MY Real Street 275 build
11-03-2014, 04:36 PM
#801
We already tried wrapping the main harness and wires with foil. Didn't make a lick of difference.
Ron,
We've already shielded just about every wire in the main harness that could cause an issue. To shield the others we'd have to completely re-wire the car and re-do the harness.
The car has run fine up to 136.5mph and 5.33 E.T. with the harness in the same position that now causes it to not run for more than 5-10 seconds. If you hold that harness away from the engine in an attempt to distance the main harness from the coils it runs fine. Note that each time we've moved the harness away from the engine the issue has gotten better. Now it won't even run for more than 10 seconds with the harness in the same position that allowed it to run 5.33 before.
Nothing has been changed in that harness since those passes other than undoing a few shielding grounds that were in a "loop". Those shielding grounds have since been re-done in a "loop" which allowed the car to run that E.T. and MPH. I find it hard to believe that a wire or crimp could of come loose between now and then.
I guess it is possible, but it still seems EMI/RFI related.
EDIT ADDED** Jonathan even lengthened the cam sensor harness this morning while I wasn't here by about 3-4'. He just told me this about an hour ago. The car idled perfectly fine for him after doing so, but when he got in the car to drive it around the building and park it under our awning it attempted to shut off twice. It never actually shut off, but the car would lunge and the RPM will drop then it seems to catch itself and continues to run. I don't mean lunge as in cam surge, I mean it lunges due to the engine wanting to shut off so violently and unexpectedly and then catches itself and continues to run.
Don,
At this point I'd love to have the GM computer I originally planned to use with Boost Leash/pulse combo.
This car would already be in the 5.0's if it weren't for this ignition issue. That 1.22 60' showed that this thing has a ton in it still and if we can put the back half I have with that 1.22 60' it would easily be a 5.teen@136-137.
Still has a ton left in the tank in regards to boost, fuel and timing.
Ron,
We've already shielded just about every wire in the main harness that could cause an issue. To shield the others we'd have to completely re-wire the car and re-do the harness.
The car has run fine up to 136.5mph and 5.33 E.T. with the harness in the same position that now causes it to not run for more than 5-10 seconds. If you hold that harness away from the engine in an attempt to distance the main harness from the coils it runs fine. Note that each time we've moved the harness away from the engine the issue has gotten better. Now it won't even run for more than 10 seconds with the harness in the same position that allowed it to run 5.33 before.
Nothing has been changed in that harness since those passes other than undoing a few shielding grounds that were in a "loop". Those shielding grounds have since been re-done in a "loop" which allowed the car to run that E.T. and MPH. I find it hard to believe that a wire or crimp could of come loose between now and then.
I guess it is possible, but it still seems EMI/RFI related.
EDIT ADDED** Jonathan even lengthened the cam sensor harness this morning while I wasn't here by about 3-4'. He just told me this about an hour ago. The car idled perfectly fine for him after doing so, but when he got in the car to drive it around the building and park it under our awning it attempted to shut off twice. It never actually shut off, but the car would lunge and the RPM will drop then it seems to catch itself and continues to run. I don't mean lunge as in cam surge, I mean it lunges due to the engine wanting to shut off so violently and unexpectedly and then catches itself and continues to run.
Don,
At this point I'd love to have the GM computer I originally planned to use with Boost Leash/pulse combo.
This car would already be in the 5.0's if it weren't for this ignition issue. That 1.22 60' showed that this thing has a ton in it still and if we can put the back half I have with that 1.22 60' it would easily be a 5.teen@136-137.
Still has a ton left in the tank in regards to boost, fuel and timing.
Last edited by Sales@Tick; 11-03-2014 at 04:55 PM.
11-03-2014, 05:03 PM
#802
I know it would suck to just try and see, but what about extending all of the wires and moving the computer behind the driver just as a final all in deal. I'd solder all of the joints and heat shrink them.
Worst case, you're still in the same spot.
Worst case, you're still in the same spot.
11-03-2014, 06:39 PM
#804
When we initially shielded the wires after the first race we attempted to go to where the car was cutting off at idle AND down track when trying to bring boost in faster than 1.6 seconds running only 18psi it fixed the problems we were having. So the shielding worked.
I then turned it up to 26psi and it went from a 5.70@126 to a 5.40@136.
After that if I attempted to bring the boost in any faster the car would "shut off".
We then tried many other things including a new water pump, new coils, new wires, new plugs and more things that I can count on two hands and feet. Everything has been documented so far in this thread from the beginning regarding what we changed and how it affected the issue. Each time we've done something to shield or keep EMI from affecting the ECU things have gotten better.
My boss Jonathan read somewhere that when using shielding grounds you don't want to connect both ends of the wire to ground as it creates a loop. He hoped that by disconnecting one end of the shielding ground that it would solve the cutting out issue when I tried to bring the boost in faster.
Keep in mind up to this point the car would run for hours on end at an idle, would run 5.33-5.40@136 like clock work and the ONLY thing it did was shut off when I tried to bring full boost in faster than 1.6 seconds into the run.
After unhooking just that one end of each shielding ground all of the sudden the car will no longer run period. We even re-hooked those grounds back up to create the loop we had again that allowed it to run and it still will not run. At this point NOTHING in the harness has been touched.
Then today Jonathan lengthened the cam sensor wire by 3-4' and re routed it all the way behind my cowl under my windshield as far away from the coils as he could get it.
The car NOW RUNS at idle for as long as you want it to! BUT! If you try to drive it around the shop it will attempt to shut off, but it does catch itself before actually shutting off.
I just don't see how it could do all of that, get worse, then get better if it is a bad connection? We have direct cause and affect here, no?
FAST is sending me a new XFI box and we're going to try a XIM ignition box instead of the EZ-LS ignition box I have now.
11-03-2014, 08:20 PM
#806
Ron,
When we initially shielded the wires after the first race we attempted to go to where the car was cutting off at idle AND down track when trying to bring boost in faster than 1.6 seconds running only 18psi it fixed the problems we were having. So the shielding worked.
I then turned it up to 26psi and it went from a 5.70@126 to a 5.40@136.
After that if I attempted to bring the boost in any faster the car would "shut off".
We then tried many other things including a new water pump, new coils, new wires, new plugs and more things that I can count on two hands and feet. Everything has been documented so far in this thread from the beginning regarding what we changed and how it affected the issue. Each time we've done something to shield or keep EMI from affecting the ECU things have gotten better.
My boss Jonathan read somewhere that when using shielding grounds you don't want to connect both ends of the wire to ground as it creates a loop. He hoped that by disconnecting one end of the shielding ground that it would solve the cutting out issue when I tried to bring the boost in faster.
Keep in mind up to this point the car would run for hours on end at an idle, would run 5.33-5.40@136 like clock work and the ONLY thing it did was shut off when I tried to bring full boost in faster than 1.6 seconds into the run.
After unhooking just that one end of each shielding ground all of the sudden the car will no longer run period. We even re-hooked those grounds back up to create the loop we had again that allowed it to run and it still will not run. At this point NOTHING in the harness has been touched.
Then today Jonathan lengthened the cam sensor wire by 3-4' and re routed it all the way behind my cowl under my windshield as far away from the coils as he could get it.
The car NOW RUNS at idle for as long as you want it to! BUT! If you try to drive it around the shop it will attempt to shut off, but it does catch itself before actually shutting off.
I just don't see how it could do all of that, get worse, then get better if it is a bad connection? We have direct cause and affect here, no?
FAST is sending me a new XFI box and we're going to try a XIM ignition box instead of the EZ-LS ignition box I have now.
When we initially shielded the wires after the first race we attempted to go to where the car was cutting off at idle AND down track when trying to bring boost in faster than 1.6 seconds running only 18psi it fixed the problems we were having. So the shielding worked.
I then turned it up to 26psi and it went from a 5.70@126 to a 5.40@136.
After that if I attempted to bring the boost in any faster the car would "shut off".
We then tried many other things including a new water pump, new coils, new wires, new plugs and more things that I can count on two hands and feet. Everything has been documented so far in this thread from the beginning regarding what we changed and how it affected the issue. Each time we've done something to shield or keep EMI from affecting the ECU things have gotten better.
My boss Jonathan read somewhere that when using shielding grounds you don't want to connect both ends of the wire to ground as it creates a loop. He hoped that by disconnecting one end of the shielding ground that it would solve the cutting out issue when I tried to bring the boost in faster.
Keep in mind up to this point the car would run for hours on end at an idle, would run 5.33-5.40@136 like clock work and the ONLY thing it did was shut off when I tried to bring full boost in faster than 1.6 seconds into the run.
After unhooking just that one end of each shielding ground all of the sudden the car will no longer run period. We even re-hooked those grounds back up to create the loop we had again that allowed it to run and it still will not run. At this point NOTHING in the harness has been touched.
Then today Jonathan lengthened the cam sensor wire by 3-4' and re routed it all the way behind my cowl under my windshield as far away from the coils as he could get it.
The car NOW RUNS at idle for as long as you want it to! BUT! If you try to drive it around the shop it will attempt to shut off, but it does catch itself before actually shutting off.
I just don't see how it could do all of that, get worse, then get better if it is a bad connection? We have direct cause and affect here, no?
FAST is sending me a new XFI box and we're going to try a XIM ignition box instead of the EZ-LS ignition box I have now.
11-03-2014, 10:28 PM
#807
The grounding of one end or both ends is an "it depends" deal. Glad you tried it both ways.
EMI shielding is tricky.
If I lived closer, I'd come over with a scope and a spectrum analyzer and measure the interference. I used to do such work.
Since others have had issues with the Fast stuff, I'm wondering what they did for a fix? Also wondering why it's even susceptible in the first place. Cars are inherently noisy environments. So shielding and bypassing inside the box are critical.
Hopefully the new parts work!
I'm sure you have been all over the various grounds.
Ron
EMI shielding is tricky.
If I lived closer, I'd come over with a scope and a spectrum analyzer and measure the interference. I used to do such work.
Since others have had issues with the Fast stuff, I'm wondering what they did for a fix? Also wondering why it's even susceptible in the first place. Cars are inherently noisy environments. So shielding and bypassing inside the box are critical.
Hopefully the new parts work!
I'm sure you have been all over the various grounds.
Ron
11-04-2014, 11:51 AM
#810
The grounding of one end or both ends is an "it depends" deal. Glad you tried it both ways.
EMI shielding is tricky.
If I lived closer, I'd come over with a scope and a spectrum analyzer and measure the interference. I used to do such work.
Since others have had issues with the Fast stuff, I'm wondering what they did for a fix? Also wondering why it's even susceptible in the first place. Cars are inherently noisy environments. So shielding and bypassing inside the box are critical.
Hopefully the new parts work!
I'm sure you have been all over the various grounds.
Ron
EMI shielding is tricky.
If I lived closer, I'd come over with a scope and a spectrum analyzer and measure the interference. I used to do such work.
Since others have had issues with the Fast stuff, I'm wondering what they did for a fix? Also wondering why it's even susceptible in the first place. Cars are inherently noisy environments. So shielding and bypassing inside the box are critical.
Hopefully the new parts work!
I'm sure you have been all over the various grounds.
Ron
11-04-2014, 11:16 PM
#812
I wonder If there could be a sound/harmonics issue being transmitted from the hard block to the rigid mounted coils. My GEN I 434 was filled and I could not believe how much noise eminated from the cylinder case. I originally was thinking your issue was a ground getting tugged on with the chassis flex from the increased power application but you now say it goes kaput or stumbles in a multitude of instances. Seems to me you've exhausted all electrical possibilities. Pillow mounted coils/suspended perhaps....? Awesome build !!!!
11-05-2014, 05:43 PM
#813
The grounding of one end or both ends is an "it depends" deal. Glad you tried it both ways.
EMI shielding is tricky.
If I lived closer, I'd come over with a scope and a spectrum analyzer and measure the interference. I used to do such work.
Since others have had issues with the Fast stuff, I'm wondering what they did for a fix? Also wondering why it's even susceptible in the first place. Cars are inherently noisy environments. So shielding and bypassing inside the box are critical.
Hopefully the new parts work!
I'm sure you have been all over the various grounds.
Ron
EMI shielding is tricky.
If I lived closer, I'd come over with a scope and a spectrum analyzer and measure the interference. I used to do such work.
Since others have had issues with the Fast stuff, I'm wondering what they did for a fix? Also wondering why it's even susceptible in the first place. Cars are inherently noisy environments. So shielding and bypassing inside the box are critical.
Hopefully the new parts work!
I'm sure you have been all over the various grounds.
Ron
I wonder If there could be a sound/harmonics issue being transmitted from the hard block to the rigid mounted coils. My GEN I 434 was filled and I could not believe how much noise eminated from the cylinder case. I originally was thinking your issue was a ground getting tugged on with the chassis flex from the increased power application but you now say it goes kaput or stumbles in a multitude of instances. Seems to me you've exhausted all electrical possibilities. Pillow mounted coils/suspended perhaps....? Awesome build !!!!
At this point I am not ruling anything out!
12-10-2014, 12:19 PM
#816
Fast told me that they had a customer with the exact same problems my car has. Shutting off at idle, shutting off under a load.
Customer had the same FAST EZ LS EFI ignition box I do. Swapped to the older style XIM ignition box, and no more problems.
Season has been over for us here for a while now so I am in no real hurry, but I want to get the new XIM box Fast sent me on the car soon and see what happens.
Customer had the same FAST EZ LS EFI ignition box I do. Swapped to the older style XIM ignition box, and no more problems.
Season has been over for us here for a while now so I am in no real hurry, but I want to get the new XIM box Fast sent me on the car soon and see what happens.
12-15-2014, 09:40 AM
#820
I'm hoping the XIM box will fix mine. If not, I may have to make that move.
It's not as hard as it seems, but track prep comes into play the most IMO.
If the track isn't there it's nearly impossible to get a good E.T. out of these tires. The 3754X(Pro Version of what I run) is more forgiving in that sense, but it still needs a tacky bed of rubber to run well.
This car has been a 1.21 60' and I feel it will go into the teens once I get more seat time and data.
It's not as hard as it seems, but track prep comes into play the most IMO.
If the track isn't there it's nearly impossible to get a good E.T. out of these tires. The 3754X(Pro Version of what I run) is more forgiving in that sense, but it still needs a tacky bed of rubber to run well.
This car has been a 1.21 60' and I feel it will go into the teens once I get more seat time and data.