BLKMGK Posted October 25, 2001 Share Posted October 25, 2001 Okay, I'm trying to understand exactly how this thing works and what it's function is. My goal is to find out if it can be replaced with a regular distributor and the EFI moved to an older SBC. I'm quizzing a local EFI guy on this but can't reach him for a few days. Another guy I'm speaking to via e-mail seems to feel it's a no go. I'm honestly not sure - we just replaced this piece on our Impalla and opening it up (old part) I'm surprised it looks so much like a regular distributor - I just have no idea what signals it sends out Looking inside of the Opti I see a short rotor, 8 lugs, a center electrode, a vac connection, and a plug going ito the base that I've not yet opened. The potting on it covers the connections from the "cap" studs to 8 plug wire connectors - looks like a crab style cap! The unit uses a single coil - a surprise to me since I thought it used coil packs. This was also replaced on our Impalla because it was "corroded". Let's hear it for GM techs I will open the base up when I have time to get greasy. Anyone know anything about how this thing works? Where's the "Opti" part? P.S. Guy I'm talking to via E-mail says go TEC2 for a total cost of $3500 w/intake, injectors, ECU, and TB. Only thing not included is pumpfilter apparently. That's the price to beat I think. Pics! http://www.charm.net/~mchaney/optisprk/optisprk.htm HRM!!!! -> http://www.google.com/search?q=cache:SnUj2K2WxFw:users.hit.net/~rah/noopti.html +optispark&hl=en http://www.ag.auburn.edu/users/gparmer/efi/myfaq.htm (Hrm, how do I get a distributor to duplicate THESE characteristics?!) [ October 24, 2001: Message edited by: BLKMGK ] Quote Link to comment Share on other sites More sharing options...
Guest nosz350 Posted October 25, 2001 Share Posted October 25, 2001 i do know you can replace it with a normal dist. they make a intake for it as far a carb. they also have a block off plate to put up front in place of the opti spark. any advice on how to start a web page?? Quote Link to comment Share on other sites More sharing options...
Guest Justin Posted October 25, 2001 Share Posted October 25, 2001 Not sure if I'm reading your post right, but if your planning on swapping an LT1 EFI setup onto a normal SBC, I think it'd wind up being simpler and cheaper going with the TPIS miniram setup...virtually identical to an LT1 setup, but the intake works with a normal distributor... Not sure what'd it take to get a regular distributor to work with an LT1 intake. Quote Link to comment Share on other sites More sharing options...
Guest super280z Posted October 25, 2001 Share Posted October 25, 2001 Blkmgk, i might be going on a brain vacation here but it's seems to me that the opti will not fit on anything but an LT1 block. the moving the distributor ordeal has been a great topic of debate over on the Camaro board. something about a guy swapping a 1st gen 434 small block into an f-body.. hehe... those guys were talking about a simple crank trigger system. my recent expierence with EFI has lead my to want to retrofit everything i own to a GM based LT1 edit style of fuel injection. when i switch my Dakota over to EFI again, i think i'll go with an LT1 edit retrofit system. (poor mans DFI) the whole total adjustability factor for under 500 bucks really appeals to this poor white boy. i hope my ramblings didnt throw you off too far.. Quote Link to comment Share on other sites More sharing options...
Guest RyalC Posted October 26, 2001 Share Posted October 26, 2001 The opti is only applicable to the LT1. A regular distributor will not work on the LT1. The engine internals to drive the distributor aren't there and the LT1 intake manifold has no provision for a regular distributor. The LT1 manifold won't work on a regular SBC because the LT1 has a completely different cooling system than the regular SBC (reverse cooled and dry manifold), and no provision for a regular distributor. I can get you references on how the opti works if you really want to know. Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted October 26, 2001 Author Share Posted October 26, 2001 Would like to see the Opti refrence Here's the deal - I'm attempting to put the LT1 INJECTION (94-95) onto my existing 383. I'm aware the LT1 intake won't work but the TPIS MiniRam WILL as would a converted carb intake. The EFI won't care what the intake is (shrug). However the Opti will NOT retrofit to the block I've got now - I know this. I would like to find a way to create a signal like the Opti using a distributor or wheelpickup. I've found that the Opti puts out TWO signals - one high rez, the other low which gives cam position. How to simulate that is the bear.. Make sense now? Reread my previous post - should make more sense now Local guy says it can be done but we didn't talk about the Opti and I can't reach him for a few more days. He may be full of it or a genius. I'd be VERY interested in a link to the F-body discussion as it's exactly what I'm trying to do except in a Z. Electromotive made a unit that sorta' replaced the Opti but it didn't give an accurate cam position. They tried to synthesize (sp?) the signal from the mag pickup but it wandered and wasn't always right. I talked to a guy that owned one I'm thinking a high rez signal from the mag pickup and a low rez for cam position from the distributor maybe? Trick here is to do this for less than another system. The Holley system in Summit is about $2K+ w/intake. Converting this system may cost more, especially if I use the TPIS. I'm trying to decide if it's worth it, I won't know till I see how difficultexpensive creating an Opti will be (sigh). Holley system is lookin' REAL good right about now but the LT1 unit is probably more sophisticated and a bigger challenge. At some point you just have to say "good enough" though Still searching... Oh, a distributor CAN be put in an LT1 block and a carb intake used just fine. There's a stubdummy distributor in those cars to drive the oil pump. My block has a one piece crank seal so perhaps I could use a real Opti with some work (not sure year of block) but considering what I've read on their reliability I wouldn't touch one. Ours was just replaced on the Impalla P.S. Guy I ran into who's gong to SEMA is leaving Tuesday and I've given him a ton of questions to ask aboout EFI Quote Link to comment Share on other sites More sharing options...
Guest super280z Posted October 26, 2001 Share Posted October 26, 2001 Blk, i see your predicament now. thats quite a hurdle. rigging the opti to run off of an older block could make you a rich man. i actually hadnt thought of that problem but if it could be done... definately keep us posted as to which route you go, holley or the DIY route. Camaroz28.com has the thread your looking for. the guy's post name is Mr. Horsepower i hope it's helpful. sure made me wanna go out and retrofit something to efi. good luck Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted October 27, 2001 Author Share Posted October 27, 2001 Pulled the Opti completely apart now.. One single very thin metal disk for a wheel inside. Mitsu sensor hangs over it and must have two sets of LEDs. The outer ring of the sensor wheel has what I believe to be 360 slots. More towards the middle are 4 small slots alternated with larger gaps that aren't all the same size I see no easy way to duplicate this with mag wheels. If I were to try and use the crank for the 360 wheel the degree of accuracy on the wheel and mount would be pretty sick. Have to remember how much bigger around that trigger wheel would be and you'll see what I mean. Not sure about the 48 gap weirdo ring either. It's the one being used for cam position I'm told. Only way I see to do this right now is to mount the original wheel in a distributor - yuck! Will check out that guys comments and add what I can - perhaps he's seen something i haven't... P.S. Spoke to the local tuner about this. He's the one who suggested this. Seems he's never done this before either and is scratching his head as well. He's suggesting possibly going with a Ford EEC to get to MAF but then I'll be dependant on him to tune it. No datalogging either. He doesn't like strictly MAP systems like the Commander I'm sending him E-mail. He posts there nearly as much as I post here and I'm not finding the thread [ October 26, 2001: Message edited by: BLKMGK ] Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted October 27, 2001 Share Posted October 27, 2001 BLKMGK, I understand what you want to achieve and it doesn't sound so hard for an ee guy to quickly tell you whether it's easily achievable or not. I suggest hopping on the DIYEFI list where the ee brainpower is astounding IMO. At least one their understands opti as it was discussed a while back AIR. I'd be suprised if a crank trigger generating signals conditioned and sent thru to LT1ECU couldn't generate what you want, although the opti is tied directly to the cam who's rotation is not geared same as crank but I still think it could be done without waking up Einstein. a quick search for diy-efi etc should pop it up quick. Be as technical as you can listing all hard data you have as they really appreciate those that do their homework. And then naturally pass it on to us in plain English [ October 26, 2001: Message edited by: Ross C ] Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted October 27, 2001 Author Share Posted October 27, 2001 I've gone through a pile of their archives, more specifically the DIY-GMECM list. No search function which blows. I did at one point find a description of the outputs but looking at this wheel I think it's a bit off. Those lists are VERY high volume so I've not signed up yet. Worse comes to worse I will, I'll also be chatting with an electronics friend of mine who could certainly tell me if this doable - or worth it. Hope to write a doc comparing features and prices tonight bu tit's going to take awhile... Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 27, 2001 Share Posted October 27, 2001 I remember years ago when that list spun off of John DeArmond's Hotrod list. That was a great list too. Yeah, after the first few years, I gave up even saving the unread DIYEFI digests. Jim, I bet the inner 4 slots are to tell the computer where the engine is in relation to cylinder number. And the 360 are to tell in fine detail where it is and what the rpm are. I agree that if you were to make similar wheels larger with proportionally the same size slots, you could build a crank trigger wheel and have leds/sensors to do the same thing. The problem would be dirt, etc. So magnets and hall effect sensors and the correct circuitry to mesh with the GMECU would be needed. I like the idea of putting the wheel and sensor in a distributor house, but then you have cam rotational harmonics that MIGHT play havock with it at high rpm. Just talking out of my ... well you know. Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted October 27, 2001 Author Share Posted October 27, 2001 Pete, you're more the engineer than me so I'll ask you.... If I make the wheels a larger diameter with proportionally wider spacing don't I have to worry more about minor errors in machining make a much bigger error than I would with the smaller wheel? Intuition says yes but I'm not sure. I cannot imagine duplicating the 360tooth wheel. Under the distributor is a hostile environment - mostly dirt I'd think but harmonics don't worry me so much. It was bolted to the front of the cam in the LT1! We'll see, as I posted elsewhere using the GM ECU may actually be pretty cost prohibitive Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 27, 2001 Share Posted October 27, 2001 As the disc gets larger in diameter, the tolerances would go UP proportionally, so it'd be easier to make, in that sense. I'd think you'd want a rotary table and a punch to do it with though. That's why I think putting it IN a distributor would be easier. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.