[SATINSTEEL1LE]

I forgot to post this. But I made the switch from the stock AC delco wires to MSD LT1/LT4 plug wires. I read somewhere on here someone said the stock wires were best and had the lowest resistance. Yeah bull spit they do.

I measured the resistance on the stock wires and was seeing consistent 2100ohms. Yes twenty one hundred.

I then measured the MSD wires and was getting 30ohms. Thats THIRTY. Yes 2070 less ohms of resistance on the MSD wires over the AC Delco stock wires. Thats a MASSIVE difference. And on the box they say you should see about 40ohms of resistance, so they were even better than that.

HERES THE CATCH...

Not sure how, why or for what reason, but soon after the plug wires were swapped the dreaded cluster/radio going black during driving started happening. NEVER happened before to me. 21 ZL1 with just over 5k miles. So I immediately figured it was some sort of electrical issue with the new wires. Not sure where I read it because I was feverishly looking for google answers, but I had found a post somewhere that there was a TSB on this and the dealer would reflash the PCM to fix it.

Well I have HP Tuners and my car is tuned and I have the tune file, so I said lets see what happens when I reflash my car. I basically did a write complete of the same tune that was on the car already, basically overwriting it.

Well what do you know, the cluster/radio going off completely stopped. Not sure how or why this worked, but something was pissing off communication between the PCM and the cluster/radio. I was even getting codes for it.

But yes the MSD wires in terms of resistance are worlds better than the stock wires. I was able to open the gap on my plugs to .040 and have seen 2x better idle and part throttle driving performance.

Im not sure if the cluster thing was unrelated to the wires being swapped and the dramatic drop in resistance, but it had to have some effect on the car's electrical system throwing something out of wack. Flashing the entire PCM must have reset something and from there it was and has been perfect. That was like two weeks ago. Since then, not a single time the dash went out.

[Ventmaster]

very interesting... one moment I was ready to replace my wires and the next I was thinking "if she ain't broke, don't fix it!"

It will be interesting to see if there are other theories as to the issue.

[Spaceme1117]

So did some reading on spark plug wire resistance.

The main reason it seems for resistance in the wires is because the wires have a lot of shielding in them to prevent interference in other electronics of the car particularly the radio.

https://www.hagerty.com/media/mainte...s-demystified/

So it would make sense that your radio had issues after putting on the MSD wires.

Maybe the MSD wire will give a hotter spark and an extra few HP. I would say run them as long as you don't have issues from electrical interference in the car.

[Curr]

Originally Posted by Spaceme1117

So did some reading on spark plug wire resistance.

The main reason it seems for resistance in the wires is because the wires have a lot of shielding in them to prevent interference in other electronics of the car particularly the radio.

https://www.hagerty.com/media/mainte...s-demystified/

So it would make sense that your radio had issues after putting on the MSD wires.

Maybe the MSD wire will give a hotter spark and an extra few HP. I would say run them as long as you don't have issues from electrical interference in the car.

Agree that shielding should have zero effect on the resistance of the wire end to end. That just to reduce radiated / coupled signal. Which as you point out, could be the source of those errors.
I'd be curious to talk to an automotive engineer to see the reason for value, though.

2,1kΩ to 30Ω is a fairly significant difference. Not sure I'd change them without some further research.

(I'm a 25 year EE in RF / µW space)

[LT4Greg]

I can believe the results you are getting with the new wires as back in the day when I had my 1998 Camaro SS I changed out the original wires for a set of red 8mm GM Performance Parts wires that really made a difference in the performance of that small LS1. I’m seriously thinking about changing the wires on my ZL1 but not sure now after what you experienced with yours.

[laynlo15]

Those are old codes, just clear them. This happens sometimes but not sure why. With your set up you'd normally lower your gap to about .026 to .028. Did you just reflash again?

[Vtor_ZL1]

At the voltages they operate at (40,000 bolts, very low amperage) the resistance does not contribute to weaker spark. Lower resistance does contribute to shit ton more electrical noise. There's lots of research around the topic and yet marketing around this stuff is astounding, errmagohd lower is better and for only $9.99 !



My opinion: Risky business flashing a tune on "noisy" electrical system.

[SATINSTEEL1LE]

Originally Posted by Vtor_ZL1

At the voltages they operate at (40,000 bolts, very low amperage) the resistance does not contribute to weaker spark. Lower resistance does contribute to shit ton more electrical noise. There's lots of research around the topic and yet marketing around this stuff is astounding, errmagohd lower is better and for only $9.99 !



My opinion: Risky business flashing a tune on "noisy" electrical system.

You don’t flash the car when it’s running so that wouldn’t matter. The ignition is on but the car is off when you flash it.

I was just astounded how much of a difference in resistance the new wires were in comparison to the stock wires. The gap I had before was .032 and the car idled rough and I was seeing tip in stumbling. Ted and I went round and round tweaking and logging. The bigger gap plugs and wires took care of that and the bonus was a smoother idle and better part throttle performance. I can tell a difference.

[Joshinator99]

I’ve run stock and MSD over the years. But I’m currently running the top tier Granatelli ones and they are *really* nice. Seem to really stand up to the header heat too.
https://granatellimotorsports.com/i-...%7Cyear%3D2017

[KingLT1]

Sounds like a bad set of stock wires. I have seen stock wires measured before and they didn't have anywhere near that amount of resistance. I believe Andrew @ CSP tested them and that is why he had Stainless works make a CSP variant long tube header designed to work with stock plug wires.

[ctrlz]

Originally Posted by SATINSTEEL1LE

I measured the resistance on the stock wires and was seeing consistent 2100ohms. Yes twenty one hundred.

I went back and reread to make sure you said "wires" and not just one. If all 8 measure the same, then I would suspect it's by design, and not a problem.
So, did me some edumacation reading, as my knee-jerk reaction was that resistance should be low. Turns out the engineers have to strike a balance:
https://www.hagerty.com/media/mainte...s-demystified/

[Gunkk]

Another "I changed my wires and my car is broke" thread.

Color me shocked.

[SATINSTEEL1LE]

Originally Posted by Gunkk

Another "I changed my wires and my car is broke" thread.

Color me shocked.

Taken completely out of context but I guess that's the way of the world. Sit in your bassinette and enjoy the pretty colors.

[SATINSTEEL1LE]

Originally Posted by KingLT1

Sounds like a bad set of stock wires. I have seen stock wires measured before and they didn't have anywhere near that amount of resistance. I believe Andrew @ CSP tested them and that is why he had Stainless works make a CSP variant long tube header designed to work with stock plug wires.

No. Every single stock wire was within that same 2000-2100ohms of resistance. Nothing was bad and none of them were broken.