spark plug gap

I now run .025 gap per RPE. Dont want a spark blown out at high boost.

Bryan
 
Dang! I thought a tight .032 was small, you 2 make it seem like I'm going after mileage;)
 
LOL.
I used to run .032 as well. Bobby said to back it down ! I just follow the builders advice, he knows way more than I do.
I don't think you need as much spark to ignite a forced induction motor as a NA motor, but you sure don't want to lose that spark at high boost/RPM

Bryan
 
^ whats the problem? if spark blow out at high boost and RPM gap the plugs .02 tigher and try again. i would also check plug wires and coil as well
 
^ whats the problem? if spark blow out at high boost and RPM gap the plugs .02 tigher and try again. i would also check plug wires and coil as well

Its cutting out about 52-5500 and I first thought it was just the limiter.Turbo Tweak told me my limiter is set at 6375 so it wasnt that.

I also realized I dont have a good ground for the coil/module as the bracket and intake are painted so I need to address that also.

I am going to put a new set of plugs in at .025 and add a ground strap to the coil bracket and see what happens.
 
0.025-27 here. Ran the stock crank, stock rods and wisecos .035 over to 6400 rpm no problem with a 210/210 110 cam and bowl ported irons only at 17psi boost. If I ran 0.032 or higher it would pop around 5000 rpm or so.
 
The loosest ive gone with anything over 500hp is a tight .028. .023-.025 on my black car. If your making some power and start mis-firing under power you will hurt it.
 
The loosest ive gone with anything over 500hp is a tight .028. .023-.025 on my black car. If your making some power and start mis-firing under power you will hurt it.


Well it is making some power and I hope I havent hurt it.:(

I am putting in a new set of 43's gapped at a tight .025.
 
^ you more then likely didnt hurt anything.

Not sure on your setup but how much boost? what cam?

also a set of NGK UR5's would work well. If you want delco get AC CR42TS

I would check plug wires. gapping tighter will tell you if its spark or not. even a weak coil pack could cause poping.
 
^ you more then likely didnt hurt anything.

Not sure on your setup but how much boost? what cam?

also a set of NGK UR5's would work well. If you want delco get AC CR42TS

I would check plug wires. gapping tighter will tell you if its spark or not. even a weak coil pack could cause poping.


20-25 not exactly sure yet as I am still tracing down these gremlins.
I would see 18-20 last saturday before it would hit the problem area which I thought was the limiter.

I got cr43ts and already gapped them and they are going in the car tonight.

I have brand new MSD wires and the orignial low mileage coil.

Like I said before I need to add a ground strap to the coil as everything is painted.

I have a brand new coil to try also if this doesnt take care of it.
 
I was running a .028 r42ts delco plug. I never tried anything looser when I was at 28lbs.
Now I'm at a tight .030 but I'm only at 22 lbs.
 
Went out again over the holiday weekend....ran absolutely awesome.I gapped them at a tight .025 and it ran good enough to make the clutch slip.

Thanks guys for the replies.
 
I'm using Denso "iridium" plugs that are factory gapped at .040 and I am using at the factory setting. According to Denso the iridiums take approx. half the voltage to fire as standard plugs and withstands heat well.

I am running 12/14 psi of boost thou with pump gas and the car has run 10.80's with the working air off. :) So it's making some power and the car has not missed yet with that wide of a gap. If I were to push the boost up to the low 20's I would close the gap to .035/.032 to start off with to be safe. Car runs clean on the street with the TT street chip.
 
wow, .025

i would open them up to .028 and see if it starts to have issues. .25 might be hiding/masking a ign problem
 
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