done and it's been fine. You could even go as far as to installed MSD's quality cap and rotor onto the GM opti unit if you desire.

Don't buy some japanese made opti from the local parts stores.

If you don't like that option there are conversion kits out there to convert the LT1 over to coil packs,,,,,this will set ya back about $700 or so.

**jimmybling31** · 03-26-2008, 02:15 PM

you have to do the timing adjustment in the tuning anyways. it just allows for more tuning. it's great if you are running a big shot of nitrous. retard the timing up to 4 degrees and make it safe to run bigger shots. if I were doing a nitrous setup already I would go with the msd just because of the timing thing

**Firebirdjones** · 03-26-2008, 03:03 PM

Originally Posted by jimmybling31

you have to do the timing adjustment in the tuning anyways. it just allows for more tuning. it's great if you are running a big shot of nitrous. retard the timing up to 4 degrees and make it safe to run bigger shots. if I were doing a nitrous setup already I would go with the msd just because of the timing thing

I understand that,,,but,,,,is it easily done while on the car with the water pump and all in the way?????

I am thinking this is just more than a simple screw to turn. I believe the entire distributor has to be clocked in one direction or the other,,,,in which case it's not that easy to access and play with.

If nitrous is the goal,,,,,It would make much more sense to wire in a timing control box with a switch that automatically pulls what ever amount of timing you need via the retard box as soon as the nitrous is activated,,,thats the way I would do a nitrous setup.

**5.0THIS** · 03-26-2008, 04:46 PM

Originally Posted by jimmybling31

you have to do the timing adjustment in the tuning anyways. it just allows for more tuning. it's great if you are running a big shot of nitrous. retard the timing up to 4 degrees and make it safe to run bigger shots. if I were doing a nitrous setup already I would go with the msd just because of the timing thing

Thats about the last way I would do it with nitrous. Set the distributor and tune via the PCM if you want the bottle.

**jAgZ28** · 03-26-2008, 05:07 PM

can i just do the msd cap and rotor on the stock opti and save myself $200. will that work? or can you not use the msd cap on the stock opti? also do you guys think the opti is the problem? also how much of a pain in the ass is this going to be on a scale of 1-10. spark plugs being an 8.5

**Firebirdjones** · 03-27-2008, 03:47 AM

Originally Posted by jAgZ28

can i just do the msd cap and rotor on the stock opti and save myself $200. will that work? or can you not use the msd cap on the stock opti? also do you guys think the opti is the problem? also how much of a pain in the ass is this going to be on a scale of 1-10. spark plugs being an 8.5

Yes you can install just the MSD cap and rotor on the GM opti.

The biggest issue here, and I have had this happen on more than one opti,,,,is the screws that hold the cap on will break off. Since the screws are mild steel and the opti housing is aluminum,,,,they corrode badly, and they are very tiny and snap easily. Steel against aluminum doesn't mix too well and causes corrosion.

If you are lucky the screws will come out. If not you will have to remove the opti distributor and start drilling and tapping. Since this is metric thread and very very small,,,,,you may not have a tap,,,,and sometimes this process doesn't work anyway and is very time consuming.

Which is why I suggested to just go to GM and pickup and brand new opti unit that comes with a GM cap and rotor, completely assembled. No fuss, no hassle. Before you install it,,,remove the distributor cap screws and put a light coat of anti-seeze on them for next time

I also suggest this route because 9 out of 10 opti failures are usually due to the bearing and not the opti trigger itself.
There is a sealed bearing inside the housing that holds the distributor shaft. When this bearing wears it causes the shaft to wobble, with a wobbly shaft the spark is irratic and causes high rpm misfires. Unfortunately these bearings are a dry sealed bearing and receive no oil lubrication from the engine,,,,,unlike the good old distributors of the Gen 1 motors that had constant lubrication.
(Another brilliant idea from GM

) So once they get some miles on them,,,,the bearing becomes a concern, hence another reason why I just do the entire opti distributor. Hope that helps.

Just wanted to add on the bearing issue,,,,this is where MSD may have a slight advantage. Since the housing is a more precise billet machined piece of aluminum rather than GM's cast aluminum piece. And MSD also uses a different sealed bearing design that is said to be better than original. Can't confirm but something to look into if interested. But I've never had a problem getting 100,000 miles out of the stock GM unit. Sooooo,,,,$270 for a GM piece verses something like $500 for MSD,,,,,I lean towards the new GM opti.

**Firebirdjones** · 03-27-2008, 03:54 AM

Originally Posted by jAgZ28

can i just do the msd cap and rotor on the stock opti and save myself $200. will that work? or can you not use the msd cap on the stock opti? also do you guys think the opti is the problem? also how much of a pain in the ass is this going to be on a scale of 1-10. spark plugs being an 8.5

To answer your other question,,,,,,
I'm not sure what the problem is you are having, misfires??? codes???

But for me it would come down to how many miles are on the car to the extent I would take the repairs.

If you are talking about a 100,000 mile car, then I personally would also do the water pump, a complete opti distribtor,,,,and be done with it. Go another 100,000 miles without worries.

On a scale of 1-10 for difficulty I would say a 5. It's not that it's difficult,,,just a little time consuming. The water pump has to come off anyway, and like I said, with alot of mileage it just makes sense to replace it while you're in there. With routine antifreeze maintainance some mechanical water pumps go much longer, even 150,000 miles and many years,,,,it's really up to you.

I buy the GM water pumps as well which run about $170 at my local dealer. Comes complete with a thermostat as well,,,,so if you run a cooler stat you'll have to switch it. Some fresh coolant and your ready to go.

**jAgZ28** · 03-27-2008, 10:04 AM

thanks a lot for the help jones. i think i am going to do a stock replacement opti since my main complaint is the high rpm misfire.

**brianswimmer23** · 03-30-2008, 08:21 PM

yea deff stick with stock on this part!!

**jimmybling31** · 03-30-2008, 09:18 PM

Originally Posted by 5.0THIS

Thats about the last way I would do it with nitrous. Set the distributor and tune via the PCM if you want the bottle.

you have to do that... it's just the msd allows for more... that's why you need one to be able to run big shots on lt1's

**N20LT4** · 03-30-2008, 09:50 PM

Originally Posted by jimmybling31

you have to do that... it's just the msd allows for more... that's why you need one to be able to run big shots on lt1's

You do not need an MSD unit to run large shots of nitrous. Tuning through the PCM is optimal.

**jimmybling31** · 03-30-2008, 09:58 PM

Originally Posted by N20LT4

You do not need an MSD unit to run large shots of nitrous. Tuning through the PCM is optimal.

yeah I know that. it's just you can't retard the timing as much as you would want to for big shots without an msd. the limit on max retard with the stock one is only 2 degrees. the msd is 4. that is a huge difference when you are wanting to run big shots of nitrous. I know you need to tune it through the pcm, but there are limits to what you can do there and one of them is the opti spark. I actually know someone who is putting nitrous on his lt1, but he is waiting to run any more than a 100shot because he can't retard the timing any more in lt1edit.

so yes. if you want to run the right timing for a big shot of nitrous you pretty much need an msd or you won't get the full retard that is optimal to prevent detonation.

also you are correct in that you need to tune the pcm, but like I said you have limits to it and those limits are ones such as the opti spark

**5.0THIS** · 03-31-2008, 02:24 AM

Originally Posted by N20LT4

You do not need an MSD unit to run large shots of nitrous.

that pretty much sums it up.

**Firebirdjones** · 03-31-2008, 03:23 AM

Originally Posted by jimmybling31

yeah I know that. it's just you can't retard the timing as much as you would want to for big shots without an msd. the limit on max retard with the stock one is only 2 degrees. the msd is 4. that is a huge difference when you are wanting to run big shots of nitrous. I know you need to tune it through the pcm, but there are limits to what you can do there and one of them is the opti spark. I actually know someone who is putting nitrous on his lt1, but he is waiting to run any more than a 100shot because he can't retard the timing any more in lt1edit.

so yes. if you want to run the right timing for a big shot of nitrous you pretty much need an msd or you won't get the full retard that is optimal to prevent detonation.

also you are correct in that you need to tune the pcm, but like I said you have limits to it and those limits are ones such as the opti spark

Like I mentioned,,,,thats what they make retard boxes for. So the timing retard function can be done electronically when the switch is activated.

Doing it at the distributor everytime you want to use it is not necessary and quite frankly would be a pain.
Pop the hood and fiddle with the opti everytime you want to hit the nitrous,,,,no thanks. Not to mention it's not easy to access anyway,,,who wants to do that all the time???? Not me.

Get yourself a timing retard box and do it the right way. It's cheaper too. Besides,,,those thinking they want a BIG SHOT of nitrous and pulling only 4 degrees out of the distributor is going to be enough is only running that motor on borrowed time.

**tamatt79** · 04-13-2008, 07:06 AM

This site is so helpful, i recently purchased a 95LT1, and have these concerns and questions. This post helps out so much, Thanks!

**N20LT4** · 04-13-2008, 11:08 AM

Originally Posted by tamatt79

This site is so helpful, i recently purchased a 95LT1, and have these concerns and questions. This post helps out so much, Thanks!

What color did you get? And what mods (if any) are done to the car?

**tamatt79** · 04-13-2008, 11:55 AM

Originally Posted by N20LT4

What color did you get? And what mods (if any) are done to the car?

Silver and other then exhaust, i dont believe it has any mods. I felt the need to save this car, it has 200,000 miles of hard life. In the process of gathering the body parts needed to fix the exterior. Will be having it painted in a few months, and am going with a 2-tone silver and dark blue metallic. Not sure at this time how the scheme is going to come together, but i hope it comes out as good as i think it will. Performance mods will come in time. Have another project going on with a 10th Ann TA that needs my $$$ first.

**N20LT4** · 04-13-2008, 12:33 PM

Originally Posted by tamatt79

Silver and other then exhaust, i dont believe it has any mods. I felt the need to save this car, it has 200,000 miles of hard life. In the process of gathering the body parts needed to fix the exterior. Will be having it painted in a few months, and am going with a 2-tone silver and dark blue metallic. Not sure at this time how the scheme is going to come together, but i hope it comes out as good as i think it will. Performance mods will come in time. Have another project going on with a 10th Ann TA that needs my $$$ first.

Ironic. I owned a Sebring Silver '95 T/A back in '00. It was a 6-speed, gray cloth, t-top car with a little under 100k miles. Ended up wrapping it into the side of someones garage

Had big plans for that car.