The 2.8 Duramax was going to be my donor. I was initially looking at a 2.7 I5 Mercedes Benz in keeping with the Jeep theme. It was on some Cherokees of the time. In California, the donor must be newer and a bunch of other regulations. Not to mention the 2.7 Mercedes would cost more and be less productive. While researching, the 2.8 Duramax seemed like it would perfect.
My factory rail has over 170k on the clock and is perfectly capable of providing adequate spark for me to make 300 whp. If heat were an issue it would have failed a long time ago and certainly would not put up with the boost I have been running.
Also the Wrangler PCM outputs less coil dwell than the Viper PCM. By doing this mod it is possible that the coil is not working at peak efficiency. It could very likely be running less voltage than the factory rail.
Also the Wrangler PCM outputs less coil dwell than the Viper PCM. By doing this mod it is possible that the coil is not working at peak efficiency. It could very likely be running less voltage than the factory rail.
Good point. Should have tested voltage anyway, just to be sure. What mods do you have to make 300hp?
Didn't consider that.
Discussion police gonna fine you as well now.
Oh, so bigger is better? Well, I'm pleased with my lil turbo. Voltage is fine. Runs great. Thanks for your concern.
I do have the RIPP supercharger coil. There might be a slightly smoother idle and maybe a bit less tendency to misfire near redline, but I haven’t seen any significant changes. Overall I’m happy with it.
I originally bought it to try and troubleshoot an occasional misfire at high RPM. I also bought a tune for the engine through FRP. Neither of those solved the issue, but the tune significantly improved power and torque. The tune is actually strong enough I might even just stick with 4.10s indefinitely on 35s just for the extra fuel economy. (I actually get 1-2 mpg better now because I can consistently hold 6th gear.)
The actual solution to my occasional misfire came when I realized it was most likely preignition, not failure to ignite, as was evidenced by the pinging noises from the engine under high load. The first solution I tried was to replace the Autolite XP985 spark plugs with the XP5405, which is the exact same plug but with a colder heat range. This solved the issue almost entirely and instantly.
If you’re running a tune, or especially forced induction, and have a pinging or spark knock issue, definitely try colder plugs before spending cash on a significantly more expensive coil.
Note that colder plugs will not help in cases of carbon fouling, and may actually make the problem worse. If you drive like a grandpa, colder spark plugs are going to only cause more issues.
I originally bought it to try and troubleshoot an occasional misfire at high RPM. I also bought a tune for the engine through FRP. Neither of those solved the issue, but the tune significantly improved power and torque. The tune is actually strong enough I might even just stick with 4.10s indefinitely on 35s just for the extra fuel economy. (I actually get 1-2 mpg better now because I can consistently hold 6th gear.)
The actual solution to my occasional misfire came when I realized it was most likely preignition, not failure to ignite, as was evidenced by the pinging noises from the engine under high load. The first solution I tried was to replace the Autolite XP985 spark plugs with the XP5405, which is the exact same plug but with a colder heat range. This solved the issue almost entirely and instantly.
If you’re running a tune, or especially forced induction, and have a pinging or spark knock issue, definitely try colder plugs before spending cash on a significantly more expensive coil.
Note that colder plugs will not help in cases of carbon fouling, and may actually make the problem worse. If you drive like a grandpa, colder spark plugs are going to only cause more issues.
Here's what I know. Gale is pretty sharp. I've never seen him mention the need to upgrade the coil. If there was, he is certainly smart enough to get with a company and get one put together to offer as an option or mention so that folks know where it is.Rather than just say "no benefits," let me share some of my non-guru thoughts.
The rail sits in a hot location on the engine. Electric components and heat are not a good mix. If this design was so genius, why don't they still use it? Yes, I understand engine design, but you likely get my point. Sometimes bad designs go away and don't come back. With the relocation bracket, it moves it away from the block. This may provide longer life and avoid catastrophic failures on the trail.
Have you ever had to isolate one cylinder with the rail design? You really can't. Not without taking it off first. That alone is a benefit. Period.
One other thing, in my case, that may be the reason (aside from the rail becoming coincidentally damaged right after adding a turbo) for my dramatic benefits (by the way remain outstanding today) is that a hotter spark may compensate for "turbo spark blow-out." If someone didn't read that this is a Banks turbo with intercooler, they might not consider that. However, when you add compressed/ cold air to a system, you likely will need to dial in a few other systems. Next is going to be big exhaust air. Get that little wheel spinning quicker.
This is a hobby for me. I could have gone crate 1000hp on a CJ (well, at least the VIN) over 60s. But, that's not MY project. My project is trying to bring the most out, while keeping the most I can in.
Although, could you imagine a turbo diesel 4cyc option for the TJ! Wanted to do that bad. But, I live in California and just thinking about doing that resulted in a fine from the thought police.
I really hope to share my completed Rubi in December (February more likely). Perhaps enough of you will see what I was going for to get me that sweet, sweet Ride O' the Month title.
I may not post in every thread here and elsewhere but I do read a fair bit and then use that to understand common issues. If the heat damage to coils were an issue and the engineers were stupid enough to not take that into account, we would see a lot more threads about failed coils than we do. I've worked on more than a few TJ's for various reasons, I've never replaced a faulty coil rail.
What I do see and what others see as well is the lack of understanding that any rig with a rail is a waste fire system. That means each plug fires twice as often as it should with the consequence of that being a 30,000 mile service interval which we commonly see overlooked out to over 100,000 miles. The gap on those plugs is usually nearly 3x what the OEM spec is. The stock coil rail has plenty of power if it works with those gaps.
And finally, having messed some forced induction, we never had any issue with the coil rail not being sufficient as 6psi+.
Don't take any of that to mean your answer didn't work for your problem.
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They make more power. Better is a subjective matter. Maybe I'm reading your reply wrong, but it seems like you felt offended or something. No offense was intended in my reply. I was just answering your question.
Yeah, you sounded bro'd-up, so I poked back. I was hoping to hear more of your project. Maybe a link. Some pics. Instead I sit hear suffering from turboenvy.
Mostly stock engine with a turbo. I can't speak to the size of the Banks unit, but mine is a GT3071R running around 10-12 psi. If you want the details the link is in my sig.
Damn. My 5-6 pounds of supercharged boost put down about 300 power and 400 torque at the crank. No problem believing 10-12 pounds of turbo puts down 300 at the tire. That’s pretty cool.
Yeah, it was 306hp and 359tq at the tires. Something like 10 or 12psi I honestly can't remember. Probably 350-375 crank. I've been running it that way since May no issues with the spark at all. I am running one heat range colder plug. I'm planning on cranking it up to destruction sometime in the near future.
I see it now. The water tank's on the drivers side. Electric pump tucked somewhere, I guess. Do you run a radiator or just use the mass off the water?
Yep, there's a Bosch electric water pump mounted under the tank. Heat exchanger is mounted between the grille and A/C condenser.
Back to the topic here, I had a couple of coils laying around, so I thought I would measure the primary and secondary resistance on both to see if there were any differences.
First I have an actual Viper coil from a 2006 third generation. The results were as follows.
Primary Resistance:
1.13
1.11
1.10
Secondary Resistance:
12.76k
12.67k
12.74k
The Wrangler coil rail was from a 2006.
Primary Resistance:
1.32
1.30
1.35
Secondary Resistance:
15.58k
15.61k
15.55k
What does all this mean? I don't know for sure. I know it has been said that coils with less primary resistance can produce more energy on the secondary side, but the winding ratio must be correct to achieve any gain. Based on the resistance values from both coils the primary to secondary ratio is around 12:1 for both coils which could mean that the winding ratio is about 12:1 for both as well. That is of course assuming a few things like winding wire size and construction are similar. It could also be noted that the decreased primary resistance of the Viper coil will require greater current from the PCM. The only way to get true data regarding secondary output would be to measure the secondary voltage for both coils under the same conditions. I unfortunately don't have that equipment.
First I have an actual Viper coil from a 2006 third generation. The results were as follows.
Primary Resistance:
1.13
1.11
1.10
Secondary Resistance:
12.76k
12.67k
12.74k
The Wrangler coil rail was from a 2006.
Primary Resistance:
1.32
1.30
1.35
Secondary Resistance:
15.58k
15.61k
15.55k
What does all this mean? I don't know for sure. I know it has been said that coils with less primary resistance can produce more energy on the secondary side, but the winding ratio must be correct to achieve any gain. Based on the resistance values from both coils the primary to secondary ratio is around 12:1 for both coils which could mean that the winding ratio is about 12:1 for both as well. That is of course assuming a few things like winding wire size and construction are similar. It could also be noted that the decreased primary resistance of the Viper coil will require greater current from the PCM. The only way to get true data regarding secondary output would be to measure the secondary voltage for both coils under the same conditions. I unfortunately don't have that equipment.
The actual resistance means less than does the ratio between the primary and secondary. Generally speaking a higher winding/resistance ratio between the primary and secondary windings means the coil will put out a higher voltage.