gapping spark plugs

[bigjohnson4.6gt]

how do you gap them? is there a special tool that measures the gap?

 

[cobraclone]

AutoZone got the kit its some little L shape tools that have different sizes for gapping and theres this thing they usually lying around the cashiers that look like a silver dollar that tells you the gap size. both will go around 3 bucks

 

[bigjohnson4.6gt]

whats the benefit of gapping?

 

[Jrgunn5150]

In theory they are factory gapped, but in theory communism works lol. Setting the gap to what is optimum for your car will result in better throttle response, fuel mileage, and power (not dramatic though). If they are to small in gap, you are not burning your fuel as fully as you could, too much and they get blown out at higher rpms wasting gas and power also.

You need the tools to measure gap, but to actually do it you only need needly nose pliers. Tapping them against something hard will close the gap, grabbing the ground strap on either side with you plier's, you can open them up.

 

[lizzyfan]

 

[voidfinger]

Yep, you need to gap them bad boys to .054 i think. I hear that on nitros cars and FI cars you need around .034 ! I ran some coppers gapped to .034 and it sucked... So why do you need to have them gapped so close on a nitros car that is my question ???

 

[Jrgunn5150]

Nitrous bumps cylinder pressure way up, it'll blow the spark out just like boost.

 

[voidfinger]

yea i got ya, i know that when i gapped them to .034 it really hit my mpg ... went from like 22 to 19 or so.

 

[coats04]

when i bought my 97 npi the plugs where fubarded..075-.080 gaps

i put in regular motorcraft plugs not platinums and gapped them at .44 the things has killer responce and i wouldnt change them at all.at least with the npi settup. :banana:

 

[lizzyfan]

When I upped the boost to 13 psi, I gapped mine to .30

 

[Jrgunn5150]

yea i got ya, i know that when i gapped them to .034 it really hit my mpg ... went from like 22 to 19 or so.

A change of .005 even is quite a bit. I mean if you had a day to waste sometime, you could spend it screwing around with gaps and the differences they make, lol

 

[voidfinger]

yea i got ya, i know that when i gapped them to .034 it really hit my mpg ... went from like 22 to 19 or so.

A change of .005 even is quite a bit. I mean if you had a day to waste sometime, you could spend it screwing around with gaps and the differences they make, lol

Naw, i think i'm just going to get some stock motorcraft duel plat. and gap to the factory .054 and then call it a day. after another 100k i'll change them again But for now i'm slappen the npi intake back on and just working on the car till i'm ready for the 4v motor. But i think it will be pretty nice when i get my 17X9/17X10.5's with big back tires and some 4.30's with the t45 lol that will be killer lol. That way i can practice my launch before the better motor :banana:

 

[voidfinger]

When I upped the boost to 13 psi, I gapped mine to .30

why so low? i thought you usually went to .034

 

[lizzyfan]

When I upped the boost to 13 psi, I gapped mine to .30

why so low? i thought you usually went to .034

Up to about 10 psi or so .34 is good, I was having issue with the spark being blown out. Gapped em' down and I'm golden :thumb:

 

[9psi 98]

When I upped the boost to 13 psi, I gapped mine to .30

why so low? i thought you usually went to .034

Up to about 10 psi or so .34 is good, I was having issue with the spark being blown out. Gapped em' down and I'm golden :thumb:

I had the same problem with my car when I first bought it. It tried everything I knew to mess with, but It ended up being the damn spark plug gap. I'm pushing 9psi, and .034 was too big of a gap. I talked to a guy that races and builds fox body turbo cars and he said to go down to .022.... it erased all of my problems that I spent countless hours chasing down. I'm currently at .026 and it's running perfect. I may be able to open them up a few more thousandths, but the time it takes to regap them all isn't worth the minute power gains that I'd get. .034 ran like crap, .026 runs perfect.....good enough for me.

 

[voidfinger]

o ok, i guess .034 would be good for about 100/125 shot for now lol >