optispark

[94formulaLT1]

i am in the process of rebuilding my top end now, it has been a while since i have been on here.. i was wondering what is the best optispark? would the GM performance replacement suffice? is the MSD opti better? does an engine really need that much spark or is most of the actual spark wasted? i think i am going to settle on a GM opti and buy a coil upgrade, like msd for less resistance. i think that would suffice. thanks for your help.

[Injuneer]

I doubt anyone can tell you if the MSD Opti is able to live up to its promises.... the first ones were only delivered about 2 weeks ago.

Replacing the Opti doesn't have to do with "that much spark". Its about addressing the problems with the stock Opti design - poor case sealing against moisture, breakdown of the cap's dielectric properties using high voltage ignition systems, corrosion of the internals by ozone from the high voltage discharge, replacing the low quality bearing, etc.

If you are looking at a stock Opti, you can consider two options....

1. Upgrade to the "vented" unit used in the 95 and up engines. Unfortunately, that involves a lot of additional expense because you need the vacuum harness, electrical harness, new timing set, new timing cover and either a new (95+) cam or drilling a hole in your 94 cam.

2. Use the unvented Opti, but remove the high voltage functions from the Opti, using the LTCC 8-coil conversion, or the Delteq 4-coil conversion.

Additionally, there are aftermarket Optis from Accel (unknown quality - too new to the market) and Dynaspark (good feedback, been around for about 5 years, but expensive).

[94formulaLT1]

i am deffinately going with the 95+ opti..already have that figured out..could you tell me exactly what vaccum hoses i will be needing?

my heads are in NC right now getting worked on. http://www.advancedinduction.com/AiProductsLT1.html is the website. i got the 190cc street/strip package with the competition cams valvetrain kit at the bottom (the one around $750 or whatever.) that will give you an idea of what im getting. im also getting the double roller timing chain so i will be upgrading my opti to 95+ and getting the 95+ valve cover with everything else. im getting an electric water pump..and some odds and ends. I hope to be making over 450hp at the wheels, HOPEfully more..stressing hopefully... tell me what you think..

I doubt anyone can tell you if the MSD Opti is able to live up to its promises.... the first ones were only delivered about 2 weeks ago.

Replacing the Opti doesn't have to do with "that much spark". Its about addressing the problems with the stock Opti design - poor case sealing against moisture, breakdown of the cap's dielectric properties using high voltage ignition systems, corrosion of the internals by ozone from the high voltage discharge, replacing the low quality bearing, etc.

If you are looking at a stock Opti, you can consider two options....

1. Upgrade to the "vented" unit used in the 95 and up engines. Unfortunately, that involves a lot of additional expense because you need the vacuum harness, electrical harness, new timing set, new timing cover and either a new (95+) cam or drilling a hole in your 94 cam.

2. Use the unvented Opti, but remove the high voltage functions from the Opti, using the LTCC 8-coil conversion, or the Delteq 4-coil conversion.

Additionally, there are aftermarket Optis from Accel (unknown quality - too new to the market) and Dynaspark (good feedback, been around for about 5 years, but expensive).

[fastTa]

i am deffinately going with the 95+ opti..already have that figured out..could you tell me exactly what vaccum hoses i will be needing?

my heads are in NC right now getting worked on. http://www.advancedinduction.com/AiProductsLT1.html is the website. i got the 190cc street/strip package with the competition cams valvetrain kit at the bottom (the one around $750 or whatever.) that will give you an idea of what im getting. im also getting the double roller timing chain so i will be upgrading my opti to 95+ and getting the 95+ valve cover with everything else. im getting an electric water pump..and some odds and ends. I hope to be making over 450hp at the wheels, HOPEfully more..stressing hopefully... tell me what you think..

Not saying that you can't put 450 to the tire with those heads , but just be prepared to go with a fairly aggressive cam to make that kind of power.

I think your 2 best choices would be the Dynaspark and the GM vented Opti.

[Injuneer]

i am deffinately going with the 95+ opti..already have that figured out..could you tell me exactly what vaccum hoses i will be needing?

A "vented" Opti is vented by an air supply line from the inlet elbow and a vacuum line from the intake manifold. The required parts are described in this "how to":

http://para.noid.org/~muttvette/opti.html

my heads are in NC right now getting worked on. http://www.advancedinduction.com/AiProductsLT1.html is the website. i got the 190cc street/strip package with the competition cams valvetrain kit at the bottom (the one around $750 or whatever.) that will give you an idea of what im getting. im also getting the double roller timing chain so i will be upgrading my opti to 95+ and getting the 95+ valve cover with everything else. im getting an electric water pump..and some odds and ends. I hope to be making over 450hp at the wheels, HOPEfully more..stressing hopefully... tell me what you think..

I'm with Kevin.... 450rwHP out of 190cc heads is a challenge. Is this an A4 (535flywheelHP reauired) or an M6 (515flywheelHP)?

Why do you need a 95+ valve cover? There is no difference between the valve covers on 93-97.

[94formulaLT1]

so sorry...i meant timing cover, not valve cover..i know you need the 95+ timing cover the pin driven

A "vented" Opti is vented by an air supply line from the inlet elbow and a vacuum line from the intake manifold. The required parts are described in this "how to":

http://para.noid.org/~muttvette/opti.html


I'm with Kevin.... 450rwHP out of 190cc heads is a challenge. Is this an A4 (535flywheelHP reauired) or an M6 (515flywheelHP)?

Why do you need a 95+ valve cover? There is no difference between the valve covers on 93-97.