Quote:

Quote:

The thing about THIS site in particular, is that experience with something is of little to no use. Because when you say something that others don't agree with, they are going to search out enough "experts" to debunk your input and say "see, I told you".

Just like all this talk about factory cars........I DON'T care. We are not talking about factory cars.

What I DO know, is that EFI race cars with high HP applications are VERY sensitive to noise and how they are wired. I found this out by having serious issues with a customers car and searching out some help to solve that problem. Rewiring the car with the "floating" ground system FIXED that car. I have since wired several other cars with that system and had ZERO problems. I guess I could have "argued" with the guy that told me to do that and tried to shoot his theory all full of holes..........but instead, I noticed that he had a LOT of really fast cars out there that he had wired up. "Hey, this guy must know something" was my thoughts........he did.

Bottom line, I was only trying to pass on some information that worked for me, NOT get in a theoretical debate. So guys just need to do what they want or are comfortable with..........because it really doesn't matter to me

Monte


I'm not disputing that your fix repaired your issues. I guess I'm coming off wrong. We both agreed that the roll cage works in many instances. My digging was to find out why your method overcame the issue. So far I haven't been able to understand why it worked, which obviously it has. There are different methods to diagnose a problem. Use scientific knowledge or try things and see what works. Both have their merits. Many times there is no choice. We just have to work it out and see what happens. What I think is beneficial is learning how all systems function. Hopefully this discussion has done that. I'm still curious. If I knew why your method fixed your issue I might be able to use that knowledge to repair a future problem. I didn't mean to seem argumentative, just trying to learn.
Doug

The answer is very easy actually. We know EMI noise is a very REAL issue, on normal and high HP applications. High HP cars have tremendous cylinder pressure, meaning VERY hard to light off. This taxes the ignition system VERY heavily. When that happens, you get spikes, flyback voltage and all sorts of other things that can wreck havoc on somewhat delicate sensors.

FastMop is talking about a high rpm miss when the boost gets up.....SOMETHING is noisy. Slammed R/T has a TPS issue........SOMETHING is noisy. If EVERYTHING on the car is grounded to one big ground circuit, the chassis, NOTHING is "clean". Ground the water or fuel pump, to the same stud where the ECU or ignition box is and you are ASKING to have a problem, even on a carbed car. Most take the ground circuit of their car for granted, when it is EASILY the MOST important electrical circuit on the whole damn car.

MrP and other tech are talking about ground issues, burning up wheel bearings and trans parts. How does that happen?.....backfeeds, spikes and other things from a poorly performing ground system is how. I had a customer fight a high speed miss in an IHRA Pro-Stocker for TWO years. Rewired the car a couple times, as well as replaced EVERY electrical part on it. Turned out, the chassis had become magnetized and was wrecking the ignition system at high rpm. Far fetched, YES, but it happened. So how did they fix it? "Floating ground" and took the chassis out of the equation. I didn't fix it or find it.....somebody MUCH smarter than me did, but what I DID do was pay attention to what he was telling me.

Just like I mentioned the "factory" LS coils earlier. They are regarded as very good "hotrod" coils and they are. There are millions of them on the road causing ZERO issues on factory cars. We had no problems with them either, when coupled with the Holley ECUs, until some turbo guys starting making SERIOUS boost. Our boxes have 5 times the filtering of a factory GM ECU, yet these guys were smoking our boxes right and left. We tested them at the plant and they were great until you put them in a REALLY high stress environment, ie HIGH cylinder pressure and then the "flyback" voltage became crazy high. Enough to smoke ECUs. So now our boxes have enough filtering to probably work on the damn space shuttle..........This was the reason I said earlier that I don't CARE how factory cars are wired, because it is NOT an apples to apples comparison. Some seem to forget, I work FOR Holley and have access to some very high tech testing equipment, procedures and data. I don't say this stuff just to hear myself talk, or because I THINK it's right. I have SEEN it. We have a chamber, that I can completely PUT THE FIRE OUT of an MSD 10 box, with pressure. If you could see what happens inside that cell, when we load a chamber that hard, some of this would be MUCH easier to understand

Monte