What plugs for 1000hp and beyond?
 

I’m running Brisk Racing RR12S gapped at 0.022” right now, and I seem to be getting intermittent choppyness at high RPM’s.

Not sure of my actual whp, but I’m pushing about 20lbs through 95mm TB, long runner intake and 2” primary long tube headers.

Im also using OEM coils and GMPP plugs.

Rr12s should be good, i ran the same gaped at .025 made 1006whp at 21psi but took it down to 950 just to be safe because its on pump gas

Maybe it’s not the plugs then. I’m beginning to wonder if I’m spraying too much meth. I turned it down a tad earlier and it is no longer breaking up, but this issue seems to come and go so time will tell.

Edit: what other mods you running? I’m trying to get a feel for how close to 1k whp I am.

This c7 is not like the c6 & c5 seem like this car will foul out the plugs much faster than the LS. With that SAID HERE you should have your tuner do the setting for the meth & do it for the tune and also never chg it again. It will make a diff's on the car plus the gap of your plugs can be to small & your rwhp may need to be a little more r less. Ever motor is diff and a lot of this stuff you just need to play with until you find the sweet spot for your set up..

At the plug gap at 22 are you getting a lot of gas at the tail pipe you can be not getting a good burn but also don't want to be to wide it will blow out on you also.. Robert

I am using Brisk Silvers for my setup got them at Katech (1 step colder). Good so far!

Thanks for the replies guys. I'm going to stick with the Brisk's and maybe just order another set in case my current ones are fouled. I'm hoping to catch the breaking up issue in my logs, and then I should know for sure.

Does it happen on the same cylinder? If so, swap the plug wires (and probably coils) to another cylinder. If missing remains in the same cylinder, its the plug. If not, then its the wire or coil

Thanks. I’ve swapped the wires and coils for new already, but I think I will get some new plugs when I’ve finished tuning the car fully

If it's breaking up at high RPM then it could be short on fuel. Have you logged it when this happens?

Where is your meth controller set? 20 PSI with what fueling mods?

I have managed to capture a log, but I think I may have found the culprit(s)....

https://cimg0.ibsrv.net/gimg/www.cor...3749f642a4.jpg
The orange coating isn't rust, but I'm pretty sure it is from the NF Octane Booster that I have been running. I thought I'd done my due diligence on this stuff, but as it turns out lots of people are claiming fouled plugs due to it if you run it in high concentrations ( like I have)

Also, when I removed my spark plug wires I noticed this:

https://cimg5.ibsrv.net/gimg/www.cor...85ce5faaf4.jpg

The black line is soot, and it lines up perfectly with my header gasket. I re-checked the torque of my header bolts and it looks like they loosened off! My guess is that at high RPM's the amount of exhaust gasses escaping has caused my AFR's to be off, and probably caused fuelling issues.

I'm going to put in new plugs, dump the octane booster and re-torque all the bolts - then see how it behaves.


To answer the other Q's, my meth controller is at full whack (but with 2x 640cc/min nozzles) and I have a secondary low-side fuel pump. I'm also gearing up to install a CR-Fueller system with FIC 1000cc injectors

Damn Jim... you’re gonna show me up! :lol:

Thought you may find this interesting found this yesterday after I had some misfire issues up top. Thought my low side aka secondary pump wasn't getting triggered by my Holley setup but turns out car wasn't making boost due to misfire, so it kept my regulator from hitting 70+ psi of pressure also, I am around 78psi or so at 18psi.

I have Brisk RR14S gapped .28 I may have to gap smaller. It's been running great up to this point. I have all new MSD wires just in case with kevlar boot covers (need those b/c even with I see a minor bit of melting on wire boots). I have a message to Brisk I will report back b/c I am not too happy with that tip coming off in my cylinder.

I also noticed the ground strap on the plugs on some are off center, is that normal? I would imagine they need to be directly centered over the tip?

https://cimg7.ibsrv.net/gimg/www.cor...93d2897906.jpg
https://cimg1.ibsrv.net/gimg/www.cor...ccd100618a.jpg
https://cimg5.ibsrv.net/gimg/www.cor...83d7f77b31.jpg

Ive just bulk ordered a load of brisk plugs, so you’ve scared me with this post!! I will check the tips on mine when they arrive tomorrow as all the NGK, ACDelco etc plugs I’ve had in the past have had the ground perfectly aligned with the tip!

Has the broken off tip caused any damage?

On a side note I’ve found those Kevlar boots to be crap, and in some way I think they even transmitted more heat to the boot. I tried the ACCEL ceramic spark plug wires too, and they had a really loose connection to the plug.

In the end I went for GMPP wires which allow you to use the stock metal heat shields and I had them jethot coated for extra protection!

Thanks, Jim for that, unfortunately, I have the Katech coil relocation so I am not sure if the GMPP wires will be in my length (they are good bit longer). I do agree not real happy with the heat transferred past those kevlar boots most all my MSD boots were showing signs of heat. One wire went bad.

I am thinking my issue could be to heat or gap issues. I found a couple of my plugs at nearly .30 and most were .28. I think I need to be around .25/26 for my power level. My heat range is 14SS and it's also possible I should be running 12SS two steps colder. At least that would help with reliability over engine damage vs just carbon build up or low speed / idle issues. I don't mind changing my plugs often either. I have a Daytona road course track even April 4/5th so I have to get these bugs worked out by then. I for sure may run 12SS at that event since most of it is running the car pretty hard.

I wouldn't worry too much yet Jim I did tons of research yes people had had issues with Brisk plugs broken ceramic / tips etc. but I would bet most of those were due to detonation or lean conditions, too much heat. I know my air / fuel is more rich than lean (holley CRFueler with my wideband) but I think I am running a step too hot plug (1 step colder than stock) and also gapped a bit too much. I am not giving up yet (most may) to the NGK's only b/c of what I stated and others have had great success on LT platforms with these plugs. I will keep you posted!

i would think you need to run the 12’s, 14 is hot for your boost level and power, on my car that run pump gas and make 1000whp with 21 boost i run 12s or even 10s never had a tip go of with brisk, but with ngk the tip was most of the time broken, i would recommend you to go a step colder (rr12s) and stick with brisk plugs, also try to gap them to 0.025 it should be good to go.

good luck

Were all of your plugs gapped the same when you installed them? Sounds like pretty rapid wear if so!

This is what happened to my MSD’s with Kevlar boots, you can see the weave melted into it:

https://cimg3.ibsrv.net/gimg/www.cor...bb810b368.jpeg

Thanks I am going to do just that switch to 12s. Appreciate the feedback.

I think I missed one or two in a rush. I had them all out on my bench and probably just human error. I am usually pretty good about that because I know how critical plug gap is. I didn’t see any premature wear. The color also looks fine. Even on the new plug I put in #7 I pulled it back out to check and color is dead on.

Does the color change much when running E85? I know alcohol can be hard to tune but ethanol I am curios if you can still read the plug color as you would 93 octane?

As as for the MSD boot no mine weren’t near that bad. Just little warping and some small discoloring. I really want to find a good heat protector from these kooks headers. May just have to ceramic coat one day.

Well, I didn't get around to gapping my passenger side plugs Chris pulled logs today my driver side was fine no misfires (plugs gapped at .25) passenger side I was planning on doing tonight. Pulled them 3 were at .30 way too large of a gap. I hope that is what keeps causing this b/c now #6 had a missing tip!!!!!!!!!!!! I am going to give them one more shot ALL gapped correctly at .25 if this happens again Brisks are history.



https://cimg6.ibsrv.net/gimg/www.cor...f0dd7c94a1.jpg

i’m still using my NGK 6510’s gapped at .025