Anyone use different spark plugs?

With the built engines we have been installing recently we have been able to do some more testing with other forced induction kits. @MACAWS Slingshot came in with the HAHN turbo kit on it and as most are aware @rabtech also has a HAHN turbo kit installed on his built DDMWorks engine. While we are installing and testing @MACAWS engine on the dyno we saw some slight differences with the air/fuel ratio on the wideband compared to @rabtech and wanted to look into it further. Both of the builds were almost identical, except for the spark plugs that were being used in the engines. @rabtech was using the stock spark plug that ships with the HAHN kit which is a LZTR5A-13 and @MACAWS we installed the spark plugs that we use on all of our forced induction kits - LTR6ix-11. The LZTR5A-13 is a nickel plated, stock heat range of 5, 1.3mm gap spark plug. The LTR6ix-11 is a iridium tipped, 1 step cooler plug (heat range 6) with a 1.1mm gap. Both plugs use a copper core.

So what we wanted to know is if there would be any difference in the power produced on the dyno and if air/fuels would change with the different plugs, here is the dyno -

On the dyno, there are 2 lines, a orange one and a green one. They are both on the same vehicle with exactly the same setup, just different spark plugs. We installed the spark plugs as they were delivered in the package at the stock gaps, we did not change anything on these plugs, just installed them. The graph shows that the power is very consistent between both spark plugs at this power level between the 2 different spark plugs, the lines almost overlap. We were also monitoring air/fuel ratio's during the run and they were also almost identical, with the HAHN plugs being just a tick richer on all the pulls, around .1-.2 difference on the air fuels. We are hoping to have another test session with a turbo setup soon and will try some more plugs out on that setup hopefully to see how the power and air/fuels perform on that setup also.

Hope that helps,
Dave

@Dave@DDMWorks

if we can set up a track day, we can try the same test again on mine
I will double check but I think the Hahn instructions call for a .035 gap not what is packed in the box @rabtech would be able to confirm.

Better yet when you have @Wrenchmn up and rolling I can make a trip down

Shoot me a PM and we can discuss more

35 thousandths is what my gap is set at.

The problem with setting the plug gap at .035 using the 4306 NGK is that the ground electrode has to be bent too much to get that gap which results in a massive angle to the center electrode. Not a good idea to have a reasonable flame travel. The LTR6BI-9 comes out of the box at .036. I believe the LTR6iX-11 comes out of the box at .044. The most I would ever alter a spark plug gap is .015, but that's MY personal thoughts and would defer to Dave and his vast experience and knowledge on these engines

disclaimer: The above is my personal opinion and in no way is a recommendation being made on my part that any spark plug I mentioned be used based on what was written by me.

Quote from funinthesun

The problem with setting the plug gap at .035 using the 4306 NGK is that the ground electrode has to be bent too much to get that gap which results in a massive angle to the center electrode. Not a good idea to have a reasonable flame travel. The LTR6BI-9 comes out of the box at .036. I believe the LTR6iX-11 comes out of the box at .044. The most I would ever alter a spark plug gap is .015, but that's MY personal thoughts and would defer to Dave and his vast experience and knowledge on these engines

disclaimer: The above is my personal opinion and in no way is a recommendation being made on my part that any spark plug I mentioned be used based on what was written by me.

We have not used that plug before, but for higher boost setups, that should work pretty well right out of the box. From what we have found the stock 1.1mm gap on the LTR6ix-11 work well up to around 13psi, then they can start misfiring, so for most builds they will work, but that LTR6BI-9 should work well if you are planning on going above that level of boost. I will order up a set and do some more tests with them also, nice find.

Can I ask why u are not looking at or using E3 plugs??

We tried them years ago and never had any big difference with them on the boosted applications. I guess we can order up another set though if we will be trying the other ones also and have a Spark plug testing day, let me know if anyone else has suggestions of what they want to see tested.

I can confirm that the LTR6iX-11 gapped at 36 misfire passed 13-14 psi. I assumed it was TC engaging but it was actually misfire.

I replaced mine with LTR6BI-9, let gap stock, as per suggestion from the guys who sold me the pistons, and I dont have this issue anymore.

Quote from Dave@DDMWorks

We tried them years ago and never had any big difference with them on the boosted applications. I guess we can order up another set though if we will be trying the other ones also and have a Spark plug testing day, let me know if anyone else has suggestions of what they want to see tested.

I am not boosted but am running them and did notice a difference in throttle response. Felt good!

I installed Brisk Spark plugs in my Sling. No gaps to deal with.

Quote from SA Sling Rider

I installed Brisk Spark plugs in my Sling. No gaps to deal with.

Is performance significantly upgraded from a conventional plug?

Quote from Street Doc

Swapped out the NGK LTR6IX-11 with the E3.74 today and what a difference! I put the NGKS in when I boosted it 2900 miles ago, but recently it started missing bad under load at higher RPMs. I can actually break the rear wheel loose in 3rd gear and could never do that before. Anyone else have a similar improvement using the E3s?

I too went to the E.3 plugs and LOVE them! Great throttle response and performance

Quick update for everyone. We had a set of the Brisk EVO plugs sent to us for testing, very cool looking plugs, here is some information on them -

Brisk Racing Premium Evo Spark Plugs | Spark Plugs

We ran them on a supercharged Slingshot we had here for an install, then swapped in our standard spark plug - NGK LTR6IX-11, then swapped back in the Brisk plugs. Basically, no difference between the power runs and didn't notice any other changes with the plugs swap. Here is the dyno -

Just some more information for everyone.

@Dave@DDMWorks are you running the 95mm pulley on that supercharger? If so how are they working out with the stock engines?

Let's revive this thread!

So what is everyone using for Spark Plugs and why? Gap?

I am still Naturally Aspirated so that is my focus atm. I am curious to try these E3 plugs. I have 28k miles on the sling now and I have Bob's tune.

E3
NKG Iridium
NKG Platinum

E3 Sparkplugs

Quote from BlackDeath

Let's revive this thread!

So what is everyone using for Spark Plugs and why? Gap?

I am still Naturally Aspirated so that is my focus atm. I am curious to try these E3 plugs. I have 28k miles on the sling now and I have Bob's tune.

E3
NKG Iridium
NKG Platinum

Display More

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FYI ..the AC Delco Iridium plugs installed at the factory are manufactured by NGK on the same line as their own offering ..... just re-branded .....

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Quote from Orangeman

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FYI ..the AC Delco Iridium plugs installed at the factory are manufactured by NGK on the same line as their own offering ..... just re-branded .....

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Thanks @Orangeman that is good to know. Question I am really looking to get answered is the type of plug.. not what fits