I’m wondering if anyone here has seen a difference in hi resistance plug wires vs low resistance? Like moroso wires vs magnecor wires. What effect does the resistance have on combustion, especially boosted?

J.R. though not a boosted application, I’ve tried all the popular brands over the last 3+ decades and ain’t ever found a performance advantage on the time slip. After running MSD wires for many years, I switched to Moroso Ultra 40 unsleeved custom fit 8.65mm wires about 10 years ago, If for no other reason than the boots are better. They are also rated at 40 ohms/ft. I use part #73712 which run under the headers on my dragster and part #73728 which run over the valve covers on my firebird.





Moroso Race Wires are used by the majority of professional bracket/class engine builders and most Pro Stock teams.

Moroso Ultra 40 Unsleeved Custom-Fit Wire Sets
The new standard in ignition wires for racers on a budget! Moroso Ultra 40 unsleeved custom-fit ignition wire sets are the most powerful and RFI/EMI-resistant wires available for racing today. Plus, their closely woven fiberglass, silicone-impregnated insulation provides up to 8,000 extra volts of protection.

Features:

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* Locking stainless steel plug terminals

This message has been edited. Last edited by: 1320racer,

What kind of noise problems are you having?

High resistance wires are for noise suppression.

2.0 amp coil alky moroso ultra 40 sleeved wires since they came out no problems

May have been the most helpful post I've ever seen be Ed. Nice work.

Ed any reason you run the unsleeved instead of the sleeved Moroso wires?

Steve, I don’t like the look of the sleeved and I ain’t ever seen sleeve wires on a pro stock engine.

I run thew Moroso Ultra 40 sleeved wires from Smileys racing about half price of Moroso and literally come in same box.
They have worked very well for me.

Not only aren’t they the same wire, 8mm vs. 8.65mm and 800 ohm vs. 40 ohm, they cost $106.99 for sbc only while the specific part #s I stated cost $87.99 for the under header set and $108.99 for the over valve cover set without the pro shop discount

From smileys website…


• Small Block Chevy Spiral Core Sleeved Wire Sets
• 8 mm 800 ohm Spiral Core Wire pre-terminated at both ends
• Complete, pre-assembled ready to install sets with 36" coil wire
• Each wire is tested for continuity and resistance after termination to ensure race-ready performance
• High-temp silicone 90° Black spark plug boots provide maximum heat protection
• Shrink tubing at each ends completes the wire-to-boot sealing
• Numbered ID tags simplify installation
• Application Options: Over Valve Cover or Under Header
• Distributor Cap Style: HEI or Non-HEI
• Insulating sleeve runs the entire wire length, adding 8,000 volts of additional insulation
• Available in Black, Red or Blue with Smiley's logo on connector

So what does the Ohms effect on how the wire works? I have moroso now but also own a set of magnecor. L;arge difference in ohms per foot between the 2

I am using the Moroso 73622 sleeved set, that is my only option with Moroso and a Crab cap with HEI terminals. I like the sleeve because my blower motor naturally sweats oil so the sleeve protects the wire itself and makes them easy to clean.
Looks like the Summit price has jumped about $50 a set since the last set I bought

quote:

Originally posted by seabass:
So what does the Ohms effect on how the wire works? I have moroso now but also own a set of magnecor. L;arge difference in ohms per foot between the 2

I don't know that I can clearly answer your question. But I can give you some observations.
For years, the idea was to have the lowest resistance wire possible in order to allow the maximum amount of current/energy flow to the plug and deliver the strongest spark. This was particularly important before the high powered msd ignitions came onto the market. But we have held onto the low resistance belief, and there is some science to back it up.
However, when the bigger msd's hit the market, most applications had more than enough spark. As said, you could put virtually any decent quality, non leaking wire on and deliver all the power to the plug that is needed. Additional power beyond that simply makes no improvements.
Now comes complicators.
Power adders greatly increase the pressure in which the plug has to fire. This makes it much much harder to fire that plug consistently. So more energy is often needed. Nobody wants to run a mag with all the advantages of the electronic ignitions. Plus with all the electronics in our cars today, the mags can play hell with all that stuff.
The smart coils even from the factory can really pour the coals to spark energy if driven correctly. Most aftermarket ecu's allow you to adjust the dwell to push them harder during boost. But now with all the energy being pushed to the plugs, noise can be a real issue. A friend made a neat test chamber to screw a plug into, that had a sight glass and a pressure port so it could be pressurized to simulate real world conditions. What a difference the pressure makes! And the amount of noise is crazy. It would fritz his cell phone during recordings.
It can play hell with a lot of things electronic, and believe it or not, boot seal becomes very important. The spark can find the path of least resistance which can be straight to the nearest ground to the boot.
I played around with, and had some good success with resistor plugs. I'm not sure why as it's a little counter intuitive. But it cleared up any misfire issues I was encountering. I will say some EFI systems are much more sensitive to EMI than others.
Just my experience and I don't claim to be any kind of expert on the matter.

Bottom line is ohms per foot means nothing on the time slip.

Ohms is a measurement of resistance and nothing else

The best connection you could have would be milli-ohms and only a solid core wire could read such a low reading

It would have an RF around the wire. A magnetic field and could wreak havoc on sensitive electronics

That’s the only reason we run carbon core resistance wires

Our ignitions are so powerful they can fire plugs very well thru this conductor

High boost or nitro pushes that and they do some things to better fire their plugs. 2 super powerful mags and whatever wires they have found that survive and work in that environment

I can tell you first hand how much trouble using even a non resistor spark plug can cause from RF noise vs the proper resistor plug. Way worse than just radio static !

In our cars the non resistor plugs themselves don’t cause any problems

It all has to do with electronic noise. In most efi instructions it tells you to run a resistor plug. Most plug applications dont allow that so i run magnecor wires with holley efi. Certain ecus care some dont. I saw nothing power wise between all those wires but it did take care of a miss and locked up datalogs

quote:

Originally posted by Allen Chamberlin:
It all has to do with electronic noise. In most efi instructions it tells you to run a resistor plug. Most plug applications dont allow that so i run magnecor wires with holley efi. Certain ecus care some dont. I saw nothing power wise between all those wires but it did take care of a miss and locked up datalogs

I will say it wasn't straight forward finding a comparable plug in a resistor to what I was using. Took a bit of searching. The vast majority of race cars do not have resistor plugs in them. That's all I'm going to use in my car. My son's car with same ecu only non boosted application doesn't seem to care and we do not push his coils hard as we just don't need to.

I'm following the last few posts in this thread. While I have been advised from Holley & others about the RFI issues with my Sniper ECU. My plan is to continue to run the MSD 8.5 super conductor wires, but I have to find an appropriate resister plug. I prefer to stick with NGK plugs, but I haven't found one that has non-projected tip (for the ProCharger).

Everything I have done so far with the car is to limit the RFI or keep it isolated from sensitive ECU & wiring.

I don’t think they are necessarily worth any ET but I have the Magnecor wires and am pleased. They clean up nicely and I don’t like the sleeved wires either. I carry my old MSD wires for spares.

Did you get the sniper with the computer in the throttle body? Thats the worst. Puts the computer right on top of the engine.

quote:

Originally posted by Allen Chamberlin:
Did you get the sniper with the computer in the throttle body? Thats the worst. Puts the computer right on top of the engine.

Yes & I have followed the instructions to the T.