Grounding

Hello. Hoping someone can clear up my grounding setup on the car.

Now, in the course, it states you should ground the block to the chassis via a single point. Simple enough. I have run my car with a large earth strap from the block to the chassis rail.

In other sources I have heard its best to run two earth straps from the engine to the chassis, mainly for redundancy, since if one fails, you still have a car that runs. Is this a good idea. I have also seen it suggested as a good idea to run a ground from the block to the chassis rail and a ground from the head to the bulkhead?

My other question, again based on other sources, is that I should have a large ground strap from the engine to the chassis (obviously) but that I should also have one from the battery to the block. Since my battery is mounted farther away in the interior behind the passenger seat. This mainly so that you do not get high loads through the chassis when using the starter and to reduce voltage drop leading to better starting.

Can anyone confirm the best practices in these cases?

Thanks a lot.

Block is RB26, so heavy steel, body is steel monocque.

So, I found the star point earthing webinar. And from that it would seem that its not a requirement for the battery to be wired to the block also. I knew this of course because I had run my car like this for a long time.

However, I always felt the cranking could be faster. Would I see any benefit from doing this anyway or is it likely that I could gain as much from changing to a thicker gauge strap from block to chassis?

Since I am completing an entire nut and bolt restoration and overall on my entire car, I shall be making sure all grounding studs are large and very clean.

Hello, I have generally the same question, though for different reasoing. I have made it through the fundamentals course and am mid practical wiring - club level course (past the grounding/earthing lesson). I also watch Devin Vanderhoof's YouTube videos. He recommends a chassis ground/battery, engine block/battery, ECU/battery, as well as engine block/chassis. This may pertain to certain brands of EFI though, as it seems from how far I've got in the lessons. My application follows, and I'm seeing if I should follow Devin's method or if the HPA method suits better?

HPA: 2 star grounds - 1 chassis & 1 engine block, 1 large cable chassis to engine block, 1 large cable engine block to battery negative (please correct me if I'm misunderstanding that).

Devin (HCR): Battery to block, chassis to battery, block to chassis (still has a star earth for chassis and a star earth for block, kind of).

I'm leaving the ECU power and grounds out of both as I'm pretty certain with the Holley that I must go to the battery directly for power and ground.

For detail: Holley Dominator EFI, Holley Smart Coils w/cam sync for sequential injection, Hyperaktive 12-1 trigger wheel (hall effect I believe), attached to a small block Chevy. This is a street/strip car that competes in Drag Week style events. The battery is in the trunk with a dual pole, single throw kill switch that separates the alternator and battery chassis side wiring.

Thank you in advance for any assistance, or any info on thread manners of if this should have been a separate thread.

From my continued reading, it would normally be bad to have the ECU wired to the battery, except in the cases where the ECU asks for it, which is usually the cheaper ones. If I find my resources for this again I will post here.

For now, for me, I do not plan on adding another cable from the battery to the block, just increasing the size of the wire that grounds the block to the chassis, to decrease resistance, going to use a fairly substantial one.

It was pointed out that in general the chassis on a unibody car is more effective than any cable.

I agree, and that's what I've gathered as well. The Holley specifically asks for it; I should have worded that differently. According to Holley, it's a must.

I believe I recall what you're talking about possibly. I did a forum search and came across the information you might be referencing before I replied in this thread; I believe they were talking about a Fuel Tech specifically and referencing cheaper ECUs overall? If that's not it, I look forward to finding your source if you find it!

Speaking of unibody, if it will matter response wise in the future, my car is a full frame with a 12-point roll cage welded to the frame (NHRA spec), so my chassis ground is a lug on the roll cage in the rear and a lug on the front frame rail in the engine bay. I also have the body ground to the chassis lug in the engine bay for the factory wiring grounds that use the body.