ignition vs power on built LT1s *Misfire *falls on face
11-15-2008, 12:42 PM
#1
Registered User
Thread Starter
Join Date: Mar 1999
Location: Orange, Ca. USA
Posts: 219
ignition vs power on built LT1s *Misfire *falls on face
built motors on spray.
The Basics
for us making over 400RW+ on motor what is the general rules on ignition systems for spraying into the 500, 600, 700 RWHP ranges?
My setup and issue
358 fully forged 4 bolt hyd roller 11.8:1
434RW @ 6800 RPM NA on 91 CA pumpgas thru a high stall 4L60E
works great NA..
Wiseco Piston to wall clearence, & Total Seal ring gap double confirmed with MFG support.
Results
turn on stage one to the tune of .042 jet and it falls on its face.
Grumpy misfires in the upper RPM range.
Iginition
New Opti, Ford TFI coil driven from the Alt via relay via 10 gauge,
taylor 10.4mm wires, TR6 @ .035 gap,
everything is datalogged via datamaster timing is retarderd 3* for every 50HP of n20
Fuel
62.5lb Seimens Deka injectors.
Single feed Walbro 255 pump NA @ 50 PSI.
Unit arms dual feed fuel system 2x walbro 255s holding 65 PSI on the dyno runs.
DynoJet Wide band on bank1 and Motec Wide Band confirm fuel on bank2.
questions
Spark scatter in the cap?
What about going colder ... BR7EFS plug?
LTCC is in stock I just have not installed it yet...
every boosted LT1 I have done over 500RW needed an LTCC but Murfy sleeps in my dyno bay.
The Basics
for us making over 400RW+ on motor what is the general rules on ignition systems for spraying into the 500, 600, 700 RWHP ranges?
My setup and issue
358 fully forged 4 bolt hyd roller 11.8:1
434RW @ 6800 RPM NA on 91 CA pumpgas thru a high stall 4L60E
works great NA..
Wiseco Piston to wall clearence, & Total Seal ring gap double confirmed with MFG support.
Results
turn on stage one to the tune of .042 jet and it falls on its face.
Grumpy misfires in the upper RPM range.
Iginition
New Opti, Ford TFI coil driven from the Alt via relay via 10 gauge,
taylor 10.4mm wires, TR6 @ .035 gap,
everything is datalogged via datamaster timing is retarderd 3* for every 50HP of n20
Fuel
62.5lb Seimens Deka injectors.
Single feed Walbro 255 pump NA @ 50 PSI.
Unit arms dual feed fuel system 2x walbro 255s holding 65 PSI on the dyno runs.
DynoJet Wide band on bank1 and Motec Wide Band confirm fuel on bank2.
questions
Spark scatter in the cap?
What about going colder ... BR7EFS plug?
LTCC is in stock I just have not installed it yet...
every boosted LT1 I have done over 500RW needed an LTCC but Murfy sleeps in my dyno bay.
Last edited by TurboSS; 11-15-2008 at 12:46 PM.
11-16-2008, 11:19 AM
#2
Administrator
Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,647
Are you sure it "falls on its face" due to ignition problems? Are you sure its simply not getting the required nitrous or fuel flow? I've had 100HP disappear with a simple internal problem with the bottle valve.
Normally at the level you are running, I'd expect to see a multiple-spark box, like the MSD, but it appears you are leaning toward the LTCC. Why not install the LTCC and see if it solves the problem.
Normally at the level you are running, I'd expect to see a multiple-spark box, like the MSD, but it appears you are leaning toward the LTCC. Why not install the LTCC and see if it solves the problem.
11-16-2008, 12:03 PM
#3
Registered User
Thread Starter
Join Date: Mar 1999
Location: Orange, Ca. USA
Posts: 219
Injuneer, Thanks for the reply.
85% sure.
It feels, sounds and looks like ignition
the graph look just like when FI cars run out of ignition.
Fuel flow I have in spades.
Mechanical and electric guage both jive at 62PSI durring the dyno runs.
have two wideband AFR guages onboard. One per bank.
I started at 11.0:1 AFR and worked down to 12.4 AFR.
The pulls made more power and were cleaner twards 12.5
The pulls were grummpier and had more misfires starting earlyier at 11.0:1 AFR.
The datalogger shows injector pulse width up and spark down from NA.
I should have taken a picture when I had the plugs out.
Nitrous flow, It could be diminished.
I should check my N20 filter.
it was making an extra 55RWTQ on a .042 jet @ 890-900PSI at 5500RPM.
That seems a little shy on power.
It is a 20lb NOS bottle mounted at an uphill angel.
Tell me more about internal bottle problems plz. >> ??
I stay away from aftermarket ignition boxes with the opti.
The LTCC is in stock w/ coils I just need some time to put it on the car.
I just can't decide were to mount the coils,
and I am going to be redoing my headers and dont want to run into header vs brand new wire wars.
This post is mainly a head check against the community at large.
What kind of igintion is needed at 500+RW on spray.
Are you sure it "falls on its face" due to ignition problems?
It feels, sounds and looks like ignition
the graph look just like when FI cars run out of ignition.
Are you sure its simply not getting the required nitrous or fuel flow?
Mechanical and electric guage both jive at 62PSI durring the dyno runs.
have two wideband AFR guages onboard. One per bank.
I started at 11.0:1 AFR and worked down to 12.4 AFR.
The pulls made more power and were cleaner twards 12.5
The pulls were grummpier and had more misfires starting earlyier at 11.0:1 AFR.
The datalogger shows injector pulse width up and spark down from NA.
I should have taken a picture when I had the plugs out.
Nitrous flow, It could be diminished.
I should check my N20 filter.
it was making an extra 55RWTQ on a .042 jet @ 890-900PSI at 5500RPM.
That seems a little shy on power.
I've had 100HP disappear with a simple internal problem with the bottle valve.
Tell me more about internal bottle problems plz. >> ??
Normally at the level you are running, I'd expect to see a multiple-spark box, like the MSD, but it appears you are leaning toward the LTCC. Why not install the LTCC and see if it solves the problem.
The LTCC is in stock w/ coils I just need some time to put it on the car.
I just can't decide were to mount the coils,
and I am going to be redoing my headers and dont want to run into header vs brand new wire wars.
This post is mainly a head check against the community at large.
What kind of igintion is needed at 500+RW on spray.
11-16-2008, 10:27 PM
#4
Administrator
Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,647
Took the car in for a dyno check after some exhaust changes. Spraying 300HP, it was 100HP shy, running pig rich. Tried everything, the shop substituted one of their bottles, and the 100HP reappeared immediately. They said it was a bad valve. Did not pull the old valve apart, just threw it away.
11-18-2008, 08:54 AM
#5
Registered User
Join Date: Oct 2006
Posts: 997
You might be experiencing...spark blow-out.
Does it sound like the last pull in this vid.
http://www.youtube.com/watch?v=CddWtyOKm70
His issue was fixed by replacing the MSD stock replacement coil with a better coil.
I don't know any big power LT1 not running an upgraded ignition box/coil on nitrous. You need the extra firing power to keep the plugs lit under the cylinder pressure.
I am running the MSD Digital 6 and the MSD 8252 coil since 2000...still on the stock opti
Does it sound like the last pull in this vid.
http://www.youtube.com/watch?v=CddWtyOKm70
His issue was fixed by replacing the MSD stock replacement coil with a better coil.
I don't know any big power LT1 not running an upgraded ignition box/coil on nitrous. You need the extra firing power to keep the plugs lit under the cylinder pressure.
I am running the MSD Digital 6 and the MSD 8252 coil since 2000...still on the stock opti
11-18-2008, 09:49 AM
#6
Registered User
Thread Starter
Join Date: Mar 1999
Location: Orange, Ca. USA
Posts: 219
Does it sound like the last pull in this vid.
IF it sounds like "buh b buh b b bbbuuu b b b B bbuh bb b b"
kinda like a big heavy half wet blanket being wrapped and snapped in the wind.
Then YES it sounded like that.
11-18-2008, 11:57 AM
#8
Registered User
Thread Starter
Join Date: Mar 1999
Location: Orange, Ca. USA
Posts: 219
I have LS1 style coil per cyl ignition system to go on the car.
I just need to figure out how I want to mount it and muster the time to put it on the car.
TAD
I just need to figure out how I want to mount it and muster the time to put it on the car.
TAD
Last edited by TurboSS; 11-18-2008 at 12:02 PM.
01-04-2009, 12:16 AM
#9
Registered User
Join Date: Aug 2000
Location: Dallas,TX
Posts: 1,071
I was having similiar issues in the upper rpms on the spray also. It was getting VERY ERATIC towards the end. Went with the MSD 8252 coil and I could tell a big difference. I haven't redynoed the car since installing it, but I'm sure it will be alot better now. I already had the MSD Digi6 ign.
You might be experiencing...spark blow-out.
Does it sound like the last pull in this vid.
http://www.youtube.com/watch?v=CddWtyOKm70
His issue was fixed by replacing the MSD stock replacement coil with a better coil.
I don't know any big power LT1 not running an upgraded ignition box/coil on nitrous. You need the extra firing power to keep the plugs lit under the cylinder pressure.
I am running the MSD Digital 6 and the MSD 8252 coil since 2000...still on the stock opti
Does it sound like the last pull in this vid.
http://www.youtube.com/watch?v=CddWtyOKm70
His issue was fixed by replacing the MSD stock replacement coil with a better coil.
I don't know any big power LT1 not running an upgraded ignition box/coil on nitrous. You need the extra firing power to keep the plugs lit under the cylinder pressure.
I am running the MSD Digital 6 and the MSD 8252 coil since 2000...still on the stock opti
01-04-2009, 09:25 AM
#10
Registered User
Join Date: Nov 2006
Location: Camanche IA
Posts: 393
I put a fair amount of miles on my car running a mallory 685 box and msd coil with no opti problems and sprayed it with two .057 nitrous jets at the end of that season before the stroker went in. I don't beleave there is any problems running a box with the opti.
The problem I see with the coil on plug is it is real easy to pull timing with multiple kits with an aftermarket box. The 685 olly has one timing retard but there are other options that will allow you 3 different retards.
If you get it on the dyno again let us know how it goes.
The problem I see with the coil on plug is it is real easy to pull timing with multiple kits with an aftermarket box. The 685 olly has one timing retard but there are other options that will allow you 3 different retards.
If you get it on the dyno again let us know how it goes.
05-25-2009, 01:24 AM
#12
Registered User
Join Date: Jan 2002
Location: Mission, Kansas
Posts: 1,743
I ran a msd cap/rotor, stock back part of the opti, no ignition box, made 520rwhp on 150rwhp jets, never dyno'd on the 325rwhp jets. Now on the turbo setup the ignition box did seem to help me out.
05-25-2009, 11:41 AM
#13
Administrator
Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,647
05-25-2009, 11:42 PM
#15
Registered User
Thread Starter
Join Date: Mar 1999
Location: Orange, Ca. USA
Posts: 219
LTCC igniton in progress
If I can dig up a set of custom wires for the LTCC I may make it to the drags on the 30th.
Looks like autozone sells Lt1 wire sets for $25 Lifetime.
Maybe I could make up a temp set while I'm waiting for my performance wires to show.
http://www.autoclubspeedway.com/Tick...b-Dragway.aspx
May 30, 2009 is NHRA Street Legal Drags
Gates open at 6:00am
Ticketing/Tech opens at 7:00am
Racing starts at 9:00am
Prices: Car/Driver $20.00
Spectator/Crew: $10.00
If I can dig up a set of custom wires for the LTCC I may make it to the drags on the 30th.
Looks like autozone sells Lt1 wire sets for $25 Lifetime.
Maybe I could make up a temp set while I'm waiting for my performance wires to show.
http://www.autoclubspeedway.com/Tick...b-Dragway.aspx
May 30, 2009 is NHRA Street Legal Drags
Gates open at 6:00am
Ticketing/Tech opens at 7:00am
Racing starts at 9:00am
Prices: Car/Driver $20.00
Spectator/Crew: $10.00