I'm having a weird spark problem where the engine pulls hard and then hits a mysterious rev limiter at 4800rpm. I'm trying to figure out the right settings for crank reference angle and inductive delay (LT1 with Delteq).

FAST says opti should have a reference of 1* BTDC and no mention of the delay, however, the classic manual show 96uS and the XFI manual says 40uS.

BS3 says opti should have a reference of 6* BTDC and inductive delay of 24uS.

What does everyone here use? I'm using FAST classic with 1* and 96uS.

 

Funny you mention this as I'm still researching this myself. Look at my friends FAST classic setup he's got his reference set @ 6*. No delteq but still that's his reference. My base XFI tune has the reference @ 10* w/ a 40us. Now I wish I could give the final result but I've yet to crank the car....dead battery but I'm using the delteq and XFI. Hope it starts and I hope you get your answer.

 

Hey Roadie. I was actually looking for you. I was talking to ZBLKHELLRZR (John) about your setup. We are both currently working on very similiar setups and trying to figure out Crank reference angle ourselves. My program has 10 degree angle and 40uS delay. I'm actually trying to figure out how to connect the XFI harness to the OPTI and Delteq. I've completely removed the original PCM and harness. How is yours setup? Still utilizing factory harness? I'm pretty sure I can modify the Delteq harness and XFI ignition adapter harness to work, schematically anyway. Do you think your problem is in the reference angle or delay? I talked to Lance at FAST and he hasn't seen anyone run the Delteq over 5800 rpm sucessfully using the FAST ECU (XFI anyway). I'm starting to lean towards going with a different ignition setup, I would love to keep the Delteq though. There is a guy in Texas who uses an MSD crank trigger, LS1 coils, LS1 coil harness and extras, and some mods to the OPTI to run everything utilizing a FAST XFI and XIM box. Very expensive though, over $2000, without the FAST ECU. Thanks, Rob.

 

Ouch Rob. Are you serious? 2K+ more? Man I don't know if I can do that I may just have to revert back to the the Opti which I don't want to do. Selling the Delteq though would cover the Crane ignition setup though. My biggest problem is since my harness was custom I'd have to tear that whole thing apart just to get to 2 lousy wires to reuse the opti.

Hopefully Roadie will chime in sometime today. Never heard about no one not exceeding 5800rpms.

 

My setup is a FAST classic box, White Racing PCB interface, and stock harness.

I don't believe my problem is the reference angle because that will simply affect timing across the board...

However, I do think that the inductive delay is a key part of the problem I am having. That is RPM-related since it affects timing as RPM changes. Mine is set at 96uS right now (from the FAST Classic manual). If 40uS is the right number, then mine is advancing timing as RPM increases. I planned to fix my header leak this weekend and then drop the number to see if I pick up more RPM. (It's worth a try... afterall, BS3 says 24uS).

PS. (as stated in the other thread), I'm also using a custom Delteq bypass cable as opposed to the one that came with the Delteq.

 

Talked to JC from Delteq. Since I'm getting the flashing light on the box he said I'm running the older style opti box. I've had his Delteq close to 4 yrs now and he's like "yeah that's the oldie". He's sending me a new box today so hopefully I'll be able to start it this time but if not then it's the opti itself even though it's brand spanking new from GM. Hope that isn't the case. I won't need the harness like what you have since my wire harness is spliced into the factory wiring. At least that's what he said once I explained how I'm wired up.

Hope you find out what the deal is w/ that timing situation. I'm keeping a close eye on this.

 

Subscribing... lets keep this one updated guys.