Danno74Z

Scottie, If that guy is going to be using that turbo on an LT1 engine he will most likely have to throw out the OEM system and make a ton of other engine mods too boot. But that cat is spending a lot of money least on the list is tosing the Opti. I would like to know what internal engine changes he is making - WOW! Danno74Z

Hi Rick, My reply to your thread was to make others aware of what you loose by dropping the Opti. ignition system. Don't get me wrong, I think the MS DIY FI system is way cool but as you noted it IS expensive (not as most others) and labor intensive. Just like 90% of what we due to our Z's. From what I know (not much) the sequential FI helps with emissions mostly at idle and low rpm's. As soon as the engine move up to say 2000 rpm the injectors are firing so fast it is practically bank to bank anyway. The MAF does restrict some flow but it does compensate for SOME engine mods before you have to reprogram the computer. With a SD system every engine change you make you have to dial in the trim tables again. Most racers use SD but again it will take a lot of effort (dyno time) to get it right. I really want to get rid of my opti system too but I'm weighing all my options. What is CAS? Danno74Z

Using the MSII system is a unique way to eliminate the Optispark. I looked into this system a long time ago myself and felt like it was one way on eliminating the opti but it requires a lot of work. The Megasquirt is a true DIY FI system and for the most part you are on your own - not much support. Do your homework if you really want to go this way. To my knowledge you will loose your sequential fuel injection and your MAF. You will have to go bank to bank and use a MAP sensor. When it comes to tuning you will have to generate your own fuel and spark tables. Is it worth all the work just to loose the Optispark? I just don't know. Some people have no problems with them and others hate it. It does tend to self-destruct at very high RPM's but in a normal operating range I think it does OK. Final Note. If you really want to get rid of the Opti at a minimum it's going to run you $1000 to get MSII, crank wheel and sensor, North Star coils and the list goes on and on. Danno74Z

Here is what I'm doing with my fuel rails and plumbing. I got these fittings (both are -6 AN) from TPI_Parts on Ebay. http://cgi.ebay.com/ebaymotors/93-97-LT1-LS1-Camaro-Corvette-Fuel-Rail-6-AN-Fittings_W0QQcmdZViewItemQQcategoryZ42604QQihZ012QQitemZ220152054154 I also picked up this fuel rail with a Aeromotive fuel regulator - great deal on Ebay too. I'm going to polish the rails. When I'm done sell my original fuel rail and regulator. I will most likely purchase several 90 degree elbows to route the main fuel lines down and under the regulator. Danno74Z

That is great news - almost got it licked! Might be a volume issue now with the smaller diameter feed lines.

Guy, Nice pictures of your LT1 fuel system. I had a question about the middle picture. My Camaro fuel rail has one pipe - front and rear that connects the left and right fuel rails. I noticed that yours has twin rear pipes. Did you do this mod or did it come from the factory this way? Danno74Z

Bart, you mentioned that you are using the stock 73Z fuel lines except swapped the return line. IMO you need to be using some bigger fuel lines in your car. What size lines does Guy use in his LT1? You may have BOTH a low voltage issue and a volume problem. Your car is somewhere around 450HP at the crank. From everything I have read you need at least -6 or -8 lines going to the engine. You will fix the voltage issue but you will run out of pressure and flow as soon as you get on it a little. Guy is using -6 (3/8") hard and flex lines on his engine. If I'm not mistaken the early Z's were 5/16" dia. Danno74Z

31PSI - Wow that is low. That level psi would probably get by with a stock LT1 engine but with your mods you probably need to be up at the 47psi level. I know you have 30lb/hr. injectors what size fuel lines are you running? Did your friend also check to make sure the regulator itself is OK? Is the reg the stock unit or an aftermarket? Just maybe you have solved you stumble problem - or getting very close! Danno74Z

Bart, When you said the pressure was low, what is the actual reading on the pressure gauge? So you think this is a voltage drop to the fuel pump? Thanks, Danno74z

Vin, These guys are referring to the engine harness not the chassis harness. To really know what one is doing and to make it easier a schematic to the PCM pinouts definitely helps to sort things out. Danno74Z

gvincent, Like I mentioned a few threads back, I just remembered reading (a long time back) some members had problems with drivability not using the VSS. As Wheelman mentioned he had stalling problems. I can't say which the better way to go on this issue is. All 240, 260 and 280 models had a cable go from the transmission to the speedo. So if you go with a cable x box or a derivative the only thing you are adding is the x box and a few wires. Pretty simple solution and you keep everything stock appearing if that is your thing. I believe it cost about $300. You could try and put something together on your own but that all depends on time and skill etc. Some people as you know gut everything including the dash so running Autometer gauges is just part of their look. I personally like the modern look of the Autometer gauges and their accuracy far exceeds something that is 30+ years old but hard work is needed to make it all work. Danno74Z

Wheelman, Did your T5 transmission come with a mechanical speedo cable only? It sounds like it did and then you feed the VSS signal off the cable to the computer. Nice Job! Us T56 guys with trannys from OEM cars don't have the mechanical output so we can't go this route very easily. Sounds like LT1-280Z developed his own VSS generator - a lot of work like he mentioned. How do you know when your going over 140 with the stock speedometer Danno74Z

sstallings, The LT1 engine needs the input from the VSS in order to run correctly. A lot of calculations and adjustments are being used by the computer and ALL the sensors - MAF, MAP (yes the LT1 has one) VSS, TPS, knock, Temp, and others to make this swap emission legal (In CA). In CA (please correct me if I'm wrong) don't they put the car on a dyno and put it through its paces while they are sampling exhaust? As they vary loads and SPEED the computer is taking all this into consideration and altering spark and fuel. I would not convert it over to a mechanical speedo. IMO If I'm not mistaken, I think some HybridZ members who went to a mechanical system on the LT1 eventually went back to the original electronic system for better drivability. Danno74Z

Bart, Did you keep the original Datsun fuse box or did you change that out too? The JTR Datsun V8 Swap Book tells you which wires to keep to fire up a GM V8 350 engine. The book with a 240Z on the front cover doing a burnout. Danno74Z

getZ, ezzzzzzz Just a couple of days ago I went up on Craigslist and got a brand new 14088646/153T for $125 (I made sure it was new and not turned) Still in the Genuine GM part box. Guy had to abandon his project. This flywheel is 16lbs - VERY NICE! Thanks for your input. Danno74Z

89firebirdformula Go to this thread: http://forums.hybridz.org/showthread.php?p=803563#post803563 Danno74Z

89firebirdformula, I am not an expert but here is a link that should get you going. Danno74Z "Lt1 into 3rd Gen swap wiring" By Oneslowz28 "I do not hold any liability to damage to any property. This write up is just a reference guide to help you wire up your car. You should always double check the wiring schematics in the factory service manuals. If you follow these instructions your car will start up on the first try. This write up was made using the 3rd Gen C100 bulkhead connector I highly suggest using yours or going to a junkyard and getting another one. All you will need is the side that is not part of the headlight harness you can leave that on your car. This write up was made using A lt1 from a 94 with a 94 wiring harness and a 94 ECU, and under hood relay/ fuse block. . Other years may be different but this will work with a 95." Here is the Link: http://web.camaross.com/forums/showthread.php?t=474185

Can Anybody Help? Danno74Z

I'm getting ready to purchase a clutch flywheel package for my LT1 T56 project and would like some recommendations. I have a custom bellhouse and HTB that can accommodate either the 153T/12.75" flywheel or the larger 168T/14" flywheel. GM Performance has three flywheels that will work in my setup. They are: 14088646/153T/16LBS/$262, 14088650/153T/~25LBS/$239 and 14088648/168T/30LBS/$172. Would anybody go with the 168T 30LBS unit? If you want to add some clutch suggestions throw them in too! Thanks, Danno74Z

All, Has anyone used TTS Datamaster to log there LT1 engine? Thanks, Danno74Z

gvincent, I'm still working on my LT1 project too. I know you mentioned the "Bible Paper" from 73LT1Z back last December. (I have a hard copy of it too) Do you know if 73LT1Z is still around? Just wondering if he has an updated/final paper on the LT1 wiring? Danno74Z