Watterson02

So I’ve been only able to go like 5,000 miles on a single set of spark plugs before they start to blow out at full boost. Replacing the spark plugs seems to fix it temporarily. It clears up at very peak rpm’s sometimes though. I’m thinking it’s due to the high cylinder pressure at peak torque causing it to blow out. But regardless, I didn’t think this should be an issue with the R8 coil on plugs. For an idea of what I’m working with, the car is a BP4W that’s fully built with low compression pistons. The car is currently tuned to be at 26psi and 11.2:1 AFRs on a MSPNP2. I’ve always ran NGK BKR7E spark plugs at .030” with good success until I put the bigger turbo on and turned up the boost, but simultaneously I put the R8 COPs on.

Is this possibly a COP failing, poor choice on spark plugs, or just that I need stronger COPs? Anyone else running the R8 coil packs at 20+ psi? I’ve heard that they should be able to support a lot more than the 100whp per cylinder that I’ve been asking from them. Thoughts? Regardless of the real issue, should I be running different spark plugs at this point?

Watterson02

Oh, also I’ve got the dwell set at 2.0ms static since the MS2 doesn’t have a dwell table like the MS3. But regardless, the software is exactly how Flowforce recommends.

Also, maybe even less of a gap on the spark plug? Would cleaning the plugs with brake cleaner possibly help LOL

patsmx5

iTrader: (16)

Iridium plugs for sure will help. What spark advance are you running when it misfires in boost? Also 11.2:1 AFR is hard to light off too. Not sure if 2ms dwell is a good amount on those coils, but sounds low to me in general.

To me it sounds like you're doing some, to a lot, of things that make it hard to fire off the mixture.

Watterson02

The Flowforce website says to do 1.9-2.0ms of dwell time on MS2 with the R8 cops and then 11.2:1 is just to be extra safe with knock. From what I’ve read the R8 COPs require a much shorter dwell. I could try slightly higher, like 2.2ms but past that I’d be somewhat nervous about the lifespan of the COPs. Regardless, there’s not really any reason why I couldn’t do like 11.5:1, but I wasn’t really wanting to go past that at this high of boost on pump gas.

Edit: Pat, I'm running very low ignition timing on this tune, like 8-9 at peak torque. Haven't had the opportunity to actually tune it yet. I've started mixing in the unleaded VP Octanium octane booster though. Hoping to give it a handful more degrees when I get it back out this weekend before the drag races.

Reverant

iTrader: (10)

Yeah just run BKR8E-IX. The cops are not your problem, we run these on 1300whp 4 cylinder cars. The spark plugs you use, that's the problem. Also, just run 3.0ms on the coils.

engineered2win

The R8 coils pull a lot of current:
1.6ms should be sufficient for basically any N/A and low boost setup.
1.6ms @ 14v = 8 amps
2.5ms @ 14v = 16 amps
12.8ms @ 14v = 18 amps (MAX)

One possible issue is insufficiently spec'ed harness. If using Tefzel, then 18AWG would only be ok for ~9amps; 16AWG would get you ~12amps, which would be sufficient for ~2.0ms. If you're using cheaper (PVC) wire, then you may need larger than 16AWG.

Watterson02

I opted to try the NGK 92400 FR7BHX-S Ruthenium HX Plug. It's only a 7-heat range plug, but it is supposed to be even better than iridium plugs. I've checked the dimensions and it should fit regardless of the fact that it says it is incompatible. I guess we will find out tomorrow.

On the brief drive I had today, I set the static dwell to 2.8ms and it seems to be fine now. I'm still gonna change the plugs regardless but the issue seems to be resolved.
I found this exact same post myself. I believe the 12.8ms is a typo and should be 2.8ms. There's practically no way that is supposed to be 12.8ms... regardless 2.8ms fixed my problem without even changing anything else.

Anyways, thanks for the help guys. I consider this issue to be fixed, and relatively easily too. I probably didn't need to post about it, but ehh whatever. It might help someone else in the future though. I wonder why flowforce suggests 2.0ms? It was sufficient for normal for low boost like mentioned, but who is buying upgrading COPs for low boost. Whatever lol