vettef6

Please don't post and tell me this is not the way to go and rather install a FAST, Bailey, Delteq or LTCC system. This is not a race car, it is driven on the street.

I would like to hear from someone who did this conversion, not using a distributor but rather a 36-1 trigger wheel.

I need to know:
which gauges won’t work anymore..
which MS are you using..
are you using an EDIS 8 to fire up the coils..

Thanks

Former Ford Boy

I'm looking at a similar solution for my '87. I've wanted to use the MegaJolt lite Jr on my L98 to allow for distributorless ignition. Its a very similar setup (same developers IIRC), but only controls spark using the 36-1 wheel and Ford's EDIS. It's appealing because you can get into a reliable DIS for around $500.00. The only question revolves around how the computer handles spark advance and if the signal is compatible with the MegaJolt.

This would also allow running an LS type motor with the factory computer and harness. I know that the LS computer is better than the factory electronics, but I lose some dash functions and I have to radically rewire the car to make it work.

To answer one of your questions, the 36-1 wheel is specific to Ford, no one else did this (Mazda notwithstanding). It was a way to allow DIS without having to integrate a cam sensor. So you would have to use the Ford EDIS to utilize the 36-1 wheel unless the MegaSquirt guys have integrated it into their computer design.

vettef6

What is bothering me is, loosing too many gauges when converting to a MS system. My engine is tuned and running real good, except for the opti spark which now and then go bad. I would consider a system that only controls the spark. I know I would need an EDIS 8. I already have a 36-1 trigger wheel and sensor.

Do you have a link or more info on the MegaJolt lite Jr???

Former Ford Boy

http://www.autosportlabs.net/MegaJolt_Lite_Jr gives a description of the setup. If you read enough on the site, you'll find the info for 8 cyl. setups. It can be stand alone, and it can use a knock sensor for advance, fully independent of the engine's ECM. This would make the LT1 computer basically responsible for fuel, idle control, and emissions. The Megajolt does have an input for an analog signal from the existing ECM, but i don't know if the LT1 system could be leveraged to use it. If it could, the ECM might not even realize that the optispark has been replaced.

vettef6

Thanks for the link. As I see it, it's probably best suited for what I'm looking for.

I'll contact this company and see what they say about the Corvette tach. As far as I can tell it might work but would have to buy an Interface for the correct pulse. I'm no electronic expert and don't even know how many volts or waves my tach actually needs to work. Hope they know more than I do.

The only additional thing I would order would be a MAP sensor. I won't need a knock or TPS sensor to set up my timing.

merlot566jka

Why not run the 7730 ecm, and use the est signal to run a dis... like the northstar dis pack. Some moats parts for live emulation, and you are set. i think all you need is a 9x reluctor wheel, and you can make that yourself.

BTW, I have used the 7730 on a few different engines, made my own reluctor wheel, and it works great. DIS is easy stuff. The EST signal is normally sent to the gm distributor, but the ICM will take it and make sense of it.

At the same time, I havent done this for the LTx. But I am under the impression that the spacing on the reluctor wheel within the opti would satisfy the requirements.... you could just use a 555 timer on the out put of the opti if the hi-lo is a lo-hi, and you can use that signal as the crank sensor. so really, you may not even have to remove anything on the engine to get it going.
if you relocate the ICM you could do COP setup... I just did that on a SCIII 3800.

Just wanted to share that. GM ECM's are thousands times better than ms or the low price aftermarket ecm's. You just have to know more to get things done with the factory stuff.

vettef6

Jonathan, thanks for your input, even though I only understand half of it.

I absolutely want to completely get rid of the opti spark not only the cap and rotor. I tried this before with the Delteq system, which only worked for a few months. I have two Northstar ignition modules and two sets of coil packs.

I'm in contact with Megajolt and it might work. The problem is, the stock ECM will not operate the fuel pump and injectors with a code 41 or 42. This means, the ECM must see high and low resolution signals.

Jonathan, I wish I had as much knowledge as you. If I did, I think I would have figured this one out a long time ago.

5abivt

I have heard good things about the mgasquirt. To be honest I dont think I'd buy it just because the name reminds me of Peter North but I do have a Gen 7 DFI. Im not trying to talk you into dfi just saying that i ripped out my stock ecm and all wiring in the engine bay. rewired the gen 7 and that runs the motor. ALL my instruments digital and analogue on my 93 work perfectly. All I get is the occasional sys because the ccm cant communicate with the ecu which doesnt bother me at all.

it can be done !

5abivt

I just realized you have an LTX like me.. I purchased the standard SBC model ECM for a distributor. You can keep the opti if you like I just chose to run a dizzy since Im spinning well over 8k.

theres a few pics of my setup early in my old video... before and after engine shot.. I tried to make everything look stock. Most people dont even notice the distributor.
http://www.youtube.com/watch?v=nwnL5ouKLno

vettef6

Nice car you have there 5abivt. I don't rev mine that high, only to 6900 rpm, see sig..
I absolutely don't want the opti spark anymore!!! I can't use a distributor because of the intake I'm using, there is no place for a distributor....
Megajolt has no way of running the ignition because my stock ECM needs the high and low resolution signals from the optical sensor. So now I'm stuck and might have to change to a complete engine management system.
OK, then it's a 36-1 trigger wheel and a management system where I won't loose any gauges. I contacted someone selling "Fast" systems and he told me I would loose ABS, speedometer, cruise control and mpg!!!!

Here a few pictures of my self made tunnel ram intake.

5abivt

Very Nice intake ! Why not just run the efi connection setup for ls1 sensors and coils? uses all GM parts with custom reluctors etc inside the timing cover and removes the opti. IMO its one of the best setups for an LTX because it uses an LS pcm and there are tuners for them EVERYWHERE !!

Check it out.. tons of people have switched to it already. works great.

http://www.eficonnection.com/eficonnection/24x.aspx

5abivt

What I am doing is running a traditional dual sync. because of failures though I ordered a magnetic outer shell from ATI to go right on the balance and using an msd pickup. that will give me crank. im trying to find a good way to get a 1x signal for the cam still.

vettef6

Yes I know, quite a few have done it. The thing is, it's expensive >$2000 and if you want to tune it yourself, another $450--$1200 for the software. Even with this system I don't know which of the IP and driving info center gauges wont work anymore.

This is my biggest worry, doesn't matter which system is being used. Too bad there isn't anyone with first hand experience who can tell me which of the gauges won't work after conversion.

merlot566jka

What is your issue with the opti? It was a brilliantly designed piece! Just a bad location of the weepholes on the water pump.
The opti actually has a 360* resolution... which is about 40 times better than any other distributor or DIS system. The capability of the optispark is astounding. Get rid of the high voltage side, and it would be a painless system.

If you want to know more about the systems I was talking about, read around 60degreev6.com, thirdgen.org, moats, pick up a few books on tuning from amazon... It took years of research and learning, but once you know, you know. \

If you want more information, just ask... I can turn this thread into a wealth of information. I am busy, but I can post atleast 5 times a week. I have full time work at the FAA, Naval Reserves, full time mechanical engineering at OU, and I drive about 1000mi twice a month to see my daughter.

Nathan Plemons

I have no input at all other than to just say that's a sharp looking intake. You make it yourself or have it done?

Beach Bum

To the OP, I recommend you PM member LT401vette (Phil Tobin) He has an LT-1 corvette. (Well actually its a big block nowadays, but he tuned and raced it for years when it was an LT-1 and knows the motor as well as anybody could)

Phil is a designer for MegaSquirt.... I know he gets into the nitty/gritty stuff with MegaSquirt and if anybody would know the answers to your questions, he would. As a note, I believe they also have a Megasquirt Message Forum that he posts at somewhere... do a search for it.

Good Luck.

vettef6

Nathan, yes I built it about 2 years ago and never had a chance to install it because the last two winters I was chasing other problems which had priority. I will have to wait though for the weather to get better before I can actually drive my Vette. I guess I'll also have to tune my VE table somewhat, but that's not much of a problem.

If anyone is interested just follow the link to this and other projects I have completed.

Yes, I heard of Phil Tobin and I even have a bin file from his 401 ci engine. I used some of the data from the bin file to tune my 397 ci engine. I found someone in FL who knows quite a lot about MS systems and also sells them. I will probably buy one from him, set up especially for my needs. There is a MS forum and I'm about to register there.

BrianCunningham

Didn't know Phil worked for them

MS is a good unit, serveral FSAE teams use it.

sorry I can't help you with the install

Ditto on the intake

dclafleur

I'm going to have to pick your brain on DIS sometime, I've been kicking around the idea since the '85 ECM is a little one off I've been hesitant to invest too much in tuning or playing around with it.

71VETTEWI

Just buy the MS3 like I did. It can run Seq. Injection As well as COP all from the Opti. It uses it for the signal only. So no high energy ignition running through it. So just use the Opti for a built in trigger.
Good Luck