Spark plug gap?
 

So on the advice of checking my plugs after my dyno (fail) run, i pulled them and checked the gap...... .040-.042 on all of them. I couldn't find a definitive answer to what the correct gap should be. Running 10psi. I'm thinking .028-.030 is what it should be, but i want to makw sure. So...... what should it be?

I run .025 on mine. Dosn't seem to hurt anything and keeps it firing under nitrous at 7K.

You want the biggest gap possible that does not blow out with boost. With your factory cops I'd bet you could leave them at stock .045

On stock coils you need to tighten them up, atleast with my weak '99 coils. At 9 psi i was blowing at pretty bad with .035 which is standard gap for NGK BKR7Es. So i gapped them down to .025-.026 and haven't had a misfire yet.

well, when i dyno'ed, i guess the signal was breaking up because there are whole sections of dyno plot missing. I was told this is because the spark was being blown out/bad signal. I'd feel good saying that where the dyno plot is missing is where boost was spiking due to the crappy MBC. Might i be right? The plugs im running are NGK ZFR7F-11

Old plug wires will do that. I take it he was getting signal off the little short wire, have you ever replaced those? Most miata plug wires go bad (dyno quality wise) after 30-50k miles.

it's got a set on Magacore wires that are less than 10k mi :(

bear in mind he has the 01+ cops, which JasonSBB tested as pretty freakin good at his lab.

mike, if spark were blowing out, you'd feel it as a misfire. it could be crappy wires. or it could be a crappy pick up at the dyno.

The plug gap for a 04-05 MSM with the factory COP is .028 - .031.

I forget the data, but they didnt test quite as good as the 99-00 coils.

Well, on my 1st 2 runs at the dyno with the slightly higher boost, i did get several misfires and the dyno plot show'd missing segments on those runs. But on the last run, which felt clean as far as i could tell, there were still missing segments on the plot. I'm goign to tighten up the gap a bit tonight to ~.03 and see how the car feels. The 2 plugs i pulled looked fine though.

I'm also going to try to get some time in with Ed.... but they said i'd be looking at 2-3 hrs for tuning (at $150/hr... i think when they mean a "few hours", they are probably thinking a 'start from scratch' map...since i have a good base, i hope i can keep it under 2 hrs).

I know you have a boner for the Dynojet, but you need to go elsewhere to tune.

thanks for the info:cool:

i don't honestly give a flying fuck as to what kind of dyno they use, monitoring a/f's is monitoring a/f's and thats all that's needed to tweak the map (and maybe keep an eye on the knock sensor). I have yet to find anyone who has first-hand experience with tuning a Hyrda other then Ed. If you know someone who has specifically tuned a Hyrda, then by all means tell me who.:fawk::noob:

horse shit.
there's a lot to do with tuning, very little of which has to do with "monitoring a/fs". there's nothing you can do on a dynojet other than take a few WOT pulls and tweak fuel somewhat. 10 minutes.

if you're going to put down money for a few hours worth of dyno tuning, you need to get on a load dyno, where you can start tuning fuel for real, and then get to your spark map. power is made in the spark map.

na...power is made on the power map....maybe the turbo and boost maps too.

Ummm Dynolabs and BPM use the same dyno.

and neither one is worth a damn

wtf is a power map?

I think you can file 'power map' under 'humor'
Mike fixes computers for a living...

hehehe...

MUST AD MORE POWERMAPS!! Powermaps are what Tom uses to show that the PCP adds intercooler effect.


Ben, i did call BPM and asked about the dyno, they did add the brake system you asked about the other day. As for load bearing.... i stand corrected. Is Dynolabs dyno a load bearing?

it looks like this...

h A (To-Ti)

I haven't been to BPM in a couple years, but they did not have an eddy brake at that time. But since they carry, install, and tune AEM I'm glad that they have one now.

If they
indeed have the eddy brake
.......and
actually use it
then they'll have the equipment to create a good tune for you. It would be totally up to Ed, and in Ed I'd trust.

Dynolab has the base model Dynojet, to the best of my knowledge. Which is what I thought BPM had as well.

Since Jeremy@FM is coming down for the Mitty, perhaps you could rent a shop's dyno and pay him to tune your car? There are some Mustangs around the RA area. Worth asking about...

Well, im hoping to get this done before my next track day at TGP on the 18th. I'm going to go ahead and get some new plugs and maybe a spare set of plug wires too. I also need to recalibrate my WB and re-run the knock test...argh.