LT-1 issue - Page 7

Ed Wright · 04-27-2015, 08:43 PM

Only way there is more power in Sequential Modevis tuning each cylinder individually. Of course, otherwise it runs in Batch Fire. And how much depends on how far your cylinder-to-cylinder fueling and spark is.
BS3 runs just fine on an LT1. A friend of mine is running that on his.I have worked with BS3, ACCEL DFI, GM's MEFI, and Holley (both old & new systems) and I much prefer FAST. Holley's new system would be my second choice. I'm not going into it here, but I can make FAST XFI do something I can't make the others do. Maybe the new Holley, if I had the time.

John Nechiporchik · 04-28-2015, 02:33 PM

Update # 2:
After much discussion and several adult beverages to assure clear thinking.....Today I spent the big bucks and got a FAST XFI 2.0 system coming my way.
Hopefully my next update will report on a satisfactory outcome to this issue.
Thanks for everyone's input.

John

Ed Wright · 04-28-2015, 03:20 PM

Good move John.

pbp1 · 04-28-2015, 03:44 PM

John, I a little late to the party here but Ill offer what I know.
The Optispark adapter harness that we (FAST) sell is made to allow you to use the Low Resolution ring on the disk as a crank trigger. This is what you would use on a street car if you did not want to go with a full blown external crank trigger. This would work OK if you were dead set on using the Opti for crank signals.

In your application, there are really only two good choices, first, you could run a crank trigger for crank signal, use the opti unit as a cap and rotor only, and run in bank to bank mode. While Sequential will offer some potential gains in idle quality and individual cyll tuning, I have several super stockers running bank to bank that run perfectly well, idle great, and are bad fast! The XFI 2.0 allows you to switch from Bank/Bank to Sequential anytime you wish.

Your second option has a few variables. You can do the same as above, but modify the opti to generate a cam signal. Wiring wise, you would need the Optispark Adapter harness we sell and you would have to move one wire in the harness. I can easily walk you through the necessary changes. The next part sounds hokey but it actually works pretty well. You can get some good quality foil tape and cover all the holes in the disk. Then, identify the position of the optical sensor when the crankshaft is at 60 - 120 degrees BTDC compression stroke. This is a very wide window where the XFI looks for a cam signal. You then poke out one of the holes in the Low Res ring on the disk so that the single open hole passes the optical sensor somewhere between 60 - 120 BTDC. This will generate your cam signal and allow proper sequential fueling.

I have seen some take and gut the inside of the Opti and make an aluminum wheel with a single magnet that runs off the stock opti distributor shaft. They then mount an MSD pickup to read off this wheel.

If you are interested in setting one of these methods up to run sequential, PM me and Ill walk you through it.

David Page
FAST

John Nechiporchik · 04-28-2015, 08:49 PM

pbp1 (David) you have a PM

John Nechiporchik · 05-11-2015, 03:11 PM

Installed the FAST XFI 2.0 system on the LT1 and fired it up today. Fired up on the first hit and appears to be running smoothly.
With a little luck, we will take it to Milan this week and get the calibration dialed in. I am fortunate to have a very experienced tuner that is helping me.
In addition, throughout the installation process I placed several calls to the FAST tech line and got outstanding support each time.

Hopefully, this chapter will be closed soon and the racing will begin!
John

joelster · 05-11-2015, 07:08 PM

Good to hear John!

Ed Wright · 05-11-2015, 07:33 PM

Good move!

ss3011 · 05-11-2015, 07:38 PM

Just in time for Norwalk !

04-27-2015, 08:43 PM	#61
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: LT-1 issue Only way there is more power in Sequential Modevis tuning each cylinder individually. Of course, otherwise it runs in Batch Fire. And how much depends on how far your cylinder-to-cylinder fueling and spark is. BS3 runs just fine on an LT1. A friend of mine is running that on his.I have worked with BS3, ACCEL DFI, GM's MEFI, and Holley (both old & new systems) and I much prefer FAST. Holley's new system would be my second choice. I'm not going into it here, but I can make FAST XFI do something I can't make the others do. Maybe the new Holley, if I had the time. __________________ Ed Wright 4156 SS/JA Last edited by Ed Wright; 04-27-2015 at 08:47 PM.

04-28-2015, 02:33 PM	#62
John Nechiporchik Member Join Date: Mar 2007 Location: Grosse Ile Mi. Posts: 316 Likes: 84 Liked 13 Times in 7 Posts	Re: LT-1 issue Update # 2: After much discussion and several adult beverages to assure clear thinking.....Today I spent the big bucks and got a FAST XFI 2.0 system coming my way. Hopefully my next update will report on a satisfactory outcome to this issue. Thanks for everyone's input. John

04-28-2015, 03:20 PM	#63
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: LT-1 issue Good move John. __________________ Ed Wright 4156 SS/JA

04-28-2015, 03:44 PM	#64
pbp1 Junior Member Join Date: Mar 2013 Posts: 80 Likes: 12 Liked 27 Times in 6 Posts	Re: LT-1 issue John, I a little late to the party here but Ill offer what I know. The Optispark adapter harness that we (FAST) sell is made to allow you to use the Low Resolution ring on the disk as a crank trigger. This is what you would use on a street car if you did not want to go with a full blown external crank trigger. This would work OK if you were dead set on using the Opti for crank signals. In your application, there are really only two good choices, first, you could run a crank trigger for crank signal, use the opti unit as a cap and rotor only, and run in bank to bank mode. While Sequential will offer some potential gains in idle quality and individual cyll tuning, I have several super stockers running bank to bank that run perfectly well, idle great, and are bad fast! The XFI 2.0 allows you to switch from Bank/Bank to Sequential anytime you wish. Your second option has a few variables. You can do the same as above, but modify the opti to generate a cam signal. Wiring wise, you would need the Optispark Adapter harness we sell and you would have to move one wire in the harness. I can easily walk you through the necessary changes. The next part sounds hokey but it actually works pretty well. You can get some good quality foil tape and cover all the holes in the disk. Then, identify the position of the optical sensor when the crankshaft is at 60 - 120 degrees BTDC compression stroke. This is a very wide window where the XFI looks for a cam signal. You then poke out one of the holes in the Low Res ring on the disk so that the single open hole passes the optical sensor somewhere between 60 - 120 BTDC. This will generate your cam signal and allow proper sequential fueling. I have seen some take and gut the inside of the Opti and make an aluminum wheel with a single magnet that runs off the stock opti distributor shaft. They then mount an MSD pickup to read off this wheel. If you are interested in setting one of these methods up to run sequential, PM me and Ill walk you through it. David Page FAST

04-28-2015, 08:49 PM	#65
John Nechiporchik Member Join Date: Mar 2007 Location: Grosse Ile Mi. Posts: 316 Likes: 84 Liked 13 Times in 7 Posts	Re: LT-1 issue pbp1 (David) you have a PM

05-11-2015, 03:11 PM	#66
John Nechiporchik Member Join Date: Mar 2007 Location: Grosse Ile Mi. Posts: 316 Likes: 84 Liked 13 Times in 7 Posts	Re: LT-1 issue Installed the FAST XFI 2.0 system on the LT1 and fired it up today. Fired up on the first hit and appears to be running smoothly. With a little luck, we will take it to Milan this week and get the calibration dialed in. I am fortunate to have a very experienced tuner that is helping me. In addition, throughout the installation process I placed several calls to the FAST tech line and got outstanding support each time. Hopefully, this chapter will be closed soon and the racing will begin! John

05-11-2015, 07:08 PM	#67
joelster Member Join Date: Nov 2007 Location: Tonawanda, NY Posts: 106 Likes: 0 Liked 0 Times in 0 Posts	Re: LT-1 issue Good to hear John!

05-11-2015, 07:33 PM	#68
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: LT-1 issue Good move! __________________ Ed Wright 4156 SS/JA

05-11-2015, 07:38 PM	#69
ss3011 Senior Member Join Date: Feb 2002 Location: Southeast Michigan Posts: 909 Likes: 70 Liked 239 Times in 114 Posts	Re: LT-1 issue Just in time for Norwalk !